Nervous System of Hydra

Hydra is a small aquatic animal. It is found in fresh water ponds, rivers and lakes. It is predatory animal. Hydra is a simple multicellular animal and does not possess a brain. Hydra has a tubular body up to 10 mm long. Its mouth is surrounded by many thin, mobile...

Neuron

Neuron – Unit of Nervous System The nervous system of animals consists of a network of specialized cells called neurons or nerve cells. Function of neuron or nerve cells is to carry information from receptors to brain and then from brain to effectors in the form...

Human Nervous System

The nervous system of human beings consists of brain, spinal cord and nerves. Brain The brain is the anterior part of the central nervous system. It is situated within the hard bones of the skull. It is wrapped in three separate membranes called meninges. The space...

Receptors and Effectors

       Animals control and coordinate their activities with the help of nervous system and endocrine system. The nervous system consists of a group of organs which control and coordinate the activities of the various parts of the body in response to changes in...

Photoperiodism

The affect of duration of light (or photoperiods) on the growth and development of plants, especially flowering and seed germination is called photoperiodism. For example, flowering of tobacco plants can be done in summer by decreasing the light hours. The chemical...

Plant Movements

Movement may be defined as the change in position of an organism with respect to its surrounding. Although all the plants are fixed at a place, yet they show movements. In plants the movements are shown by their parts in the form of growth. These movements are caused...