Animals and Their Young Ones

Explain the following terms: a) Embryo:

Answer explanation

An embryo is the early stage of development of a multicellular organism. It is formed after fertilization of an egg cell by a sperm cell and undergoes various stages of growth before becoming a fetus.

Explain the following terms: b) Incubation:

Answer explanation

Incubation refers to the period between exposure to a pathogen and the appearance of symptoms. During this time, the pathogen multiplies and the individual may be contagious.

Give scientific reasons for the following: a) Fish lay plenty of eggs, yet only few develop into adults.

Answer explanation

Fish lay plenty of eggs as a survival strategy due to high mortality rates from predators, diseases, and environmental factors. This ensures that at least some offspring will survive to adulthood and continue the species.

Give scientific reasons for the following: b) Dolphins are considered as mammals.

Answer explanation

Dolphins are considered mammals because they have mammary glands to nurse their young, give birth to live offspring, and have hair at some point in their life cycle.

Answer the following questions: a) Why are eggs kept under incubation?

Answer explanation

Eggs are kept under incubation to provide the necessary conditions for embryos to develop and hatch successfully.

Which part of an egg is very important for the growing embryo? Explain why?

Answer explanation

The yolk of an egg is very important for the growing embryo because it contains essential nutrients, fats, and proteins needed for the development of the chick.

Draw the lifecycle of a butterfly and label the stages. a. Explain the second stage in the life cycle of butterfly.

Answer explanation

The second stage in the life cycle of a butterfly is the larva stage, also known as the caterpillar stage. During this stage, the caterpillar grows and feeds voraciously to prepare for the next stage.

Draw the lifecycle of a butterfly and label the stages. b. In which stage does moulting take place.

Answer explanation

Moulting takes place during the larva stage of the butterfly lifecycle.

Compare an oviparous animal to a viviparous animal.

Answer explanation

Oviparous animals lay eggs, while viviparous animals give birth to live young.