Class 12th Biology 2017 Set2 Delhi Board Paper Solution
Question 25
Why certain angiospermic seeds are albuminous, while others are exalbuminous? Explain.
Answer
In flowering plants, during the development of seeds, along with embryo, a nutritive tissue called endosperm is also formed.
During embryo development, endosperm degenerates to release its content that helps in the growth of embryo. In some plants, the endosperm is completly used up in embryo development. In such seed endosperm is absent, e.g. pea, gram, beans, etc.
These seeds are called exalbuminous seeds. On the other hand, in some plants, the endosperm tissue persists in the viable seeds. These are called as albuminous seeds, e.g. castor.
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