Tag: human brain and sense organs

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Questions Related to human brain and sense organs

Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

In a similarity with photographic camera, retina acts as

  1. Shutter

  2. Lens

  3. Diaphragm

  4. Film
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
In a photographic camera, image is formed on the film. Similarly, in eye, image is formed on the retina which is the light sensitive surface in the eye. The light rays enter the eye through an aperture called pupil. The eye lens which is biconvex, focus the light rays on the retina and an image is formed. Both the camera and eye have the ability to regulate the amount of light for image formation.
So, the correct answer is 'Film'.
Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

A student has problem in reading as he is unable to contract his ______.

  1. Suspensory ligament

  2. Ciliary muscles

  3. Pupil

  4. Iris
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
A. Suspensory ligaments attach the eye lens with the ciliary body.
B. Ciliary muscles change the shape of eye lens to focus on nearby and distant objects.
C. Pupil is an aperture in eye through which light enters the eye.
D. Iris is pigmented and opaque structure of eye which controls the amount of light entering the eye by changing the size of pupil.
If a student has problem in reading, this means his eye lens is not able to focus on the alphabets and this is due to inability of the ciliary muscles to contract.
So, the correct answer is 'Ciliary muscles'.
Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

Which is not a refractive medium of eye?

  1. Lens

  2. Vitreous humour

  3. Aqueous humour

  4. Pupil
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
A. Lens of eye is a crystalline structure in the eye ball which is held in place by ligaments that are attached to ciliary body. It is biconvex in nature and focus the light rays on the retina.
B. Aqueous humour is a transparent fluid present between cornea and lens.
C. Vitreous humour is a transparent gel present between lens and retina.
D. Pupil is the aperture of eye through rays enter the eye.
Refraction of light occurs when it enters a different medium and its speed gets changed. Pupil is not a refractive medium because it is an aperture or hole through which light is directly passing.
So, the correct answer is 'Pupil'.
Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

Which part of lens in human eye is helpful in adjustment of focal length?

  1. Cornea

  2. Mucus

  3. Ciliary body

  4. Conjunctiva
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ciliary body is the structure in the eye that releases a transparent liquid (called the aqueous humour) within the eye. The ciliary body also contains the ciliary muscle, which changes the shape of the lens when your eyes focus on something. This process is called accommodation.

Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

Photosensitive compound in human eye is made up of

  1. Opsin and Retinal

  2. Opsin and Retinol

  3. Transducin and Retinene

  4. Guanosine and Retinol.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The photosensitive compound present in vision is called rhodopsin, also known as visual purple which consists of a large protein called opsin and retinal. Opsins are a group of light-sensitive proteins found in photoreceptor cells of the retina. Five classical groups of opsins are involved in vision, mediating the conversion of a photon of light into an electrochemical signal, the first step in the visual transduction cascade. Retinal allows certain microorganisms to convert light into metabolic energy. So, the correct answer is option A.

Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

Which part of the eye is grafted in a needy patient from a donated eye?

  1. Conjunctiva

  2. Cornea

  3. Choroid

  4. Ciliary muscles
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

When eye is donated or transplanted only cornea part of the eye is transplanted to the needy person.

The cornea is a contact lens sized, clear piece of tissue in the front of the eye.
So the correct option is 'Cornea'

Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

_________ is a decrease in the response to an ongoing stimulus.

  1. perception

  2. visual accommodation

  3. sensory adaptation

  4. both (b) and (c)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Neural adaptation or sensory adaptation is a change over time in the responsiveness of the sensory system to a constant stimulus. It is usually experienced as a change in the stimulus that is, the responsiveness to constant stimulus is decreased or stop

So, the correct option is 'Sensory adaptation'

Multiple choice biology human brain and sense organs introduction to sense organs eyes and their function the structure and function of the eye

Which of the following gives the correct path for light rays entering the human eye?

  1. Sclera, retina, choroid, lens, cornea

  2. Fovea centralis, pupil, aqueous humour, lens

  3. Cornea, pupil, lens, vitreous humour, retina

  4. Optic nerve, sclera, choroid, retina, humours
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

  1. The first thing light encounters when it enters the eye is the cornea, a protective clear covering over the pupil and iris. The cornea bends the light and begins to form an image.
  2. Light passes from the cornea to the pupil, the dark circle in the centre of the iris, which is the coloured portion of the eye. The pupil regulates the amount of light that will enter the inner eye based on environmental conditions: It dilates, growing bigger to receive more light under dim lighting conditions, and shrinks in response to bright light. This response is quicker in young individuals and tends to slow with increasing age.
  3. From the pupil, light waves travel to the lens of the eye. The lens is a clear, flexible structure that focuses an upside-down image onto the retina. It is flexible so that it can focus on images that are close or far away. Eye injuries, normal variations in the eye and age can distort the lens, making it difficult to focus on nearby or faraway objects -- you see the objects, but details are hazy. Late in life, the lens can also become clouded and form cataracts that make images seem hazy and dim.
  4. The lens focuses light and images on the retina, a layer of light-sensitive cells at the back of the eye. It is made up of two kinds of photoreceptor cells: cones and rods. The cones transmit colour and sharp images. The concentration of cones is low on the sides of the retina and increases as the cones approach the centre of the retina or the macula. The rods are more sensitive to light and are more numerous than cones; They let you see when lighting is dim, although what you see lacks colour and clear details.
  5. Once the retina senses the image, it sends impulses to the optic nerve at the back of the eye. The optic nerve then transmits them to special areas in the brain, which automatically flips the upside-down image so that it becomes upright again. Disease or injury can damage the optic nerve, resulting in varying degrees of blindness.

So, the correct answer is 'Cornea, pupil, lens, vitreous humour retina'.