Medical Technology and Applied Biology

(b) uterus

Embryos with more than 8 blastomeres (up to morula/blastocyst) from IVF are transferred into the uterus (IUT). Embryos of up to 8 blastomeres are transferred into the fallopian tube (ZIFT). The cervix and fimbriae are not sites of embryo transfer.

(b) Gamete intra fallopian transfer

GIFT is Gamete Intra Fallopian Transfer: ova collected from a donor or the female are transferred into the fallopian tube of a female who cannot produce ova but can provide a suitable environment for fertilisation. The other options give incorrect expansions.

(b) Cell-mediated immune response

Graft rejection is a tissue-specific response mediated mainly by T-lymphocytes (cell-mediated immunity) against foreign MHC antigens. Humoral, passive and innate responses are not the main cause.

(c) Zygote into the fallopian tube.

In IVF, fertilisation occurs outside the body. The zygote or an early embryo of up to 8 blastomeres is transferred into the fallopian tube (ZIFT). An embryo with more than 8 blastomeres goes into the uterus (IUT), so the 16-blastomere option (a) is wrong, and (d) is wrong because a zygote goes to the fallopian tube.

(c) ZIFT involves IVF to help women who have damaged Fallopian tubes to bear a child.

In ZIFT the zygote or early embryo (up to 8 blastomeres) formed by IVF is transferred into the fallopian tube, which suits women with damaged or blocked tubes but a functioning ovary. GIFT transfers gametes and requires a woman who can provide ovum or a suitable donor. IUI is for low sperm count in the male, and does not help premature menopause.

(a) ZIFT and IUT

In ZIFT the zygote or early embryo (up to 8 blastomeres) is transferred into the fallopian tube, and in IUT the embryo (more than 8 blastomeres) is transferred into the uterus, so both transfer embryos to women who cannot conceive. GIFT transfers gametes (not an embryo), and ICSI injects a sperm into an ovum in the laboratory.