Fraternal twins are developed by fertilization of two eggs (ova) by two sperm to produce two genetically unique children. When a fertilized egg undergo splitting and develops two children having the same genetic information, identical twins are born. Identical twins with joined bodies are called as Siamese twins. 

Fraternal twins occur when two fertilized eggs are implanted in the uterine wall at the same time that is when the mother releases two eggs and both become fertilized by two different sperms.
Identical twins occur when a single egg is fertilized by a single sperm to form one zygote, but the zygote divides into two separate embryos.
Siamese twins are conjoined twins that are monozygotic twins whose bodies are joined together at birth. This occurs where the single zygote of identical twins fails to separate completely perhaps because they split very late in the development.

Numerous children have been produced by in vitro fertilisation without any abnormality. Foetal sex determination test should be banned as it is being misused for female foeticide.

In in-vitro fertilization, only the male and female gametes fuse outside the female body. After the formation of zygote, it is transferred in the female body.  

Both the methods are used to improve the herd genetics by adding a new set of desired genes to the herd. This increases the quality of the gene pool of the herd.  

GIFT referred as a gamete intra Fallopian transfer. In this, the egg from the donor and the sperm from the father (or the donor male) is taken and are transferred to the oviduct or the Fallopian tube of the recipient. 

In Intra-Uterine Transfer (IUT) embryo with more than 8-blastomeres stage (morula) is used for transfer into the uterus after induced fertilisation in the laboaratory.

In vitro fertilization is a method in which fertilization of male gamete (spermatozoon) and female gamete (ovum) outside the body in almost similar conditions as that in the body followed by zygote or embryo transfer(ET). The zygote or early embryo(upto 8 blastomeres stage) then transferred to fallopian tube called zygote intra fallopian transfer or ZIFT. So, the correct answer is 'Zygote into fallopian tube'.

The zygote or early embryo (upto 8 blastomeres stage) is transferred to fallopian tube called zygote intra fallopian transfer or ZIFT. IUT (Intrauterine transfer), the embryo with more than 8 blastomeres is transferred into the uterus. So, the correct answer is 'Uterus'.

ZIFT ( Zygote Intrafallopian transfer) is a technique in which oocyte and sperms are taken and fertilization takes place outside the female's body i.e. in vitro. Early embryo with more than 8 blastomeres is transferred to the fallopian tube.

In vitro fertilization stands for fertilization outside the body in almost similar condition as that in the body is a method of assisted reproductive technology. In this method to ovum from the wife or donor and sperm from the husband of doner are collected and fused to form zygote in the simulated condition in the laboratory. The zygote or the early embryo up to 8 blastomeres is transferred into the fallopian tube which is known as zygote intrafallopian transfer when the embryos are more than 8 blastomeres then they are transferred into the uterus and this is known as an intrauterine transfer.

Common methods of ART include:

1. In vitro fertilization (IVF) - Fertilization outside of the body. IVF is the most effective ART. It is often used when a woman’s fallopian tubes are blocked or when a man produces too few sperm. Doctors treat the woman with a drug that causes the ovaries to produce multiple eggs. Once mature, the eggs are removed from the woman. They are put in a dish in the lab along with the man’s sperm for fertilization. After 3 to 5 days, healthy embryos are implanted in the woman’s uterus.

2. Zygote intrafallopian transfer (ZIFT) or Tubal Embryo Transfer is similar to IVF- Fertilization occurs in the laboratory. Then the very young embryo is transferred to the fallopian tube instead of the uterus.

3. Gamete intrafallopian transfer (GIFT) involves transferring eggs and sperm into the woman’s fallopian tube. So fertilization occurs in the woman’s body. Few practices offer GIFT as an option.

4. Intracytoplasmic sperm injection (ICSI) is often used for couples in which there are serious problems with the sperm. Sometimes it is also used for older couples or for those with failed IVF attempts. In ICSI, a single sperm is injected into a mature egg. Then the embryo is transferred to the uterus or fallopian tube.

 ART procedures sometimes involve the use of donor eggs (eggs from another woman), donor sperm, or previously frozen embryos. Donor eggs are sometimes used for women who can not produce eggs. Also, donor eggs or donor sperm is sometimes used when the woman or man has a genetic disease that can be passed on to the baby.

 So, the correct answer is “Both A and B”.

IVF or In Vitro fertilisation is an artificial method of fertilisation, for the parents who can't conceive naturally. In this process egg or ovum from the mother (or a donor female) and sperms from father is taken and are fertilised outside the mother's body, in the laboratory conditions. This is done in a large number, so as to ensure the fertilisation. Then this fertilised zygote(s) are implanted in the mother's (or a surrogate mother's) uterus.  

IVF is a technique of fertilisation done outside the mother's body . These fertilised zygotes (2 or 4) at 4-8 celled stage are placed in the fallopian tube of the mother by process of Zygote Intrafallopian Transfer (ZIFT). Excess fertilised eggs are cryopreserved for use in case of implantation failure