Question

Human Beings are-
a. Ovoviviparous
b. Oviparous
c. Parthenogenetic
d. Viviparous

Answer 1

Hint: After the fertilization of egg and sperm, formation of zygote takes place. This zygote might develop inside the mother, or outside the mother’s body. Depending upon where the zygote develops as a whole individual, different names are given to the respective type of development. The type of development from species to species depends upon various factors.

Complete answer:
• After the formation of zygote inside the female’s body, embryonic development may take place inside the female’s body or outside her body.
• If the development of the zygote takes place outside the body of the mother, the development is called “Oviparous”.
• This type of development of embryo is commonly observed in birds, most reptiles, most of the Arthropods, etc.
• In this type of embryonic development, the yolk of egg supports enough nutrients so that the egg can develop even outside the body of the mother.
• The fertilized egg or zygote is ejected out of the mother’s body just after sometime of the fertilization.
• The development of embryos takes place inside the egg in Oviparous animals.
• On the other hand, if the mother retains the egg for a longer time inside her, till the embryo develops into an individual and gets ready to hatch, this type of development of embryo is called Ovoviviparous.
• Ovoviviparity is observed in many frogs and insects.
• Parthenogenesis is a process in which fertilization does not take place. An individual develops through repeating mitotic divisions in the egg cell and formation of the whole individual takes place with mitotic divisions.
• Parthenogenesis is observed in wasps, some bees, aphids and a few vertebrates like fishes, reptiles as well.
• The last type of development of embryo includes the development of the whole individual inside the body of the mother.
• Organisms exhibiting this type of development are called Viviparous.
• In viviparous organisms, the developing embryo connects with the mother with the help of placenta and exchanges food, nutrients and gas.
• Viviparous organisms never lay eggs and that is how they are different from oviparous and ovoviviparous organisms.
• Examples of viviparous organisms are- cats, dogs, humans, etc.

Hence, the correct answer is option (D).

Note: Viviparous embryos will not survive if proper care is not taken and will result in death of the embryo. Viviparous organisms do not lay eggs as the egg does not contain enough yolk so as to support the development of the growing embryo and hence, it extracts the nutrient from the mother with the help of placenta. Viviparous organisms ensure safety to the developing embryo whereas in oviparous and ovoviviparous animals, protection of the growing embryo is not ensured as they grow outside the mother’s body.