Fertilisation and implantation — practice questions

Question 1 · difficulty L1 · recall

Where does fertilisation normally occur in the human female reproductive tract?

• A. Uterine fundus
• B. Cervix
• C. Ampullary-isthmic region of the oviduct
• D. Vagina

Question 2 · difficulty L2 · understanding

Twins are born to a family that lives next door to you. The twins are a boy and a girl. Which of the following must be true?

• A. They were conceived through in vitro fertilization.
• B. They have $75 \%$ identical genetic content.
• C. They are monozygotic twins.
• D. They are fraternal twins.

Question 3 · difficulty L2 · understanding

What is the immediate result of fusion between the male and female gametes?

• A. Release of hCG from the pituitary
• B. Formation of a haploid morula
• C. Implantation of the blastocyst
• D. Formation of a diploid zygote

Question 4 · difficulty L3 · understanding

Receptors for sperm binding in mammals are present on :

• A. Zona pellucida
• B. Corona radiata
• C. Vitelline membrane
• D. Perivitelline space

Question 5 · difficulty L3 · application

Which stage normally implants into the uterine endometrium?

• A. Blastocyst
• B. Primary oocyte
• C. Morula immediately after fertilisation
• D. Spermatozoon

Question 6 · difficulty L4 · analysis

A fertilised human egg undergoes normal cleavage but the trophoblast cannot attach to the endometrium. Which process fails most directly?

• A. Spermatogenesis
• B. Implantation
• C. Ovulation
• D. Formation of the male pronucleus

Question 7 · difficulty L5 · analysis

A zygote reaches the uterus but has failed to develop a normal blastocyst cavity and trophoblast organisation. Which later event is most directly threatened?

• A. Sperm production in the testes
• B. Meiosis in the mother's ovary before ovulation
• C. Successful implantation in the endometrium
• D. Release of semen into the vagina