Skip to the content

Life Sciences Paper 1, November 2024

81 questions · 150 marks. Answer any question here and see it marked like the exam, mark by mark.

Practise this paper, marked Write it timed

This is the November 2024 Paper 1 for Life Sciences, written as 81 questions that add up to 150 marks. By topic the marks are human responses to the environment (52), human reproduction (41), endocrine system and homeostasis (34), plant responses to the environment (13), reproduction in vertebrates (8) and scientific investigation and graphs (2). Of the 150 marks, 96 are for recalling facts and terms, 31 for explaining, 21 for reading data from diagrams, tables and graphs, 1 for method and working and 1 for the correct final answer. Most questions are worth one to three marks, so the exact word matters more than the length of the answer.

Questions here are based on the National Senior Certificate paper, in our own words. Each answer is marked against the points a marker looks for. The Diagnostic Report for this paper says candidates most often lose marks by explaining a different thing from the one asked, giving only the letter or the name of a labelled part, and describing numbers where a trend was wanted. Try the questions in order, or jump to the topic you find hardest.

Where marks are lost: in our words, from Department of Basic Education, NSC 2024 Diagnostic Report, Part 1 (Book 1).

No sign-up to try. Your first 3 answers are marked free. The original paper and memo are on PapersZA.

Every question

These questions are not yet checked by a teacher.

Question 1 · Endocrine system and homeostasis

[50]

Which hormone controls the amount of water in the blood by changing how much water the kidneys reabsorb? Choose the correct letter.

(2)Mark it 1.1.2

Which ONE of the following is a stage in the early development of a human embryo, from fertilisation to implantation?

(2)Mark it 1.1.3

A learner runs hard on the sports field and the carbon dioxide level in her blood rises above normal. Which ONE of the following describes what happens in her body? Write only the letter.

(2)Mark it 1.1.4

A learner runs for a bus after getting a sudden fright and the adrenal glands release adrenalin. Which ONE of the following changes takes place in the body because of adrenalin? A Less blood flows to the skeletal muscles B Blood flow to the skeletal muscles increases C Blood pressure drops D More blood flows to the digestive system

(2)Mark it 1.1.5

A boy touches a hot stove plate with his fingertips and pulls his hand away at once, before he feels any pain. Which ONE of the following shows the CORRECT order of the parts of the reflex arc in this response? A Sensory neuron → receptor in the skin → interneuron → effector muscle in the arm B Receptor in the skin → sensory neuron → interneuron → motor neuron → effector muscle in the arm C Receptor in the skin → motor neuron → interneuron → sensory neuron → effector muscle in the arm D Effector muscle in the arm → sensory neuron → interneuron → motor neuron → receptor in the skin Write only the letter (A to D).

(2)Mark it 1.1.6

The diagram below shows part of the human eye. A hiker standing on a hilltop looks at a farm windmill about 500 metres away. Which ONE of the following correctly describes the ciliary muscle (X), the suspensory ligaments (Y) and the lens (Z) while she focuses on the windmill? A: Ciliary muscle relaxed; suspensory ligaments slack; lens more convex B: Ciliary muscle contracted; suspensory ligaments slack; lens less convex C: Ciliary muscle relaxed; suspensory ligaments taut; lens less convex D: Ciliary muscle contracted; suspensory ligaments taut; lens more convex Write only the letter (A to D).

(2)Mark it 1.1.7

Which ONE of the following parts of the human brain acts as the body’s control centre for keeping its temperature steady?

(2)Mark it 1.1.8

A pregnant woman learns about the fluid that surrounds her baby in the uterus. The list below shows functions that may be linked to the fluid inside the amnion (amniotic fluid): (i) Cushioning the foetus against knocks (ii) Keeping the temperature around the foetus steady (iii) Giving the foetus room to move (iv) Supplying the foetus with food and oxygen Which combination of functions is carried out by the amniotic fluid? A (i), (ii) and (iii) only B (ii) and (iv) only C (i) and (iv) only D (i), (ii), (iii) and (iv) Write only the letter of the correct answer.

(2)Mark it 1.1.9

The diagram below shows part of the human ear, with structures labelled P, Q and R. Very strong sound vibrations have travelled through the fluid of the cochlea. Which ONE of the following describes what happens to the extra pressure in the fluid?

(2)Mark it 1.1.10

The diagram below shows the inner ear and the pathway that nerve impulses follow to the brain. The semicircular canals and the vestibule are labelled P, the cochlea is labelled Q, the auditory nerve is labelled R, the cerebellum is labelled S and the cerebrum (auditory area) is labelled T. Which ONE of the following correctly shows how nerve impulses about balance (equilibrium) travel from the inner ear to the brain?

