Essays
Chapter 2
1. Using an annotated diagram, describe the structure of a plant cell.
(12 marks)
2.
Compare and contrast the structure of prokaryotic cells and eukaryotic cells.
(11 marks)
3.
Describe the correct procedures of using a light microscope to observe the cross section of a stem under
the high power magnification.
(12 marks)
Chapter 3
1. Compare the consequences of putting plant cells and animal cells into pure water.
(12 marks)
2. Describe and explain the structure of the cell membrane and its role in diffusion and active transport.
(11 marks)
Chapter 4
1. Describe the structure of an enzyme molecule and explain how the properties of enzymes are related to
this structure.
(10 marks)
Any diagrams included in your answer must be fully annotated.
2. Describe the structure and function of enzymes. Explain how their activity is influenced
temperature and inhibitors.
Any diagrams included in your answer must be fully annotated.
by
pH,
(10 marks)
3. What is meant by enzyme inhibition? Describe in detail how each type of inhibitors functions and the effect
of increasing the substrate concentration on the rate of enzymatic reaction.
(12 marks)
Chapter 5
1. Describe the structure and outline the role of proteins in living organisms. Any diagrams included in your
answer must be fully annotated.
(9 marks)
2.
Discuss the structure and functions of lipids in humans.
(9 marks)
3.
Contrast the structure and functions of triglycerides and phospholipids.
(11 marks)
4.
Discuss the structure of carbohydrates as well as its functions in human body.
(11 marks)
Chapter 6
1. Digestion is completed in the small intestine. Give an account of the uptake of the products of digestion.
Describe what happens to each product once it has entered the body.
(10 marks)
2.
Explain how the structures of the walls of the stomach and ileum are related to their functions. (10 marks)
3.
Describe how lipids are digested in our body and the fate of the absorbed products of lipid digestion.
(10 marks)
Chapter 7
1. Explain why oxygen in the air sac can enter the blood in the capillary efficiently.
(8 marks)
2.
(9 marks)
Describe how inhalation is achieved during ventilation
Chapter 8
1. Explain how tissue fluid is formed and how it may be returned to the circulatory system.
2.
(10 marks)
Describe the structure of arteries and veins. Explain how the features described help these blood vessels
carry out their functions.
(9 marks)
Chapter 9
1. Write an essay on the structure of a dicotyledonous plant leaf and its adaptation to gas exchange.
(11 marks)
2.
Plants absorb water from the soil via their roots.
Describe the pathways and mechanisms by which water passes from the soil to the xylem vessels in the
root.
(9 marks)
Chapter 10
1. Describe how the rate of transpiration is increased by external factors.
(7 marks)
2.
Describe the structure of plant phloem tissue.
Discuss the transport of materials within the phloem.
Any diagrams included in your answer must be fully annotated.
(10 marks)
3.
A rose and a tulip were put in a glass without water. After an hour the tulip stalk bent but the rose stalk
remained upright. Explain.
(9 marks)
Chapter 11
1.
Give an account of mitotic cell division which includes mitosis and cytokinesis.
2.
Describe the events that occur in meiotic cell division and explain the importance of meiotic cell division
to organisms.
(12 marks)
Chapter 12
1. Describe how an insect-pollinated flower is adapted to its functions.
2.
(12 marks)
(11 marks)
Explain the importance of seed dispersal and describe three different methods of seed dispersal.
(12 marks)
Chapter 13
1. Before birth, the placenta is the organ of gas exchange; after birth, the air sacs in the lungs take up this
function. Compare and contrast the adaptations of the placenta and air sacs to gas exchange.
(9 marks)
2.
What are the benefits of breast-feeding to both the newborn babies and their mothers?
3.
Compare and contrast the male gametes and female gametes in humans.
(10 marks)
(9 marks)
Chapter 14
1. Name the three main requirements for the germination of seeds and explain why each is necessary.
2.
Describe how food reserves are mobilized during germination.
(10 marks)
Explain how a cell in the meristem develops into a mesophyll cell of a leaf.
(10 marks)
Chapter 15
1. How can we detect sound? Write an essay on the processes involved in the detection of sound waves in the
cochlea and the generation of nerve impulses.
(10 marks)
2.
Describe how the actions of different structures in a human eye help focus the light rays from a distant
object and then the light rays from a near object onto the retina.
(12 marks)
Chapter 16
1. Using a labelled diagram show the structure of the spinal cord. Describe the nerve pathways involved in
the flexion of the arm in response to touching a hot surface.
