grade 10 life sciences formal task 3 assignment may 2023

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Life sciences grade 10 latest assignment and memos caps.

Life Sciences Grade 10 Latest Assignment and Memos for CAPS Curriculum (Syllabus) South Africa: A National Curriculum and Assessment Policy Statement (CAPS) is a single, comprehensive, and concise policy document introduced by the Department of Basic Education for all the subjects listed in the National Curriculum Statement for Grades R – 12.  CAPS gives detailed guidance for teachers on what they should teach and how to assess.

On this page you will find Life Sciences Grade 10 Assignment and Memos for Term 1, Term 2, Term 3, and Term 4.

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Geography Grade 4 Latest Lesson Plans for all Terms CAPS

Geography Grade 4 Latest Lesson Plans for all Terms for CAPS Curriculum (Syllabus) South Africa: A National Curriculum and Assessment Policy Statement (CAPS) is a single, comprehensive, and concise policy document introduced by the Department of Basic Education for all the subjects listed in the National Curriculum Statement for Grades R – 12.  CAPS gives detailed guidance for teachers on what they should teach and how to assess.

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Geography grade 5 latest lesson plans for all terms caps.

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On this page you will find Geography Grade 5 Lesson Plans for all Terms for Term 1, Term 2, Term 3, and Term 4.

• 1 Available Lesson Plans for all Terms Geography Grade 5

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Geography grade 6 latest lesson plans for all terms caps.

Geography Grade 6 Latest Lesson Plans for all Terms for CAPS Curriculum (Syllabus) South Africa: A National Curriculum and Assessment Policy Statement (CAPS) is a single, comprehensive, and concise policy document introduced by the Department of Basic Education for all the subjects listed in the National Curriculum Statement for Grades R – 12.  CAPS gives detailed guidance for teachers on what they should teach and how to assess.

On this page you will find Geography Grade 6 Lesson Plans for all Terms for Term 1, Term 2, Term 3, and Term 4.

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Life Sciences Practical Tasks Grade 11 SBA for all Terms: Education Resource

Life Sciences

Most of the exam papers are available in English and Afrikaans

Summaries for Gr 10 Life Sciences

No June Exams was written due to covid

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Pre- and post-session questionnaires were used to assess changes in student reported confidence in surgical skills and attitude towards virtual surgical skills training (Fig.  2 ). At baseline 40% of students ‘agreed’ or ‘strongly agreed with the statements “I feel confident in how to correctly use and handle instruments” and “I feel confident in my basic suturing capabilities” and 30% ‘agreed’ or ‘strongly agreed’ with the statement “I feel confident in tying a reef knot and slip knot”. Overall, 75% perceived an improvement in their confidence in instrument handling, 80% in cable knot tying, and 70% in suture tying. Following the session, the majority of students disagreed that virtual delivery of surgical skills training negatively impacted their view of live demonstrations, interaction with instructors or the level of supervision they received.

In modern societies, training reading skills is fundamental since poor-reading children are at high risk of struggling both at school and in life. Reading relies not only on oral language abilities but also on several executive functions. Considering their importance for literacy, training executive functions—particularly, attentional control has been suggested as a promising way of improving reading skills. For this reason, we developed a video game-based cognitive intervention aimed at improving several facets of executive functions. This game is composed of mini-games that apply gamified versions of standard clinical exercises linked through a game environment with action video game dynamics. Here, in a study involving 151 typically-reading children, we demonstrated that after this general-domain behavioral intervention reading abilities, as well as attentional and planning skills, were significantly improved. Our results showed that training attentional control can translate into better reading efficiency, maintained at a follow-up test 6 months later.

The overall rating for the virtual surgical skills session was 8.85 (±1.19) out of a scale from 0 to 10 (10 being most satisfied). Questions regarding the delivery of teaching via the virtual platform are summarised in Fig.  3 . All students were ‘satisfied’ or ‘very satisfied with the breadth and depth of the content covered and the subject knowledge and enthusiasm of the instructors, as well as their ability to ask questions via the platform. All students were ‘satisfied’ or ‘very satisfied with the balance of different teaching methods used (lecture, video, breakout room), the lecture content, the video demonstrations, and all the practical skills sessions. One student was ‘dissatisfied’ with the surgical equipment provided. Post-session student feedback themes

Thematic analysis of open-ended questions regarding student feedback on what went well was examined and themes of practicals in breakout rooms, supervision, and individualized feedback emerged.

“Most enjoyable session of the course so far. I liked that we had instructors with us in the breakout rooms to ask about any steps we were unsure about. Also, the demonstration videos beforehand were very useful.”

“The approach going from bigger to smaller” [starting from cable tying to demonstrate knot configuration before moving to suture tying, and finally trabeculectomy releasable suture tying]

Post-session instructor feedback themes

Emergent themes were teaching flexibility, visualisation, clarity of instruction, accessibility and personalised learning.

Life Sciences Grade 10 Notes for all terms and Worksheets

On this page you will find Life Sciences Grade 10 notes for all terms (term 1, term 2, term 3, and term 4) and, Worksheets, activities, and lessons. All the content is in pdf and word documents format.

What are the Topics for Grade 10 Life Sciences?

Table of Contents

Life Sciences Grade 10 Topics

Below are Grade 10 Life Sciences Topics per terms:

• The chemistry of life
• Cells – the basic units of life
• Cell division- mitosis
• Plant and animal tissues
• Term 1 Revision
• Support and transport systems in plants
• Support systems in animals
• Term 2 Revision
• Transport systems in mammals (human)
• Biosphere to Ecosystems
• Term 3 Revision
• Biodiversity and classification
• History of Life on Earth
• Exam Revision

The chemistry of life Grade 10 Life Sciences Notes

Plant tissue grade 10 life sciences notes, animal tissue grade 10 life sciences notes, don't miss these:.

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4.3 Plant tissues

4.3 plant tissues (esg65).

Plant tissue is divided into four different types:

• Meristematic tissue which is responsible for the making of new cells by mitosis.
• Epidermal tissue which is the outer layer of cells that cover and protect the plant.
• Ground tissue which has air spaces, and manufactures and stores nutrients.
• Conducting tissue which is responsible for the transport of water and nutrients throughout the plant.

Learners need to be able to examine and identify some plant tissues using microscopes, bio viewers, photomicrographs and posters. Learners need to be able to draw the cells that make up the various plant tissues, showing the specialised structures.

TEACHER RESOURCES:

Types of plant tissues:

Plant tissues picture:

Plants are typically made up of roots, stems and leaves. Plant tissues can be broadly categorised into dividing, meristematic tissue or non-dividing, permanent tissue. Permanent tissue is made up of simple and complex tissues.

There are over \(\text{200 000}\) types of plant species in the world. Green plants provide the Earth's oxygen, and also directly or indirectly provide food for all animals because of their ability to photosynthesise. Plants also provide the source of most of our drugs and medicines. The scientific study of plants is known as botany.

Learn more about plant tissues:

Video: 2CR3

Figure 4.2 provides an overview of the types of plant tissues being studied in this chapter.

Figure 4.2: The diagram above depicts how several cells adapted for the same function work in conjunction to form tissues.

It is important that for each tissue type you understand:

• where it is located
• what its key structural features are and how these relate to function
• how each tissue type looks under the microscope
• how to draw biological diagrams of each structure

Meristematic tissue (ESG66)

Meristematic tissue is undifferentiated tissue . Meristematic tissue contains actively dividing cells that result in formation of other tissue types (e.g. vascular, dermal or ground tissue). Apical meristematic tissue is found in buds and growing tips of plants. It generally makes plants grow taller or longer. Lateral meristematic tissue make the plant grow thicker. Lateral meristems occur in woody trees and plants. Examples of lateral meristematic tissue include the vascular cambium that results in the rings you see in trees, and cork cambium or 'bark' found on the outside of trees.

