Describe the role of the following organs in excretion and homeostasis.
(a) the liver 
(b) the skin during hot environmental conditions. 

K.C.S.E Biology Q & A - MODEL 2013PP2QN07

K.C.S.E Biology Q & A - MODEL 2013PP2QN07

A scientist carried out an investigation to find out the population growth of mice under laboratory conditions. Twenty young mice were placed in a cage. The results obtained from the investigation were as shown in the table below.

​(a) On the grid provided, draw a graph of the number of mice against time. 
   GRAPH PAPER
(b) Account for the changes in mice population between
(i) O to 2 months 
(ii) 2 to 6 months 
(iii) 6 to 10 months 
(iv) 10 to 12 months. 
(c) (i) Between which two months was the population change greatest? 
(ii) Calculate the rate of population change over the period in (c)(i) above. 
(d) What change in population would be expected if the investigation was continued to the 19th month? 
(e) To obtain the observed results state two variables that were kept constant during the investigation.

The diagram below represents a mammalian pelvic girdle.

​(a) How are the structures labelled H and J adapted to their function?
(i) H 
(ii) J 
(b) State the function of obturator foramen. 
(c) (i) Name the bone that articulates with the pelvic girdle at acetabulum. 
(ii) Name the type of joint formed by the acetabulum and the bone named in (c)(i) above. 
(d) Name the bone formed by the fusion of caudal vertebrae inhuman beings.

In an investigation, a variety of pea plants grown from seeds with smooth coats were crossed with plants grown from seeds with wrinkled coats. All the seeds obtained in the first filial (F1) generation had smooth seed coats.

​(a) Using the letter R to represent the gene for smooth seed coat, work out the genotype of the F1 generation. Show your working. 
(b) If the F1 generation was sel fed, determine the phenotypic ratio of the second filial (F,) generation. Show your working. 
(c) If the total number of seeds in the F, generation was 14 640, calculate the number of seeds with wrinkled coats. Show your working.

(a) Explain the importance of the following in photosynthesis: 
(i) light;
(ii) carbon(IV) oxide;
(iii) chlorophyll.

(b) Name one appropriate food substance for each of the following enzymes: 
(i) ptyalin 
(ii) pepsin
(c) State the cause and two symptoms of Ben-ben.
 Cause             
Symptoms ​

 The diagram below represents the human ear.

​(a) Name the parts labelled E, F and G. 
E 
F.
(b) How is each of the following adapted to its function?
(i) External auditory meatus; 
(ii) Ear ossicles. 
(c) Name one defect of the human ear.

The diagram below represents a plant in the division Bryophyta.

​(i) Name the parts labelled B and D. 
B
D
(ii) State one function for each of the parts labelled A and C.
A 
C 
(b) The diagram below represents a member of the kingdom Animalia.

​(i) Name the phylum to which the organism belongs. 
(ii) Using observable features in the diagram, give three reasons for the answer in b(i).

K.C.S.E Biology Q & A - MODEL 2013PP1QN30

K.C.S.E Biology Q & A - MODEL 2013PP1QN29

Name the bone that allows the head to:
(i) nod;
(ii) turn side ways

K.C.S.E Biology Q & A - MODEL 2013PP1QN28

K.C.S.E Biology Q & A - MODEL 2013PP1QN27

K.C.S.E Biology Q & A - MODEL 2013PP1QN27