Explain the following in about 150 words each
Basic chromosome number may be different from haploid number. 8
Can an accessory chromosome become an essential chromosome 8
Ribosomes are synthesized 8
Presence of factors for all the seven characters studied by Mendel on a single chromosome would have affected Mendel's work 8
ISH has helped in better understanding of cell biology 8
How is a tertiary trisomlc identified? Draw and describe various disjunctional possibilities of the chromosome associations formed during meiosis in a tertiary trisomic. 5+20
With the help of a well established example explain transvcrsioris. 15

What is achieved through back cross breeding Describe the procedure and explain what will happen if the original parents are not pure lines 15
3.(b)Describe stepwise how goodness of fit is established for an assumption 2

What is accounted for by Lyon's hypothesis? Cite an example. 5+5 What is tripartite type of sex determination Justify your answer with suitable example.
with the help of us triangle explain the role of amphiploides in evolution of crop plants.
With the help of triangle explain the role of amphiploides in evolution of crop ·plants.
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SECTION

5.Write brief notes on the following in about 150 words each
5.(a)Endemism
5.(b)NOD genes
5.(c)Eutrophication
5.(d)Fermentation
5.(e)Allelopathy

6.(a)Describe the adverse anthropogenic effects on terrestrial ecosystems. How can these be mitigated
6.(b)Explain various physiological processes that help in fruit ..pening. How can this knowledge help overcome problems likely to be faced because of climate change
7.(a)Describe various structural and chemical defence mechanisms developed by plants.

7.(b)Describe the process explained by chemiosmotic theory.
8.(a)Describe bottom up regulation of plant respiration.
8.(b)Describe the differences and, importance of afforestation.. reforestation and social forestry. 20