Tag: twins

Questions Related to twins

Fraternal twins in humans are produced when

biology reproduction in humans twins reproduction and modern technology post fertilization events

  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

Show answer
Correct Option: D
Explanation:

Fraternal twins are also called as 'dizygotic'. This means there is fertilization of two seperate eggs(ova) by two individual sperms simultaneously. They are implanted in the uterine wall at the same time. They usually develop in two separate amniotic sacs. They are also called as 'biovular' since two eggs form two zygotes.
So, the correct is answer is 'Two ova are fertilized simultaneously'.

What are identical twins?

biology reproduction in humans twins reproduction and modern technology post fertilization events

  1. Heterozygous

  2. Homozygous

  3. Monozygotic

  4. Dizygotic

Show answer
Correct Option: C
Explanation:

Image result for monozygotic identical twin
Twins are two offsprings produced by the same pregnancy. Twins can either be monozygotic (identical twin), meaning that they develop from one zygote that splits and forms two embryos, or dizygotic (fraternal twin), which are produced from two eggs. Thus, the correct answer is option C.

Which are the two offspring developed in the same uterus but from fertilization of two different ova?

biology reproduction in humans twins reproduction and modern technology post fertilization events

  1. Dizygotic twins

  2. Monozygotic twin

  3. Fraternal twins

  4. Both A and C

Show answer
Correct Option: D
Explanation:

Dizygotic twins may occur if two or more oocytes are released in one cycle. If each is fertilized, dizygotic twins may result. Fertility drugs are a common cause for dizygotic twins, but other factors, like family history, maternal age or weight, can also lead to dizygotic twinning. Thus, the correct answer is option D.

Monozygotic twins develops from

biology reproduction in humans twins reproduction and modern technology post fertilization events

  1. Different zygotes

  2. Different ova

  3. Different sperms

  4. Same zygote

Show answer
Correct Option: D
Explanation:

  • There are two types of twins, Fraternal or dizygotic twins, and monozygotic twins.
  • When the zygote, during the cleavage, separates and forms two different cells and both of them grow individually as embryos, they form the monozygotic twins.
  • Monozygotic twins are of the same sex.
  • When 2 zygotes are fertilized by two different sperms they form the dizygotic twins.
  • They can be of different sex.

So, the correct option should be 'Same Zygote'.

Concordant type of twins are

biology reproduction in humans twins reproduction and modern technology post fertilization events

  1. Free martins

  2. Dizygotic twins

  3. Monozygotic twins

  4. Both B and C

Show answer
Correct Option: C
Explanation:
Monozygotic or identical twins are those twins which are formed by the splitting of one zygote into two embryos. They have almost the same characteristics both phenotypically and genotypically. Dizygotic or fraternal twins are formed when two different eggs are fertilized by two different sperms.
so, the correct option is ' Monozygotic twins'.

Read the following statements.
(i) Birth control pills are likely to cause cardiovascular problems.
(ii) A woman who substitutes or takes the place -of the real mother to nurse the embryo is called surrogate mother.
(iii) Numerous children have been produced by in vitro fertilisation but with some abnormalities.
(iv) Woman plays a key role in the continuity of the family and human species.
(v) Foetal sex determination test should not be banned.
Which of the following pair consists of incorrect statement ?

biology reproductive health twins reproduction and modern technology stds and infertility

  1. (i) and (ii)

  2. (ii) and (iv)

  3. (iii) and (v)

  4. None of these

Show answer
Correct Option: C
Explanation:

Numerous children have been produced by in vitro fertilisation without any abnormality. Foetal sex determination test should be banned as it is being misused for female foeticide.

In invitro fertilization, the foetus are allowed to develop outside the body.

biology reproductive health twins reproduction and modern technology stds and infertility

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

In in-vitro fertilization, only the male and female gametes fuse outside the female body. After the formation of zygote, it is transferred in the female body.  

So the correct answer is false.

Which of the following breeding techniques is used to improve herd genetics?

biology reproductive health twins reproduction and modern technology stds and infertility

  1. Artificial insemination

  2. Embryo transfer

  3. Both A and B

  4. None of the above

Show answer
Correct Option: C
Explanation:

Both the methods are used to improve the herd genetics by adding a new set of desired genes to the herd. This increases the quality of the gene pool of the herd.  

So the correct option is 'Both A & B'.

Transfer of ovum from donor to recipient oviduct is

biology reproductive health twins reproduction and modern technology stds and infertility

  1. GIFT

  2. ICSI

  3. ZIFT

  4. ET

Show answer
Correct Option: A
Explanation:

GIFT referred as a gamete intra Fallopian transfer. In this, the egg from the donor and the sperm from the father (or the donor male) is taken and are transferred to the oviduct or the Fallopian tube of the recipient. 

So the correct option is 'GIFT'.

Stage transferred to uterus after induced fertilization of ova in the laboratory is

biology reproductive health twins reproduction and modern technology stds and infertility

  1. Embryo at two-blastomere stage

  2. Morula

  3. Zygote

  4. Embryo at four blastomere stage

Show answer
Correct Option: B
Explanation:

In Intra-Uterine Transfer (IUT) embryo with more than 8-blastomeres stage (morula) is used for transfer into the uterus after induced fertilisation in the laboaratory.

So, the correct answer is 'Morula'.