Fertilization

Define fertilization

fusion of haploid male and female gametes to form one diploid zygote

Where is sperm deposited in most species?

cranial vagina

Where is sperm deposited in pigs?

cervix

Where is sperm deposited in camels?

uterine horn

Where’s the site of fertilization?

ampulla isthmic junction

What helps sperm migrate to oviduct?

uterus contractions and sperm swimming

How long are oocytes typically viable?

24 hours

How does the sperm reservoir form?

sperm binds to epithelium of ampulla

What prevents a second sperm from fertilizing the same oocyte?

cortical reaction

What mechanism pushes sperm to oocyte?

hyperactivation

What mechanism pushes the sperm through the zona pellucida?

acrosome reaction

What triggers hyperactivation?

progesterone from granulosa cells

What does hyperactivation cause?

removes sperm from oviductal epithelium, pushes sperm through oviductal secretions, and pushes sperm tightly against the oocyte

Layers of the oocyte

plasma membrane, perivitelline space, and zona pellucida

How many acrosomes does each sperm have?

1

What do acrosomes contain to degrade the zona proteins?

proteases

T/F polyspermy is non-lethal

false

Release of what from the embryo prevents polyspermy?

cortical granules

Why is mitochondrial dna used in ancestry analysis rather than nuclear dna?

it traces matrilineal heritage

What is the zinc spark?

release of intracellular zinc from fertilization

What condition does polyspermy result in?

triploidy

What species commonly fertilize through polyspermy?

birds, reptiles, and amphibians

Major reason for using IVF in livestock?

better genetics

What occurs during intracytoplasmic sperm injections?

sperm is injected directly into the oocyte

How do 3 parent babies work?

use donor mitochondria from second woman

Define parthenogenesis

an egg can develop into an embryo without being fertilized by a sperm