The following table highlights how the structure of the meristematic tissue is suited to its function.

Table 4.1: Structural adaption and function of meristematic tissue

Meristematic tissue is found in root tips as this is where roots are growing and where dividing cells are produced. Figure 4.5 shows a micrograph image of a root tip.

Figure 4.5: Image shows meristematic tissue in a root tip as observed under an electron microscope.

Permanent tissues (ESG67)

The meristematic tissues give rise to cells that perform a specific function. Once cells develop to perform this particular function, they lose their ability to divide. The process of developing a particular structure suited to a specific function is known as cellular differentiation . We will examine two types of permanent tissue:

Simple permanent tissues

• collenchyma
• sclerenchyma

Complex permanent tissues

• xylem vessels (made up of tracheids and vessels)
• phloem vessels (made up of sieve tubes and companion cells)

Epidermis tissue (ESG68)

The epidermis is a single layer of cells that covers plants' leaves, flowers, roots and stems. It is the outermost cell layer of the plant body and plays a protective role in the plant. The function of key structural features are listed in table:epidermaltissue .

Figure 4.6: Scanning electron microscope image of Nicotiana alata (tobacco plant) upper leaf surface, showing trichomes (also known as `hairs') and a few stomata.

The chemicals in trichomes make plants less easily digested by hungry animals and can also slow down the growth of fungus on the plant. As such they act as a form of protection for the plant against predation.

Guard cells and Stomata (ESG69)

A stoma is a pore found in the leaf and stem epidermis that allows for gaseous exchange. The stoma is bordered on either side by a pair of specialised cells known as guard cells . Guard cells are bean shaped specialised epidermal cells, found mainly on the lower surface of leaves, which are responsible for regulating the size of the stoma opening. Together, the stoma and the guard cells are referred to as stomata .

The stomata in the epidermis allow oxygen, carbon dioxide and water vapour to enter and leave the leaf. The guard cells also contain chloroplasts for photosynthesis. Opening and closing of the guard cells is determined by the turgor pressure of the two guard cells. The turgor pressure is controlled by movements of large quantities of ions and sugar into the guard cells. When guard cells take up these solutes, the water potential decreases causing water to flow into the guard cells via osmosis. This leads to an increase in the swelling of the guard cells and the stomatal pores open.

Practical investigation of leaf epidermis

To observe epidermal cells and stomata.

leaves of Agapanthus , Wandering Jew (Tradescantia ) or similar plants that have epidermis that strips off easily

microscopes

microscope slides and cover slips

dissecting needles

Instructions

• Rip a piece of leaf lengthwise and check for 'thinner bits' near the edges, which will be epidermal tissue (ensure that you have lower epidermis because this is where the guard cells are found).
• Use the scissors to cut off a small section of epidermis and mount it in water on a microscope slide. Cover with a cover slip.
• Focus the slide on low power and search for a section of the sample that does not have air bubbles over the stomata.
• Enlarge the part of the specimen you chose and focus on high power.
• Adjust lighting if necessary and draw one stoma and its guard cells. Label all parts.
• Describe the shape of the guard cells and normal epidermal cells.
• Which epidermal cells have chloroplasts?
• Describe the wall thickness around the guard cells and account for any visible differences.

Activity: Practical investigation of leaf epidermis

Learners to use microscope and slide preparation skills.

NOTES TO TEACHERS

Tradescantia , a common SA plant with purple leaves, works particularly well for this practical since the epidermis rips off easily.

• Learners should be encouraged to rip the leaves quickly in order to get epidermal tissue.
• They must search the entire specimen on low power, in order to get the best part to magnify. There is little value in just enlarging the first part of the leaf they focus on – there will be many stomata that have air bubbles with thick black outlines over them. Learners must search carefully and enlarge the best stoma they can find.
• Learners must be encouraged to draw the guard cells as they see them, even if they are lying at an angle.

Tradescantia , a common SA plant with purple leaves.

• Guard cells are bean shaped and normal epidermal cells are irregular, square-shaped or elongated (depending on leaf used.
• Only the guard cells.
• Guard cells have thick inner walls and thinner outer walls, as this helps them to open the pores for gaseous exchange.

We will now look at parenchyma, collenchyma and sclerenchyma cells. Together these tissue types are referred to as ground tissues. Ground tissues are located in the region between epidermal and vascular tissue.

Parenchyma tissue (ESG6B)

Parenchyma tissue forms the majority of stems and roots as well as soft fruit like tomatoes and grapes. It is the most common type of ground tissue. Parenchyma tissue is responsible for the storage of nutrients.

Table 4.2: Structure and function of parenchyma

Observing parenchyma cells.

To observe the structure of fresh parenchyma cells.

petri dishes or watch glasses

dissection needles

iodine solution

microscopes, microscope slides and cover slips

• Use the dissecting needle to lift off a small piece of the soft banana tissue.
• Put the sample onto a petri dish or watch glass and mash it slightly using the dissecting needle (and a pencil if you want).
• Lift a small sample of the tissue onto a microscope slide on which you already have placed a drop of iodine solution. Put the cover slip on.
• Observe the cells under low power and find a section where the cells are lying separate, not all over each other.
• Enlarge this section and focus carefully to see if you can find nuclei in some of the cells (they will be bigger than the purple plastids and transparent).
• Draw 2 or 3 cells and label.
• Describe the shape of the cells and their wall thickness.
• What are the plastids called which appear purple and what is their function?

Activity: Practical investigation to observe the structure of fresh parenchyma cells

The cells will be large and have very thin walls. Many cells have leucoplasts storing starch.

Encourage learners to use the diaphragm on the microscope to prevent their cells being over-exposed to light – this can make the cells difficult to see.

Cells are rounded or oval and have very thin walls.

The plastids are leukoplasts and they store starch.

Collenchyma tissue (ESG6C)

Collenchyma is a simple, permanent tissue typically found in the shoots and leaves of plants. Collenchyma cells are thin-walled but the corners of the cell wall are thickened with cellulose. This tissue gives strength, particularly in growing shoots and leaves due to the thickened corners. The cells are tightly packed and have fewer inter-cellular spaces.

Collenchyma tissues make up the strong strands observed in stalks of celery.

The growth of collenchyma tissue is affected by mechanical stress on a plant. For instance if the plant is constantly shaken by the wind the walls of collenchyma may be \(\text{40}\)–\(\text{100}\%\) thicker than those that are not shaken.

Learn more about permanent simple tissues.

Video: 2CR4

Sclerenchyma tissue (ESG6D)

Sclerenchyma is a simple, permanent tissue. It is the supporting tissue in plants, making the plants hard and stiff. Two types of sclerenchyma cells exist: fibres and sclereids .

Sclerenchyma fibres are long and narrow and have thick lignified cell walls. They provide mechanical strength to the plant and allow for the conduction of water.

Sclereids are specialised sclerenchyma cells with thickened, highly lignified walls with pits running through the walls. They support the soft tissues of pears and guavas and are found in the shells of some nuts.

Sclerenchyma tissues are important components in fabrics such as flax, jute and hemp. Fibres are important components of ropes and mattresses because of their ability to withstand high loads. Fibres found in jute are useful in processing textiles, given that their principal cell wall component is cellulose. Other important sources of fibres are grasses, sisal and agaves. Sclereid tissues are the important components of fruits such as cherries, plums or pears.

