Select the mismatched pair.

Options

A. FSH secretion- stimulate Sertoli cells
B. Secretion of relaxin in the later phase of pregnancy - Human placenta
C. Diaphragms, cervical caps and vaults - Physical barriers of contraception
D. Human egg- Fertilization in fallopian tube

Answer

To solve the question of selecting the mismatched pair, we will analyze each option provided in the question step by step.

### Step 1: Analyze the first pair - FSH secretion stimulates Sertoli cells.
- **Explanation**: Follicle Stimulating Hormone (FSH) is known to stimulate Sertoli cells in the male reproductive system. Sertoli cells are responsible for nourishing developing sperm cells (male gametes) within the seminiferous tubules.
- **Conclusion**: This pair is correctly matched.

**Hint**: Remember that FSH is crucial for spermatogenesis and acts on Sertoli cells.

### Step 2: Analyze the second pair - Secretion of relaxin in the later phase of pregnancy.
- **Explanation**: Relaxin is a hormone that is primarily secreted during the early stages of pregnancy to help relax the uterus and prepare the body for childbirth. It is not typically associated with the later phases of pregnancy.
- **Conclusion**: This pair is mismatched because relaxin is secreted early in pregnancy, not later.

**Hint**: Focus on the timing of hormone secretion during pregnancy stages.

### Step 3: Analyze the third pair - Diaphragms, cervical caps, and waltz as physical barriers of contraception.
- **Explanation**: Diaphragms and cervical caps are indeed physical barriers used in contraception. They prevent sperm from entering the uterus. The term "waltz" seems to be a typographical error, as it does not relate to contraception.
- **Conclusion**: This pair is correctly matched in terms of contraception methods, but the term "waltz" is likely incorrect.

**Hint**: Identify the correct terms used in contraception.

### Step 4: Analyze the fourth pair - Human egg fertilization in the fallopian tube.
- **Explanation**: Fertilization of the human egg typically occurs in the fallopian tube, specifically at the ampullary-isthmic junction. This is a well-established fact in human reproductive biology.
- **Conclusion**: This pair is correctly matched.

**Hint**: Recall the specific location of fertilization in the female reproductive system.

### Final Conclusion:
After analyzing all pairs, we find that the mismatched pair is **option B**: "Secretion of relaxin in the later phase of pregnancy," as relaxin is actually secreted during the early phase of pregnancy.

**Final Answer**: Option B is the mismatched pair.