Question

Double fertilization is exhibited by
A. Angiosperms
B. Gymnosperms
C. Algae
D. Fungi

Answer 1

Hint:
Different types of plants exhibit different modes of fertilization. Fertilization refers to the fusion of gametes leading to the formation of zygote and embryo. The double fertilization means the fusion occurs two times. The flowering plants have this unique feature.

Complete answer:
Double fertilization is exhibited by Angiosperms. Double fertilization is a process in which one of the male sperm fuses with the female egg and the other male sperm fuses with the two polar nuclei.
Angiosperms: The carpel/pistil is termed as the female sex organ of the flower, which consists of an ovary having many ovules. Within the ovule is present the female gametophyte called embryo sac.
Each embryo sac contains three-celled egg apparatus which are one egg cell and two synergids, three antipodal cells, and the two polar nuclei which further fuse to form a secondary nucleus. All cells are haploid.
After the formation of pollen grains in the anthers there occurs pollination. Then the pollen grains followed by germination produce two male gametes that are discharged in the embryo sac through the pollen tube
The zygote is developed by the union of one male gamete with the egg and the endosperm is developed by the union of another male gamete with the two polar nuclei. This event is called double fertilization.

The correct answer is option (A) Angiosperms.

Additional Information:
Gymnosperms- These are the plants such as conifers whose seeds are not enclosed in an ovary. In gymnosperms double fertilization is absent.
Algae- They reproduce by vegetative, asexual, and sexual methods.
Fungi- They reproduce asexually by budding, fragmentation, or by spores.

Note: The formation of pollen tubes from pollen grains to the ovules is called pollen-pistil interaction. Each pollen tube releases two male gametes at a time. The male gametes and the egg cells, synergids, three antipodal cells, and the two polar nuclei are all haploid. After the fertilization, the zygote is diploid and the primary endosperm is triploid.