A useful way to remember the difference between collenchyma and sclerenchyma is to remember the 3 Cs pertaining to collenchyma: thickened at c orners, contain c ellulose, and named c ollenchyma.

Observing sclerenchyma in pears

To observe sclerenchyma stone cells (sclereids) in pears.

soft, ripe pear

dissecting needles or forceps

• Use the forceps or needle to lift a small piece of soft pear tissue onto your microscope slide.
• Add a drop of iodine solution.
• Mash the tissue slightly to separate the cells.
• Cover with a cover slip and observe under low power. You should focus on the groups of dark "stones" that appear amongst the rounded parenchyma cells of the pear. Try to find one or two stone cells or sclereids that are separate from the rest.
• Enlarge a good specimen (or focus on the edge of a group where one cells sticks out) and adjust the lighting.
• Look carefully while you focus up and down to see the long, narrow PITS running through the extremely thick walls of these cells.
• These "stone cells" are called sclereids. They are a modified form of sclerenchyma found in pears, guavas and the shells of nuts for extra support.
• Also observe the large round cells around the sclereids.
• Do you see cytoplasm inside the stone cells? Are they living or dead cells?
• What tissue type do the large round cells around the sclereids belong to?

Activity: To observe sclerenchyma stone cells (sclereids) in pears.

• Learners need a very small amount of pear tissue for this practical – the riper the pear, the better. This practical works best in pears that are actually over-ripe and extremely soft.
• Once again, encourage learners to scan the entire slide for the best parts before enlarging. They need to find a very small group of sclereids (they will appear as “little groups of black stones” amongst the large, thin-walled parenchyma cells of the pear).
• Learners must expect that it will be very difficult to focus them – the sclereids lie in a heap at slightly different levels, so it will not be possible to focus on all of them at the same time.

The cells and pits are best seen if one FOCUSES UP AND DOWN slightly on high magnification using the fine focus adjustment – warn them not to touch the coarse focus adjustment!

• It will be necessary to adjust the diaphragm to prevent over-illumination of the material.
• No, they are dead cells.
• Parenchyma.

To investigate sclerenchyma fibres

To see sclerenchyma fibres in tissue paper.

cheap toilet paper (single ply)

iodine solution or water

microscopes and slides

• Tear a tiny piece of toilet paper off the sample and mount it in water or iodine solution.
• Place on a cover slip and examine under the microscope on low power.
• Focus on the torn edge of the paper and observe the long sclerenchyma fibres.
• Observe on high power.
• Describe the shape of these cells.
• Are they living or dead cells?
• Suggest their function.
• It’s important that learners focus on the torn EDGE of the paper, not the centre.
• Cells are very long and pointed.
• Dead cells.
• They provide strength and support and help transport water.

We will now examine the complex permanent tissues. Remember the difference between simple and complex permanent tissues is that simple permanent tissues are made up of cells of the same type whereas complex permanent tissues are made up of more than one cell type that combine to perform a particular function. We will examine the vascular tissues, xylem and phloem tissues next.

Xylem tissue (ESG6F)

Xylem has the dual function of supporting the plant and transporting water and dissolved mineral salts from the roots to the stems and leaves. It is made up of vessels, tracheids, fibres and parenchyma cells. The vessels and tracheids are non-living at maturity and are hollow to allow the transport of water. Both vessels and tracheids have lignin in their secondary walls, which provides additional strength and support.

Xylem vessels are composed of a long chain of straight, elongated, tough, dead cells known as vessel elements. The vessel elements are long and hollow (lack protoplasm) and they make a long tube because the cells are arranged end to end, and the point of contact between two cells is dissolved away. The role of xylem vessels is to transport water from roots to leaves. Xylem vessels often have patterns of thickening in their secondary walls. Secondary wall thickening can be in the form of spirals, rings or pits.

Tracheids have thick secondary cell walls and are tapered at the ends. The thick walls of the tracheids provide support and tracheids do not have end openings like the vessels. The tracheids' ends overlap with one another, with pairs of pits present which allow water to pass through horizontally from cell to cell.

In addition to transporting water and mineral salts from roots to leaves, xylem also provides support to plants and trees because of its tough lignified vessel elements.

Observing the patterned secondary walls in the xylem of fresh plant tissue

To observe the patterned secondary walls in the xylem of fresh plant tissue.

celery stalk, rhubarb stalks or pumpkin stems (macerated - chop them across and boil them in water for 3 minutes, then add an equal amount of glycerine. Cool before using. It can be stored for a few months in the refrigerator.)

eosin solution

• Lift a small piece of celery / any other tissue chosen from the dish and transfer it to a watch glass or petri dish.
• Use the dissecting needle and a pencil to tease the tissue apart (separate the thread-like, thicker cells away from each other). Try to get the long cells away from each other, otherwise bundles will be too thick to allow you to see individual cells. Ignore the thin walled parenchyma cells around them.
• Transfer the plant tissue to a microscope slide and add eosin solution. Separate a bit more if necessary.
• Examine under low power, focusing on the bundles of xylem vessels. Look for long bundles of fairly wide cells with thickening in the form of rings or spirals. Do not confuse xylem vessels with the more common and much narrower sclerenchyma fibres - fibres have walls all the same thickness, have no spirals or rings and they are pointed at the end. If necessary, make a second slide if you did not find xylem.
• Move a good part to the centre and enlarge. Examine the secondary walls of these cells.
• Describe the shape of xylem vessels.
• What secondary walls patterns do you see?
• Suggest the function of such secondary walls.

Activity: To observe the patterned secondary walls in the xylem of fresh plant tissue.

• Learners must ensure that they transfer some of the “stringy tissue” that been prepared, not just the soft tissue (which is parenchyma).
• They will need to spend a bit of time teasing the cells apart with dissecting needles; otherwise the cells are very clumped together and difficult to see properly. They need to separate the ‘stringy’ bits from the normal soft tissue and mount only the stingy stuff onto the microscope slide.
• These cells can be successfully mounted in iodine solution if eosin is not available.
• Remind learners to adjust the diaphragm and look specifically for spirals / rings in very long, tubular cells. There will be many long, pointed sclerenchyma cells with the xylem.
• It is frustrating if no such cells can be found – it may be necessary to make a second slide and try again.
• Long, tubular cells with open ends.
• Hopefully spirals and rings, maybe a reticulate / netted vessel as well.
• To provide flexibility, support and allow the stem to stretch as it grows. They also resist the suction of transpiration pull and prevent the vessels collapsing during water transport.

Phloem tissue (ESG6G)

Phloem tissue is the living tissue responsible for transporting organic nutrients produced during photosynthesis (mainly as the carbohydrate sucrose ) to all parts of the plant where these are required. The phloem tissue is made up of the following major types of cells:

Do you remember that sucrose is made up of glucose and fructose monosaccharides? Plants transport sucrose rather than glucose because it is less reactive and has less of an effect on the water potential.

• sieve elements : these are conducting cells which transport sucrose.
• parenchyma cells : which store food for transport in phloem.
• companion cells : are associated with parenchyma cells and control the activities of sieve tube elements, since the latter have no nuclei. Companion cells are responsible for providing energy to the sieve elements to allow for the transport of sucrose. Companion cells play an important role in loading sieve tubes with sucrose produced during photosynthesis. Companion cells and sieve tube elements are connected via connecting strands of cytoplasm called plasmodesmata.
• fibres : unspecialised cells and supportive cells.

In the table below, the key structural features of the phloem are related to their function.

