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 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.

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 refracts light rays into the eye.

The human eyes play an essential role in the formation and processing of the image in the brain of the human. This sensory organ is composed of different parts. The transparent part in front of the sclera is called the cornea. The cornea refracts rays into the eyes.

Redraw the picture given below. Identify the name indicated and label the parts The part that adjusts its size as the intensity of light varies.

The human eyes play an essential role in the formation and processing of the image in the brain of the human. This sensory organ is composed of different parts. The pupil can be characterised as a small opening in the iris. The pupil adjusts its size according to the intensity of the light. The pupil’s function is to adjust the amount of light entering the eye.

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.

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EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR BIOLOGY>Chapter 2 - Windows of Knowledge>Kerala Board-2019

Embibe Experts Solutions for Chapter: Windows of Knowledge, Exercise 1: Kerala Board-2019

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Embibe Experts Biology Solutions for Exercise - Embibe Experts Solutions for Chapter: Windows of Knowledge, Exercise 1: Kerala Board-2019

Attempt the free practice questions on Chapter 2: Windows of Knowledge, Exercise 1: Kerala Board-2019 with hints and solutions to strengthen your understanding. EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR BIOLOGY solutions are prepared by Experienced Embibe Experts.