Q28 of 50 Page 1

(a) Coconut palm is monoecious, while date palm is dioecious. Why are they so caled?

(b) Draw a labeled diagram of sectional view of a mature embryo sac of an angiosperm.


OR


(a) How is ‘oogenesis’ markedly different from ‘spermatogenesis’ with respect to the growth till puberty in the humans?


(b) Draw a sectional view of human ovary and label the different follicualr stages, ovum and Corpus luteum.


(a) Coconut palm is monoecious because both male and female flower borne on the same plant.


Date palm is dioecious because these plants bears exclusively either male flowers or female flowers.


(b) Diagram of sectional view of a mature embryo sac of an angiosperm-



OR



B) sectional view of human ovary:



More from this chapter

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26

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.


 27

(i) What is the primary productivity? Why does it vary in different types of eco-systems?

(ii) State the relation between gross and net primary productivity.


 29

(a) Explain the process of DNA replication with the help of a schematic diagram.

(b) In which phase of the cell cycle does replication occur in Eukaryotes ? Whatwould happen if cell-division is not followed after DNA replication ?


OR


(a) Explain Darwinian theory of evolution with the help of one suitable example. State the two key concepts of the theory.


(b) Mention any three characteristics of Neanderthal man that lived in near east and central Asia.


 30

(a) Name the technology that has helped the scientists to propagate on large scale the desired crops in short duration. List the steps carried out to propagate the crops by the said technique.

(b) How are somatic hybrids obtained ?


OR


(a) Cancer is one of the most dreaded diseases of humans. Explain 'Contact inhibition' and 'Metastasis' with respect to the disease.


(b) Name the group of genes which have been identified in normal cells that could lead to cancer and how they do so ?


(c) Name any two techniques which are useful to detect cancers of internal organs.


(d) Why are cancer patients often given α-interferon as part of the treatment ?