Figure 4.20: Xylem and phloem are the main transport vessels in plants. The figure above shows how vascular tissues are arranged in a vascular bundle.

STANMORE SECONDARY

Exam Papers and Study Notes for grade 10 ,11 and 12

Life Science(Grade 10)

Study notes.

 KZN March 2024    QP and Memo  below 

Past Year Exam Papers

(updated 2024/03/25)

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Exam Guidlines 2024

KZN  March  QP and Memo

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March  QP and Memo

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March  QP and  MEMO

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Nov P1  and Memo

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JUNE  QP and MEMO

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NOV   P1  and MEMO

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MARCH  QP and MEMO

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SEPT  P3   and MEMO

NOV  P1   and MEMO

MARCH   QP+MEMO

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Step Ahead Grade 10 Solutions

Life Orientation Grade 12 Tasks with Memos for Previous Years

Download Life Orientation Grade 12 Tasks with Memos for Previous Years Task 1, Task 2, Task 3, for 2023, 2022, 2021, 2020, and 2019.

Life Orientation (LO) is a compulsory subject for Grade 12 learners in South Africa, following the Curriculum and Assessment Policy Statement (CAPS) guidelines. Here are some of the tasks that Grade 12 learners may be expected to complete in LO:

• Critical analysis of current events: Learners may be asked to select a current event from the media and critically analyze it. They may be required to identify the underlying issues, stakeholders, and possible solutions. They may also be asked to reflect on the implications of the event for individuals, society, and the environment.
• Community service project: Learners may be required to design and implement a community service project. This project should aim to address a social or environmental issue in the community. The project should be well-planned, executed, and evaluated. Learners will need to reflect on what they learned and the impact their project had on the community.
• Health education: Learners may be asked to conduct research on a health-related issue and develop an educational resource to raise awareness about the issue. The resource may take the form of a pamphlet, poster, or video. Learners will need to explain why the issue is important, what the risks and benefits are, and how to prevent or manage the issue.
• Personal development: Learners may be required to reflect on their personal development and set goals for their future. They may be asked to assess their strengths and weaknesses, interests, and values. They will need to develop a plan for achieving their goals and consider the resources and support they will need to succeed.
• Career exploration: Learners may be asked to research different career options and evaluate their suitability for a particular career. They will need to consider their skills, interests, and values and match them with the requirements of the career. They will also need to explore the educational and training requirements and the job outlook for the career.

These are just some of the tasks that learners may be expected to complete in LO. The specific tasks will depend on the school and the teacher. It is important for learners to actively engage in the subject, participate in class, and take responsibility for their learning.

Table of Contents

Task 1 – Term 1

Life orientation grade 12 source based task 2024 pdf guide.

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LIFE SCIENCES SCHOOL BASED ASSESSMENT EXEMPLARS - CAPS GRADE 12 TEACHER'S GUIDE

LIFE SCIENCES SCHOOL BASED ASSESSMENT EXEMPLARS - CAPS GRADE 12 TEACHER GUIDE

1. Introduction  Assessment is a continuous planned process of identifying, gathering and interpreting information about the performance  of learners, using various forms of assessment. It involves four steps: generating and collecting evidence of achievement,  evaluating this evidence, recording the findings and using this information to understand and assist in the learners’  development to improve the process of learning and teaching. Assessment should be both informal (Assessment for  Learning) and formal (Assessment of Learning). In both cases regular feedback should be provided to learners to  enhance the learning experience.  School-based assessment (SBA) forms part of the formal assessment component. It is a purposive collection of learners’  work that tells the story of the learners’ efforts, progress or achievement in attaining knowledge (content, concepts and  skills) in the subject. The advantages of school-based assessment can be summarised as follows: 

• It provides a more balanced and trustworthy assessment system, increasing the range and diversity of assessment  tasks. 
• It improves the reliability of assessment because judgements are based on many observations of the learner over  an extended period of time. 
• It empowers teachers to become part of the assessment process and enhances collaboration and sharing of  expertise within and across schools. 
• It has a professional development function, building up practical skills in teacher assessment which can then be  transferred to other areas of the curriculum. 

School-based assessment forms part of a year-long formal Programme of Assessment in each grade and subject. The  assessment tasks should be carefully designed to cover the content of the subject as well as the range of skills and  cognitive levels that have been identified in specific aims. Tests, practical tasks, assignments and projects make up the  SBA component in Life Sciences.  Teachers should ensure learners understand the assessment criteria and have extensive experience using it for self- and  peer assessment in informal situations before conducting a planned formal assessment activity. Teachers should also  have used these criteria for informal assessment and teaching purposes before they conduct any formal assessment so  that learners are familiar with the criteria and the assessment process. 

2. Aims of the project  Through this publication it is envisaged that TEACHER capacity will be increased in respect of each of the following: 

• Differentiating among the nature of the different types of assessment tasks (assignments, projects, practical  tasks, tests and examinations)  
• Developing assessment tasks that are balanced in terms of cognitive levels, topics and skills 
• Is appropriate to the task 
• Clearly shows mark allocation and distribution 
• Includes alternative answers 
• Developing tasks that contain a variety of question types 

Through this publication it is also envisaged that LEARNERS will benefit by: 

• Developing an understanding of the differences amongst the nature of the various types of assessment tasks 
• Being exposed to assessment tasks that are of the same standard as those that they are exposed to during the  course of the year

3. Programme of formal assessment in Life Sciences 

• This includes all assessment tasks that make up the formal programme of assessment for the year.
• Formal assessment tasks are marked and recorded by the teacher for promotion and certification purposes. 
• All tasks must be subjected to pre- and post-moderation to ensure that appropriate standards are maintained.
• The table that follows shows the number and types of assessment tasks required in the Grade 12 year. 

NOTE: The SBA mark must be converted to 25% and the external examination counts 75% of the final mark. A description of the requirements for each of the different types of assessment tasks follows below.

3.1 Practical tasks  When designing the practical tasks, the Life Sciences teacher must ensure that: 

• Follow instructions 
• Handle equipment or apparatus
• Make observations 
• Record information or data 
• Measure accurately 
• Interpret information
• Design/Plan an investigation
• At least ONE of the practical tasks includes manipulation of apparatus and/or collection of data. 
• Any ONE practical task assesses at least 3 of the 7 skills and must include skill 6 and/or 7. 
• 20–40 marks are allocated to a practical task.  

3.2 Research Project  At least ONE of the tasks across Grades 10–12 must be a research project.  When designing the research project, the Life Sciences teacher must ensure that it: 

• Is a long-term task (at least 3 weeks of non-contact time) 
• Has a maximum mark of 100  
• covers Specific Aims 1, 2 and 3 
• Is recorded in Term 3 even if it is given and assessed in Term 1 or Term 2 
• Is an investigative task 
• Focuses on accessing knowledge through literature research as well as through primary sources such as people 
• Formulating investigative questions and hypotheses 
• Gathering information from a variety of sources
• Manipulating and processing information
• Analysing information
• Identifying patterns 
• Evaluating data
• Drawing valid conclusions
• Communicating findings

3.3 Assignment At least ONE of the tasks across Grades 10–12 must be an assignment.  When designing an assignment, the Life Sciences teacher must ensure that it: 

• Is a short-term task (1½-2 hours under controlled conditions) 
• Covers Specific Aims 1, 2 and 3 
• Is completed at school and not at home 
• Covers a variety of topics 
• Analysing and interpreting data
• Making drawings
• Plotting graphs
• Drawing tables
• Performing calculations
• Justifying conclusions 

3.4 Tests and Examinations  When designing the tests as well as the mid-year and trial examinations, the Life Sciences teacher must ensure that: 

• The test is a minimum of 50 marks. 
• The test in Term 1 covers all work done in that term. 
• The tests in Term 2 and Term 3 cover at least half of the work covered in the respective terms. 
• The mid-year examinations cover work completed in Term 1 and Term 2. 
• The trial examinations cover all work completed in Terms 1, 2 and 3, and must include the section on ‘Human  Impact’ from Grade 11. 
• Mainly Specific Aims 1 and 3 are covered. 
• Specific Aim 2 (knowledge and understanding of investigations and practical work) is also included, but in a  smaller proportion compared to Specific Aims 1 and 3. 
• Tests and examinations are balanced in terms of cognitive levels and topic weightings. In this regard weighting  grids must be used. 
• Tests and examinations are analysed diagnostically and appropriate remedial and intervention strategies are  instituted. 
• Tests and examinations follow the external examination in its design, rigour and format.

