Nonprimate mammals have

Options

A. Menstrual cycle
B. Oestrus cycle
C. Breeding seasons
D. Non breeding seasons.

Answer

To answer the question regarding what nonprimate mammals have, we can follow these steps:

### Step 1: Understand the Options
The question provides four options:
- A) Menstrual cycle
- B) Estrous cycle
- C) Breeding seasons
- D) Non-breeding seasons

### Step 2: Analyze Each Option
- **Menstrual Cycle**: This cycle is primarily associated with primates, including humans. It involves the shedding of the uterine lining if fertilization does not occur.

- **Estrous Cycle**: This cycle is typical for non-primate mammals. It involves a period of receptivity to mating (estrus) and is characterized by specific phases that prepare the female for potential fertilization.

- **Breeding Seasons**: This term refers to specific times of the year when animals mate. While many mammals do have breeding seasons, it does not specifically define the reproductive cycle itself.

- **Non-Breeding Seasons**: This refers to periods when animals do not mate or reproduce. It is a complementary concept to breeding seasons but does not define the reproductive cycle.

### Step 3: Identify the Correct Answer
Since the question specifically asks about nonprimate mammals, the estrous cycle is the correct answer. Nonprimate mammals typically exhibit an estrous cycle, which is characterized by periods of heat (estrus) when females are receptive to mating.

### Conclusion
The correct answer is **B) Estrous cycle**.

---