Biology · Reproductive Health · NEET
| Full form | ZIFT = Zygote Intra Fallopian Transfer | IUT = Intra Uterine Transfer |
| What is transferred | Zygote / early embryo (up to 8 blastomeres) | Embryo with more than 8 blastomeres |
| Site of transfer | Fallopian tube | Uterus |
| GIFT vs ZIFT | GIFT transfers an ovum (gamete) into the tube; fertilisation is in-vivo | ZIFT transfers an already-fertilised zygote into the tube |
| ICSI vs IVF | ICSI: one sperm injected directly into ovum (in vitro) | IVF: ova and sperms mixed in lab, fertilise on their own (in vitro) |
Both transfer the product of IVF, but they differ by developmental stage and site. In ZIFT (Zygote Intra Fallopian Transfer) the zygote or early embryo with up to 8 blastomeres is put into the fallopian tube. In IUT (Intra Uterine Transfer) the embryo has MORE than 8 blastomeres and is put into the uterus. Rule: up to 8 blastomeres → tube (ZIFT); more than 8 → uterus (IUT).
An ovum (a gamete), not an embryo. GIFT stands for Gamete Intra Fallopian Transfer. An ovum collected from a donor is transferred into the fallopian tube of a female who cannot produce her own ovum but can provide a suitable environment for fertilisation and development. Fertilisation happens inside her body, so GIFT is in-vivo. This is the key contrast with ZIFT, where a zygote (already fertilised) is transferred.
ICSI is IN VITRO (in the lab), not in vivo. NEET 2023 tested exactly this: a statement calling ICSI "in-vivo" is FALSE. In ICSI (Intra Cytoplasmic Sperm Injection) a single sperm is injected directly into the ovum to form an embryo in the laboratory. It is used when sperm cannot fertilise on their own, for example with very low sperm count or poor sperm.
IVF (In Vitro Fertilisation) is the general method where ova and sperms are mixed in the lab and fertilisation happens on its own. ICSI is a specialised form of IVF where the technician directly injects ONE sperm into the ovum. So ICSI is used when normal IVF fertilisation may fail (very low or weak sperm). Both make the embryo outside the body (in vitro).
NCERT prescribes Artificial Insemination (AI) when the male cannot inseminate the female or has very low sperm count — semen from the husband or a healthy donor is introduced into the vagina or uterus. In the lab, ICSI (direct sperm injection into the ovum) is also used for severe sperm problems. Do not choose IUT or GIFT here — those transfer embryos or ova, not sperm.
In which of the following techniques, the embryo are transferred to assist those females who cannot conceive?
Embryo with more than 16 blastomeres formed due to in-vitro fertilization is transferred into
The method of directly injecting a sperm into the ovum in assisted reproductive technology is called:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
IVF = In Vitro Fertilisation, ZIFT = Zygote Intra Fallopian Transfer, GIFT = Gamete Intra Fallopian Transfer, IUT = Intra Uterine Transfer, ICSI = Intra Cytoplasmic Sperm Injection. Learning the full form usually tells you what is transferred and where.
ZIFT and IUT transfer the fertilised product (zygote/embryo). GIFT transfers an ovum (a gamete). ICSI is a fertilisation step (injecting sperm into ovum), and IVF is the overall lab fertilisation method that makes the embryo.
A test tube baby refers to a baby born through IVF, where fertilisation happens outside the body in the lab. The embryo is then transferred back (by ZIFT or IUT) into the mother to complete development. The term does not mean the baby grows in a test tube.
Because NEET repeatedly tests it. Up to 8 blastomeres → fallopian tube (ZIFT); more than 8 blastomeres → uterus (IUT). This single line separates ZIFT and IUT and has been asked in 2016 and 2020.
