Register Login

Sexual Reproduction

Subject: Science

Find Your Query

Overview

The reproduction that takes place with the fusion of a male gamete and a female gamete is called sexual reproduction. This note provides an information on sexual reproduction.
Sexual Reproduction

Sexual reproduction

The reproduction that takes place with the fusion of male gamete and the female gamete is called sexual reproduction. Such reproduction usually occurs in animals and higher plant. Two parents male and female are involved in this process of sexual reproduction. In most of the animals, male and female are separate. Such animals are called uni-sexual. Man, birds, etc. in animals and papaya, pumpkin, etc. in plants are the examples of unisexual. In some animals, male reproductive organ and female reproductive organ are present in one animal. Such animals are called bisexual organisms. These organisms are also called hermaphrodite. Hydra, Earthworm. The mustard plant, etc. are the examples of bisexual organisms.

Sexual reproduction in plants

Reproduction takes place in the flowers of the plant. The male organ of flower is androecium and female organ of flower is gynoecium. Androecium produces pollen grains whereas gynoecium produces ova. Fusion of pollen grains and ova leads to fertilization. The zygote starts to form after fertilization.


Sexual reproduction in animals

There is no asexual reproduction in animals. After the sexual intercourse between male and female, the female is able to conceive the baby. After meiosis, the male reproductive system produces sperm (male gamete) and the female reproductive system produces an 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.

In animals, there are two types of fertilization. They are:

  1. External fertilization: Fertilization that takes place outside of the body is called external fertilization. Frogs and fishes do external fertilization.
  2. Internal fertilization: Fertilization that takes place inside of the body is called internal fertilization. Most of the animals does internal fertilization. Example: Humans
Things to remember
  • The reproduction that takes place with the fusion of male gamete and female gamete is called sexual reproduction.
  • Fusion of pollen grains and ova leads to fertilization.
  • Fertilization that takes place outside of the body is called external fertilization. 
  • Fertilization that takes place inside of the body is called internal fertilization. Most of the animals does internal fertilization.
  • 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
Flowers: Cross Pollination and Self Pollination
Reproduction in animals
Sexual reproduction in Animals
Sexual Reproduction In Plant
Questions and Answers

The reproduction that takes place with the fusion of male gamete and the female gamete is called sexual reproduction. The types of reproduction are:

  1. sexual reproduction in male
  2. sexual reproduction in female
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 the 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 the 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 inthe 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 bringabout the evolution of organisms.

Male gamete

Female gamete

1. It is smaller in size.

2. It is highly active.

1. It is bigger in size.

2. It is inactive.

Endosperm

Zygote

1. It is formed due to the fusion of male gamete and two polar nuclei.

2. It is triploid (3n) in nature.

1. It is formed due to the fusion of male gamete and an ovum.

2. It is diploid (2n) in nature.

Petals fall off after fertillization has occured.

Sepals of the flower fall off after fertilization.

The members of androecium called stamens fall off after fertilization.

Ovary of a flower develops into fruit after fertillization.

Ovule of the flower changes to seed after ferilization.

Quiz

© 2019-20 Kullabs. All Rights Reserved.