Define the Following: Blind Spot - Biology

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One Line Answer

Define the following:
Blind spot

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Solution

Blind spot - It is the region of no image formation because of lack of cone cells.

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Chapter 9: Nervous System - Exercise 2 [Page 116]

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Frank ICSE Class 10 Biology
Chapter 9 Nervous System
Exercise 2 | Q 3.07 | Page 116

RELATED QUESTIONS

Draw labelled diagrams of the following: Eye


Write short notes on the following: Retina 


Answer briefly:

How do you perceive the colour of an object?


How does the eye regulate the amount of light that falls on the retina?


How does the eye regulate the amount of light that falls on the retina?


Differentiate between: Rods and cones


The region of the vertebrate eye, where the optic nerve passes out of the retina, is called the

(a) fovea

(b) iris

(c) blind spot

(d) optic chaisma


Distinguish between: aqueous humor and vitreous humor


Distinguish between: blind spot and yellow spot


Myopia is an example of ______.


Fill in the blanks in the following.

The size of the pupil becomes ________ when you see in dim light.


Fill in the blanks in the following.

Night birds have _________ cones than rods in their eyes.

 


Draw a labelled sketch of the human eye.


With the help of ciliary muscles the human eye can change its curvature and thus alter the focal length of its lens. State the changes that occur in the curvature and focal length of the eye lens while viewing (a) a distance object, (b) nearby objects.


Describe the anatomy of the human eye.


Explain the mechanism of vision.


Draw a neat and labelled diagram of the structure of the human eye


Match the following:

Column I Column II
(i) Myopia (a) Converging power of eye lens becomes low
(ii) Hypermetropia (b) Converging power of eye lens remains the same
  (c) Converging power of eye lens becomes high

Why does it take some time to see objects in a dim room when you enter the room from bright sunshine outside? 


A person walking in a dark corridor enters into a brightly lit room: 

 State the effect on the pupil of the eye. 


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The descriptions of five kinds of images are given below:
(a) diminished and virtual
(b) enlarged and real
(c) enlarged and erect
(d) real and inverted
(e) virtual and the same size
Which one of these describes the image formed:
(i) on the retina of the eye?
(ii) by a magnifying glass?
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A man driving a car can read a distant road sign clearly but finds difficulty in reading the odometer on the dashboard of the car. Which of the following statement is correct about this man?
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(d) The far point of his eyes has come closer to him.


The animals of prey have:
(a) two eyes at the front
(b) two eyes at the back
(c) two eyes on the sides
(d) one eye at the front and one on the side


Name the following:

The part of the eye responsible for its shape.


Differentiate between members of the following pair with reference to what is asked in bracket.

Rod and cone cells (pigment contained)


Mention if the following statement is true (T) or false (F) Give reason.

Ciliary muscles regulate the size of the pupil


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Sometimes you remember a vivid picture of a dream you saw. What is the role of your eyes in this experience?


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With reference to the functioning of the eye, answer the question that follow:

Name the cells of the retina and its respective pigments which get activated in the light.


Give scientific reason:
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Give scientific reason:

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What is the function of iris and the muscles connected to the lens in human eye?


Define the following:
Yellow spot


Choose the correct answer.
Aperture controlling passage to light into the eye is ___________


Choose the correct answer : 
The rods and cones of a vertebrate retina function is to _________


Sketch and label V.S. of a human eye.


Answer the following question.
Trace the sequence of events Whichoccur when a bright light is focused on your eyes.


Differentiate between:

Retina and Choroid.


Name the following:
The pigmented circular area seen in the eye.


Name the following:
 The innermost layer of the eye


Name the following:
Fluid present in the posterior chamber of the eye.


Name the following:
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Give Technical Term:
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Give Technical Term:
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Long answer question

Draw the neat labelled diagram of the Sectional view of the human eye.


For the normal human eye, the near point is at ___________ cm.


Draw a scientifically correct labelled diagram of a human eye and answer the questions based on it:

  1. Name the type of lens in the human eye.
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  3. State the nature of the image formed of the object on the screen inside the eye.

A small hole of changing diameter at the centre of Iris is called _______.


For a normal human eye the near point is at _______.


In a relaxed state, the focal length of healthy eyes is _______.


Write the name.

The part of human eye that transmits electrical signals to the brain.


Write the name.

The ability of lens to adjust the focal length as per need is


Write the name.

The fleshy screen behind cornea.


Write the name.

The screen with light sensitive cells in human eye.


The image of the object in the human eye is formed on the cross screen.


The image of an object at an infinite distance is obtained in a real and erect form through a convex magnifying glass.


