KCSE PIVOT BIOLOGY

KCSE Past Papers 2018 Biology Paper 1 (231/1) Kenya Certificate of Secondary Education 2018 Biology Paper 1 Answer all the questions in the spaces provided. 1. (a) Name the cell organelle found in abundance in the white blood cells.(1 mark) (b) Give a reason for your answer in (a) above.(1 mark) 2. State two observable features that place a millipede into its Class. (2 marks) 3. Which sets of teeth would be used in chewing sugarcane for maximum extraction of sap? (2 marks) 4. A group of font two students placed a fresh leaf in warm water. They observed that air bubbles formed on the surface of the leaf. (a) What biological process were they investigating?(1 mark) (b) Name the structures from which the air bubbles were coming from. (1 mark) (c) Explain the distribution of the structures named in (b) above on the leaf surfaces of a land plant. (2 marks) 5. State why it is important for plants to lose water to the atmosphere.(3 mark) 6. The diagram below illustr...

The Kenya National Examinations Council  Kenya Certificate of Secondary Education 231/2 - Biology - Paper 2 Nov. 2018 - 2 hours Answer all the questions in the spaces provided. SECTION A (40 marks) Answer all the questions in this section in the spaces provided. 1. The diagram below illustrates a section of the mammalian kidney. (a) Name the structures labelled E and F. Region H (1 marks) E ...........(1 marks) F...........(1 marks) (b) Explain the processes that take place in the regions labelled G and H. Region G(3 marks) Region H(3 marks) 2. Below is a graphical representation of students’ height in a classroom. (a) Name the type of curve illustrated. (b) (i) State the type of variation represented by the curve. (ii) State two meiotic processes that lead to variation among organisms. (2 marks) (iii) Explain the role of variation in organisms.(2 marks) (c) EKplain the need for genetic counselling in present day health facilities. (2 marks)...

FERTILIZATION. This is the fusion of sperm and ovum to form a zygote. It occurs in the oviduct.  The human ovum is viable for only 24 hours after which in degenerates.  As the sperm approaches the ovum, it undergoes capacitation .  This is a process that involves changes in the properties of the acrosome.  Once the sperm contacts the ovum, its acrosome bursts spilling the lytic enzymes.  The enzymes digest and soften the corona radiata, zona pellucida and vitelline membrane.  Only one sperm fertlises the ovum.This is because upon the entry of the sperm, the vitelline membrane is transformed into an impenetrable membrane. Development starts immediately after fertilization.  The zygote undergoes repeated mitotic division in a process known as cleavage resulting in a mass of cells known as the morula. The cells then arrange themselves to form a hollow structure known as blastula/blastocyst. Cilia and peristaltic action of the oviduct wall p...