CBSE Class 11 Biology Neural Control And Coordination Enrichment Worksheet Set 01

Fill in the following blanks with suitable words :

(a) The two examples of effectors are .................and .....................
Answer : muscle; glands

(b) Our..................system allows us to react to our surroundings. Information from receptors passes along.................neurons to our brain. Our brain sends impulses along...........neurons to our muscles.
Answer : nervous ; sensory ; motor

(c) A neuron which carries an impulse to the brain is called a .................... neuron.
Answer : sensory

(d) The neuron which carries a message for action to a muscle or gland is known as a.................... neuron.
Answer : motor

Important Questions for NCERT Class 11 Biology Neural Control and Coordination

Ques. Which part of the human ear plays no role in hearing as such but is otherwise very much required?
(a) Eustachian tube
(b) Organ of corti
(c) Vestibular apparatus
(d) Ear ossicles 

Answer : C

Ques. Select the answer with correct matching of the structure, its location and function.
    Structure                   Location                              Function
(a) Eustachian tube       Anterior part of              Equalizes airpressure on
                                   internal ear                      either sides of tympanic membrane
(b) Cerebellum              Midbrain                       Controls respiration and gastric secretions
(c) Hypothal -amus        Forebrain                     Controls body temperature, urge for eating
                                                                          and drinking
(d) Blind spot             Near the place where      Rods and cones are present
                                 optic nerve leaves            butinactive here                                                 
                                 the eye

Answer : C

Ques. Which one of the following pairs of structures is correctly matched with their corrected description?
      Structures                            Description
(a) Tibia and fibula              Both form parts of knee joint
(b) Cartilage and cornea      No blood supply but do require oxygen for respiratory need
(c) Shoulder joint and          Ball and socket type of joint
      elbow joint
(d) Premolars and molars      20 in all and 3 rooted

Answer : B

Ques. Cornea transplant in humans is almost never rejected. This is because
(a) it is composed of enucleated cells
(b) it is a non-living layer
(c) its cells are least penetrable by bacteria
(d) it has no blood supply.

Answer : B

Ques. Bowman’s glands are located in the
(a) anterior pituitary
(b) female reproductive system of cockroach
(c) olfactory epithelium of our nose
(d) proximal end of uriniferous tubules. 

Answer : C

Ques. Bowman’s glands are found in
(a) juxtamedullary nephrons
(b) olfactory epithelium
(c) external auditory canal
(d) cortical nephrons only. 

Answer : B

Ques. When we migrate from dark to light, we fail to see for sometime but after a time visibility becomes normal. It is example of
(a) accomodation
(b) adaptation
(c) mutation
(d) photoperiodism.

Answer : B

Ques. Which of the following statements is the characteristics of human cornea?
(a) It is secreted by conjuctiva and glandular layer.
(b) It is a lacrimal gland which secrete tears.
(c) Blood circulation is absent in cornea.
(d) In old age it becomes the cause of cataract.

Answer : C

Ques. In the chemistry of vision in mammals, the photosensitive substance is called
(a) rhodopsin
(b) melanin
(c) sclerotin
(d) retinol. 

Answer : A

Ques. Light rays entering the eye is controlled by
(a) pupil
(b) iris
(c) cornea
(d) lens. 

Answer : A

Ques. Retina is most sensitive at
(a) optic disc
(b) periphery
(c) macula lutea
(d) fovea centralis.

Answer : D

Ques. Function of iris is to
(a) move lens forward and backward
(b) refract light rays
(c) bring about movements of eye lids
(d) alter the size of pupil. 

Answer : D

Ques. Iris is part of
(a) sclerotic
(b) choroid
(c) choroid and retina
(d) sclerotic and choroid. 

Answer : D

Ques. Sensitive pigmented layer of eye is
(a) cornea
(b) retina
(c) sclerotic
(d) iris.

Answer : B

Ques. Which one of the following is the correct difference between rod cells and cone cells of our retina?
                                   Rod cells Cone                   cells
(a) Overall function     Vision in poor light    Colour vision and detailed vision in
                                                                bright light
(b) Distribution         More concentrated in   Evenly distributed all over retina
                                centre of retina 
(c) Visual acuity               High                       Low
(d) Visual pigment          Iodopsin                Rhodopsin
      contained 

Answer : A

Short Answer Type Questions

Question. (a) What are the various sense organs in our body ?
(b) What is meant by receptors and effectors ? Give two examples of each.
Answer : (a) There are five sense organs in our body. They are the eyes, the ears, the nose, the tongue and the skin.
(b) A receptor is a cell present in the sense organs that are sensitive to specific stimuli.
Example: The eyes have light receptors which can detect light and the ears have sound receptors which can detect sound.

Question. (a) What is spinal cord ? What is its main function ?
(b) Give the functions of medulla.
Answer : (a) The spinal cord is a part of the central nervous system. It is a cylindrical structure enclosed by a bony cage called the vertebral column. It is responsible for spinal reflex actions and the conduction of nerve impulses to and from the brain.
(b) The medulla controls various involuntary actions such as the heartbeat, breathing, blood pressure and peristaltic movements of the alimentary canal.

Question. (a) Name the three types of nerves which constitute the peripheral nervous system.
(b) What is the difference between a reflex action and walking ?
(c) How do we detect the smell of an incense stick (agarbatti) ?
Answer : (a) The three types of nerves which make up the peripheral nervous system are the spinal nerves, the cranial nerves and the visceral nerves.

