BIOLOGY [2 Mark Question Answer]

Warm blooded animals are those animals whose body temperature remain same and is not affected by the
temperature of their surroundings, e.g. Birds, Humans. Cold blooded animals change their body temperature with the change in the temperature of their surroundings, e.g. Fish, reptiles.

Mammals are regarded as the most advanced animal because they are the most recently evolved vertebrates who have the most advanced, complex brain, are the only animals that produce milk for their young ones and give birth to babies.

The most notable characteristic of birds which is not found in any other group of animals is the presence of feathers. They are the only animals on earth which have a backbone as well as feathers which cover their entire body.
Also, their skeleton is light as their bones have air cavities and are hollow. They also have beaks with no teeth.

Annelids are invertebrates which include segmented worms. They are found in moist soil and pond water. They have a soft, cylindrical and bilaterally symmetrical body. Their body surface is marked into ring-like compartments called segments which help in movement. They have a special organ of excretion called nephridia. Examples: Leech and earthworm.

The bones of birds have large air cavities (are hollow) and hence are light. This enables them to fly. On the other hand,
bones of other vertebrates are dense and solid and form a heavy skeleton.

Warm-blooded :
a. The temperature of the body of warm-blooded animals remains constant and does not change with the temperature of their surroundings.
b. Examples: Birds, humans, dogs, etc.
cold-blooded animals:
a. The temperature of the body of cold-blooded animals changes with the temperature of their surroudings
b. Examples : reptiles, fish, frogs, etc.

Radially symmertical :
a. It is a body that can be divided vertically into two equal halves along any plane passing through the central point.
b. Examples: Starfish, jellyfish, Hydra, corals, etc.
BodyBilaterally symmetrical :
a. It is a body that can be divided into two equal halves only through one plane.
b. Examples: Tapeworm, insects, lizard, humans, etc.

Aves :
a. Their body is covered with feathers.
b. Forelimbs are modified into wings to fly.
Mammals :
a. They have hair on their body.
b. Forelimbs exist as hand, paw or hooves.

Flatworms :
a. They are also called as Platyhelminthes.
b. They have flat ribbon like bodies.
Roundworms :
a. They are also called as Nemathelminthes.
b. They have cylindrical bodies.