Question

Unitegmic ovule has ----layers of integuments​

Answer 1

Answer:

Integuments, micropyle and chalaza

An integument is a protective layer of cells surrounding the ovule. Gymnosperms typically have one integument (unitegmic) while angiosperms typically have two integuments (bitegmic).

Answer 2

The unitegmic ovule has 'One' layer of integuments. On the basis of the number of integuments enclosing an ovule, ovules can be classified into 4 parts:-

• The ovules in which the integuments are absent are Ategmic, found in some parasites.
• If the ovule has a single layer of protective covering, it is called Unitegmic, which is a characteristic feature of gymnosperms.
• If the ovule has two layers of protective covering, it is called Bitegmic, which you see in the case of angiosperms.
• If the ovule has three layers of protective covering, it is called Tritegmic.
• In the Bitegmic ovule, the outer integument is called testa, and the inner integument is called tegmen.
• Testa is the outermost layer of the seed which protects the seed from external factors.
• Tegmen is the innermost layer of the seed which provides nourishment to the seed.

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