Testosterone Flashcards
What are some effects of testosterone?
Promotes sperm production
Suppresses immune system
Activates sexual behaviour
Modulates aggressive behaviour
Where is testosterone produced?
In the interstitial cells in the testes
What experiment wad carried out to show testosterone controlled sex drive in males?
Castrated guinea pigs
Sex drive decreased
Injected them with equal amounts of testosterone and sex drive increased back to normal levels
What is the challenge hypothesis?
Changes in blood testosterone levels are a result of aggressive interactions
How did Wingfield test the challenge hypothesis?
Measured in 5 individuals
Took one male out of his territory
Waited for territory to be occupied
There were aggressive encounters between the new male and the neighbours of the new male
When the new male moved in, took blood testosterone levels of all 5 males
The neighbours of the new male had increased blood testosterone levels but non-neighbours of the territory did not have an increase
Males with aggressive encounters had higher blood testosterone levels
What is polygyny?
One male and multiple females
What are the costs of testosterone in Side-blotched lizards?
High testosterone males had a lower survival rate
