Long Answer Type(a) Describe the structure of arteries, veins and capillaries. Explain the way in which each of these is adapted for its function.
(b) Give an account of the ‘Mass Flow Hypothesis’ for translocation of solutes.
(c) Give the meaning of the following:
(i) Digestion (ii) Assimilation
(a) Give a schematic representation of non-cyclic photophosphorylation showing both the photosystem.
(b) Describe the structure of a myofibril of a striated muscle.
(c) Give four points to show the importance of vegetative propagation.
(a)
(b) Myofibril of striated Muscle: Each myofibril shows alternate dark and light cross bands. That is why these muscles are called the striated or striped muscles.
The dark bands are anisotropic and are called A-bands. Each A-band contains a light zone in its middle which is termed as the H-zone (Hensen’s line).
On the other hand, the light bands are isotropic and are called I-bands. Each I-band is crossed in its centre by a dark membrane called the membrane of Krause or Z-band. This membrane continues across the whole fibre and joins the sarcolemma surrounding by the fibre. The part of myofibril that lies between two successive Z-lines is called the sarcomere and acts as a contractile unit.
(c) The importance of Vegetative Propagation:
1. It is a quick method of developing new plants.
2. It Is the only method in such plants which do not produce viable seeds, e.g., banana, potato, sugarcane, etc.
3. It helps in restoring all the characteristics of the parent plant.
4. It helps to perpetuate particular form of plants. It is very essential method to maintain young or juvenile form in case of some plants.
(a) Describe the mechanism of inspiration and expiration in man.
(b) Draw a labelled diagram of the vertical section of the human eye.
(c) (i) What is Ageing?
(ii) Give two functions of the amniotic fluid.
(a)
(i) Draw a labelled diagram of chloroplast as seen under an electron microscope.
(ii) Name the three major photosynthetic pigments.
(b) Describe the events that take place between pollination and fertilisation in plant.
(c) Name the hormones associated with the following :
(i) The only gaseous plant regulator.
(ii) A growth inhibitor in plants.
(iii) Resorption of water from the urine in the distil convoluted tubule.
(iv) Rise in blood calcium.
(a) Explain the DDT resistance of mosquitoes to the pesticide.
(b) What are the symptoms of Diabetes mellitus?
(c) Define :
(i) Gene pool
(ii) Genetic Erosion.
(a) Write short notes on:
(i) DNA finger printing
(ii) Cryopreservation
(iii) Hemophilia
(iv) Green manure.
(b) What are the activities of Community Health Services.
(c) Give the differences between B cells and T cells.
(a) Describe Lederberg’s Replica Plating experiment to show the genetic basis of adaptation.
(b) Give an account of chromosomal aberrations (mutations).
(c) What is a pacemaker?
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