(a) In an incubator, 1,500 eggs were arranged on the trays for incubation. During candling,

Explanation

(a) (i)Percentage of unfertilized eggs

25 x 100

1500 1

= 1.67%

(ii)Percentage of fertilized eggs

No of fertilized eggs 1500 – 25

= 1475

Percentage of fertilized eggs

1475 x 100

1500 1

= 98.33%

(iii)Percentage of male chicks

475 x 100

1500 1

= 31.67%

(iv)Percentage of female chicks

No of female chicks = 1500 –25 – 475

= 1000 chicks

Percentage of female chicks

1000 x 100

1500 1

= 66.67%

(b)Signs that indicate the approach of parturition in a cow

- Widening of the cervix

- Loss of appetite

- Contraction of the uterine wall

- Restlessness

- Pains

- Enlargement of the mammary gland and secretion of milk

- Swelling of the vulva with discharge

- Frequent urination

- The animal isolates itself

(c )Vegetative materials that could be used in propagating ornamental plants

• - Leaves e.g. Bryophyllum
• - Stems e.g. stem cuttings, runners, suckers, rhizomes, tubers, corms,stolons, buds, bulbs, Roots e.g. slips

(d)Advantages of grafting

- Used to rapidly increase the number of desirable cultivars

- Used to change plant form

- Used to repair damaged plant parts

- Used to propagate plants whose cuttings are difficult to root

- It is used to provide disease resistance to a susceptible but desirable cultivar

- Virus indexing : A special technique used by plant pathologists to find out whether a plant is free from virus

- Propagate plants which cannot be propagated by seeds

- To shorten the period of fruiting