Subject: Science
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.
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.
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:
What is sexual reproduction? What are the types of reproduction?
The reproduction that takes place with the fusion of male gamete and the female gamete is called sexual reproduction. The types of reproduction are:
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. |
Give three differences between ovum and zygote.
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. |
What are differences between pollination and fertilization?
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. |
What are two significances of sexual reproduction?
The two significances of sexual reproduction are:
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. |
What happens to the petals of the flower after fertilization has occurred?
Petals fall off after fertillization has occured.
What happens to the sepals of the flower after fertilization has occurred?
Sepals of the flower fall off after fertilization.
What happens to the androecium of the flower after fertilization has occurred?
The members of androecium called stamens fall off after fertilization.
What happens to the ovary of the flower after fertilization has occurred?
Ovary of a flower develops into fruit after fertillization.
What happens to the ovule of the flower after fertilization has occurred?
Ovule of the flower changes to seed after ferilization.
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