What is In-Vitro-Fertilization (IVF) Process? and What are Viviparous and Oviparous Animals?

The study of plant anatomy and physiology is an integral part of Biology Topics.

IVF (In Vitro Fertilization): Procedure & How It Works

In a healthy woman, the fertilisation of egg by the sperm takes place in the oviduct (or fallopian tube). The oviducts of some women are blocked due to some reasons. Such women cannot produce babies in the normal way because the eggs released by their ovary cannot meet the sperms and get fertilised in the oviducts (because the oviducts are blocked). Such women who cannot produce babies are called sterile.

Even sterile women can have babies by using the ‘in-vitro fertilisation’ technique. ‘In vitro fertilisation’ means ‘in glass fertilisation’. This is because in this technique, fertilisation of an egg with sperm is carried out in a ‘glass dish’ or a ‘glass tube’ rather than in the body of a woman. This is commonly known as ‘test-tube baby’ technique. In Vitro Fertilisation is known as IYF in short.

The in vitro fertilisation technique helps the woman with blocked oviducts in having babies as follows :

1. The eggs are removed from the ovary of woman by laproscopy. In this operation, a small cut is made in the side of woman’s abdomen and an optical fibre tube is inserted into her body so that the doctor can see the ovary and take out the tiny eggs.
2. The woman’s husband provides the sperms (in the form of semen).
3. The sperms are mixed with eggs in a glass dish (or glass test-tube) to carry out fertilisation. The fertilised eggs (or zygotes) develop into embryos.
4. After about a week, one or more embryos are placed in the woman’s uterus (or womb). If the embryo gets implanted in the uterus successfully, then normal pregnancy occurs and a baby is born after about nine months.

In vitro fertilisation (IVF) technique is used to help those couples (husbands and wives) in having babies who can produce sperms and eggs but fertilisation cannot take place inside the woman’s body due to blocked oviducts (or blocked fallopian tubes).

The ‘in vitro fertilisation’ technique was initially developed for carrying out the reproduction in farm animals (like cows and buffaloes) in 1950. This technique was used successfully for reproduction in humans in 1978. A large number of babies are now born in our country by using this IVF technique.

The success rate of this technique is only about 30 to 40 per cent. The babies born through in vitro fertilisation technique are called test-tube babies because the fertilisation takes place in a glass dish or a glass test-tube. This is, however, a misnomer (wrong name) because except for a very brief period of about one week of fertilisation and very early development (which is spent in a test-tube), almost the entire growth and development of the baby takes place inside the uterus of the woman as in normal pregnancy.

Viviparous Animals And Oviparous Animals

Some animals give birth to young ones. Those animals which give birth to young ones (or baby animals) are called viviparous animals (vivi = alive ; parous = bearing). In viviparous animals, the young one develops in the uterus inside the body of the mother (female parent). When the young one is fully developed, then the mother gives birth due to which the alive young one (or baby animal) comes out from the body of the mother. The viviparous animals do not lay eggs outside their body (like the birds and reptiles do). In the viviparous animals, the mother (female parent) gives birth to a fully developed baby animal (called young one). For example, in humans beings, the mother gives birth to a baby, so humans are viviparous animals (see Figure). Some other examples of viviparous animals are: Cow, Dog, Cat, Lion, Tiger, Horse, Rabbit, Rat, Elephant and Camel. In fact, all the mammals are viviparous animals.

Some animals lay eggs which later on develop into young ones. Those animals which lay eggs from which young ones (baby animals) are hatched later on, are called oviparous animals (ovi = relating to eggs ; parous = bearing). In oviparous animals, the mother (female parent) lays eggs outside its body. The young one of the animal develops inside the egg. When the development of the young one inside the egg is complete, the egg shell breaks open and an alive young one (baby animal) comes out of it. This is called hatching.

For example, the hen lays eggs [see Figure (a)], The young one of hen (or chick) develops inside the egg. When the development of the chick inside the hen’s egg is complete, the egg shell breaks open and an- alive chick comes out of it [see Figure (b)]. Since a hen lays eggs from which its young ones (chicks) are hatched, therefore, the hen is an oviparous animal. Some other examples of oviparous animals are : Sparrow, Crow, Butterfly, Housefly, Frog, Fish, Lizard, Snake, Ostrich, and Crocodile. In fact, all the insects, birds and reptiles are oviparous animals. They are the egg laying animals.

It is easy to collect the eggs of oviparous animals because they lay the eggs outside their bodies. So, if we can collect the eggs of an animal easily, then it will be an oviparous animal. We can, however, not collect the eggs from viviparous animals (like human beings, cow, cat and dog, etc.) because they do not lay eggs outside their body. Their eggs are extremely small (or microscopic) which remain inside their bodies.