Fertilisation and embryo development

Question 1

Synchronise mice

Answer 1

Mice have a 4 day cycle so can inject with eCG at any time

eCG acts like FSH
hCG acts like Lh - ovulation

Didnt use male effect for this experiment as dont want fertilisation to occur

Question 2

Day 4 (embryo development) in mice

Answer 2

Morula- tight junctions, cell-cell communication , can no longer see individual cells, start to see paternal involvement

Question 3

Day 5 (embryo development)in mice

Answer 3

Blastocyst

Question 4

Day 6 (embryo development) in mice

Answer 4

Expanded blastocyst - puts pressure on zona pellucida so it hatches

Elongation occurs in some species

Question 5

H+ enzyme

Answer 5

An enzyme present in acrosome of sperm - breaks down cumulus cells to get to egg

H+ helps sperm reach eggs in IVF

H+ group - more sperm attached to eggs