Short Answer TypeIn which phase of the cell cycle does replication occur in Eukaryotes? What would happen if cell-division is not followed after DNA replication?
Explain Darwinian theory of evolution with the help of one suitable example. State the two key concept of the theory.
Study the graph given below and answer the questions that follow:
(i) Write the status of food and space in the curves (a) and (b).
(ii) In the absence of predators, which one of the two curves would appropriately depict the prey population?
(iii) Time has been shown on X-axis and there is a parallel dotted line above it. Give the significance of this dotted line.
Draw a sectional view of human ovary and label the different follicular stages, ovum and Corpus luteum.
How is 'oogenesis' markedly different from 'spermatogenesis' with respect to the growth till puberty in the humans?
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Spermatogenesis |
Oogenesis |
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It is the process by which sperms are formed from the sperm mother cell in males. |
It is the process by which ovum is formed from the oogonia in females. |
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After the second meiotic divisions in a single spermatogonium, 4 spermatids are obtained, which undergo maturation to form 4 sperm cells, or spermatozoa |
After the second meiotic divisions in the single oogonium, only one ovum and three polar bodies are obtained. |
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Spermatogenesis occurs in males from puberty to death. |
In females, oogenesis starts before birth and occurs until menopause. |
Draw a sectional view of human ovary and label the different follicular stages, ovum and Corpus luteum.
Mention any three characteristics of Neanderthal man that lived in near east and central Asia.
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