In which of the following organisms, the feature of menstrual cucle during sexual reproduction is observed ?
(a) Most seasonal breeders
(b) Human females
(c )Old-world monkeys and apes
(d)Tiger

Options

A. (b),(c) & (d)
B. (b) & (c)
C. (c) & (d)
D. (a) & (b)

Answer

To solve the question regarding which organisms exhibit the feature of a menstrual cycle during sexual reproduction, we can analyze each option provided:

1. **Understanding the Menstrual Cycle**: The menstrual cycle is a physiological process that occurs in some female mammals, primarily in primates. It involves the shedding of the endometrial lining of the uterus if fertilization does not occur.

2. **Analyzing the Options**:
- **(a) Most seasonal breeders**: Seasonal breeders typically experience an estrous cycle rather than a menstrual cycle. In estrous cycles, the endometrium is reabsorbed if fertilization does not occur. Therefore, this option is incorrect.

- **(b) Human females**: Human females are primates and do experience a menstrual cycle, which is characterized by regular shedding of the uterine lining approximately every 28 days. This option is correct.

- **(c) Old-world monkeys and apes**: Like humans, old-world monkeys and apes are also primates and exhibit a menstrual cycle. This option is also correct.

- **(d) Tiger**: Tigers are non-primates and, like most seasonal breeders, they also have an estrous cycle instead of a menstrual cycle. Thus, this option is incorrect.

3. **Conclusion**: The organisms that exhibit the feature of a menstrual cycle during sexual reproduction are **human females (b)** and **old-world monkeys and apes (c)**.

4. **Final Answer**: The correct options are **(b) Human females** and **(c) Old-world monkeys and apes**.