Assertion : Protandry and protogyny ensures cross fertilization. Reason : Cross fertilization introduces variation in progeny.

Step-by-step solution

Most of the animals have sex organs. They are either males or females. But in some lower animals, the organs of both the sexes are found in the same individual. These are called bisexual or monoecious animals or hermaphrodites. In these animals, testes and ovaries do not mature simultaneously. For example in earthworm, testes mature earlier, while in others, e.g., sea-squirt, ovaries mature earlier. These conditions are respectively called protandry and protogyny. They ensure cross fertilization. Cross fertilizatio