Assertion : In most angiosperms, microspores of a tetrad grow and separae from one anotehr shortly after meisois.
Reason : In the members of families Orchidaceae and Asclepiadaceae, all the pollen grains of a sporansium remain united to form a compact structure called pollinium.

Assertion : In most angiosperms, microspores of a tetrad grow and separate from one another shortly after meiosis. Reason : In the members of families Orchidaceae and Asclepiadaceae, all the pollen grains of a sporangium remain united to form a compact structure called pollinium.

Assertion : In most angiosperms, microspores of a tetrad grow and separate from one another shortly after meiosis. Reason : In the members of families Orchidaceae and Asclepiadaceae, all the pollen grains of a sporangium remain united to form a compact structure called pollinium.

Assertion : In most angiosperms, microspores of a tetrad grow and separate from one another shortly after meiosis. Reason : In the members of families Orchidaceae and Asclepiadaceae, all the pollen grains of a sporangium remain united to form a compact structure called pollinium.

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : Give reasons why : (i) most zygotes in angiosperms divide only after certain amount of endosperm is formed. (ii) groundnut seeds are exalbuminous and castor seeds are albuminous. (iii) micropyle remains as a small pore in the seed coat of a seed. (iv) integuments of an ovule harden and the water content is highly reduced as the seed matures. (v) apple and cashew are not called true fruits.

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 Reason is not correct explanation of Assertion. C. If Assertion is true but Reason is false. D. If both Assertion and Reason are false. . Assertion : Monosporic, 8 nucleate embryo sac is called Polygonum type. Reason : Polygonum type of embryo sac is formed from haploid pollen grain.