Vision defect that increases distance between the lens of the eye and retina of the eye is termed as myopia.


Write an Explanation.

Farthest distance of distinct vision


Write an Explanation.

Power of accommodation


Write scientific reason.

The movie cannot be enjoyed if seat of a viewer is too close to the screen in the cinema.


The following figure show the change in the shape of the lens while seeing distant and nearby objects. Complete the figures by correctly labelling the diagram.


The following figure show the change in the shape of the lens while seeing distant and nearby objects. Complete the figures by correctly labelling the diagram.


Complete the paragraph by choosing the right options given below.

(minimum, near point, 25 cm, farthest, farthest distance, far point)

The _______ distance of an object from a normal eye, at which it is clearly visible without stress on the eye, is called the minimum distance of distinct vision. The position of the object at this distance is called the _______ of the eye, for a normal human eye, the near point is at _______. The _______ distance of an object from a human eye, at which it is clearly visible without stress on the eye is called _______ of distinct vision. The position of the object at this distance is called the _______ of the eye.


______ is tough and thick white sheath that protects the inner parts of the eye.


______ is the structural and functional unit of living organisms.


The larynx has fold of tissue which vibrate with the passage of air to produce sound.


Why the human eye is compared with camera?


Draw the struture of human eye and label its parts.


Shylesh is a school-going kid studying standard VIII. He is crazy about playing video games on mobile phones. After a couple of months, his eyes turned red and he felt severe pain in his eyes. His science teacher enquired about this and advised his parents to take him to an eye doctor.

  1. How does excessive usage of mobile phone affect our eyes?
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In a myopic eye, the image of the object is formed


At noon the sun appears white as


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(A) (B)  (C) (D)

Which of the following statements is correct regarding rods and cones in the human eye?


In the figure of the human eye, the cornea is represented by the letter


Name the part of the eye which gives colour to the eyes.


Boojho while waving his hand very fast in front of his eyes, observes that his fingers appear blurred. What could be the reason for it?


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Write down the names of parts of the eye in the blank spaces shown in the figure.


Match the following

1. Conjunctiva a. Coloured part of eye
2. Cornea b. Photosensitive layer
3. Iris c. Refraction
4. Retina d. Protection

What is ‘white of the eye’?


Describe the parts in the external structure of the eye.


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Select the option with incorrect identification:


Which cells of the retina enable us to see coloured objects around us?


The innermost layer of human eye is ______.


Match the following:

Column - I Column - II
1. Retina a) Path way of light
2. Pupil b) Far point comes closer
3. Ciliary muscles c) near point moves away
4. Myopia d) Screen of the eye
5. Hypermetropia e) Power of accommodation

Match the following:

Column - I Column - II
1. Retina a. Path way of light
2. Pupil b. Far point comes closer
3. Ciliary muscles c. near point moves away
4. Myopia d. Screen of the eye
5. Hypermetropia e. Power of accommodation

Match the following:

Column - I Column - II
1

Retina 

a Pathway of light
2 Pupil b

Far point comes closer

3 Ciliary muscles c

near point moves away

4 Myopia d Screen of the eye
5 Hypermetropia f Power of accommodation

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What is aqueous humor?


With reference to human eye, answer the following question.

What is blind spot?


With neat, labeled diagram describe the structure of retina of eye.


Match the following:

Column - I Column - II
1. Retina a. Pathway of light
2. Pupil b. Far point comes closer
3. Ciliary muscles c. near point moves away
4. Myopia d. Screen of the eye
5. Hypermetropia f. Power of accommodation

Explain the role of the part of human eye responsible for power of accommodation of human eye. 


Match the following:

  Column - I   Column - II
1 Retina a  pathway of light
2 Pupil b

far point comes closer

3 Ciliary muscles c

near point moves away

4 Myopia d screen of the eye
5 Hypermetropia e power of accommodation

Column I Column II
1 Retina a Path way of light
2 Pupil b Far point comes closer
3 Ciliary muscles c near point moves away
4 Myopia d Screen of the eye
5 Hypermetropia e Power of accomodation

Match the following:

Column - I Column - II
1. Retina a. Path way of light
2. Pupil b. Far point comes closer
3. Ciliary muscles c. near point moves away
4. Myopia d. Screen of the eye
5. Hypermetropia e. Power of accommodation

Match the following:

Column - I Column - II
1. Retina a. Path way of light
2. Pupil b. Far point comes closer
3. Ciliary muscles c. near point moves away
4. Myopia d. Screen of the eye
5. Hypermetropia e. Power of accommodation

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