Sample 1Medium
A flow diagram of an assisted reproductive technique shows the ovum and sperm collected and fused in the laboratory under simulated conditions. Arrow 1 shows an early embryo with up to 8 blastomeres transferred into the fallopian tube; arrow 2 shows an embryo with more than 8 blastomeres transferred into the uterus. What are the procedures shown by arrows 1 and 2?
- A
1 is ZIFT and 2 is IUT
- B
1 is GIFT and 2 is IUT
- C
1 is IUT and 2 is ZIFT
- D
1 is ICSI and 2 is artificial insemination
Show the answer
The answer is A.In IVF followed by embryo transfer, a zygote or early embryo with up to 8 blastomeres is transferred into the fallopian tube (ZIFT), and an embryo with more than 8 blastomeres into the uterus (IUT).
- B.
GIFT transfers an ovum, not an embryo formed in the laboratory.
- C.
The labels are reversed: up to 8 blastomeres go to the fallopian tube in ZIFT.
- D.
ICSI injects a sperm into an ovum, and AI places semen in the female tract; neither transfers an embryo.
NCERT: Class 12 Biology, Chapter 3, 3.5
Sample 2NEET level
A woman cannot produce ova but can provide a suitable environment for fertilisation and further development. Which assisted reproductive technique transfers an ovum collected from a donor into her fallopian tube?
- A
ZIFT
- B
IUT
- C
ICSI
- D
GIFT
Show the answer
The answer is D.Gamete intrafallopian transfer (GIFT) is the transfer of an ovum collected from a donor into the fallopian tube of another female who cannot produce one but can provide a suitable environment for fertilisation and development. ZIFT and IUT transfer an embryo, not an ovum, and ICSI injects a sperm directly into an ovum in the laboratory.
- A.
ZIFT transfers a zygote or early embryo of up to 8 blastomeres into the fallopian tube, not an ovum.
- B.
IUT transfers an embryo of more than 8 blastomeres into the uterus.
- C.
ICSI forms an embryo in the laboratory by injecting a sperm into the ovum; it does not transfer an ovum into the fallopian tube.
NCERT: Class 12 Biology, Chapter 3 (Reproductive Health), Infertility