Question

The process of union of male gamete with the egg cell is called ________.
A. Fertilisation
B. Pollution
C. Double fertilisation
D. Germination

Answer 1

Hint: The process of union or fusion of male and female gamete is called fertilization which is a biological process that occurs in case of sexual reproduction and helps in the propagation of species.

Complete answer:When a male gamete, which in the case of humans is a sperm cell, fuses with a female egg cell, ovum in case of humans, it leads to the formation of a zygote, and this process is called fertilization. Fertilization doesn’t involve the fusion of two cells but of two nuclei which are haploid and form a diploid zygote in sexual reproduction. The zygote then forms into progeny.
A. Fertilisation- It is the union of haploid male and female gamete which leads to the formation of zygote. Below is the diagram showing human fertilization in which B is the male sperm entering the ovum.

B. Pollution- It is the presence of harmful substances in the environment which are either not normally present or present in very low amounts. Examples of some substances that cause pollution are carbon dioxide, carbon monoxide, hydrogen sulphide, pesticides etc.
C. Double fertilisation- It is a process of fertilisation, but it occurs in the case of Angiosperms only. It is so-called because it involves two fertilisations: one is the fusion of male gamete with an egg cell in ovule and the second is the fusion of male gamete with two polar nuclei. So while double fertilization does involve the fusion of male and female gamete it cannot be said to be the process of union of male gamete and egg cell as it involves one more process.
D. Germination- It is the process of development of an organism from a structure like a seed that may or may not involve a period of dormancy, the resting stage. In plants, the term refers to the “sprouting of seed” and the formation of a new plant. Since seeds are only present in Gymnosperms and Angiosperms, germination occurs in these two plant groups.
Hence, the correct answer is option A.

Note: Fertilisation is a process which causes the formation of zygote and from there, a whole new organism, be it a plant or an animal. It is a basic process which is essential for reproduction. It involves the union of male and female gametes, which are haploid and lead to the formation of a diploid zygote. The gametes can be formed via meiosis or mitosis. Mitosis results in gamete formation in some primitive plants such as Bryophytes. In humans, fertilization is the fusion of male sperm nuclei and female egg or ovum occurring inside the female genital tract, to be specific, in the fallopian tubes or uterus.