4. Scope of the project   This publication includes the following: 

• Requirements for the Grade 12 Programme of Assessment for the Life Sciences CAPS curriculum
• A description of the various types of assessment tasks (assignment, project, practical task and test) 
• Exemplar assessment tasks (assignment, practical task and test) 
• Marking Guidelines for each assessment task 

The following exemplars together with their marking guidelines have been included in this publication: 

5. Quality assurance process followed  A team of experts comprised of teachers and subject advisors from provinces was appointed by the DBE to develop  and compile assessment tasks. They were required to extract excellent examples of learner tasks from their respective  schools and districts. The panel of experts spent a period of four days at the DBE, developing tasks based on guidelines  and policies. Moderation and quality assurance of the tasks were undertaken by national and provincial examiners and  moderators. The assessment tasks were further refined by the national internal moderators to ensure that they were in  line with the CAPS document.

6. Assessment tasks  6.1 Practical Task 1 – Surveying human characteristics 

Task  Conduct a survey of the occurrence/frequency of dominant and recessive phenotypes for each of three traits/ characteristics (as shown in the pictures below) among the learners in your school. 

• This task must be done individually. 
• This practical must be completed at school. 
• Select 20 learners that will form part of your sample. 
• For every learner selected, record the phenotype for each characteristic. 
• Record the information for each learner in a table. At the end of the table, include the percentage of learners  displaying each phenotype for each of the three characteristics. 
• Answer the questions set. 
• List any FOUR planning steps for this investigation.  (4)
• In terms of the investigation about the type of earlobe (free or attached), name the following: 2.1 The dependent variable  (1) 2.2 The independent variable  (1)
• Formulate a hypothesis for the frequency of tongue-rollers as compared to non-rollers in your school.    (3)
• Construct a table to show the results obtained in this investigation.   (4)
• According to the results obtained, would you accept or reject the hypothesis formulated in QUESTION 3?  (1)
• State TWO ways in which you could make the results of this investigation more reliable. (2)
• Using the same system of axes, draw a bar graph to represent the percentage of learners displaying each phenotype for each of the three characteristics.  (8)
• Use the symbols R (tongue-roller) and r (non-roller) to represent the phenotypes and genotypes of  offspring resulting from a cross between two heterozygous individuals.   (6) 

6.2 Practical Task 2 – Simulating natural selection   

Task  Simulate ‘natural selection’ using a paper model. 

• This task must be done in pairs but the questions must be answered individually. 

Background information  A simulation allows one to demonstrate something that might sometimes be dangerous or that might sometimes require  a lot of time, quickly and in a simple and safe way, using models.   The different parts that comprise the paper model in this task represent different components in nature. The sheet of  newspaper and the sheet of white paper represent two different environmental conditions. The circles cut from white  paper and from newspaper represent the different appearances/phenotypes of different individuals of the same species. 

Aim  You are required to investigate the survival of the organisms with the two different phenotypes under different  environmental conditions.   Materials required 

• A sheet of white paper (preferably A3 size) to use as background 
• A sheet of newspaper (cut to A3 size) to use as background 
• Forceps/tweezers 
• Clock with a second hand/stopwatch 
• 30 x 2 cm diameter circles cut from another sheet of newspaper 
• 30 x 2 cm diameter circles cut from another sheet of white paper 
• Place the sheet of white paper on the table. 
• Spread 30 white paper circles and 30 newspaper circles randomly over the surface of the white paper. 
• Ask your partner to use a pair of forceps/tweezers to pick up as many circles as he/she can in a period of 15  seconds.
• Count the number of each type of circle that has been picked up. Record this in the table provided.
• Now repeat steps 1–4 using the sheet of newspaper instead of the sheet of white paper.

Question 1. 

• Formulate a hypothesis for the above investigation when using the sheet of white paper as  background.  (3)
• For this investigation, name: 2.1 The dependent variable  (1) 2.2 The independent variable  (1) 2.3 Any TWO fixed variables  (2)

Draw a bar graph on the same system of axes to represent the results of your investigation. (8) 

Explain the difference in results obtained for the two types of circles when using the sheet of white  paper. (3) 

State ONE way in which you could improve the reliability of the results.  (1) 

• State a conclusion for the above investigation when the newspaper was used as a background. (3)
• Based on the results obtained, will you accept or reject the hypothesis you formulated in QUESTION  1?   (1)

6.3 Assignment 1 – Response to the environment 

Instructions and information  

• Answer ALL questions.
• Number the answers correctly according to the numbering system used in this question paper.
• Draw diagrams and flow charts ONLY when requested to do so.
• This assignment is to be done under controlled conditions and must be handed in at the end of the session. 

NOTE: If it is not possible to schedule a single 90-minute session for this assignment, then SECTION A can be  done on one day in a 45-minute session and SECTION B the following day in another 45-minute session. 

________________________________________________________________________ 

SECTION A  QUESTION 1  An investigation was conducted to study apical dominance in bean plants. Four groups of plants were used. The  diagram below illustrates the process. 

The results are shown in the table below.

1.1 For this investigation, state the: (1) 

1.1.1 Independent variable (1)  1.1.2 Dependent variable (2)  1.1.3 Any TWO fixed variables (3)  

1.2 Formulate a possible hypothesis for the above investigation. (4)   1.3 Explain the difference in results for Groups 3 and 4.  (1)  1.4 Do the results allow you to accept or reject the hypothesis you formulated in QUESTION 1.2? [12]

QUESTION 3  Read the passage below and answer the questions that follow. 

The normal plasma glucose level is 100 mg/100 ml. The glucose tolerance test was conducted for three adults and the  plasma glucose level (mg/100 ml) was recorded for two hours at 30-minute intervals. The results are shown below. 

3.1 State how the glucose tolerance response test above is used to decide if a person is suffering from  diabetes.   (2)  3.2 Adult 1 is not diabetic.  

3.2.1 Describe the changes expected in insulin secretion in Adult 1 during the period 30 minutes to  90 minutes after the glucose drink.  3.2.2 Explain your answer to QUESTION 3.2.1.   (2)  

3.3 Draw two line graphs on the same set of axes to show the glucose tolerance of Adults 1 and 2. (9)  3.4 What was the percentage increase in glucose level when the glucose was at its maximum in Adult  2? Show all working.   (3) 3.5 Write down the plasma glucose level of the three adults after two hours as a ratio in simple whole  numbers. Show all working.  (2)  3.6 Suggest, with reasons, what would happen to insulin secretion for Adult 2: 

3.6.1 If the condition was IDDM (2)  3.6.2 If the condition was NIDDM  (2) 

[24]  TOTAL SECTION A: 50

SECTION B  QUESTION 4  Read the passage and information below and answer the questions that follow. 