(2)Mark it 1.2.1

Write down the correct biological term for the following description: the hormone-secreting organ that forms in the uterus wall during pregnancy and allows the exchange of substances between the blood of the mother and the blood of the developing baby.

(1)Mark it 1.2.2

Write down the correct biological term for the following description: the division of the peripheral nervous system that controls involuntary actions such as heart rate and digestion, and is made up of the sympathetic and parasympathetic parts.

(1)Mark it 1.2.3

Write down the correct biological term for the following description: the sensory structures inside the semicircular canals that detect rotation of the head in different directions.

(1)Mark it 1.2.4

Give the correct biological term for the following description: The tube in the middle ear that equalises air pressure on both sides of the eardrum by connecting the middle ear to the throat.

(1)Mark it 1.2.5

Write down the correct biological term for the following description: the directional growth of a plant shoot or root towards or away from light.

(1)Mark it 1.2.6

Give the correct biological term for the following description: The coiled, fluid-filled structure of the inner ear that contains the sensory receptors for hearing.

(1)Mark it 1.2.7

Give the correct biological term for the following description: a plant hormone that causes seeds to break dormancy and start to grow.

(1)Mark it 1.2.8

Name the structure at the tip of a sperm cell’s head that holds the enzymes used to break down the outer layers of an egg cell.

(1)Mark it 1.3.1

Read each description below and decide which of the structures in the list it fits: the first one only, the second one only, both, or neither. Type your choice as: first only, second only, both, or neither. Description: It supplies the developing baby with oxygen and nutrients from the mother’s blood. First structure: Umbilical cord Second structure: Vagina

(2)Mark it 1.3.2

Read each description below and decide which of the two structures it fits: structure A only, structure B only, both structures, or neither. Give your choice for the description that follows the two structures. Description: It is the region of the brain that regulates the rate at which the heart beats. Structure A: Cerebellum Structure B: Medulla oblongata

(2)Mark it 1.3.3

Read the description below. Decide which of the structures, X and Y, it fits. Answer with one of these: X only, Y only, both X and Y, or neither. The small spot on the retina that has no light-sensitive cells, so no image forms there.

(2)Mark it 1.4.1(a)

Look at the diagram below of the front view of the human male reproductive system. Give the LETTER and the NAME of the structure that carries both urine and semen out of the body.

(2)Mark it 1.4.1(b)

The diagram below shows the front view of the human male reproductive system, with parts labelled A to F. Give the LETTER and the NAME of the structure where sperm cells are held for a short time while they mature.

(2)Mark it 1.4.1(c)

Look at the diagram below of the front view of the human male reproductive system. Write down the LETTER and the NAME of the structure that produces the male sex hormone responsible for the development of male secondary sexual characteristics.

(2)Mark it 1.4.2(a)

The diagram below shows the male reproductive organs seen from the front, together with the bladder. The structure labelled A lies just below the bladder and surrounds the top of the urethra. Name structure A.

(1)Mark it 1.4.2(b)

The diagram below shows the front view of the human male reproductive system, with the testis labelled E. Name the type of gametogenesis that takes place in the structure labelled E.

(1)Mark it 1.5.1

The diagram below shows some structures of the human body that take part in homeostasis. Write down the LETTERS of the structures that work as endocrine glands only.

(2)Mark it 1.5.2

The diagram below shows a section through human skin, with structures labelled P, Q, R and S. Give the LETTERS and NAMES of the two structures that help to regulate body temperature.

(4)Mark it 1.5.3(a)

Name the hormone that is released from the pituitary gland (the gland labelled P in the diagram below) to help the body control the water content of the blood when a person has lost a lot of water through sweating.

(1)Mark it 1.5.3(b)

The diagram below shows a person with some organs and glands involved in keeping the body’s water balance steady. Gland P is the pituitary gland, which releases ADH when the blood becomes too concentrated. Name the organ labelled Q that responds to ADH by reabsorbing more water into the blood.

Question 2 · Human reproduction

[50]

The diagram below shows part of the female reproductive system, with structures labelled P, Q and R. Name the structure labelled P.

(1)Mark it 2.1.1(b)

The diagram below shows part of a woman’s reproductive system. The structure labelled R is the organ in which egg cells mature and from which an egg is released each month. Identify structure R.

(1)Mark it 2.1.2(a)

After fertilisation, the embryo must attach to the inner lining of the uterus, called the endometrium, before it can develop further. State TWO features of the endometrium that make it suitable for the embryo to implant in it.

