Fertilisation Flashcards Preview

Developmental Biology > Fertilisation > Flashcards

Flashcards in Fertilisation Deck (11)
Loading flashcards...
1
Q

Polyspermic zygotes are

A

Polyploid

Have multiple centrioles
Cleave abberantly at the first division
Leads to embryonic death

2
Q

Pronuclear migration

A

Overtime the sperm and egg pronuclei move closer together until they fuse

3
Q

Blastomeres

A

Many small nucleated cells produced from mitotic divisions during cleavage

4
Q

The acrosomal process

Example

A

In some species
A region of globular actin
Between the acrosome and the nucleus

Sea urchins: actin in sperm head elongates to form acrosomal process that pushes the acrosomal vesicle forward to empty it

5
Q

Haploid nuclei contain

A

Highly compacted DNA

6
Q

The centriole

A

Lies just behind the nucleus and will form one of the two spindle poles in the first division

7
Q

Vitelline membrane

A

Thin glucoprotein meshwork surrounding the egg membrane

Often involved in sperm egg recognition

8
Q

Jelly layer

A

A second glycoprotein meshwork surrounding the egg that attracts or activates sperm

9
Q

Egg cytoplasm

A

Rich in proteins (yolk), ribosomes, RNA and other components required for embryogenesis

10
Q

Egg cortex is

A

A specialises part of cytoplasm that lays just below the egg membrane containing cortical granules

11
Q

Bindin

A

Sea urchin protein
Coats inner membrane of acrosomal vesicle and the outside of the acrosomal process
Species specific
React with receptors on surface of the egg that mediate interaction between sperm and egg membranes
Bindin receptors are limiting: restrict number of sperm that can bind and interact with egg membrane