Sex determination in humans is the process of determining an offspring’s biological sex and, as a result, the sexual characteristics that they will develop. Humans usually develop as either males or females, based on the sex chromosomes they inherit from their parents.

1. A haemophilic man marries a homozygous woman who is not haemophilic. What are the possibilities that their child may have haemophilia?

(a) 100 percent

(b)75 percent

(c)50 

(d) nil

 (c) is the correct answer.

2. A colorblind guy marries a woman who carries the trait; it is assumed that the couple will have children.

(a) All sons are colorblind, while all daughters are.

(b) their entire family is colorblind.

(c) All of the daughters are normal, whereas all of the sons are colorblind.

(d) colour blindness affects some sons and daughters.

Answer: (d) color blindness affects some sons and daughters.

3. A colorblind man has a sibling who is not colorblind and a sister who is colorblind. What should the parents’ phenotypes be?

(a) Normal father, colorblind mother

(b) father is colorblind, mother is colorblind.

(c) they’re both colorblind

(d) both normal and abnormal

Correct Answer is  (b) father is colorblind, mother is a carrier

4. How is it that males with the sickness invariably die, but the trait persists in the population?

(a) Some males have it recessively and consequently pass it on to their offspring.

(b) One-half of each male and female child inherits and acts as a carrier

(c) moms pass it on to one-half of their daughters, who serve as carriers.

(d) mutations cause this to happen.

Correct Answer is  (c) moms pass it down to one-half of their daughters, who serve as carriers.

5. A family with only five daughters is expecting their sixth child. There’s a good likelihood it’ll be a son.

(a) Null

(b) Twenty-five percent

1. c) fifty percent

(d) One hundred percent

50 percent (c) is the correct answer.

6. Because it is a blood disorder, haemophilia is more common among men.

1. a) The Y chromosome carries a recessive feature

(b) the Y chromosome’s dominant character

(c) X-chromosome-based dominant characteristic

(d) X-chromosome-based recessive characteristic

Correct Answer is  (a) The Y chromosome carries a recessive feature .

Explanation:- A boy born to a man with haemophilia and a woman who is not a carrier will not have haemophilia since the Y chromosome does not carry the haemophilia gene.

7. Because women are required to be sexually active, sex-related abnormalities are infrequent in women.

 (a) homozygous 

(b) transporter

c.) Heterozygous 

(d) build up immunity

Correct Ans is (a) homozygous

Explanation:-Homozygous inheritance is a genetic condition in which a person inherits the same alleles for a gene from both parents.

8. Only one recessive trait should be able to express its influence.

(a) autosomes of any kind

(b) any of the chromosomes

(c) Female X chromosome

(d) Male X chromosome

Correct Answer is  (d) Male X chromosome

Explaination:-Males are more likely than females to have X-linked recessive characteristics. This is because males only have one X chromosome, thus they only need one mutant X to be affected.

9. The expression of recessive traits

(a) only when they are found on the male X chromosome

(b) only when they are found on a female’s X chromosome

1. c) on any of the autosomes

(d) on both male and female chromosomes

Correct Answer is  (a) only when they are found on the male X chromosome.

Explanation:- X-linked recessive inheritance is a type of inheritance in which a phenotype is always displayed in men due to a mutation in a gene on the X chromosome.

10. An extra X chromosome in a human male phenotypic is referred to as a case of
11. a) Down syndrome 

(b) the term “intersex”

1. c) Edward syndrome 
2. d) Klinefelter syndrome 

Klinefelter syndrome (d) is the correct answer.

Explanation:- Klinefelter’s syndrome is a genetic disorder in which a boy is born with an extra copy of the X chromosome. It is not inherited and develops as a result of a random genetic error after conception.

11. In 2011, the chromosomal basis for determining sex was revealed.

1. a) Melandrium 
2. b) Rumex 
3. c)  Sphaerocarpus 
4. d) Coccinea 

1. a) Melandrium is the correct answer.

Explanation:- Sex chromosomal sex determination is seen in the Melandrium album. They share the same X and Y chromosomal structure as Drosophila and Humans. The technique for determining sex is, however, significantly different from the traditional XX — XY approach. The AAXX individuals in the Melandrium album will be females, while the GALAXY ones will be males.