Two learners conducted an investigation in the following way to determine which sense organ sends the message  fastest to the brain: the eye, the ear or the skin (sight, hearing, or touch): 

• Vusi held a meter stick between his thumb and index finger just above the 100 cm mark, while Mary placed her  thumb and forefinger at the 0 mark on both sides of the stick with just the thumb touching it.
• As Vusi dropped the meter stick Mary attempted to catch it by closing her thumb and forefinger. The distance on  the meter stick that the stick fell before Mary caught it was recorded and the procedure was repeated three times. 
• They repeated the investigation to determine hearing and skin responses. For the hearing response, Mary was  blindfolded and reacted to Vusi shouting ‘DROP’ when he let go of the stick. For the skin response, Mary was  blindfolded again. Vusi tapped Mary’s free hand when he let go of the stick.  

The results they obtained are shown in the following table: 

4.1 Name the path that is described in the passage. (2)  4.2 In relation to this path, what term is used to describe each of the following in terms of the role they  play? 

4.2.1 The muscles  (1)  4.2.2 Skin sensors  (1) 

4.3 Why should you advise the two learners to repeat the procedure more than three times for each  investigation? (2) 4.4 Identify the following in their investigation: 

4.4.1 The dependent variable  (1)  4.4.2 The independent variable   (1) 

4.6.1 The actual reaction time if the meter stick dropped 9 centimetres (2)  4.6.2 The distance the ruler will drop for a reaction time of 400 milliseconds  (2) 

QUESTION 5  The graph shows the speed of a nerve impulse along neurons with different diameters, measured in micrometres  (μm). 

5.1 Describe the relationship between the diameter of a neuron and the speed of an impulse travelling  along the neuron.  (2)  5.2 Use the graph to estimate how fast an impulse would travel along a neuron with a diameter of 5  μm. (2)  5.3 Name the functional gap found between two neurons across which impulses are transmitted.  (1)  5.4 Explain the significance of the myelin sheath that covers the neurons. (2)  5.5 Draw a diagram to illustrate the structure of a motor neuron. Indicate the direction of the impulse by  means of an arrow in the diagram.  (7) 

QUESTION 6  A person sitting in a darkened room covers one eye. A dim electric bulb, positioned at varying distances from the  person, is switched on at one-minute intervals for a period of 9 seconds. During this period the diameter of the pupil of  the eye is measured. The results obtained are shown in the table below. Study the table and answer the questions that  follow.

6.1 Name the structure in the eye that controls the size of the pupil.  (1) 6.2 Between which TWO time intervals did the following changes in the diameter of the pupil occur? 

6.2.1 Smallest increase   (2) 6.2.2 Biggest decrease   (2)

6.3 State why the size of the pupil changes from interval 8 to interval 9.  (2) 6.4 Describe how the size of the pupil changes from interval 8 to interval 9.  (4) 6.5 Why is the response in QUESTION 6.3 referred to as a ‘reflex’?  (1) 6.6 What is the significance of this reflex?  (1) 6.7 At which time interval was the bulb the furthest from the eye?   (1) 6.8 Explain your answer to QUESTION 6.7.   (2) 6.9 State TWO ways in which the investigator could ensure that the results of this investigation are  reliable.   (2) 6.10 State THREE things that must be kept constant in this investigation to ensure that it is valid.  (3)

[21] TOTAL SECTION B:  50 GRAND TOTAL: 100

6.4 Assignment 2 – Reproduction 

Instructions and information

NOTE: If it is not possible to schedule a single 90-minute session for this assignment, then SECTION A can be  done on one day in a 45-minute session and SECTION B the following day in another 45-minute session.  ________________________________________________________________________

SECTION A  QUESTION 1  Read the text below and then answer the questions that follow. 

1.1 State the type of fertilisation (external or internal) that occurs in bullfrogs and describe how it occurs.  State whether reproduction in bullfrogs is viviparous, oviparous or ovoviviparous.(3) 1.2 Explain your answer to QUESTION 1.2.  (1) 1.3 Describe TWO characteristics of a frog’s egg.   (2) 1.4 Give TWO reasons suggested in the article for bullfrog eggs to be laid in water.    (2) 1.5 Frog eggs are vulnerable to predators, since there is little or no parental protection.   (2) 1.6   Explain THREE strategies that ensure a good survival rate of tadpoles. 

QUESTION 2  The electron micrograph below is that of the human sperm. Study the micrograph and answer the questions that follow.  

2.1 Draw a labelled line diagram of the human sperm represented in the electron micrograph.   (6)  2.2  Use the scale line provided to calculate the width of the sperm at its widest point. (4)  2.3  Explain THREE ways in which the sperm is structurally suited for its role in fertilisation.   (6)    

QUESTION 3  Records of human fertility for the period 1941 to 1990 have shown changes in the sperm counts of normal men. The  table below summarises the changing percentages of men with high or low sperm counts over a period of 50 years. 

3.1  During which time period was there: 

3.1.1 The highest percentage of men with low sperm counts?  (1)  3.1.2 The lowest percentage of men with high sperm counts?   (1)  3.1.3 The greatest difference between men with high sperm counts and men with low sperm counts?  (1) 

3.2 Describe the trend for men with low sperm counts, and compare it with those with high sperm counts  over the period of 50 years.   (2)   3.3  Calculate the percentage increase in men with low sperm counts from 1971 to 1990. (2)  3.4  Suggest TWO reasons for the trend described in QUESTION 3.2.  (2) 

QUESTION 4  The table below shows the results of a survey on the use of contraceptives by a sample of women in a rural area. 

Draw a pie chart to show the results of the survey. Show all working. [9]

TOTAL SECTION A: 50

SECTION B  QUESTION 5  The diagram below shows the changes in the ovary, uterus and level of hormones during a 28-day menstrual cycle.  Study the diagram and answer the questions that follow. 

5.1 Which hormone is responsible for: 

5.1.1 Ovulation (1)  5.1.2 Primary (first) thickening of the endometrium (1) 

5.2 According to the graph, on which day(s) does each of the following occur: 

5.2.1 Menstruation  (1)  5.2.2 Ovulation (1) 

5.3 Two structures in the ovaries are responsible for the secretion of two female hormones.

5.3.1 Name the TWO structures and the hormones they secrete. (4)  5.3.2 Give evidence from the graph to support your answer to QUESTION 5.3.1. 4) 

5.4 Explain the interaction that occurs between the hormones FSH and progesterone and why it is  necessary. (3)  5.5 Is the female, whose cycle is represented in the diagram, pregnant?  (1)  5.6 Give TWO reasons from the graph for your answer to QUESTION 5.5.  (2) 

QUESTION 6  The table below shows the average human foetal length of males and females over a 40-week gestation period.  

6.1 Draw TWO sets of bar graphs on the same system of axes to compare male and female foetal  length over time.  (9)  6.2 State TWO conclusions that could be drawn from the results in the graph.  (4) 

[19]  TOTAL SECTION B: 50 

6.5 Test – Nucleic acids and meiosis 

• Draw diagrams and flow charts ONLY when requested to do so. 
• This test is to be done under controlled conditions and must be handed in at the end of the session. 

SECTION A  QUESTION 1  1.1 Various possible options are provided as answers to the following questions. Choose the answer  and write only the letter (A–D) next to the question number (1.1.1–1.1.5) in the ANSWER BOOK, for  example 1.1.6 D. 

