Question

III. Give reasons: i) The water animals such as frog and fishes lay many eggs at a time. ii) Girls need to consume food rich in iron. ili) Both dog and humans are mammals. Dogs produce many puppies at a time, while humans usually give birth to only one child at a time.​

Answer 1

Answer:

1. fish and frogs lay hundreds of eggs because: - In Fish and Frogs, external fertilization occurs. - In the external medium (water), the male releases a large number of gametes while the female parent lays a large number of eggs.
2. Women need more iron than men to make up for the amount of iron they lose in their menstrual period. Around 1 mg of iron is lost for every day of bleeding. Iron deficiency is the most common nutrient deficiency in women. Insufficient iron can lead to anaemia.
3. In these species, more than one ovum is released from the ovary at the time of ovulation. Therefore, they always produce several puppies. However, in humans, a single ovum is released from the ovary every month. Thus, they usually produce only one child at a time.