(a) State four characteristics of enzymes

(b) (i) List two digestive enzymes produced in the duodenum of humans

(ii) Name the substrate that each enzyme listed in 2(b)(i) acts on.

(iii) State the products of each enzyme activity in 2(b)(ii)

(c) (i) State one way in which chlorophyll is important in plants

(ii) Name two macroelements that are required for the formation of chlorophyll in plants.

(iii) State one deficiency symptom of each macroelement named in 2 (c) (ii) above

(d) Outline the proce-dure used for testing for starch in a leaf 
 

(a) Name one instrument used for collecting:

(i) soil organism from a soil sample

(ii) tiny insects from a leaf or a stem.

(b) make a diagram 6 cm - 8 cm long of the instrument named in (a)(ii) above and label fully.

(c) Explain briefly the relationship between three examples of symbiotic organisms.
 

 (a) A child belongs to blood group 0 and the mother be-longs to group B. With the aid of genetic cross, state the possible blood groups of the father.

 (b) (i) Name two forms of adaptive communication in animals

(ii) State two reasons why organisms communicate with one an-other.

(a) Explain briefly the process of perceiving smell in humans.

(b) State the adaptive features of the egg of a domestic fowl

(c) (i) What are autotrophs?
(ii) Name two unicellular organisms that are autotrophs

(d) State five functions of the World Health Organisation

(e) Name two example each of plants and animals that live in a freshwater pond.

(f) In the table below, state five differences between the skin of a mammal and the epidermis of a leaf.

(g) A farmer has two plots of land; plots A and B. on Plot A the farmer planted several seeds of maize. On plot B, the farmer planted several seeds of maize and pepper in a small area. What type of competition would be observed on
(i) Plot A 
(ii) Plot B

Study specimens F and G carefully and answer questions 2(a) and 2(b).

(a) State three observable features of biological importance in: (i) specimen F; (ii) Specimen G.

(b) (i) Classify specimens F and G as either stem tuber or root tuber. (ii) Give two reasons each for the answer in 2(b)(i).

Study specimens H and J and answer questions 2(c) to 2(e).

(C) Classify specimens H and J into the class to which both belong.

(d) (i) state four observable differences between specimens H and J. (ii) State four observable similarities between specimens H and J.

 (e) (i) State the feeding habits of each of specimens H and J. (ii) Name two observable features used for feeding in specimen J.