(10 marks)
Any diagrams included in your answer must be fully annotated.
2.
Describe the structure and functions of the spinal cord.
(12 marks)
3.
Describe and compare reflex actions and voluntary actions.
(11 marks)
Chapter 17
1. Describe the events happen in a neuromuscular junction when a nerve impulse arrives at the ending of an
axon.
(8 marks)
2.
Explain how the difference in the elasticity of ligaments and tendons is adapted to their functions.
(9 marks)
Chapter 18
1. Describe how homeostasis is brought about by negative feedback mechanism.
2.
Explain the roles of liver and pancreas in the regulation of blood glucose level.
(9 marks)
(11 marks)
Chapter 19
1. Discuss on the facts that a cat and a pigeon are classified into two subdivisions of the same major group
of animals.
2.
Fungi belonged to a class under the kingdom Plantae in the old two-kingdom system,
classified as an individual kingdom in the modern six-kingdom system.
Discuss whether fungi should be included in the kingdom Plantae.
(10 marks)
but
it
is
now
(10 marks)
Chapter 20
1. After volcanic eruption, a barren area is formed. Ecological succession occurs on the area.
Describe how this area would change in the following few thousand years.
(10 marks)
2.
Discuss the various ways in which human activities influence the nitrogen cycle.
(10 marks)
3.
Describe the role of bacteria in the main processes of the nitrogen cycle.
(12 marks)
Chapter 21
1. What is a ‘limiting factor’? Explain, with one named factor, the effects of limiting factors on the rate of
photosynthesis.
(10 marks)
2.
Describe the Calvin cycle of photosynthesis and state the fate of the products.
(10 marks)
3.
Describe the process of photosynthesis.
(10 marks)
4.
Describe the effects of limiting factors on the rate of photosynthesis.
5.
Explain how the structure of leaves is adapted to obtaining raw materials and energy for photosynthesis.
(9 marks)
Chapter 22
1. Explain the process of aerobic cell respiration.
(8 marks)
(8 marks)
2.
Explain the conversion of the chemical energy of organic compounds into ATPin aerobic cell respiration.
(8 marks)
3.
4.
Describe the similarities and differences of chloroplasts and mitochondria interms of their structures.
(8 marks)
Describe the similarities and differences in the processes of photosynthesis and respiration.
(9 marks)
5.
Describe how ATP is produced in aerobic respiration.
(10 marks)
Chapter 23
1.
Kelly is a Primary 3 student. She likes to eat meat and deep-fried foods but not fruit and vegetables.
Describe the effects of unbalanced diet on her health.
(12 marks)
2.
Describe the long-term effects of excessive intake of alcohol of pregnant women on their body and their
foetuses.
Chapter 24
1.
Give an account on the ways of transmission of infectious diseases from oneperson to another. Name two
diseases transmitted by each way.
(11 marks)
2.
Discuss how the impact of disease on the human population can be reduced.
(10 marks)
3.
Describe the differences between viruses and bacteria as causes of infectious diseases in humans. (11 marks)
Chapter 25
1.
State the cause of coronary heart disease and discuss how smoking increases therisk of having this disease.
(11 marks)
2.
Give an account of allergies.
(10 marks)
Chapter 26
1.
Explain the production of antibodies.
(8 marks)
2.
Discuss the advantages and disadvantages of vaccination.
3.
Describe how vaccination enhances the immunity of an individual.
(9 marks)
4.
Discuss the problems associated with the use of influenza vaccines.
(10 marks)
(11 marks)
Chapter 27
1.
Based on your knowledge of genetics, analyse the causes of Mendel’s great success.
(12 marks)
2.
Describe the structure of DNA molecules.
(12 marks)
Chapter 28
1.
Explain the consequences of altering a DNA base in the genome of an organism.
2.
Give an account of RNA structure and function in protein synthesis.
(8 marks)
(10 marks)
Chapter 29
1.
Discuss the ethical, legal and social issues that arise from the Human Genome Project.
(11 marks)
2.
Describe the major steps of DNA fingerprinting and discuss the applications of DNA fingerprinting in
forensic science.
(11 marks)
Chapter 30
1.
Discuss different hypotheses for the origins of life.
2.
The diagram below shows a fossil. Describe how such fossil was formed and discovered.
(9 marks)
(11 marks)
Chapter 31
1.
Explain two examples of the evolution of specific populations of organisms in response to environmental
change.
(8 marks)
2.
Discuss how different mechanisms of isolations leads to speciation.
(11 marks)