Railway Science (Biology-Reproduction in Animals) (Part-II)

Total Questions: 50

1. Is there a visible difference between sperms which contain X chromosomes and sperms which contain Y chromosomes? [RRC Group D 27/09/2022 (Morning)]

Correct Answer: (b) No, there is no difference in size or motility.
Solution:

Chromosomes are thread-like structures present in the nucleus of both plant and animal cells and they play a primary role in heredity, cell division, variation, mutation, repair and regeneration.
Discovered by - Walther Flemming in 1882. X and Y chromosomes (sex chromosomes) determine the sex of a baby. X Chromosome is present in both males and females but Y Chromosome is present only in males.

2. Which is the best option for A Woman About To Give Birth? [RRC Group D 28/09/2022 (Afternoon)]

Correct Answer: (c) giving birth in a well equipped hospital
Solution:

The average length of pregnancy is counted as 40 weeks which is divided into three trimesters - First trimester (Conception to 12 weeks), Second trimester (13 to 27 weeks) and Third trimester (28 to 40 weeks).

3. What is covered under 'Maternal Health'? [RRC Group D 28/09/2022 (Evening)]

Correct Answer: (a) Care during prenatal, natal and postnatal period
Solution:

Goal to Improve maternal health is reducing eminently preventable deaths of Mother/Child. Maternal Mortality Ratio (MMR) : The number of mothers who die from complications in pregnancy for every one lakh live births.

4. The uterine wall in females prepares itself to receive the developing fertilized egg. In case there is no fertilization, the thickened lining of the uterine wall breaks down and goes out of the body along with blood. This is called: [RRC Group D 29/09/2022 (Evening)]

Correct Answer: (b) Menstruation
Solution:

Menstruation. Menopause - Marks the end of their reproductive years. Secondary sexual characters - Growth of facial hair, Shoulder become wider, Voice becomes hoarse, Breasts enlarge and mammary glands develop, Voice becomes shrill. Adam's apple - The protruding part of the throat formed due to the enlargement of larynx. This enlargement of the larynx or voice box occurs during puberty.

5. How does a loop act as a contraceptive? [RRC Group D 30/09/2022 (Afternoon)]

Correct Answer: (a) It blocks access to the fallopian tubes.
Solution:

The copper-coated IUD prevents pregnancy by not allowing the sperm to fertilize the egg. It may also make it harder for a fertilized egg to implant in the uterus. An IUD coated with progestin works in a similar way, but also thickens the cervical mucus and thins the uterine lining.

6. Which part of the human sperm is responsible for determination of sex of the zygote? [RRC Group D 30/09/2022 (Evening)]

Correct Answer: (b) Part A only
Solution:

Head : They contain acrosome at the apical end, which contains several important enzymes that help the entry of sperm into the ovum.
Middle piece : This region has multiple mitochondria, and these mitochondria provide energy for the movement of sperm, in order for fertilization to take place. Tail : This region has a flagellum that protrudes out of the cell body and is helpful in providing vigorous motility to the sperms.

7. A perfect pair of sex chromosomes is found in: [RRC Group D 06/10/2022 (Morning)]

Correct Answer: (a) human women
Solution:

Human Women have a perfect pair of sex chromosomes XX while men have a mismatched pair in which one is a normal-sized X and the other a short one Y which is XY. Most of the snakes exhibit a ZZ / ZW sex chromosome system, with different stages of degeneration. Chromosome of Starfish (Asteroidea) : 36.

8. Identify the true statement. [RRC Group D 06/10/2022 (Afternoon)]

Correct Answer: (c) Sperms containing X chromosomes have 23 chromosomes and sperms containing Y chromosomes also have 23 chromosomes.
Solution:

The 23rd pair chromosome in a female is XX, whereas the genetic makeup of a male is XY. The female is homogametic, forms X - gamete while male is heterogametic, forms X - gamete and Y- gamete.
During fertilization, when sperm carrying X chromosome fuses with egg having X chromosome, results in female child Whereas if sperm carries Y chromosome fuses with egg (X chromosome), results in male child. The chromosome responsible for sex determination in a male is the Y chromosome.

9. Which of the following is a disadvantage of using contraceptive pills? [RRC Group D 07/10/2022 (Evening)]

Correct Answer: (a) They may produce hormonal imbalance.
Solution:

Combined birth control pills contain two synthetic hormones - estrogen and progestogen. They work by stopping ovulation. These are very effective and have a failure rate of 1%.
Birth control is any activity, medicine, or equipment used to prevent pregnancy. Other Birth control Methods - Creating a barrier that blocks sperm from reaching the egg, Killing sperm, Changing the cervical mucus to hinder sperm from moving into the uterus, Altering the tissue lining the uterus so that a fertilized egg can't implant.

10. What kind of diet does an adolescent require to develop a healthy reproductive system? [RRC Group D 11/10/2022 (Morning)]

Correct Answer: (b) Nutritionally well-balanced
Solution:

Reproductive health is defined by the World Health Organization (WHO) as the total well-being in all aspects of reproduction. Examples - Behavioural, emotional, physical, and social. Some ways to maintain reproductive health during adolescence: Balanced Diet, Personal Hygiene, Adolescent Pregnancy and No to Drugs.