Go through the following statements
(i) Mammary glands are modified sweat glands and each mammary gland consists of 15-25 lobules of the compund tubulo-alveolar type.
(ii) The tertiary follicle is characterised by a fluid filled cavity called antrum
(iii) Both LH and FSH attain a peak level towards the middle of menstrual cycle
(iv). In oogenesis, both first and second meiotic divison are unequal
Which of these are correct?

Options

A. (a) (ii) & (iii)
B. (b) (i), (iii) & (iv)
C. (c) (i),(ii) & (iv)
D. (d) All are correct

Answer

To determine which statements about human reproduction are correct, let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement (i)**: "Mammary glands are modified sweat glands and each mammary gland consists of 15-25 lobules of the compound tubulo-alveolar type."
- **Analysis**: This statement is true. Mammary glands are indeed modified sweat glands and are responsible for lactation in mammals. They consist of 15-25 lobules, which are of the compound tubulo-alveolar type, containing alveoli that produce milk.

2. **Statement (ii)**: "The tertiary follicle is characterised by a fluid filled cavity called antrum."
- **Analysis**: This statement is also true. The tertiary follicle, also known as the Graafian follicle, is characterized by the presence of an antrum, which is a fluid-filled cavity that plays a crucial role in the development of the secondary oocyte.

3. **Statement (iii)**: "Both LH and FSH attain a peak level towards the middle of the menstrual cycle."
- **Analysis**: This statement is true. Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) both reach peak levels around the time of ovulation, which occurs approximately in the middle of the menstrual cycle (around day 14).

4. **Statement (iv)**: "In oogenesis, both first and second meiotic divisions are unequal."
- **Analysis**: This statement is true. In oogenesis, the first meiotic division produces one large ovum and a smaller polar body, while the second meiotic division also produces one large ovum and another polar body, resulting in unequal distribution of cytoplasm.

### Conclusion:
All four statements are correct. Therefore, the correct answer is:
**D) All statements are correct.**