Reproduction (non-mammalian) Flashcards
How many ovaries do female birds have?
One (two in some raptor species).
How does colony size affect testis size in birds? What does this indicate?
Testis size increases with colony size.
Greater sperm competition in colonies.
Where is the bed is the eggshell formed?
Uterus or shell gland.
Where in the bird is the yolk produced?
Ovary.
What hormone stimulates the release of the yolk?
LH (luteinizing hormone)
What is the first sign of sexual maturity in chickens?
Comb development.
Why do domesticated chickens lay eggs all year round?
Changes in the gene that encodes for the thyroid stimulating hormone receptor (effects perception of day length).
What are gyandromorphs?
Individuals showing both male and female characteristics.
Name the 3 reproductive modes in fish.
Viviparity
Ovoviviparity
Oviparity
Which amphibians produce sperm packets?
Newts and salamanders.
How do females utilise sperm packets?
They are taken up by the cloaca and eggs are fertilised as they pass through the cloaca.
Which group of amphibians fertilise eggs externally?
Caecilians.
What is the PLF in reptiles?
Pre-laying fraction.
Duration of retention of eggs in utero, relative to the total length of embryonic development.
Which type of reptiles have a pair of hemipenes?
Squamates (including snakes and lizards), these are often covered in spines/hooks to remain attached to the female.
Give evidence for sperm storage in some reptiles.
Data show female turtles can store sperm for many years and it will still be viable.
