Give appropriate biological/ technical terms for the following: The sensory organ in Cochlea.

The whole inner ear or the cochlea, responsible for hearing perception. The sense organ in cochlea includes the organ of Corti. Along with this the inner ear endo- and perilymph is also responsible for hearing. The complex afferent and efferent innervation of the hair cells respond to further fine processing of the hearing stimulus.

Give appropriate biological/ technical terms for the following: Structure which helps in the adjustment of the size of the pupil.

The coloured circular structure concentrically surrounding the centre of the eye is called iris. The amount of light entering the eye, is controlled by the size of the pupil. It is adjusted by the iris's dilator and sphincter muscles present in the iris.

Give the biological reasons for the following statement: We cannot distinguish colours in dim light.

Cells sensitive to light cover the inner eye. Rods and cones are the two types of photoreceptor cells present in human eye. Pigments vary in the cones making different cones sensitive to the varying wavelengths of light. Rods are abundant in the retina and are sensitive to dim light. Example: we cannot distinguish colours in moonlight due to the fact moonlight is not able to stimulate the cone cells and the rod cells respond to dim light. Hence, we can see the colours in dim light.

Name the following: The part of the brain which is concerned with memory.

Brain is part of the central nervous system. The cerebrum the part of the forebrain which is concerned with memory, and hippocampus is a complex brain structure embedded deep into temporal lobe also concerned with memory. It also plays a key role in intelligence, consciousness, will power and voluntary actions such as walking, eating, jumping, etc.

Given below are sets of five terms each. Rewrite the terms in correct order in a logical sequence beginning with the first word that is underlined: Conjunctiva , Yellow spot, Pupil, Vitreous Humour, Aqueous Humour.

The eye has three main layers. They are the sclerotic layer or sclera, choroid layer and retina. The outermost thick, tough, fibrous, non-elastic and white coloured layer is the sclera. The sclera bulges and forms the cornea. The end of the sclera connects to the optic nerve. The second layer is the choroid layer. This layer is black and contains a lot of blood vessels. It encloses the eye except for the part of the pupil. The part is formed by the choroid layer around the pupil is the iris. Conjunctiva is a jelly-like layer which covering the inner white parts of the eye. Radial and circular muscles are present in the iris. The biconvex lens is present ultimately behind the pupil, attached to the ciliary muscles and suspensory ligaments. The lens divides the inner space of the eyeball into an aqueous chamber and a vitreous chamber. The area of no vision, called the yellow spot is present in the retina. C o n j u n c t i v a → A q u e o u s H u m o u r → P u p i l → V i t r e o u s H u m o u r → Y e l l o w s p o t

Given below are sets of five terms each. Rewrite the terms in correct order in a logical sequence beginning with the first word that is underlined: Stimulus , Response, Receptor, Effector, Spinal cord

A reflex action is a process for the body to automatically and immediately respond to a stimulus to reduce any further damage to the body. It follows this common sequence and does not involve the brain: S t i m u l u s → R e c e p t o r → S p i n a l c o r d → E f f e c t o r → R e s p o n s e The nerve pathway supported by a reflex action is called a reflex arc. For example, a simple reflex arc occurs if we accidentally touch something hot. A receptor in the skin detects a stimulus (the temperature change). The sensory neurone sends impulses to the relay neurone. The motor neurone sends impulses to the effector. Effector produces a response (muscle contracts to move the hand away).