21.

Give scientific terms for each of the following

The formation of blood cells in the bone marrow.

State the best known contribution of:

(i) Nawaschin (ii) John Otto

(iii) Went (iv) T.R. Malthu

f) Expand the following:

(i) ECG    (ii) AIDS

(iii) NAA    (iv)ACTH

(a) Draw a neat and fully labeled diagram of a T.S of dicotyledonous stem.

(b) List three differences between micronutrients and macronutrients of plants.

(c) Describe the significance of osmosis in plants.

(a) Describe the cohesion and transpiration pull theory of ascent of sap.

(b) Explain the sequence of events between pollination and fertilisation in plants.

(c) State and explain Blackman’s Law of Limiting Factors.

(a) Write two functions each of:

(i) Amniotic fluid (ii) Human placenta

(b) Briefly explain the procedure followed for haemodialysis.

(c) Explain the origin and conduction of heart beat in man.

a) What is reflex action? Draw neat labeled diagram of reflex arc.

(b) Mention a cause and symptom of each:

(i) Osteoporosis (ii) Constipation.

(iii) Asthma (iv) Tetany

(c) Write four functions of the human skeletal system.

(a) Explain the effects of gibberellins on plants.

(b) Describe the mechanism of pulmonary gaseous exchange.

(c) Mention the site of secretion and function of the following hormones:

(i) Choleystokinin    (ii) Oxytocin

(iii) Insulin

(a) Describe the procedure of hybirdisation in plants.

(b) Name the causative agent and the main preventive measure for each of the following diseases:

(i) Amoebiasis

(ii) Rabies

(iii) Pneumonia

(c) What is manure? Explain any two types of manures.

(a) State three differences between Homologous and Analogous organs and give an example of each.

(b) Explain the resistance of mosquitoes to pesticides such as DDT

(c) What is the importance of preservation the germplasm of wild species?