The number of autosomes present in a human secondary spermatocyte
Show Hint
- 44
- 22
- 23
- 46
The Correct Option is B
Solution and Explanation
Step 2: Humans have 46 chromosomes in total (diploid), with 44 autosomes and 2 sex chromosomes. In a haploid cell, the chromosome number is halved, so it has 23 chromosomes (22 autosomes + 1 sex chromosome).
Step 3: Since the question asks for autosomes, we exclude the sex chromosome: 23 - 1 = 22 autosomes.
Thus, the number of autosomes in a human secondary spermatocyte is 22.
Top Questions on Human Reproduction
Given below are few statements with reference to the ovaries of the human female reproductive system:
(i) It is 2--4 cm in length and is connected to the pelvic wall by tendons.
(ii) It is covered by a thin epithelium which encloses the ovarian stroma.
(iii) The stroma is divided into a peripheral medulla and an inner cortex.
(iv) The ovaries are the primary female sex organs that produce the female gamete (ovum).
(v) Ovaries are located one on each side of the lower abdomen.
Choose the option with all the true statements from the given options:- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
Student to attempt either option (A) or (B):
(i) Identify ‘P’ and ‘Q’ labelled in the diagram.
(ii) Specify the source of the hormone ‘P’ and ‘Q’ marked in the diagram.
OR
(i) Identify ‘P’ and ‘Q’ labelled in the above diagram.
(ii) Write down the role of hormone ‘P’ in both males and females.- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
- (a) Abbreviations used for the different modes of assisted reproductive technology are given below. Expand the abbreviations:
(i) ZIFT (ii) ICSI (iii) IUT (iv) GIFT
(b) Why is there a statutory ban on Amniocentesis? Give at least two reasons.- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
Student to attempt either option (A) or (B):
(A)
(i) Draw a diagrammatic sectional view of human seminiferous tubule (enlarged) and label the following:
(a) Cell that undergoes spermiogenesis
(b) Cell that nourish male gametes
(c) Cell which undergoes meiosis I and meiosis II.
(ii) State what is seminal plasma. Mention two constituents of seminal plasma. How is it different from semen?
OR
(B)
(i) Mention the event that induces the completion of the meiotic division of the secondary oocyte in humans.
(ii) Trace the journey of the zygote until its implantation inside the uterus.- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
- Assertion (A): Corpus luteum secretes the hormone, progesterone.
Reason (R): Hormone Progesterone is essential for maintenance of the endometrium.- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
Questions Asked in CBSE CLASS XII exam
(a) Calculate the standard Gibbs energy (\(\Delta G^\circ\)) of the following reaction at 25°C:
\(\text{Au(s) + Ca\(^{2+}\)(1M) $\rightarrow$ Au\(^{3+}\)(1M) + Ca(s)} \)
\(\text{E\(^\circ_{\text{Au}^{3+}/\text{Au}} = +1.5 V, E\)\(^\circ_{\text{Ca}^{2+}/\text{Ca}} = -2.87 V\)}\)
\(\text{1 F} = 96500 C mol^{-1}\)- CBSE CLASS XII - 2025
- Electrochemistry
Define the following:
(i) Cell potential
(ii) Fuel Cell- CBSE CLASS XII - 2025
- Electrochemistry
Calculate the emf of the following cell at 25°C:
\[ \text{Zn(s)} | \text{Zn}^{2+}(0.1M) || \text{Cd}^{2+}(0.01M) | \text{Cd(s)} \] Given: \[ E^\circ_{\text{Cd}^{2+}/\text{Cd}} = -0.40 \, V, \, E^\circ_{\text{Zn}^{2+}/\text{Zn}} = -0.76 \, V \] \[ [\log 10 = 1] \]- CBSE CLASS XII - 2025
- Electrochemistry
Write chemical equations of the following reactions:
(i) Phenol is treated with conc. HNO\(_3\)
(ii) Propene is treated with B\(_2\)H\(_6\) followed by oxidation by H\(_2\)O\(_2\)/OH\(^-\)
(iii) Sodium t-butoxide is treated with CH\(_3\)Cl- CBSE CLASS XII - 2025
- Alcohols, Phenols And Ethers
Give a simple chemical test to distinguish between butan-1-ol and butan-2-ol.
- CBSE CLASS XII - 2025
- Alcohols, Phenols And Ethers