What is spermatogenesis? Briefly describe the process of spermatogenesis.
Solution and Explanation
Spermatogenesis is the process of the production of sperms from the immature germ cells in males. It takes place in seminiferous tubules present inside the testes. During spermatogenesis, a diploid spermatogonium (male germ cell) increases its size to form a diploid primary spermatocyte. This diploid primary spermatocyte undergoes first meiotic division (meiosis I), which is a reductional division to form two equal haploid secondary spermatocytes. Each secondary spermatocyte then undergoes second meiotic division (meiosis II) to form two equal haploid spermatids. Hence, a diploid spermatogonium produces four haploid spermatids. These spermatids are transformed into spermatozoa (sperm) by the process called spermiogenesis.
Top Questions on Human Reproduction
Study the graphs given below for Case 1 and Case 2 showing different levels of certain hormones and answer the question that follows:
(a) Which hormone is responsible for the peak observed in Case 1 and Case 2? Write one function of that hormone.
(b) Write changes that take place in the ovary and uterus during follicular phase.
Student to attempt either sub-part (c) or (d):
(c) Name the hormone Q of Case 2. Write one function of hormone Q.
OR
(d) Which structure in the ovary will remain functional in Case 2? How is it formed?- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
- Shyam and Radha are expecting their first child with Radha being in her second month of pregnancy with no complications. Shyam’s family has a history of cystic fibrosis while Radha’s family has a history of Down’s syndrome, leading to a concern that the baby may have one of these conditions.
(a) Suggest and explain a way of testing if their baby is at risk for any genetic disorders.
(b) In case of presence of one or both of the abnormalities and posing a risk to the mother’s health, mention one possible option for them to consider. Is that option safe for Radha at the current gestational age? Justify.
(c) Under what conditions is the process mentioned in (b) illegal?- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
- Assertion (A): Saheli is the World’s first non-steroidal oral contraceptive pill.
Reason (R): It has been developed by National Institute of Immunology, New Delhi.- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
Match the following items of Column-I with that of Column-II:
- CBSE CLASS XII - 2025
- Biology
- Human Reproduction
- "Sex of a newborn baby in humans depends on the father, not the mother." Confirm this statement with the help of a flow chart.
- CBSE Compartment X - 2025
- Science
- Human Reproduction
Questions Asked in CBSE CLASS XII exam
- Figure shows variation of Coulomb force (F) acting between two point charges with \( \frac{1}{r^2} \), \( r \) being the separation between the two charges \( (q_1, q_2) \) and \( (q_2, q_3) \). If \( q_2 \) is positive and least in magnitude, then the magnitudes of \( q_1, q_2 \), and \( q_3 \) are such that:
- CBSE CLASS XII - 2025
- Electrostatics
- A meeting will be held only if all three members A, B and C are present. The probability that member A does not turn up is 0.10, member B does not turn up is 0.20 and member C does not turn up is 0.05. The probability of the meeting being cancelled is:
- CBSE CLASS XII - 2025
- Probability
- If $A = \begin{bmatrix} 2 & 3 \\ -1 & 2 \end{bmatrix}$, then show that $A^2 - 4A + 7I = 0$.
- Reactant ‘A’ underwent a decomposition reaction. The concentration of ‘A’ was measured periodically and recorded in the table given below:Based on the above data, predict the order of the reaction and write the expression for the rate law.
Time (Hours) [A] (M) 0 0.40 1 0.20 2 0.10 3 0.05 - CBSE CLASS XII - 2025
- Chemical Kinetics
- ‘But the game he is watching so intently is out of his reach.’ What are the factors that have made their game inaccessible to Saheb? (Lost Spring)
- CBSE CLASS XII - 2025
- Literature
Concepts Used:
Gametogenesis
The gametogenesis process includes the formation of reproductive cells or sex cells in living organisms. In plants, it is carried throughout mitosis whereas, in animals, it is carried through meiosis. The formation of male and female gametes are the two basic steps that take place during the gametogenesis process.
Based on the living organism, the process of gametogenesis occurs in:-
Plants: It occurs by the meiotic division of diploid gametocytes. In higher plants, it happens along with sporogenesis.
Animals: It occurs by meiosis where gametes are formed from their diploid mother cells exist in organs called gonads.
Stages of Gametogenesis
The gametogenesis process occurs in three steps. They are as follows;
- Mitotic divisions together with cell growth of precursor germ cells.
- The happening of Meiosis I and Meiosis II for producing haploid daughter cells.
- Metamorphose haploid daughter cells for the production of functional gametes.