1.1.1 All nucleic acids are made up of … 

• deoxyribose sugars, nitrogenous bases and phosphates.
• sugars, nitrogenous bases and phosphates.
• ribose sugars, nitrogenous bases and phosphates
• sugars, nitrogenous bases and sulphates. 

1.1.2 If a DNA molecule contains 20 000 base molecules, of which 20% are cytosine, how  many adenine molecules will be present? 

1.1.3 DNA replication ensures that all daughter cells formed as a result of … 

• mitosis, have identical genetic material.
• meiosis, have identical genetic material.
• mitosis, have half the number of chromosomes as the parent cell.
• meiosis, have half the number of chromosomes as the parent cell.

1.1.4 In individuals with normal haemoglobin, the mRNA for haemoglobin includes the codon  GAA. This sequence is changed in individuals with sickle cell anaemia so that their mRNA  has a codon GUA at the same location. This suggests that the DNA has undergone a  mutation involving a change of base sequence from ... 

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• CAA to TAA.
• CTT to CAT.
• CUU to CAT.
• CTT to CTA. 
• Only suspect X was involved.
• Only suspect Y was involved.
• Suspects X and Y were both involved.
• Neither suspect X nor suspect Y was involved. (5 x 2) (10) 

1.2 Give the correct biological term for each of the following descriptions. Write only the term next to the  question number (1.2.1–1.2.4) in the ANSWER BOOK. 

1.2.1 Specific lengths of DNA which carry codes for specific characteristics of organisms 1.2.2 The part of protein synthesis taking place in the nucleus  1.2.3 The bonds between the two strands of a DNA molecule  1.2.4 The chromosome condition/ploidy of a somatic cell (4) 

1.3 Indicate whether each of the statements in COLUMN I applies to A only, B only, both A and B or  none of the items in COLUMN II. Write A only, B only, both A and B, or none next to the question  number (1.3.1–1.3.3) in the ANSWER BOOK.

(3 x 2) (6)  TOTAL SECTION A: 20

Identify the amino acids which will be brought to organelle G according to the code provided by the  mRNA found on G. (3)  2.6 Write down the triplet of DNA bases that correspond to each of the molecules B, F and H, respectively. (3) 

[15]  TOTAL SECTION B:  30  GRAND TOTAL:  50

7. Marking guidelines  7.1 Practical Task 1 – Surveying human characteristics 

• Seek permission✓ to conduct the investigation. 
• Decide how the learners are to be selected✓ for your sample. 
• Identify the 20 learners✓ who will form a part of the sample.
• Arrange a date✓/time/venue for surveying the different characteristics. 
•  Design a table✓ for recording information. 
• Study the different phenotypes for each characteristic✓ in order to correctly identify them.  (4) (any 4) 
•             2.1 Number of learners ✓ that have free or attached ear lobes   (1) 2.2 Characteristic✓/type of ear lobe/attached or unattached earlobes   (1)
• There are more✓ learners✓ in the school that are tongue rollers than non-rollers✓
• There are more✓ learners✓ in the school that are non-rollers than tongue rollers✓ 
• The number of learners✓ in the school that are tongue rollers is equal✓ to the number of  non-rollers✓ (any 1 x 3) (3)
• Support✓(if the results obtained are in line with the hypothesis stated by the learner in Question 3) OR Reject✓ (if the results obtained contradict the hypothesis stated by the learner in (Question 3) (1)
• Increase the sample size✓ 
• Repeat the investigation✓   (2)

7.2 Practical Task 2 – Simulating natural selection 

• More✔ white circles✔ than newspaper circles✔ will be picked up from the white sheet OR More✔ newspaper circles✔ than white circles✔ will be picked up from the white sheet OR An equal number✔ of newspaper circles✔ and white circles✔ will be picked up from the white sheet 2.  (3) 
• Same size of newspaper and white paper used as a background✔
• Same size of white and newspaper circles✔
• Same number of white and newspaper circles at the start✔
• Same amount of time allowed for picking up the circles✔
• Same forceps/tweezers used throughout the investigation✔
• Same person used to pick up circles throughout the investigation✔ 
• Same hand used to pick up circles throughout the investigation✔ (any 2)   (2)
• Fewer✔ white circles✔ were picked up from the white paper, because white circles are not easily  seen against the white paper✔  OR More✔ newspaper circles✔ were picked up from the white paper, because newspaper circles are easily seen against the white paper✔    (3) 
• Increase number of attempts✔ and work out the average number picked  
• Repeat the investigation ✔ (any 1)    (1)
• More✔ white circles✔ than newspaper circles✔ were picked up from the newspaper background (3) 
• Support✓ (if the results obtained are in line with the hypothesis stated by the learner in Question 1) OR  Reject✓ (if the results obtained contradict the hypothesis stated by the learner in Question 1)   (1) 
• The white sheet represents the light tree✓
• and the newspaper sheet represents the dark tree✓. 
•  The circles represent the moths.✓
• Picking up the circles represents birds feeding on the moths✓.
• More circles of one type rather than the other type being picked up✓ represents natural selection✓ (any 5) (5) 

7.3 Assignment 1 – Response to the environment QUESTION 1  1.1 

1.1.1 Presence/absence of auxins✔  (1)  1.1.2 Growth of lateral buds✔  (1)  1.1.3

• Use bean plants of the same species✔ 
• Conduct investigation under same environmental conditions✔ 
• Use bean plants of the same height/age✔ (any 2)   (2)

1.2 Auxins✔ at the growing tip of the stem stimulate✔ the growth of lateral buds✔  OR  Auxins✔ at the growing tip of the stem inhibit✔ the growth of lateral buds✔  OR  Auxins✔ at the growing tip of the stem have no effect✔ on the growth of lateral buds✔  (3)  

• Auxin present✔ in Group 3 as it was applied to the tip and therefore it inhibited✔ the growth  of the lateral buds 
• Auxins not present✔ in rest of stem in Group 4 due to the barrier so lateral buds grew✔/  growth of lateral buds was not inhibited  (4)  

1.4 Support✓ (if the results obtained are in line with the hypothesis stated by the learner in   Question 1.2)  OR  Reject✓ (if the results obtained contradict the hypothesis stated by the learner in  Question 1.2)   (1) 

QUESTION 2  2.1  Gravity✔   (1)  2.2   

• Due to gravity, auxins accumulate✔ 
• on the lower side of the root✔. 
• A high concentration of auxins in the lower part of the root inhibits✔ growth.
• Cells on the upper part of the root grow faster✔ 
• where the auxin concentration is lower✔. 
• The root curves downwards✔.
• It is said to be positively geotropic✔. (any 6)    (6) 

2.3 Cell division ✔; cell elongation✔; the development of fruit✔; the abscission of leaves and fruit✔; the development of adventitious roots in stem cuttings ✔ (any 2)  (2)   2.4  Yes ✔ (1)   2.5  The growth is in response to gravity✔ and not light✔  (2)  2.6  Moisture is essential✔ for germination✔.  (2) 

QUESTION 3  3.1 Patient is diabetic if blood glucose level is above 200 mg/100 ml✔ for up to two hours after the  glucose test drink✔.   (2)  3.2 

3.2.1 Insulin level will increase between 30 and 60 minutes✔ and then  decrease✔. (2)   3.2.2 The level would initially increase when glucose level is higher than  normal✔then decrease when the level of glucose decreases✔.  (2) 

(260 mg/100 ml – 130 mg/100 ml) = 130 ✔   130/130 X 100✔  = 100%✔     (3) 

