Question

Three features which distinguish angiosperms are

• A. Naked seeds, flowers, double fertilization.
• B. Double fertilization, covered seeds, flowers.
• C. Dominant gametophyte, covered seeds, flowers.
• D. Dominant sporophytes, naked seeds, double fertilization.

Answer 1

The correct option is B

Double fertilization, covered seeds, flowers.

Angiosperms or flowering plants are the most evolved plants with elaborate sexual organs called flowers. The flowers bear the megasporophyll i.e. the embryo sac and the microsporophyll or the pollen sac. Angiosperms bear numerous adaptations for the transfer of pollen grains to the stigma (pollination). The Embryo sac contains one egg cell, two synergids, three antipodals and one central cell with two polar nuclei. Each pollen on germination forms two male gametes. One fuses with the egg cell to form the zygote while the other fuses with the two polar nuclei to form the primary endosperm nucleus which develops into the triploid (3n) endosperm. Hence, fertilisation in angiosperms is called double fertilisation. After fertilisation, the ovules form the seeds while the ovary forms the fruit. Hence, in angiosperms, seeds are always enclosed within a fruit (covered seeds).