(a) Explain in detail the digestion of carbohydrates, as the food passes through the alimentary canal.
(b) Describe step by step what happens in the different phases of the cardiac cycle in human beings.
(c) Write the effects of cytokinins on plants.
(a) Write about the chemical changes which occur during contraction of skeletal muscles.
(b) Draw a neat labelled diagram of the L.S. of a kidney.
(c) What is chloride shift ?
a) Explain how the human ear helps in hearing.
b) Briefly describe the events that occur during the prolifearative phase of the menstrual cycle.
(c) Mention the site of secretion and function of the following :
(i) Glucocorticoids
(ii) Calcitonin
(iii) Glucagon
(a) Explain the evolution of the long neck of giraffe according to Darwin and Lamarck.
(b) Explain briefly :
(i) Environmental resistance
(ii) Albinism
(iii) Plant introduction
(iv) Palaeontology
(c) Write two uses of each of the following :
(i) Emblica officinalis
(ii) Adhatoda vasica
(a) Give four applications of tissue culture in crop improvement.
(b) What do you understand by the term population growth ? Give three ways of discouraging population growth.
(c) Define :
(i) Coacervates
(ii) Gene bank
(a)
(i) Tissue culture is the method of rapid multiplication of a plant under favourable conditions.
(ii) It helps in obtaining, large number of offspring’s or plantlets every year.
(iii) The progeny of these plants can be obtained in millions, which multiply with difficulty by conventional methods.
(iv) Cloning can be throughout the year in a very small space under controlled conditions.
(v) Offspring’s of sterile plants can be obtained or rare hybrids of extra-ordinary characters e.g., oil palm.
(b) Population growth is the total number of increase in the organisms occupying a certain area.
The various methods to discourage population growth are :
(i) People should be given proper education.
(ii) Government agencies should aware people through mass media like radio, television,newspaper, magazines, posters, etc.
(iii) Family planning methods :
1. Use of vaginal diaphragms.
2. Use of oral contraceptive by women.
3. Surgical techniques of birth control like tubectomy in females & vasectomy in males.
4. Use of intra-uterine contraceptive devices (IUCD) like loop or copper.T.
5. Medical termination of pregnancy.
(c)(i) Aggregates or clusters of large, complex organic molecules, capable of growth and replication, which are supposed to have given rise to cell like structures.
(ii) Gene bank is a conservation spot where valuable plant material, likely to became irretrievably lost in the wild or in cultivation.
(a) Explain the role of Rh factor in blood incompatibility.
(b) State the main morphological changes that occurred in the ancestors of modern man.
(c) Describe briefly the functions of the following :
(i) CT Scan
(ii) External prosthesis
(iii) Pacemaker
a) Explain the role of a genetic counsellor.
(b) Write the causative agent and the main symptoms of the following diseases,
(i) Poliomyelitis (ii) Typhoid
(iii) Tuberculosis (iv) Cholera
(c) State two'similarities between the chromosomes of man and apex.