Sexual Reproduction in Animals

Subject: Science

Find Your Query

Overview

Sexual reproduction in animals is the integrated processes of meiosis, mitosis, and fertilization. Gamete is formed after meiosis in male and female reproductive cells. This note explains how sexual reproduction occurs in animals.
Sexual Reproduction in Animals

Definitions

  1. Hermaphrodites: Those animals that contain both male and female reproductive organs in the same individual are called hermaphrodites.
  2. Fertilization: The process of fusion of male and female gamete is called fertilization.
  3. Internal fertilization: Fertilization, the process of fusion of male and female gamete, which takes place inside the female body, is called internal fertilization. It occurs in higher vertebrates. It is safer and no watery medium is required.
  4. External fertilization: Fertilization, the process of fusion of male and female gamete, which takes place out of the female body, is called external fertilization. It occurs in lower vertebrates. For this fertilization to occur water medium is required and it is not safe.

Procedure of sexual reproduction in animals

After meiosis, the male reproductive system produces sperm (male gamete) and the female reproductive system produces egg (female gamete). Then male releases its gamete that fuses with female gamete. The fusion may be internal (in higher organisms) or external (in lower organisms). If it is external then a medium, that carries male gamete, is required and mostly it is water. After fertilization, the egg becomes zygote and undergoes mitosis to become an embryo. Embryo again with the help of mitosis becomes a new individual.

Abroad Studies Opportunities

Difference between male and female gamete:

Male gamete Female gamete
1. It is also called microgamete, as it is smaller than female gamete. 1. It is also called mega gamete, as it is larger than male gamete.
2. It is motile as it can swim with the help of flagella. 2. It is immotile.
3. It is produced after meiosis in male reproductive cells. 3. It is produced after meiosis in female reproductive cells.

Difference between gamete and Zygote

Gamete Zygote
1. It is formed after meiosis in male and female reproductive cells. 1. It is formed after the fusion of male and female gamete.
2. It contains haploid number of chromosome. 2. It contains diploid number of chromosome.
3. Gamete does not divide further. 3. Zygote does divide further and give embryo.
Things to remember
  • Sexual reproduction in animals is the integrated processes of meiosis, mitosis, and fertilization.
  • Male gamete are micro gamete whereas female gamete are mega gamete.
  • Gamete is formed after meiosis in male and female reproductive cells.
  • Zygote is formed after the fusion of male and female gamete.
  • It includes every relationship which established among the people.
  • There can be more than one community in a society. Community smaller than society.
  • It is a network of social relationships which cannot see or touched.
  • common interests and common objectives are not necessary for society.
Videos for Sexual Reproduction in Animals
Reproduction in animals
SEXUAL REPRODUCTION IN ANIMALS
Questions and Answers
Organisms reproduce to produce offspring for maintaining their race and genetic continuity.

The fusion of male gamete and female gamete during the sexual reproduction of organism is called fertilization.

External fertilization

Internal fertilization

i. The fusion of male and female gametes takes place outside the female's body.

ii. The embryo is not protected from external injuries as it develops outside.

i. The fusion of male and female gametes takes place inside the female's body.

ii. The embryo is protected from external injuries as it develops inside the female's body.

Ovum

Zygote

i. It is produced by females through meiosis cell division of reproductive cells.

ii. It is haploid (n) in nature, i.e. it has half the number of chromosomes as that of parent cell.

iii. It does not have an independent existence.

i. It is formed as a result of the fusion of male and female gametes.

ii. It is diploid (2n) in nature, i.e. the chromosomes exist in pair.

iii. It has an independent existence.

Pollination

Fertilization

1. It is the transfer of pollen grains from stamen to stigma.

2. It takes place outside the ovary.

1. It is the fusion of male gamete with the female gamete.

2. It takes place inside the ovary.

The reproduction in which male and female gametes fuse to form a zygote is called sexual reproduction. Sexual reproduction brings variation among the offspring of the same parents. So, sexual reproduction is necessary for the evolution and origin of new species.
The organism that has both male and female reproductive parts in the body is called hermaphrodite. As earthworm has both male and female reproductive parts in itself, it is a hermaphrodite.
The two significances of sexual reproduction are:
  1. Due to the increase in the number of organisms, the race of a species is maintained.
  2. Due to crossing over and fusion of male and female gametes, variation that results brings about the evolution of organisms.
Quiz

© 2019-20 Kullabs. All Rights Reserved.