Long Answer Type(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) 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) If the mother is Rh- and has Rh+ baby, the mother's body may make antibodies (substances that protect the body from outside invaders) against the Rh protein. When a woman gets pregnant again with an Rh+ baby, these antibodies will become active. An abnormal pregnancy, abortion, miscarriage, or abdominal injury can also make these antibodies active. These antibodies can cause serious problems in an unborn baby.
If the blood of an Rh+ve person is transferred to a Rh-ve person and vice versa, many complications arise. Extravascular haemolysis more often occurs due to immune antibodies of the Rh system. The clinical manifestations are relatively less severe and usually consist of malaise and fever but shock and renal failure may rarely occur. Some patients develop delayed reactions in which the patient develops anaemia due to destruction of red cells in the RE system about a week after transfusion.
b) The characteristics that have been developed in human beings during evolution are :
(i) Enlargement and rounding of cranium.
(ii) Narrowing and elevation of nose.
(iii) Formation of chin and reduction in body hair.
(iv) Increase in the size of the brain and intelligence.
(v) Development of curves in vertebral column for erect posture.
(vi) Ability to walk on two legs.
(c) Function of
i. CT Scan -
(a) To detect tumours and the possibilities of their spread in neighbouring tissues and organs.
(b) Helps in diagnosis of diseases of the brain, spinal cord, chest and abdomen.
(c) Helps to determine the feasibility of operative treatment and to assess the result of treatment.
ii. External prosthesis -
Prosthesis is an artificial substitute for any part of the body which enable many physically handicapped persons to live a decent and productive life.
Prosthetic devices range from dentures to artificial eyes, nose, arms and legs. These devices may also be attached or inserted under the skin.
iii. Pace maker -
Pace maker is one of the therapeutic instruments. It is a tiny computerized, electrical device which is implanted in the patients body to regulate his heart beat. It is usually inserted near the shoulder. It could also be worn externally. The electrodes from it are usually connected to the right ventricle.
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.
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