Here we will study about fertilization process in animals assignment help offered by Tutorspoint.
Fertilization Process In Animals
Fertilization is a process in which sperm and egg fuse for the formation of zygote. Zygote formed continuously divides resulting in the formation of an embryo. A fully developed embryo with well-identified body parts is known as a foetus.
Animals are also classified as oviparous or viviparous. Fertilization process marks the beginning of reproduction. Generally, many sperms come in contact with ovum but only one sperm can fuse with an ovum which results in the development of a zygote.
Fertilization process is generally divided into two types internal and external. For Fertilization Process In Animals Assignment Help call Tutorspoint.
Fertilization if taking place inside female body is known as internal fertilization. Humans are an example of this class.
In this process, fertilization takes place outside the female body. Sperms with the help of its long tail generally move towards an egg for fusion. Aquatic animals like fishes etc belong to this class.
Test Tube Babies
Sometimes women are not able to bear babies due to anatomical complications. In this case, sperm and egg are fused outside the body and the zygote thus formed is transferred back to the uterus. Zygote starts developing inside and babies resulting from this process are known as test tube babies.
Development of an embryo
Zygote formed as a result of the fusion of gametes keeps on dividing further which results in the development of an embryo. Embryo gets attached to uterus and divides further making groups of cells leading to different organ formation. During this division, a stage appears when all the body parts of a developing embryo are clearly visible. At this stage, the embryo is termed as a foetus.
Viviparous and oviparous animals
Animals which directly give birth to young ones are known as viviparous while there are certain animals which lay eggs from which individuals are developed. This kind of animals is known as oviparous, e.g. hens. In the case of hens, the embryo develops outside the body. A protective layer is formed around the zygote which is the white shell what we see.
Metamorphosis In Certain animals the young ones and the adults are different e.g. frogs. In the case of frog egg give rise tadpole (larva) which gives rise to adults. Certain changes take place in larva stage which results in adults. This process of transformation is known as metamorphosis.