Hydra and cold blooded animals

Important features of hydra:

Hydra:

• It is coelenterate means its body has two layers.
• It is a fresh water coelenterate only seen by microscope.
• It has a cylindrical body with many thread-like tentacles at its one end which help in capturing the prey.
• Its outer layer bears a number of poison cells which are used in paralyzing the prey.
• It has a mouth in between tentacles which opens in a hollow space called coelenteron which helps in digestion of food.
• The end of its body is opposite to its mouth therefore it attached to some object in water.

Define the term cold blooded?

These are animals which keep their body temperature do not normal. They change their body temperature with their environment. For instance reptiles & cold areas animals get the period of hibernation and come out in summer season.

Describe scientific methods?

• Observation
• Hypothesis
• Deduction
• Experiment
• Result
• Theory
• Law

What is cutaneous respiration?

Gaseous exchange takes place by skin is called cutaneous respiration. It is often found in frog and other small animals it is called cutaneous respiration.

How many parts of the heart?

A heart is a pumping organ and it has three chambers.

These are:

• Right auricle or atrium
• Left auricle or atrium
• Ventricle

Write down the salient features of mammals?

Mammals are named so mammals because they have mammary glands in their skin. They are also vertebrates. Mammary glands are functional and secrete milk in females. These are used to feeding to the babies of mammals. Human beings are also belonging to class of mammals. Their skin is covered with hairs and also consists of sweat glands, scent glands and sebaceous glands. They have both upper and lower jaws in their mouth. They are warm blooded animals. Most of the mammals give birth to their live young ones. Mammals are also divided into three groups:

• Egg laying mammals
• Pouched mammals
• Placental mammals