IB myp 4-5 Biology – Practice Questions- All Topics
Topic :Evolution-Reproduction
Topic :Evolution– Weightage : 21 %
All Questions for Topic : Life Cycles,Natural Selection,Cell division,Mitosis,Meiosis,Reproduction,Biodiversity,Inheritance and variation,DNA and genetics
Question:
GnRH causes secretion of LH and FSH. What evidence for this is there in the graph?
▶️Answer/Explanation
Ans: GnRH increases in concentration before LH and FSH rise.
Question:
One of the effects of LH is to cause the testes to secrete more testosterone. Testosterone causes production of sperm and also secondary sexual characteristics such as pubic hair. At approximately what age do you expect the hypothalamus to start secreting GnRH?
▶️Answer/Explanation
Ans: At the age when boys begin puberty/10/11/12/13/14/15.
Question:
What would happen if a boy was lacking the GNRH1 gene?
▶️Answer/Explanation
Ans: The boy would not enter puberty/develop secondary sexual characteristics (unless artificially stimulated).