3.Developmental Period-Week 1 & 2

Question 1

Morula is_____ celled stage?

Answer 1

16-64 celled

Morula-multicellular-may be 16 celled

Advanced morula- >16 celled—enters uterina cavity.

Question 2

On which day advanced morulla enters uterine cavity?

Answer 2

Day 4

Morula os 16-64 celled stage

Question 3

Implantation of blastocyst occurs on which day?

Answer 3

Day 6

Question 4

FERTILIZATION occurs in ?

Answer 4

Ampulla of fallopian tube.

Question 5

Zona pellucida is biochemically______

Answer 5

Glycoprotein membrane

Question 6

Zona pellucida short notes

Answer 6

1. GLYCOPROTEIN.
2. ACELLULAR STRUCTURE.
3. ATTRACTS SPERMS FOR FERTILIZATION.
4. COVERS ZYGOTE EVEN AFTER FERTILIZATION TO PREVENT ABNORMAL IMPLANTATION (AS ZYGOTE IS STILL IN FALLOPIAN TUBE BUT IMPLANTATION HAS TO OCCUR IN UTERINE CAVITY.
   * [PREVENTS ABNORMAL IMPLANTATION]*
5. PREVENTS POLYSPERMY

Question 7

Events on Day-1, 2, 3, 4, 5, 6 and 12 ?

Answer 7

Day-1-Single celled stage

***By end of day 4–Blastocyst is formed covered by zona pellucida ( preventing implantation).

[ IMPLANTATION is week long process ]
[ Day 5-Day 12 ]

Question 8

Correct sequence of embryonic events

Answer 8

Acrosome reaction—Cortical reaction—Zona reaction.