Which of the following statement is correct?

Options

A. Small number of gametes are released by animals performing external fertilisation
B. Chimpanzee exhibits oestrous cycle
C. Oviparous animals always lay fertilised eggs covered by hard calcareous shell
D. The type of parthenogenesis observed in honeybees is arrhenotoky

Answer

To determine which statement is correct, we will analyze each option one by one:

1. **Statement 1**: "A small number of gametes are released by animals performing external fertilization."
- This statement is incorrect. Animals that perform external fertilization typically release a large number of gametes. This is because the chances of gametes being destroyed in the environment are high, so they release many to increase the likelihood of successful fertilization.

2. **Statement 2**: "Chimpanzees exhibit an estrous cycle."
- This statement is also incorrect. Chimpanzees, being primates, do not exhibit an estrous cycle; instead, they exhibit a menstrual cycle. The menstrual cycle is characteristic of primates, including humans.

3. **Statement 3**: "Oviparous animals always lay fertilized eggs covered by a calcareous shell."
- This statement is incorrect as well. Oviparous animals can lay eggs that are either covered by hard calcareous shells or by leathery shells. Therefore, it is not accurate to say they always lay fertilized eggs with a calcareous shell.

4. **Statement 4**: "The type of parthenogenesis observed in honey bees is arhenotoky."
- This statement is correct. In honey bees, arhenotoky is a form of parthenogenesis where only males are produced from unfertilized eggs. This is a specific reproductive strategy observed in honey bees and some other insects.

After analyzing all the statements, the correct answer is **Statement 4**.

### Summary of the Correct Answer:
The correct statement is: "The type of parthenogenesis observed in honey bees is arhenotoky."