3.5   Adult 1: Adult 2: Adult 3 = 80 :240 :160✔ = 1 :3 :2✔   

3.6.1 IDDM - no insulin is produced✔  because the pancreatic cells responsible for insulin secretion are not functioning✔/do not produce insulin. (2)  3.6.2 NIDDM – insulin secretion will increase✔  since the pancreas is not affected✔/cells that normally respond become less sensitive to insulin (2) 

SECTION B QUESTION 4  4.1 Reflex arc ✓ ✓   (2) 4.2   

4.2.1 Effectors✓  (1) 4.2.2 Receptors✓   (1)

4.3 To improve ✓the reliability✓ of the investigation  (2) 4.1

4.4.1 Distance on meter stick/reaction time ✓ (1) 4.4.2 Different senses (sight/hearing/touch) ✓ (1)

5 cm + 6 cm + 6 cm = 17 cm ✓  17 cm = 5,7 cm ✓    3 ✓                                                     (3)

4.6.1 475 ✓ milliseconds ✓  (2)  4.6.2 3 ✓ cm✓  

QUESTION 6  6.1  Iris✔  (1)  6.2 

6.2.1 2✔to 3✔  (2)  6.2.2 6✔ to 7✔   (2) 

6.3 Dim light conditions✔ causes pupil to adjust  so that more light can enter✔ the eye (2)  6.4     

• Radial muscles✔ of iris contract✔
• Circular muscles✔of iris relax✔ 
• Pupil dilates✔ (any 4)  (4) 

6.5  It occurs automatically✔/involuntarily/without the control of the will (1)  6.6  It protects✔ the eye from damage in bright conditions  (1)  6.7  Interval 5✔ (1)  6.8  Diameter of the pupil✔ was at its widest✔  (2)  6.9 

• Repeat the investigation✔
• Take more than one reading at each time interval✔  
• Increase the time of exposure to light at each time interval✔ (any 2)  (2) 
• Use the same light bulb✔
• Same eye must be covered✔ throughout the entire investigation  
• Same person must be used✔ for the entire investigation  (3) 

[21]  TOTAL SECTION B:  50  GRAND TOTAL:   100

7.4 Assignment 2 – Reproduction SECTION A  QUESTION 1  1.1 Fertilisation occurs externally ✔ (1)        Eggs are released into the water and then male releases sperms✔ which fertilise eggs in the water✔ (2)  (3)  1.2  Oviparous✔ (1)  1.3 

• Eggs are laid✔
• and the embryos develop outside the mother’s body within the eggs✔ (2) 
• Eggs are small ✔
• Eggs are protected by a gelatinous mass and membranes✔ (2) 
• Prevents drying out✔ 
• Easier for frog sperm to reach the eggs✔  (2) 
• Large numbers of eggs are produced✔  because many are eaten✔
• Eggs hatch into tadpoles within 3-5 days✔  which ensures that they can swim away from predators✔
• Nearby plant matter shelters hatching tadpoles✔  preventing them from being eaten✔  (6) 

1 µm = 4 mm✔  Width of sperm = 12 mm✔ = X µm   1 µm = 4 mm  X µm = 12 mm ✔  X = 3 µm ✔                            (4)  

• The acrosome produces enzymes ✔  which help the sperm to penetrate the ovum ✔
• The middle piece of the sperm contains mitochondria ✔  that supply the energy for the sperm’s activity✔
• A tail is present✔  to move the sperm through the seminal fluid✔    (6)  

QUESTION 3  3.1 

3.1.1 1981–1990 ✔   (1)  3.1.2 1981–1990 ✔   (1)  3.1.3 1941–1950 ✔   (1) 

3.2 Men with low sperm counts have increased ✔ while  men with high sperm counts have decreased ✔  (2)   3.3  

% increase = 18- 14 ✔   = 4 ✔ %                             (2)  

• Changed diets✔/eating more processed foods by men have caused the change
• Increased stress✔/changed lifestyle has caused the change  (2) 

QUESTION 4  CALCULATIONS: 

[9]  TOTAL SECTION A: 50

SECTION B QUESTION 5  5.1 

5.1.1 LH ✔  (1)  5.1.2 Oestrogen ✔   (1) 

5.2.1 0–7 days ✔ (1)  5.2.2 Day 14 ✔      (1) 

• Graafian follicle ✔ - oestrogen ✔ 
• Corpus luteum ✔ - progesterone ✔   (4) 
• When Graafian follicle is formed ✔ 
• there is an increase in oestrogen ✔ 
• When corpus luteum is formed ✔
• there is an increase in progesterone✔  (4) 
• An increase in progesterone level ✔ 
• inhibits the release of FSH✔ 
• to prevent FSH from stimulating the development of an ovum✔ 
• since no further ova are required if pregnancy results✔ (any 3)  (3) 

5.5  No ✔ (1)  5.6 

Corpus luteum has degenerated ✔ Progesterone has decreased✔  FSH started to increase at the end of the cycle✔ (any 2)      (2) 

• Average foetal length of both males and females✓ are the same from 8 to 13 weeks✓ (9)
• Average foetal length of males is greater✓ than the average foetal length of females from 16  to 40 weeks✓ 
• Average foetal length increases for males and females✓ over the 40-week period ✓  (any 2 x 2)    (4) 

QUESTION 7  7.1 

Allocate marks for the following labels:   P1/parents and F1/offspring✓  Meiosis and fertilisation✓ (1 compulsory* + 6 others)   (7)  7.2 

(1 compulsory* + 6 others) 

(5)  [19]  TOTAL SECTION B: 50  GRAND TOTAL:  100

7.5 Test – Nucleic acids and meiosis SECTION A  QUESTION 1  1.1

1.1.1 B✓✓  1.1.2 C✓✓  1.1.3 A✓✓  1.1.4 B✓✓  1.1.5 D✓✓ (5 x 2) (10) 

1.2.1 Genes✓  1.2.2 Transcription✓  1.2.3 Weak hydrogen bonds✓ 1.2.4 Diploid✓ (4) 

1.3.1 B only✓✓  1.3.2 A only✓✓  1.3.3 A only✓✓  (3 x 2) (6)

TOTAL SECTION A: 20

SECTION B QUESTION 2  2.1 Protein synthesis✔ (1)  2.2  Translation✔ (1)  2.3 

• According to the mRNA codons✓
• tRNA with matching anticodons✓ 
• bring the required amino acids✓ to the ribosome 
• The amino acids become attached by peptide bonds✓ 
• to form the required protein✓ (any 5) (5) 
• Both are single-stranded 
•  Both are made up of ribose sugar 
• Presence of cytosine, guanine, adenine and uracil (any 2) (2) 

2.5 Histidine ✔ cysteine ✔ serine ✔ (3)  2.6 GTT ✔ GGT ✔ AGC ✔ (3) 

B – centromere✔ (2)  E – homologous chromosomes✔/bivalent 

• They allow for attachment of chromosomes✔ (2)
• They contract to pull the chromosomes/chromatids to the poles✔ 

3.3 Crossing over✔ takes place Chromatids overlap✔  Segments of chromatids are exchanged✔ (any 2)  (2) 

 Table ✔  (5)  3.5  Two✔  (1)  3.6 

• Chromosome number 21 fails to separate✔ 
• during anaphase 1✔
• Gametes will be formed with 24 chromosomes/one extra copy of chromosome number  21✔ 
• If such a gamete fuses with a normal gamete with 23 chromosomes✔
• The resulting zygote will have 47 chromosomes✔ (any 3)   (3) 

 [15]  TOTAL SECTION B:   30 GRAND TOTAL:   50

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