Sec 4 Biology Reproduction topical questions

Distinguish between asexual and sexual reproduction.

Name the male and female parts of an insect-pollinated flower, and state what the anther produces.

State where fertilisation occurs in the human female reproductive system and name the two nuclei that fuse.

State two ways HIV is transmitted and one route by which it is NOT transmitted.

Name the two parts of a stamen and state the function of each.

Explain why meiosis must occur before fertilisation in sexual reproduction.

State three differences between an insect-pollinated and a wind-pollinated flower, and explain how each difference suits its pollinator.

A human body cell has 46 chromosomes. State the chromosome number of (a) a sperm cell, (b) a zygote, and name the type of division that produces each from a body cell or gametes respectively.

Describe the main events of a 28-day menstrual cycle, naming the hormones involved and the fertile phase.

A plant’s body cells each contain 24 chromosomes. State the number of chromosomes in (a) a root hair cell, (b) a pollen grain nucleus, and (c) a leaf cell produced by mitosis, explaining each answer.

Describe the sequence of events from a pollen grain landing on a compatible stigma to fertilisation inside the ovule.

Explain how the structure of the placenta makes it efficient as an exchange organ between mother and foetus.

Describe what happens from the fusion of gamete nuclei to implantation, naming the site of fertilisation, the early divisions and the final destination of the ball of cells.

Describe the exchange that occurs across the placenta, name the structure that connects it to the foetus, and explain why the mother’s and foetus’s blood must not mix.

Compare self-pollination with cross-pollination, and explain why cross-pollinated offspring are generally better suited to surviving change.

Compare mitosis and meiosis in terms of the number of daughter cells, their chromosome numbers and their genetic content, and state one role of each.

A woman’s last three cycles lasted 28, 26 and 30 days. Assuming a steady 14-day post-ovulation phase, calculate the expected ovulation day of each cycle, and explain why assuming ovulation always falls on day 14 can mislead.

A country screens every unit of donated blood for HIV, and transfusion-related infections fall to almost zero — yet new infections continue among people who inject drugs. Explain why screening solved one route but not the other, and state two further measures that would reduce the remaining route.