PART - 2 - Unit V : CH - 19 Chemical Coordination and Integration — BIOLOGY STD 11 Science — Question

The arrangements of ovules within the ovary is known as placentation. What does the term placenta refer to? Name and draw various types of placentations in the flower as seen in T.S. or V.S.

Both gymnosperms and angiosperms bear seeds, then why are they classified separately?

Which features distinguish blood from lymph?

Give a detail description of plastids with the help of suitable diagram.

Once Amit's teacher took his class to an educational tour where they saw people manufacturing leather from the skin of different animals by the tanning process. Amit found this an interesting process and asked many questions regarding this. After knowing the process, he argued that it is unethical and illegal to use animals for obtaining leather. The teacher appreciated Amit for his action.

1. Which features of this tissue are useful to obtain leather?
2. Name the kind of dense connective tissue involved in this.
3. Write any two unique features of this tissue.
4. What values of Amit are reflected from the above discussion?

Describe meiosis II with the help of suitable diagrams.

Describe the internal structure of a dorsiventral leaf with the help of labelled diagrams.

Write three differences between prokaryotic and eukaryotic cells. Give examples of both.

You have learnt that a characteristic feature of endocrine system is the presence of feed back loops. By this what is meant if hormone A stimulates gland ‘X’ to secrete hormone B, the production of ‘A’ could be modified when the level of B changes in our blood. An example is the relation between hormones LH and estrogen (E₂). An old woman exhibits the following features. High levels of LH in blood but low levels of E₂ in the blood. Another woman exhibits high level of LH in blood and also high level of E₂ in the blood. Where is the defect in both these women? Provide suitable diagram to support this answer.

Distinguish between families Fabaceae, Solanaceae, Liliaceae on the basis of gynoecium characteristics (with figures). Also write economic importance of any one of the above family.