Twins

Q. why are offspring's that are produced a sexually similar and not identical to parent

Q.

What is the full form of GA In biology?

Q.

Is it possible for eggs to be fertilized by two different sperm cells?

Q.

Write a note on the formation of twins.

Q. How are twins are born

Q. The twins formed from a single embryo during early embryonic development are called ___.

1. 
   monozygotic twins
2. 
   siamese twins
3. 
   fraternal twins
4. 
   dizygotic twins

Q. What are the basic events of reproduction ?
DNA copies generated during reproduction will be similar but may not be identical. Justify the statement

Q. Jack and Jill are twins.
Which among the following types can they be classified under?

1. Conjoined twins
2. Monozygotic twins
3. Dizygotic twins
4. Siamese twins

Q.

The twins which are fused with each other wholly or in part called as

1. Siamese twins

2. fraternal twins

3. identical twins

4. None of these

Q. Identical twins are

1. Monozygotic
2. Bizygotic
3. Both A and B
4. None of the above

Q.

Siblings share ____$\%$ of their genes while fraternal twins share ____$\%$ and identical twins share ____$\%$ of their genes (on average).

1. 50, 50, 50

2. 100, 100, 50

3. 100, 100, 100

4. 50, 50, 100

Q. "Gametes must be produced by meiosis for sexual reproduction". Why is it so? [3 MARKS]

Q. If at a time one egg is fertilized by 2 or more sperm, what will happen?

Q.

Identify the statements as true/false.
Fraternal twins are produced from two eggs.

1. True
2. False

Q. When two sperms fertilise two different eggs in the fallopian tube, it results in twins.

1. maternal
2. identical
3. fraternal

Q. Differentiate between monozygotic twins and dizygotic twins.

Q. How is amount of genetic material restore during the sexual reproduction?

Q. Does Fraternal twins carry the same DNA?

Q.

Which among the following are not similar in the case of identical twins?

1. Genetic makeup

2. Handwriting

3. Fingerprint

4. Physical appearance

Q.

An offspring gets one set of chromosome from mom and other from dad. Now how can twins get there total chromosomal number if they are identical twins?

Q. Monozygotic twins are produced when

1. Two ova are fertilized simultaneously
2. Incomplete cleavage of zygote
3. First cleavage of zygote is followed by separation into two
4. There is no cleavage

Q. What are the twins formed from a single embryo during early embryonic development called?

1. 
   Monozygotic twins
2. 
   Homozygotic twins
3. 
   Dizygotic twins
4. 
   Heterozygotic twins

Q.

Siblings share ____$\%$ of their identy while fraternal twins share ____$\%$ and identical twins share ____$\%$ of their identity (on average).

1. 50, 50, 50

2. 50, 50, 100

3. 100, 100, 100

4. 50, 50, 100

Q. Sometimes the separation of twins is incomplete and these are born attached or remain so even after. What are those twins known as?

1. Fraternal
2. Dizygotic
3. Identical
4. Siamese

Q. What are identical twins?

1. Heterozygous
2. Homozygous
3. Dizygotic
4. Monozygotic

Q. Fraternal twins in humans are produced when

1. Two sperms fertilize an ovum and the first two blastomeres separate from each other
2. One sperm fertilizes an ovum and the first two blastomeres separate from each other
3. Egg develop parthenogenetically and first two blastomeres separate from each other
4. Two ova are fertilized simultaneously

Q. Two offspring developed in the same uterus from fertilization of two different ova are

1. Monozygotic twins
2. Dizygotic twins
3. Fraternal twins
4. Both B and C

Q. Identical twins are syngeneic with similar chromosomal contents. Natural clones are those who possess identical chromosomes.
Fill up with the suitable word given in the brackets.
(a) Identical twins are
(natural clones/artificial clones)
(b) Identical twins are
(dissimilar to each other/ similar to each other)

Q. Differentiate between :
(a) semen and sperm
(b) implantation and pregnancy
(c) follicle and corpus luteum
(d) amnion and allantois
(e) impotency and sterility
(f) prostate gland and Cowper's gland (the nature of secretion)
(g) identical twins and fraternal twins

Q. twins develop from a single fertilised egg.

1. Fraternal
2. Paternal
3. Identical
4. Dizygotic