Question 21M.2.SL.TZ1.6a
| Date | May 2021 | Marks available | [Maximum mark: 3] | Reference code | 21M.2.SL.TZ1.6a |
| Level | SL | Paper | 2 | Time zone | TZ1 |
| Command term | Describe | Question number | a | Adapted from | N/A |
Describe the genetic and hormonal control of male sexual characteristics in a human.
[3]
a. male if (X and) Y chromosomes present ✔
b. gene on Y chromosome/SRY promotes development of testes (from embryonic gonads) ✔
c. testes secrete testosterone ✔
d. testosterone stimulates sperm production/spermatogenesis ✔
e. testosterone stimulates development (in fetus) of male genitals/primary sexual characteristics ✔
f. testosterone stimulates development of male secondary sexual characteristics
OR
testosterone causes changes to become adult male during puberty ✔
Allow first alternative for mpf if two secondary sexual characteristics are named instead of the general term ‘secondary sexual characteristics’.
There were some excellent answers that easily scored the three marks, but also many poorer ones, sometimes with no mention of genetic control or testosterone.
