A LEVEL BIOLOGY 1ST TERM (CORONA) HOLIDAY WORK 2020

DUE DATE: Day of opening 2nd term

J T MACHINYA 0772733186 RUFARO HIGH SCHOOL
ANSWER ALL QUESTIONS
1. (a) Compare simple diffusion with facilitated diffusion as mechanisms to transport
solute across membranes. [5]
(b) Describe the process of endocytosis. [5]
(c) Explain how an impulse passes along the membrane of a neuron. [8]
2. (a) Describe the movement of energy and nutrients in an ecosystem. [6]
(b) Explain how sexual reproduction can eventually lead to evolution in offspring. [8]
(c) Using simple external recognition features, distinguish between the plant phyla
bryophyta and angiospermophyta. [4]
3. (a) Describe the process of fertilisation in humans. [6]
(b) Outline the way in which a pregnancy can be detected at a very early stage. [4]
(c) Explain the factors that cause a population to follow the sigmoid (S-shaped)
growth curve. [8]
4. (a) Draw a diagram of a prokaryotic cell. [6]
(b) Outline the structure of the nucleosomes in eukaryotic chromosomes. [4]
(c) Explain how DNA replication is carried out by eukaryotes. [8]
5. (a) Draw a diagram to show the structure of a cell membrane. [5]
(b) Outline the ways in which substances move passively across membranes. [5]
(c) Explain how ATP is produced by photophosphorylation in chloroplasts. [8]
6. (a) Compare the way in which autotrophic, heterotrophic and saprotrophic
organisms obtain energy.[6]
(b) Outline the international system used for naming species of living organism. [4]
(c) Discuss the definition of the term species. [8]
7. (a) Outline the process of karyotyping and its uses. [5]
(b) Describe the inheritance of ABO blood groups. [5]
(c) Explain the relationship between Mendel.s Law of Segregation and the movement
of chromosomes in meiosis.[8]

MY COMPANY NAME
YOUR COMPANY NAME CO, TD;
8. (a) Outline the absorption of light by photosynthetic pigments in plants. [5]
(b) Describe the effect of different light intensities on the rate of photosynthesis. [5]
(c) Explain how the rate of photosynthesis can be determined by using direct and
indirect methods.[6]
9. (a) Outline the role of phagocytic leucocytes. [4]
(b) During an infection, B-lymphocytes produce, by mitosis, clones of identical cells
programmed to produce antibodies. Describe briefly the process of mitosis.[8]
(c) Antibodies are proteins that are specific to one type of antigen. Explain the
relationship between one gene and one polypeptide and its significance in the
formation of antibodies.
10. (a) Draw and label a simple diagram showing how DNA nucleotides are linked
together in a single strand. [4]
(b) Outline a basic technique for gene transfer involving plasmids. [6]
(c) Explain the process of DNA replication. [8]
11. (a) Draw and label a mitochondrion as seen in electron micrographs. [4]
(b) Outline the cellular locations of different named processes in both photosynthesis
and cell respiration. [6]
(c) Explain the energy flow in a food chain as exemplified by a pyramid of energy. [8]
12. (a) Draw the external and internal structure of a named dicotyledonous seed. [4]
(b) Using a table, compare the processes of spermatogenesis and oogenesis in
humans.[6]
(c) Explain how sexual reproduction promotes variation in a species. [8]
13. (a) Outline the effects of factors that increase or decrease the size of a population.
[4]
(b) Describe the production of antibodies as the response of the immune system to the
entry of pathogens into the body. [6]
(c) Explain the control of glucose levels in the blood. [8]
14. (a) Draw a labelled diagram of the heart showing the chambers, associated blood
vessels and valves. [4]
(b) Describe the relationship between the structure and function of blood vessels. [6]

MY COMPANY NAME
YOUR COMPANY NAME CO, TD;
(c) Explain the mechanisms involved in the ventilation of the lungs. [8]
15. (a) Draw a labelled diagram of the adult female reproductive system. [4]
(b) Describe how natural selection leads to evolution. [6]
(c) Explain the consequences of altering a DNA base in the genome of an organism.
[8]
16. (a) Draw a labelled diagram showing the ultrastructure of a typical prokaryote. [4]
(b) Outline how three different environmental conditions can affect the rate of
photosynthesis in plants. [6]
(c) Explain how the emission of gases, both naturally and through human activity, can
alter the surface temperature of the Earth. [8]
17. (a) State four elements that are needed by living organisms, other than carbon,
hydrogen and oxygen, giving one role of each.[4]
(b) Outline how light energy is used and how organic molecules are made in
photosynthesis.[6]
(c) Explain the significance of complementary base pairing for replication,
transcription and translation.[8]
18. (a) Draw a labelled graph showing a sigmoid (S-shaped) population growth
curve.[4]
(b) Describe what is meant by a food chain and a food web.[6]
(c) Explain the relationship between rises in concentration of atmospheric gases and
the enhanced greenhouse effect.[8]
19. (a) State four molecules transported by the blood.[4]
(b) Outline the control of the heartbeat.[6]
(c) Discuss the cause, transmission and social implications of AIDS.[8]
20. Explain how flowering is controlled in long-day plants and short-day plants. [6]
21. (a)Draw and label a simple diagram showing how DNA nucleotides are linked
together in a single strand. [4]
(b) Outline a basic technique for gene transfer involving plasmids. [6]
(c) Explain the process of DNA replication. [8]
22. (a) Draw and label a mitochondrion as seen in electron micrographs. [4]

MY COMPANY NAME
YOUR COMPANY NAME CO, TD;
(b) Outline the cellular locations of different named processes in both photosynthesis
and cell respiration. [6]
(c) Explain the energy flow in a food chain as exemplified by a pyramid of energy. [8]
23. (a) Draw the external and internal structure of a named dicotyledonous seed. [4]
(b) Using a table, compare the processes of spermatogenesis and oogenesis in humans
[6]
(c) Explain how sexual reproduction promotes variation in a species. [8]
23. (a) Outline the effects of factors that increase or decrease the size of a population.
[4]
(b) Describe the production of antibodies as the response of the immune system to the
entry of pathogens into the body. [6]
(c) Explain the control of glucose levels in the blood. [8]
24. (a) Outline the advantages of using light microscopes in comparison with electron
microscopes. [3]
(b) Distinguish between the structure of plant and animal cells. [6]
(c) Explain how the structure and properties of phospholipids help to maintain the
structure of cell membranes.[9]
25. (a) Describe the significance of water to living organisms. [6]
(b) Outline the role of condensation and hydrolysis in the relationship between amino
acids and dipeptides.
(c) Explain the use of two named enzymes in biotechnology. [8]
26. (a) Draw a diagram of the human digestive system. [4]
(b) Describe the role of enzymes in the process of digestion of proteins, carbohydrates
and lipids in humans. [7]
(c) Explain how blood glucose concentration is controlled in humans. [8]

MY COMPANY NAME
YOUR COMPANY NAME CO, TD;