Development from Zygote to Blastocyst

Q.

What is the difference between totipotent cells and pluripotent cells?

Q.

Is a morula stage before blastocyst?

Q.

Cleavage in the fertilised egg of humans

1. Is discoidal

2. Starts in uterus

3. Is meroblastic

4. Starts when egg is in fallopian tube

Q. Which one of the following pairs of plant structures has haploid number of chromosomes?

1. Nucellus and antipodals
2. Egg nucleus and secondary nucleus
3. Megaspore mother cell and antipodal cells
4. Egg cell and antipodal cells

Q. Fill in the blanks:
(j) Zygote divides to form which is implanted in uterus.

Q. The image given below depicts a diagrammatic sectional view of the female reproductive system of humans. Which set of I-V have been correctly identified?

1. I - Zygote, II - Ovum, III - Morula, IV - Blastocyst, V - Implantation of blastocyst
2. I - Ovum, II - Morula, III - Zygote, IV - Blastocyst, V - Implantation of blastocyst
3. I - Ovum, II - Zygote, III - Morula, IV - Blastocyst, V- Implantation of blastocyst
4. I - Ovum, II - Zygote, III - Blastocyst, IV - Morula, V - Implantation of blastocyst

Q.

The embryo at the 16-celled stage is known as

1. morula

2. gastrula

3. blastula

4. blastomere

Q.

Write about cleavage.

Q. In a fertilized embryosac, the haploid, diploid and triploid structures respectively are

1. Synergid, zygote, primary endosperm nucleus
2. Synergid, antipodal, polar nuclei
3. Antipodal, Synergid, Primary endosperm nucleus
4. Synergid, polar nuclei, Zygote

Q. Gastrula is the embryonic stage in which

1. cleavage occurs
2. blastocoel forms
3. germinal layers form
4. villi form

Q. After which cell-stage does the blastulation occur?

1. 4-8 cells
2. 8-16 cells
3. 24-30 cells
4. 60-72 cells

Q.

What is a blastocyst?

Q.

How long does blastocyst take to implant?

Q. Match the following and choose the correct answer

A	Zona hatching	(i)	mitotic division of the zygote
B	Trophoblast	(ii)	embedding of the blastocyst in the endometrium
C	Cleavage	(iii)	blastocyst releasing from zona pellucida
D	Implantation	(iv)	outer layer of blastocyst attached to the endometrium

1. A- (iii), B-(iv), C-(i), D-(ii)
2. A- (ii), B-(i), C-(iii), D-(iv)
   
3. A- (ii), B-(iv), C-(iii), D-(i)
   
4. A- (iii), B-(i), C-(ii), D-(iv)
   

Q.

Which layer of blastocyst is nutritive in function?

Q. The embryo sac in female gametophyte is seven celled and eight nucleated structure.Justify the statement with the help of a labelled diagram.

Q. Study the following statements and answer the question.

In the transport of ovum in the female reproductive system, a process known as ‘A’ occurs and the ‘B’ division starts as the zygote moves through the ‘C’ of the oviduct towards the ‘D’. Identify A, B, C and D.

1. A→Blastulation, B→Meiotic, C→Ampulla , D→Uterus
2. A→Parturition, B→Meiotic, C→Infundibulum, D→Uterus
3. A→Implantation, B→Mitotic, C→Fimbriae, D→ Ovary
4. A→Cleavage, B→ Mitotic, C→Isthmus, D→ Uterus

Q.

At the time of implantation, the human embryo is called:

1. embryo

2. blastocyst

3. zygote

4. foetus

Q. Given below are four statements (i)-(iv) regarding embryonic development in humans.
(i) Cleavage divisions bring about considerable increase in the mass of protoplasm.
(ii) With more cleavage divisions, the resultant blastomeres become smaller and smaller.
(iii) The blastomeres in the blastocyst are arranged into two layers, trophoblast and endometrium.
(iv) Cleavage divisions result in a solid ball of cells called morula.
Which of the above two statements are correct?

1. (i) and (iii)
2. (ii) and (iv)
3. (i) and (ii)
4. (iii) and (iv).

Q.

How is embryo protected inside uterus?

Q.

Why in humans embryo gets attached to the uterine wall?

Q.

Cleavage in the fertilised egg of humans

1. Starts in uterus

2. Is meroblastic

3. Starts when egg is in fallopian tube

4. Is discoidal

Q.

Complete the following by using suitable words

The embryo inside the uterus is protected from jerks or mechanical shocks by __________.

Q. The image given below depicts a diagrammatic sectional view of the female reproductive system of humans. Which set of I-V have been correctly identified?

1. I - Zygote, II - Ovum, III - Morula, IV - Blastocyst, V - Implantation of blastocyst
2. I - Ovum, II - Morula, III - Zygote, IV - Blastocyst, V - Implantation of blastocyst
3. I - Ovum, II - Zygote, III - Morula, IV - Blastocyst, V- Implantation of blastocyst
4. I - Ovum, II - Zygote, III - Blastocyst, IV - Morula, V - Implantation of blastocyst

Q.

What is the difference between blastulation and gastrulation?

Q. Gastrula is the embryonic stage in which

1. cleavage occurs
2. blastocoel forms
3. germinal layers form
4. villi form

Q.

Morula differs from the blastula in the

1. Absence of cavity

2. Presence of cavity

3. Absence of yolk

4. None of these

Q. Which structure is called as embryosac or the female gametophyte?

1. E
2. A
3. B
4. None of the above

Q. Cleavage in the fertilised egg of humans__________.

1. starts in uterus
2. starts when fertilised egg is in fallopian tube
3. results in the formation of embryo with 8-16 blastomeres called as blastocyst
4. starts in cervix

Q. Type of cleavage in fertilized egg depends on

1. Amount of yolk
2. Number of cells
3. Number of mitochondria in the sperm
4. Number of testes