(b) Reflex action Walking
A reflex action is an involuntary action that is a rapid and automatic response to stimuli. Walking is a voluntary action that requires our thinking and is under our control.
(c) When the smell of the incense stick reaches our nose, the olfactory receptors present in our nose detect it and send this information to our brain in the form of electrical signals. The brain interprets this information as the smell of incense stick where it has been already stored

Question. (a) What substances are made by endocrine glands ?
(b) What is the function of receptors and effectors in our body ?
Answer : (a) The endocrine glands secrete chemical substances called hormones.
(b) Receptors receive stimuli from the surrounding environment and send the messages conveyed by them to the spinal cord and the brain as electrical impulses through the sensory nerves. On the other hand, effectors respond to stimuli according to the instructions sent from the nervous system.

Question. (a) Name the hormones secreted by the following endocrine glands :
(i) Thyroid gland (ii) Parathyroid glands (iii) Pancreas (iv) Adrenal glands
(b) Write the functions of testosterone and oestrogen hormones.
Answer : (a)
(i) Thyroxine
(ii) Parathormone
(iii) Insulin
(iv) Adrenaline
(b) The functions of testosterone hormone are to control the development of male sex organs and male characters such as deepening of voice, moustache, beard and other body hair.
The functions of oestrogen hormone are to control the development of female sex organs and female characters such as feminine voice and soft skin.

Question. (a) Write the names of the regions in hindbrain. Give one function of each region.
(b) Name the functions of cerebrum.
Answer : (a) The hindbrain has three regions: the pons, the cerebellum and the medulla.
The pons takes part in regulating the respiration.
The cerebellum helps in maintaining posture and balance of the body.
The medulla controls various involuntary actions such as the heartbeat, breathing, blood pressure and peristaltic movements of the alimentary canal.
(b) The cerebrum is the logical part of the brain. It is the site of our faculties such as learning, reasoning, intelligence, personality and memory. All of our thoughts, sensations, actions and movements are controlled by the cerebrum.

Question. (a) The human brain can be broadly divided into three regions. Name these three regions.
(b) What is cranium ? What is its function ?
Answer : (a) The hindbrain has three regions: the pons, the cerebellum and the medulla.
The pons takes part in regulating the respiration.
The cerebellum helps in maintaining posture and balance of the body.
The medulla controls various involuntary actions such as the heartbeat, breathing, blood pressure and peristaltic movements of the alimentary canal.
(b) The cerebrum is the logical part of the brain. It is the site of our faculties such as learning, reasoning, intelligence, personality and memory. All of our thoughts, sensations, actions and movements are controlled by the cerebrum.

Question. (a) How does chemical coordination take place in human beings ?
(b) Why is the use of iodised salt advisable ?
Answer : (a) Chemical coordination takes place through hormones in human beings. Hormones instruct the brain when to pace up or slow down a particular function.
(b) Iodised salt contains iodine which is essential for making thyroxine by the thyroid gland.

Question. What is the function of insulin hormone ? What type of patients are given insulin injections ?
Answer : The function of insulin hormone is to lower the blood sugar level. Insulin controls the metabolism of sugar. Deficiency of insulin causes diabetes. Diabetic patients are treated by giving injections of insulin.

Question. Compare the nervous system and endocrine system (hormonal system) for control and coordination in humans.
Answer : Nervous system: The nervous system refers to the brain, nerves, spinal cord, ganglia, and other receptor organs that receive and interpret stimuli.
1. Made of neurons.
2. Messages are transmitted in the form of electric impulses.
3. Messages are transmitted along nerve fibers.

Endocrine system: The endocrine system comprises endocrine glands and hormone-producing dispersed tissues/cells distributed throughout our bodies.
1. Made of secretory cells called glands.
2. Messages are transmitted in the form of chemicals called hormones.
3. Messages are transmitted through the bloodstream

Question. State the functions of the following hormones :
(a) Thyroxine (b) Adrenaline (c) Growth hormone
Answer : (a) The function of thyroxine hormone is to control the rate of metabolism of carbohydrates, fats and proteins in the body.
(b) The function of adrenaline hormone is to regulate heartbeat, breathing rate, blood pressure and carbohydrate metabolism.
(c) The function of growth hormone is to control the development of bones and muscles.

Question. Write the names of all the major endocrine glands present in the human body. Which of these glands also function as exocrine glands ?
Answer : (a) The five endocrine glands found in the human body are:
Pituitary gland which secretes growth hormone.
Thyroid gland which secretes thyroxine hormone.
Parathyroid gland which secretes parathormone.
Pancreas which secretes insulin.
Adrenal glands which secrete adrenaline.
(b) Hormones reach the target organ through the blood and act on it.
(c) Hypothalamus regulates the secretion of hormones from the pituitary gland.
(d) An increase in the amount of adrenaline in our body increases our heartbeat, breathing rate, blood flow into the muscles and causes the liver to put more stored glucose in our blood. All these actions of adrenaline produce a lot of energy in our body very quickly and enable us to take quick action.
(e) Iodine deficiency in our diet causes goitre. The main symptom of goitre is swelling of the thyroid gland which is present in the neck.

CLASS XI NEURAL CONTROL AND COORDINATION ENRICHMENT WORKSHEET-5

1. Name the chemical released at the synaptic junction.

2. List the structure involved in the protection of brain.

3. Rearrange the following in the correct order of involvement in electrical impulse movement. Synaptic knob, dendrites, cell body, Axon terminal, Axon.

4. Which sensory organ is involved in vertigo (sensation of oneself or objects spinning around)?

5. What is the function ascribed to Eustachian tube?

6. Name the parts of human forebrain indicating their respective functions.

7. Explain the structure of middle and internal ear with the help of diagram.

8. Describe vestibular apparatus.

9. Distinguish between

a. Aqueous humor and vitreous humor

b. Blind spot and yellow spot

10. Give a brief account of mechanism of synaptic transmission.