Scientists investigated how incubation temperature affects sex determination in a species of alligator. They incubated two groups of alligator eggs: one group at a cool temperature (29∘C29^\circ\text{C}29∘C) and another group at a warm temperature (33∘C33^\circ\text{C}33∘C). The scientists then recorded the sex of the alligators when they hatched.
The graph below shows their results:
The scientists incubated 350350350 eggs at the warm temperature (33∘C33^\circ\text{C}33∘C). Calculate how many male alligators hatched from these eggs.
Describe the relationship between incubation temperature and the sex of the alligators.
The scientists found that eggs incubated at the cool temperature (29∘C29^\circ\text{C}29∘C) have a higher activity of the enzyme aromatase, which converts testosterone to estrogen (the female sex hormone). Explain how this can account for the results shown in the graph.
In humans, sex is determined genetically rather than by temperature. Which factor determines sex in humans?
Tick (✓\checkmark✓) one box:
- The temperature of the surroundings during embryonic development
- The presence or absence of a Y chromosome
- The overall size of the sex chromosomes
- The total number of autosomes present