Seeds of some plants germinate immediately after shedding from the plants while in order plants they require a period of rest before germination. The later phenomena is called as dormancy. Give the reasons for seed dormancy and some methods to break it:

Seeds of some plants are unable to germinate even when conditions are favorable. This is called:

On germination a seed first produces shoots with leaves, flowers appear later. How is this advantageous to the plant?

These questions consist of two statements each,printed as Assertion and Reason.While asnwering these questions you are required to chose any one of the following four responses. If both Assertion and Reason are true and Reason in correct explanation of Assertion. If both assertion and Reason are true but reason is not correct explanation of Assertion. If Assertion is true but Reason is false. If both Assertion and Reason are false. Assertion:An essential element is irreplaceable for plant growth. Reason:An essential element occurs in plant seeds.

ASSERTION TYPE QUESTIONS : These questions consist of two statements each, printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses. A. If both Assertion and Reason are true and Reason is correct explanation of Assertion B. If both Assertion and Reason are true but Reasou is not correct explanation of Assertion. C. If Assertion is true but Reason is false. D. If both Assertion and Reason are false. Assertion : Seeded plants are highly evolved. Reason: In spermatophyta, seeds are formed.

These questions consist of two statements each, printed as Assertion and Reason. While answering these questions,you are requied to choose any one of the following four responses If both Assertion and Reason are true and Reason is a correct explanation of the assertion If both Assertion and REason are true but Reason is not a correct explanation of the Assertion If Assertion is true but Reason is false If both Assertion and Reason is false. Assertion:Cotton and jute are fibre yielding plants. Reason: Cotton is obtained from seed hair and jute fibres are obtained from stalks of retted jute.

These questions consist of two statement each, printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses. A. If both Assertion and Reason are true and Reason is a correct explanation of the Assertion. B. If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion. C. If Assertion is true but Reason is false. D. If both Assertion and Reason are false. Assertion: Cotton and jute are fibre yielding plants. Reason: Cotton is obtained from seed hair (lint)and jute fibres are obtained from stalks of retted jute.

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : A flower of tomato plant following the process of sexual reproduction produces 240 viable seeds. Answer the following questions giving reasons: (a) What is the minimum number of pollen grains that must have been involved in the pollination of its pistil? (b) What would have been the minimum number of ovules present in the ovary? (c) How many megaspore mother cells were involved? (d) What is the minimum number of microspore mother cells involved in the above case? (e) How many male gametes were involved in this case?