KCSE BIOLOGY PAPPER TWO 231/2 -ESSAYS FROM 1995 -2022

1. a). Describe how insect pollinated flowers are adapted to pollination (KCSE1995)
   • Describetheroleoreachofthefollowinghormonesinthehumanmenstrualcycle
     1. Oestrogen
     2. Progesterone

• Luteinizinghormone

2. Describe how excretion takes place in: (KCSE1995)
3. MammalianKidneys
4. Greenplants
5. a).Explainhowthemammalianskinisadaptedtoperformitsfunctions(20marks;KCSE 1996)

b). Describe how new plants arise by asexual reproduction (20 marks; KCSE 1996)

4. a). What is parasitism? (KCSE1997)

b). Describe how the tapeworm is adapted to a parasitic mode of life (KCSE 1997)

5. a). What is meant by the term digestion? (KCSE1997)

b). Describe how the mammalian small intestine is adapted to its function (KCSE 1997)

6. Discuss the various evidences, which show that evolution has taken place (20 marks; KCSE 1998)
7. Explain how the mammalian intestines are adapted to perform their function (20 marks; KCSE 1998)
8. a). Describethe:
9. Process of inhalation in mammals (KCSE 1999)
10. Mechanisms of opening and closing of stomata in plants (KCSE1999)

b). Explain how the various activities of man have caused pollution of air (20 marks; KCSE 1999)

9. a). Describe the role of hormones in the human menstrual cycle (20 marks; KCSE2000)

b). How are leaves of mesophytes suited to their functions (20 marks; KCSE 2000)

10. a). State the functions of the following parts of the mammalian ear; (KCSE2001)
11. Tympanicmembrane
12. Eustachiantube

• Earossicles

b). Describe how semicircular canals perform their functions (KCSE 2001)

11. a). Describe the process of fertilization in a flowering plant (KCSE2001)

b). State the change that take place in a flower after fertilization (KCSE 2001)

12. a). Describe the role of hormones in the growth and development of plants (20 marks; KCSE 2002)
13. a). Name three types of skeletons found in multicellular animals (KCSE2002)

b). Describe how the cervical, lumbar and sacral vertebrae are suited to their functions

(KCSE 2002)

14. a). Describe the functions of the various parts of the human eye (20 marks; KCSE2003)

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(b). Describe how fruits and seeds are suited to their modes of dispersal (20 marks; KCSE 2003)

15. a). How is the mammalian skin adapted to its functions? (20 marks; KCSE2004)

b). Explain how a biotic factors affect plants (20 marks; KCSE 2004)

16. a). Describe how gaseous exchange takes place in terrestrial plants (20 marks; KCSE2005)

b). How is the human eye adapted to its function? (20 marks; KCSE 2005)

17. a). Describe how human kidney functions (20 marks; KCSE2006)

b).Describehowwatermovesfromthesoiltotheleavesinatree(20marks;KCSE2006)

18. a). Describe the structure and functions of the various parts of the human ear (20 marks; KCSE 2007)

b). Describe causes and methods of controlling water pollution (20 marks; KCSE 2007)

19. Describe the nitrogen cycle (20 marks; KCSE2008)
20. a). State four characteristics of gaseous exchangesurfaces

b). Describe the mechanism of gaseous exchange in a mammal (16 marks; KCSE 2008)

21. a). How are flowers adapted to wind and insect pollination? (20 marks; KCSE2009)

b). Describe the role of the liver in homeostasis in the human body (20 marks; KCSE2009)

22. a). Describe the process of fertilization in flowering plants (20 marks; KCSE2010)

b). Describe how a finned fish such as tilapia moves in water (20 marks; KCSE 2010)

23. a). Describe the exoskeleton and its function in insects (13 marks; KCSE2011)

b). Describe how accommodation in the human eye is brought about when focusing on a near object (7 marks; KCSE 2011)

24. Using a relevant example in each case, describe simple and conditional reflex action (20 marks; KCSE2012)
25. a).Usingarelevantexample,describehowanallergicreactionoccursinahumanbeing

(10 marks; KCSE 2012)

b).Describehowenvironmentalfactorsincreasetherateoftranspirationinterrestrialplants

(10 marks; KCSE 2012)

26. a). Describe the process of blood clotting in human beings (10 marks; KCSE2013)

b).Howarerespiratorysurfacesinmammalsadaptedtotheirfunctions?(10marks;KCSE 2013)

27. Describe the role of the following organs in excretion andhomeostasis
28. The liver (10 marks; KCSE2013)
29. The skin during hot environmental conditions (10 marks; KCSE2013)
30. a). Explain how each of the following factors affect the rate ofphotosynthesis:
31. Temperature (2 marks; KCSE2014)
32. Chlorophyll concentration (2 marks; KCSE2014)

b). Describe the process of carbohydrate digestion in human beings (16 marks; KCSE2014)

29. a). How does excretion take place in plants (4 marks; KCSE2014)

b). Describe the role of the human skin in homeostasis (16 marks; KCSE 2014)

30. a).Explainthevariouswaysinwhichseedsandfruitsareadaptedtodispersal(20marks; KCSE 2015)

b). How is a mammalian heart structurally adapted to its function? (20 marks; KCSE2015)

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31. (a).Usingarelevantexampleineachcase,describesimpleandconditionalreflexaction

(20 marks; KCSE 2016)

b). Describe how the mammalian heart is structurally adapted to its function (20 marks; KCSE 2016)

32. a) Explain the importance of protecting the forest ecosystem with reference to the following (20 marks; KCSE 2017)
33. a) Climate change
34. b) Biodiversity

c)Biotechnology

d)Water conservation

1. e) Pollution

1. b) Describe how a mammalian eye is structurally adapted to its functions (20 marks)

33. a) Describe the mode reproduction in a named fungus (5 marks)

1. b) Describe the roles of hormones in the menstrual cycle (15 marks; KCSE 2018)

34. a) Giving examples, describe the following among organisms (20marks; KCSE 2019)
35. Predator-prey relationship
36. Symbiosis

• Parasitism

1. b) Explain the effect of increased physical activity on the following organ system (20 marks)
2. Heart
3. Lungs

• Kidney

1. Skin

35. a)(i)Explain the role of the liver in blood regulation (3 marks ; KCSE 2020)

• Describe how a mammalian heart is adapted to its functions (17 marks)

1. b) (i) Explain how the presence of chloroplast in guard cell affect the opening of the stomata (5marks)

(ii) Describe how various environmental factors affect the rate of photosynthesis (15marks)

36. a) (i) Explain the role of placenta during pregnancy(10 marks) (KCSE 2021)
37. ii) Explain features and mechanisms that hinder self pollination and self fertilization(10 marks)

b)( i) Describe how xylem is structurally adapted to its functions  (5marks)

(ii) Describe the functions of mammalian blood in the human body(15 marks)

37. a i) Describe how plants eliminate waste products(8 marks;KCSE2022)

ii)Describe the structure and function of mammalian nephron (12marks)

1. b) i. Describe five tropic responses and their survival values (15marks)

ii)Describe how mammalian heartbeat is controlled                (5mks)