CBSE Class 12 Biology 2024-25: Chapter 2 Human Reproduction Competency-Based Questions with Answers; Download Free PDF

Get ready for your CBSE Class 12 Biology exams with our easy guide on Chapter 2: Human Reproduction. This chapter is very important, especially with the new exam pattern starting in the 2024-25 school year. The CBSE will include 50% more competency-based questions. These questions ask you to use what you've learned in real-life situations.

In this article, we focus on key questions from Chapter 2: Human Reproduction. These questions help you think and solve problems. You’ll find different types of questions, such as multiple-choice, true-false, gap-filling, and short-answer questions. Each question has clear answers to help you understand the concepts better.

To help you study, you can download a free PDF that has all the competency-based questions from Chapter 2: Human Reproduction along with their answer keys.

CBSE 10 Biology Chapter 2 :Human Reproduction Competency-Based Questions

Q1. Which of these cells of the human male reproductive system is haploid?

A. Spermatid

B. Sertoli cell

C. Leydig cell

D. Spermatogonium

Ans. A. spermatid

Q2. Organisms possessing identical sex chromosomes are referred to as the homogametic sex. Organisms with different sex chromosomes are known as the heterogametic sex.

Which of the following is CORRECT about humans?

A. Both males and females are homogametic.

B. Both males and females are heterogametic.

C. Males are homogametic while females are heterogametic.

D. Males are heterogametic while females are homogametic.

Ans. D. Males are heterogametic while females are homogametic.

Q3. Two statements are given below - one labelled Assertion (A) and the other labelled Reason (R).

Assertion (A): Only one sperm can fertilise an ovum.

Reasoning (R): During fertilisation, a sperm comes in contact with zona pellucida layer of the ovum.

Which of the following is correct?

A. Both A and R are true, and R is a correct explanation of A.

B. Both A and R are true, but R is not a correct explanation of A.

C. A is true, but R is false.

D. A is false, but R is true.

Ans. A. Both A and R are true, and R is a correct explanation of A.

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CBSE Class 12 Biology Chapter 1 Sexual Reproduction in Flowering Plants: Important Competency-Based Questions 2024-25	Click Here
CBSE Class 12 Biology Chapter 2 Human Reproduction: Important Competency-Based Questions 2024-25	Click Here

Q4. Globozoospermia is a condition where sperms have a characteristic round head lacking the acrosome.

Which of the following functions will a sperm NOT be able to do because of the above condition?

A. Enter the cervix

B. Penetrate the ovum

C. Leave the ejaculatory duct

D. Swim to the Fallopian tube

Ans. B. penetrate the ovum

Q5. Which of these statements about the female reproductive system is FALSE?

A. Menarche marks the initiation of oogenesis.

B. The germ layers start forming after implantation.

C. The oocyte completes meiosis after the entry of sperm.

D. Ovulation and menstruation stop permanently after menopause.

Ans. A. Menarche marks the initiation of oogenesis.

Q6. Which of these hormones would be detected in both a pregnant female and a female who is not pregnant?

A. Relaxin

B. Prolactin

C. Progesterone

D. Human chorionic gonadotropin

Ans. C. progesterone

Q7. Which of the following statements describes the difference between placenta and umbilical cord?

A. The placenta secretes hormones whereas the umbilical cord does not.

B. The placenta persists after pregnancy while the umbilical cord is expelled.

C. The placenta is lined with veins and arteries while the umbilical cord is not.

D. The placenta interlocks with foetal tissues whereas the umbilical cord interlocks with the uterine tissue.

Ans. A. The placenta secretes hormones whereas the umbilical cord does not.

Q8. Meiotic arrest is a phenomenon noticed during oogenesis in human females where oocytes are arrested in the primary oocyte stage.

(a) What is the chromosomal count of these primary oocytes?

(b) How are these primary oocytes converted to ovum?

Ans. (a) 46

(b) 0.5 marks for each step:

- each primary oocyte is converted to primary follicle

- primary follicles further develop to form secondary and tertiary follicles

- the tertiary follicles are converted to secondary oocytes

- initiated by the action of FSH at puberty

Q9. Polyspermy is an extremely rare condition in which an ovum is fertilised by more than one sperm.

(a) How many chromosomes will a zygote contain if 2 sperms fertilised an ovum?

(b) How is polyspermy prevented in humans?

Ans. 1 mark for each of the following:

(a) 69 chromosomes

(b) Contact between a sperm and ovum causes changes in the zona pellucida that block the entry of other sperms.

Q10. Answer the following questions:

(i) For a human male, out of the two sex chromosomes, we can tell which sex chromosome is from which parent. Can we assume the same for a human female? Give a reason for your answer.

(ii) What is the probability of fertilisation between an ovum and a sperm containing the Y chromosome? Give a reason.

Ans. (i) 0.5 mark for each of the following:

- No

- Reason: Unlike males, a human female contains of a pair of the same sex chromosome 'X', one from each parent.

(ii) 0.5 mark for each of the following:

- 50%

- Reason: Half of the sperms (50%) carry X chromosome and the other half (50%) carry Y chromosome.

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👉 Read Also - CBSE Class 12 Half-Yearly/Mid Term 2024-25 : Most Important Questions with Answers; PDF Download (All Subjects)

👉 Read Also - How CBSE’s New Exam Pattern Will Impact Class 11 and 12 Students

👉 CBSE Class 12 Study Materials

CBSE Class 12 Syllabus 2024-25	CBSE Class 12 Previous Year Papers
NCERT Books For Class 12 Books	NCERT Class 12 Solutions
CBSE Class 12 Full Study Material	CBSE Class 12 Sample Paper 2024-25