12. Male XX and female XY are sometimes seen as a result of

(a) Elimination

1. b) segment transfer in the X and Y chromosomes
2. c) the presence of aneuploidy

(d) hormonal discord

Correct Answer is : (b) segment transfer in the X and Y chromosomes

Explaination:-Sex is a polygenic trait in humans, with some genes on the X chromosome and others on the Y chromosome having a cumulative influence.

13. Which of the following is an example of a sex-related illness?
14. a) AIDS
15. b) Color deficiency
16. c) Syphilis 
17. d) Gonorrhoea

Color blindness (b) is the correct answer.

Explanation:-Color blindness is a prevalent hereditary disease that affects people of all ages. It’s a recessive sex-linked characteristic. The genes are found in the Xq28 region of the X chromosome.

14. A sick man marries a healthy woman. They have three boys and five daughters. All of the daughters were sick, but the sons were healthy. This condition is caused by a gene called

(a) Dominant sex-related

(b) recessive sex-linked

1. c) a sex-restricted character

(d) autosomal dominant inheritance

Correct Answer is : (a) dominant sex-related

Explaination:-Sex-linked dominant inheritance is an uncommon form of inheritance in which a trait or disorder is passed down across the generations. A sex-linked dominant disease can be caused by a single faulty gene on the X chromosome.

15. The sex of Drosophila is determined by

(a) the number of X-chromosomes divided by the number of autosome sets

(b) chromosomes X and Y

(c) the proportion of X-chromosome pairs to autosome pairs

(d) whether or not the egg is fertilised and develops parthenogenetically

Correct Answer is  (a) the number of X-chromosomes divided by the number of autosome sets

Explanation:-In Drosophila, the X:A ratio, or the number of X chromosomes to the number of sets of autosomes, is the most important factor in determining sex.

16. In humans, recessive genes on the X chromosome are always expressed.

(a) Females are the ones who have it.

(b) Deadly

c) Non-fatal

(d) Males have this gene.

Correct Answer is : (d) Males have it.

Explanation:-Because a female can be homozygous or heterozygous whereas a male is always hemizygous, the recessive genes on the X-chromosome in humans are always expressed in males.

17. A normal woman married to a normal man whose father was colorblind. The sons would be delighted.

(a) everyone who is colorblind

(b) 75% of the population is colorblind.

(c) 50% of the population is colorblind.

(d) everything is normal

Correct Answer is : (c) 50% of the population is colorblind.

Explanation:-Photopigments — chemicals that detect colour in the cone-shaped cells, or “cones,” in your retina, are incorrect due to genes passed down from your parents.

18. In men, sex-related traits are primarily passed on through the father.

a) autosomes 

b) X chromosome 

c) Y chromosome

(d) each and every one of them

b.) X chromosome is the correct answer.

19. A human egg that has not been fertilised includes

(a) one chromosome of the Y chromosome

(b) chromosomes X and Y

(c) chromosomal XX

d) a single X-chromosome

correct answer is  (d) a single X chromosome

20. A colorblind person is unable to discriminate between colours.

a) green-blue 

(b) a red-blue combination

1. c) a mix of green and red

(d) nil

Correct Answer is (c) 

21. In humans, a male child will have chromosomes.

(a) XO

(b) XXY

(c) XY

(d) XX

Correct answer is Answer:  (c) XY 

22. When you’re 22 years old, you’ll have a son.

(a) During pregnancy, the mother consumes more nutritious foods.

(b) the father has more authority than the mother

(c) XY chromosomes are present in the foetal

(d) the XX chromosomes are present in the foetal

Correct Answer is (c) the XY chromosomes are present in the foetus.

23. How many chromosomes does a human female ovary have? 23. 242

(a) One sex chromosome and 22 pairs of autosomes

(b) One sex chromosome and 22 autosomes

(c) 44 autosomes and one pair sex chromosome

(d) 22 pair autosomes

Correct Answer is : (b) 22 autosomes and one sex chromosome

24. Genes causing colour blindness in man are located on

(a) Y chromosome

(b)X chromosome 

(c) both X or Y chromosome

(d) either X or Y chromosome

(b) X chromosome is the correct answer.