In which of the following methods of assisted reproductive technology is a sperm directly injected into the ovum?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → ICSI
Assisted reproductive technologies (ART) help couples who cannot have children. The methods differ in where the sperm and the ovum meet and in what is placed back into the female body.
Option (1) ICSI — Correct. ICSI (Intra cytoplasmic sperm injection) is a specialised laboratory method. A single sperm is injected directly into the ovum to form an embryo. It helps when the sperms cannot enter the ovum on their own.
Option (2) IUT — Incorrect. IUT (intra uterine transfer) is the transfer of an embryo with more than 8 blastomeres into the uterus. Fertilisation has already taken place before IUT, so no sperm is injected.
Option (3) ZIFT — Incorrect. ZIFT (zygote intra fallopian transfer) places a zygote or an early embryo (up to 8 blastomeres) into the fallopian tube. It also comes after fertilisation and does not inject a sperm.
NCERT Extract:
Infertility – “… The zygote or early embryos (with upto 8 blastomeres) could then be transferred into the fallopian tube (ZIFT–zygote intra fallopian transfer) and embryos with more than 8 blastomeres, into the uterus (IUT – intra uterine transfer), to complete its further development. … Intra cytoplasmic sperm injection (ICSI) is another specialised procedure to form an embryo in the laboratory in which a sperm is directly injected into the ovum.”