Go through the following statements
(i) HCG from placenta stimulates the sertoli cells of the male foetus to produce testosterone and is thus indirectly ivolved in the development of male external genitalia
(ii) Sertoli cells secrete a protein called inhibin, which suppresses FSH synthesis.
(iii) Humans have haemo-endothelial type of placenta.
(iv) oxytcin stimulates the placenta to secrete prostaglandins which in turn stimulate more contractions of uterus.
Which of these correct?

Options

A. (i) & (iv)
B. (ii) & (iv)
C. (i), (ii) & (iv)
D. All are correct

Explanation

To determine which of the statements are correct, let's analyze each one step by step:

### Step 1: Analyze Statement (i)
**Statement:** HCG from placenta stimulates the Sertoli cells of the male fetus to produce testosterone and is thus indirectly involved in the development of male external genitalia.

**Analysis:** This statement is incorrect. Human Chorionic Gonadotropin (HCG) does not stimulate Sertoli cells. Instead, it stimulates Leydig cells in the male fetus to produce testosterone, which is crucial for the development of male external genitalia.

### Step 2: Analyze Statement (ii)
**Statement:** Sertoli cells secrete a protein called inhibin, which suppresses FSH synthesis.

**Analysis:** This statement is correct. Sertoli cells do secrete inhibin, which plays a role in regulating the male reproductive system by inhibiting the secretion of Follicle-Stimulating Hormone (FSH) from the anterior pituitary gland.

### Step 3: Analyze Statement (iii)
**Statement:** Humans have haemo-endothelial type of placenta.

**Analysis:** This statement is incorrect. Humans have a hemochorial type of placenta, not haemo-endothelial. In a hemochorial placenta, the chorion is in direct contact with maternal blood.

### Step 4: Analyze Statement (iv)
**Statement:** Oxytocin stimulates the placenta to secrete prostaglandins which in turn stimulate more contractions of the uterus.

**Analysis:** This statement is correct. Oxytocin does stimulate the release of prostaglandins, which are involved in promoting smooth muscle contractions in the uterus, thereby facilitating labor.

### Conclusion
Based on the analysis:
- Statement (i) is incorrect.
- Statement (ii) is correct.
- Statement (iii) is incorrect.
- Statement (iv) is correct.

Thus, the correct statements are (ii) and (iv).

### Final Answer
The correct statements are: **(ii) and (iv)**.

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