Sex Differences 3 Flashcards
What needs to be present for a hormone to work?
Receptors
What are steroids able to do because they are lipid soluble?
Can cross the cell membrane easily to bind to intercellular receptors in the cytoplasm or nucleus
What do proteins and other water soluble hormones do because they can’t pass through the cell membrane?
Bind to cell surface receptors that activate intracellular signal transduction pathways
What do G proteins do?
Activate adenylate cyclase which produced cAMP in the cell
cAMP is a second messenger
What are the two things that genetic variability with sexual reproduction allows?
- Faster adaptation to changing conditions
2. Better defence against pathogens
What is sexual dimorphism?
Differences in body size and shape, physiology and behaviour
When is the first time gonads are observed in embryos?
When the germinal ridge develops
What happens if the SRY gene is not transcribed?
No testis determination factor (TDF) is produced and the outer part of the germinal ridge develops into an ovary
What are the male and female ducts called?
Female: Mullerian
Male: wolffian
What are the two key testicular hormones and what do they do?
Testosterone and mullerian inhibitory hormone
Promote the regression of the Müllerian ducts and formation of male structures
What are the chromosomes for males and females in birds?
Females= heterogametic ZW Males= homogametic ZZ
What are gynandromorph chickens?
Half male half female
What was concluded in Zhao et al.’s study on the chicken?
Sex is assigned to cells at fertilisation in avian sex determination- hormonal influence is secondary because the left and right halves exposed to the same hormones
What happens if a female quail is exposed to male hormones?
She will show mounting behaviour so male behaviour will develop
What happens if a male quail is exposed to female hormones?
They stop their mounting behaviour
