Biology

Question 1

Diversity of animals mean

Majority of the animal phyla are formed from?

Answer 1

The different forms and variety of animals

Sea, freshwater and land

Question 2

1. The general features of animals are?

2. What is the key challenge of terrestrial animals and why

Answer 2

1. They include active movement
   Sexual reproduction,divers in form,no cell walls, unicellular and multicellular heterotrophs and embryonic development.
2. The key challenge is temperature variation, the reason is because structures of chemical bonding are regulated by temperature,it alter them and their functions..

Question 3

Why is reason animals have active movement?

Answer 3

They have active movement because they lack rigid cells and evolution of nervous and muscular tissues.

Question 4

1. Name one mammal that can fly

2. State the features of sexual reproduction in animals

Answer 4

1. Bat, flying squirrel

2. They are non motile eggs which are larger than the flagellated sperm cells, there is no alternation of generations

Question 5

Embryonic development include?

2. Some animals have an opening called?

Answer 5

Since most animals have similar embryonic development,it starts from when the zygote undergoes mitotic division to form (cleavage), then it forms solid balls of cells called( morula), then forms hollow balls of cells called ( blastula).
2. The opening is called blastopore, and at this stage, the embryo is called grastula.

Question 6

Later growth of the gastrula forms?

Answer 6

The digestive system which vary from phylum

Question 7

What are ectoderms and endoderms( embryonic layers) based on adaptation of animals

Answer 7

Endoderms are animals which maintain their temperature irrespective of the external surrounding,they have high cost of energy production eg birds and mammals.
Ectoderms allow their temperature to conform with the surrounding temperature.