Long Answer TypeExplain how does:
(a) a primary succession start on a bare rock and reach a climax community?
(b) the algal bloom eventually choke the water body in an industrial area?The following is the illustration of the sequence of ovarian events (a to i) in a human female.
i) Identify the figure that illustrates ovulation and mention the stage of oogenesis it represents.
(ii) Name the ovarian hormone and the pituitary hormone that have caused the above mentioned event.
(iii) Explain the changes that occur in the uterus simultaneously in anticipation.
(iv) Write the difference between c and h.
(v) Draw a labeled sketch of the structure of a human ovum prior to fertilization.
How does the megaspore mother cell develop into 7-celled, 8 nucleate embryo sac in an angiosperm? Draw a labeled diagram of a mature embryo sac.
What is the inheritance pattern observed in the size of starch grains and seed shape of Pisum sativum? Workout the monohybrid cross showing the above traits. How does this pattern of inheritance deviate from that of Mendelian law of dominance?
The starch synthesis in pea plants is controlled by a single gene. It has two alleles B and b. BB homozygotes produce starch effectively and therefore produce large starch grains. Whereas the bb homozygotes are less efficient in starch production and hence produce smaller grains. After maturation the BB seeds were found to be round and bb was wrinkled. Heterozygotes produce round seeds, and so B was considered to be the dominant allele. But when they were crossed the resultant progeny were intermediate-sized Bb seeds.
P generation BB × bb
↓
F1 Generation Bb × Bb
|
|
B |
b |
|
B |
BB (long grains) |
Bb (intermediate grains) |
|
b |
Bb (intermediate grains) |
bb (small grains)
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