(2)Mark it 2.1.2(b)

The diagram below shows a part of the reproductive system of a different woman, drawn at one point in her menstrual cycle. Using only what you can see in the diagram, give TWO observations that show she has a greater chance of fertilisation occurring at this stage.

(2)Mark it 2.1.3

The diagram below shows part of the female reproductive system. Structure C is the cell released from the ovary and drawn next to the funnel-shaped opening of the oviduct. Name the process by which structure C is produced in the ovary, and describe how this process takes place.

(6)Mark it 2.1.4

A tubal pregnancy is a type of ectopic pregnancy. The fertilised egg implants inside the fallopian tube instead of in the uterus. In most cases the embryo stops developing and dies, and the mother may be in danger. Explain why an embryo that implants in the fallopian tube is unlikely to survive.

(3)Mark it 2.2.1

Using the table, state the day on which the level of progesterone was at its highest.

(1)Mark it 2.2.2

Name the hormone from the pituitary gland whose level starts to rise towards the end of the cycle, from day 24, in the table above, so that a new follicle can begin to develop.

(1)Mark it 2.2.3

In the previous part, you were asked what happens to the uterine lining at the end of the cycle (days 24 to 28). Using figures from the table, give a reason for that outcome by linking the hormone trend to the events in the pituitary gland.

(2)Mark it 2.2.4

Use the table to calculate the percentage increase in the progesterone level from day 16 to day 20 of the cycle. Show ALL your working.

(3)Mark it 2.2.5

Describe how the progesterone level after day 24 would be different if this female had become pregnant during this cycle.

(1)Mark it 2.2.6

Explain what causes the progesterone level to stay high instead of falling, in a woman whose egg has been fertilised and has implanted in the uterus.

(2)Mark it 2.3.1

Use the passage to answer this question. Which type of glaucoma is linked to a problem with the kidneys?

(1)Mark it 2.3.2

Use information in the passage to explain how a corneal scar can lead to loss of vision.

(5)Mark it 2.4.1

A learner has hypermetropia (long-sightedness). Explain how the structure of her eyeball causes problems with her vision when she reads a notice on the board two hand-spans in front of her without wearing her spectacles.

(3)Mark it 2.4.2

A learner has hypermetropia (long-sightedness), so she cannot see nearby objects clearly. Explain how wearing glasses with convex lenses helps her to see the words on a page clearly when she reads.

(2)Mark it 2.5.1

The diagram below shows a neuron that has a long axon with a myelin sheath, a cell body with many short branched dendrites at one end, and axon terminals at the other end. This type of neuron carries impulses from the central nervous system to a muscle. Name the type of neuron shown.

(1)Mark it 2.5.2

The diagram below shows a nerve cell that carries impulses from the spinal cord to a muscle. The cell is a motor neuron, which has a cell body at one end, one long axon and several short dendrites. State ONE feature visible in the diagram that shows this is a motor neuron and not a sensory neuron.

(1)Mark it 2.5.3

A reflex arc includes a neuron that carries impulses from the spinal cord to a muscle in the hand, so that the hand pulls away from a hot object. This neuron has a long axon, cell body in the grey matter of the spinal cord and endings at the muscle. Describe the function of this type of neuron in the nervous system.

(3)Mark it 2.5.4

The diagram below shows a motor neuron with three structures labelled P, Q and R. Write down the letters P, Q and R in the order in which a nerve impulse travels through this neuron.

(2)Mark it 2.5.5

Some nerve fibres are wrapped in a fatty insulating layer called the myelin sheath. Name the disorder of the nervous system in which this layer gradually breaks down and the person loses control of movement and sensation.

(1)Mark it 2.6.1(a)

The diagram below shows how the speed of nerve impulses changes with axon diameter in myelinated neurons. Read from the graph: what axon diameter, in µm, gives an impulse speed of 60 m/s in a myelinated neuron?

(1)Mark it 2.6.1(b)

Use the graph of the unmyelinated neuron in the diagram below to read off the axon width, in µm, that goes with a nerve impulse travelling at 15 m/s.

(1)Mark it 2.6.2(a)

Study the two graphs below. Use them to describe how the speed of nerve impulses in myelinated neurons compares with the speed in unmyelinated neurons.

(2)Mark it 2.6.2(b)

Look at the graph below, which shows how fast nerve impulses travel along the axons of a certain type of neuron. Describe the relationship between the axon diameter and the impulse speed shown in the graph.

Question 3 · Reproduction in vertebrates

[50]

Read the passage below about a seabird. Penguins are flightless seabirds that feed on fish and squid. A female penguin lays one or two eggs, which both parents keep warm on their feet until the chicks hatch. After hatching, the parents take turns to bring food to the chick. Give ONE reason from the passage why penguins are described as oviparous.

