Observe the illustration and answer the following questions. Name the cells (A) and (B).

Photoreceptors can be characterised as specialized cells that are found in the retina of the eye. The receptors of the eyes are extremely specialized neuroepithelial cells. There are two types of photoreceptors present in the eyes of the human. These are rod and cone cells. In the given diagram A represents rod cells and B represents cone cells.

Observe the illustration and answer the following questions. Explain the role of these cells in making vision possible.

Photoreceptors can be characterised as specialized cells that are found in the retina of the eye. The receptors of the eyes are extremely specialized neuroepithelial cells. There are two types of photoreceptors present in the eyes of the human. These are rod and cone cells. Cone cells help in colour vision. When light falls on cone cells, the photopsin in them dissociates into retinal and opsin. Rod cells help in dim light or low light vision. When light falls on rod cells, the pigment rhodopsin in them dissociates into retinal and opsin. This chemical change creates impulses and sends signals to the brain for the processing of images.

Observe the given steps related to the experience of taste and arrange them properly. Impulses reach the brain through the nerves. The taste detecting chemoreceptors are stimulated. The substances reach the taste buds through saliva. Substances responsible for taste dissolves in saliva. Forms the experience of taste. Impulses form in the chemical receptors.

Taste can be characterised as a physiological process by which we can know the nature of the food. At first, we intake the food and the foods are broken into pieces by teeth and lubricated by saliva. The tongue facilitates the process of mixing food with saliva. The food particles are sensed by the taste buds. Then the chemoreceptors get stimulated and the impulses for the taste are carried by the glossopharyngeal nerve. This nerve carries the impulse to the brain. After the processing of impulses, the individual can experience the taste of the food. The steps are arranged and given below: Substances responsible for taste dissolve in saliva. The substance reaches the taste buds through saliva. The taste detecting chemoreceptors are stimulated. Impulses form in the chemical receptors. Impulses reach the brain through the nerves. Forms the experience of taste.

Redraw the picture given below. Identify the name indicated and label the parts The part of Retina where plenty of photoreceptors are seen.

Fovea centralis can be characterised as a small hole in the centre of the macula lutea. In the macula, the fovea centralis contains only cone cells. Macula means ‘spot’ and ‘lutea’ means yellow. Hence, it is also called a yellow spot. This is the part of retina where maximum photoreceptors are present. It is a highly pigmented and sensitive area on the centre of the retina. The yellow colour of macula lutea is due to the presence of a yellow pigment known as macular pigment.

Observe the illustration and answer the following questions. How impulses are generated in these cells when light rays fall on it?

Photoreceptors can be characterised as specialized cells that are found in the retina of the eye. The receptors of the eyes are extremely specialized neuroepithelial cells. There are two types of photoreceptors present in the eyes of the human. These are rod and cone cells. Cone cells help in colour vision. When light falls on cone cells, the photopsin in them dissociates into retinal and opsin. Rod cells help in dim light or low light vision. When light falls on rod cells, the pigment rhodopsin in them dissociates into retinal and opsin. This chemical change creates impulses and sends signals to the brain through the optic nerve for the processing of images.

Analyse the given symptoms and identify the disease. Low metabolic rate Hypertension Inflammation in tissues

Myxoedema occurs due to a deficiency of thyroxine in adults. The person has a low metabolic rate, low body temperature, reduced heart rate, pulse rate, hypertension, inflammation in tissues, and lower cardiac output. The given symptoms indicate the myxoedema condition in the body of an individual.

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What is skin structure and function?

Important Questions on Control and Coordination

EASY

Science>Biology>Control and Coordination>Introduction to Control and Coordination

Acharya Jagadish Chandra Bose proved the property of _____ by sending electrical impulse in Mimosa and Desmodium plant. (stimulation of leaf movement/ stimulation of stem movement)