CBSE Class 11 Biology NCERT Solutions: Chapter 21, Neural Control and Coordination
In order to be good at a subject, the best way is to practice the different types of problems based on conceptual topics explained in that subject. For this, NCERT books are considered to be the best source as these books offer a variety of questions/problems to practice.
The questions given in NCERT textbooks at the end of each chapter not only help for understanding the concepts in a better way but are also important from the examination point of view. Hence, we suggest students to read the NCERT books thoroughly and solve the questions given at the end of each chapter.
Here we are providing the NCERT solutions for class 11 Biology chapter - Neural Control and Coordination. These solutions are explained by the subject experts and will help students find the right approach to solve the Biology NCERT questions.
Some of the questions and their solutions from NCERT Solutions for Class 11: Neural Control and Coordination, are as follows:
Q. Answer briefly:
(a) How do you perceive the colour of an object?
(b) Which part of our body helps us in maintaining the body balance?
(c) How does the eye regulate the amount of light that falls on the retina?
Ans. (a) Photoreceptors are cells that are sensitive to light. They are of two types – rods and cones. These are present in the retina. Cones help in distinguishing colours. There are three types of cone cells – those responding to green light, those responding to blue light, and those responding to red light. These cells are stimulated by different lights, from different sources. The combinations of the signals generated help us see the different colours.
(b) Vestibular apparatus is located in the internal ear, above the cochlea and helps in maintaining body balance. Crista and macula are the sensory spots of the vestibular apparatus controlling dynamic equilibrium.
(c) Pupil is the small aperture in the iris that regulates the amount of light entering the eye. Cornea, aqueous humour, lens, and vitreous humour act together and refract light rays, focussing them onto the photoreceptor cells of the retina.
Q. Explain the following:
a) Mechanism of generation of light-induced impulse in the retina.
b) Mechanism through which a sound produces a nerve impulse in the inner ear.
Ans. a) Retina is the innermost layer of the eye. It contains three layers of cells – inner ganglion cells, middle bipolar cells, and outermost photoreceptor cells. Photoreceptor cells are composed of a protein called opsin and an aldehyde of vitamin A calledretinal. When light rays are focused on the retina through the cornea, retinal gets dissociated from opsin. As a result, the structure of opsin gets changed. This in turn causes the permeability of the membrane to change, thereby generating a potential difference in the cells. Consequently, an action potential is generated in the ganglion cells and is transmitted to the visual cortex of the brain via the optic nerves. In the cortex region of the brain, the impulses are analysed and the image is formed on the retina.
b) The pinna of the external ear collects the sound waves and directs them to the tympanic membrane (ear drum) via the external auditory canal. The ear drum then vibrates the sound waves and conducts them to the internal ear through the ear ossicles. The ear ossicles increase the intensity of the sound waves. These vibrating sound waves are conducted through the oval window to the fluid in the cochlea. Consequently, a movement is created in the lymph. This movement produces vibrations in the basilar membrane, which in turn stimulate the auditory hair cells. These cells generate a nerve impulse, conducting it to the auditory cortex of the brain via afferent fibres. The auditory cortex region interprets the nerve impulse and sound is recognised.
Q. The region of the vertebrate eye, where the optic nerve passes out of the retina, is called the
(c) Blind spot
(d) Optic chaisma Answer
Ans. (c) Blind spot
Blind spot is the part where the optic nerve passes out of the retina. Photoreceptors are absent from this region.
Get the complete the NCERT solutions for Class 11: Neural Control and Coordination, from the following link:
Students may download the NCERT solutions for Class 11 Biology chapter- Neural Control and Coordination, in the form of PDF.
Class 11 Biology NCERT Chapter: Neural Control and Coordination
In order to get a crisp of the concepts and theories explained in Class 11 Biology, NCERT book is considered the best source. Here, we are providing the CBSE Class 11 Biology NCERT chapter- Neural Control and Coordination. Students are advised to thoroughly read this chapter to grasp all the concepts as this will help you understand the problem discussed in a question and then come with an appropriate answer.
Main topics discussed in Class 11 Biology chapter: Neural Control and Coordination are:
- Neural system
- Human neural system
- Neuron as structural and functional unit of neural system
- Generation and conduction of nerve impulse
- Transmission of impulses
- Neural system
- Reflex action and reflex arc
- Sensory reception and processing
Find below the link to download the complete Chapter:
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