(1)Mark it 3.1.1(b)

Using the passage, give ONE reason why flamingos have a good chance of their chicks surviving even though each female lays only a single egg.

(1)Mark it 3.1.2

Fertilisation in crocodiles takes place inside the body of the female. Give TWO advantages of this type of fertilisation to the survival of the species.

(2)Mark it 3.1.3

State TWO features of newly hatched young that show altricial development.

(2)Mark it 3.1.4

Explain why birds with altricial development usually have a short incubation period.

(2)Mark it 3.2.1(a)

The diagram below shows the front view of a human eye with two parts labelled P and Q. Part P is the black circular opening at the centre of the coloured structure. Name part P.

(1)Mark it 3.2.1(b)

The diagram below shows the front view of a human eye. Part P is the opening at the centre, and part Q is the coloured ring of tissue around it. Name part Q.

(1)Mark it 3.2.2

A learner steps from a bright playground into a dim classroom. Within a second, the pupils of her eyes widen without her deciding to do so. Explain why this change in the pupils is classified as a reflex action.

(3)Mark it 3.2.3

A learner walks from a bright classroom into a dimly lit hall, and the pupils of her eyes change size automatically. Name the TWO types of effector muscle in the iris that bring about this pupillary mechanism.

(2)Mark it 3.2.4

The diagram below shows the same person’s eye photographed in two different rooms. In Room 1 the pupil is small. In Room 2 the pupil is much wider. Room 2 is the darker room. Give a reasoned account of why the pupil changing from the Room 1 size to the Room 2 size benefits the person.

(4)Mark it 3.3.1

A researcher studied how the hormone thyroxine affects the resting heart rate of rats. She placed 12 rats in each of two groups. Group P received daily injections of thyroxine for two weeks. Group Q was given daily injections of a salt solution with no thyroxine. All other conditions were the same for both groups. State the purpose of Group Q in this investigation.

(2)Mark it 3.3.2

After a meal, the hormone insulin is released and the blood glucose level falls back to normal. Describe TWO ways in which insulin brings about this decrease in blood glucose.

(4)Mark it 3.3.3

Look at the results in the table. Which group, P or Q, consists of the people with healthy blood glucose control? Write only the letter.

(1)Mark it 3.3.4

A study looked at how insulin affects blood glucose. Two groups of eight adults each drank 75 g of glucose. Group P was healthy. Group Q had diabetes. Blood was sampled before the drink and again 60 and 120 minutes later. Using data from the table, explain why Group Q is the group with diabetes.

(3)Mark it 3.4.1(a)

The flow diagram below shows how the level of calcium in the blood is kept steady in the human body. Each rise or fall in the level triggers a hormone response that moves the level back towards its normal value. Name the type of control mechanism shown by the diagram.

(1)Mark it 3.4.1(b)

The diagram below shows how the level of a hormone in the blood is kept steady by the pituitary gland and a gland in the neck. Name the gland labelled P in the diagram.

(1)Mark it 3.4.1(c)

The diagram below shows how the level of thyroxin in the blood is kept steady. Gland Y in the neck makes thyroxin, and the pituitary gland sends a hormone (TSH) to gland Y. Name the disorder in which gland Y becomes enlarged because of a lack of iodine in the diet.

(1)Mark it 3.4.2

The thyroid gland releases a hormone called thyroxin into the blood. Give ONE function of thyroxin in the human body.

(1)Mark it 3.4.3

The diagram below shows how the level of thyroxin in the blood of a healthy person is kept steady. A low thyroxin level at point X is detected by the body. Explain how the pituitary gland helps to bring thyroxin back to its normal level.

(4)Mark it 3.4.4

A person has a thyroid gland that continuously secretes too little thyroxin. Explain why this may cause the person’s body mass to increase.

(2)Mark it 3.5.1(a)

Name the independent variable in this investigation.

(1)Mark it 3.5.1(b)

Read the investigation described above and look at the diagram below. State TWO variables that were kept constant (controlled) in this investigation.

(2)Mark it 3.5.2(a)

Seedlings of the same species were grown in a dark cupboard for three days. In the setup described below, state what you would expect to see in the seedlings of Set P.

(1)Mark it 3.5.2(b)

A learner studied how auxins affect the growth of shoots, using the set-up described and shown in the diagram below. State the result you would expect for the plants in the control group, Group Z.

(1)Mark it 3.5.3

Explain how the researchers made sure the results of this investigation were reliable.

(2)Mark it 3.5.4

After 72 hours in darkness, the shoots of the seedlings in set Q all curved towards the left-hand side. Explain these results.

Updated 12 November 2026