Lakhmir Singh Manjit Kaur Class 10 Biology 2nd Chapter “Control and Coordination” solution

Lakhmir Singh and Manjit Kaur Biology solution: “Control and Coordination” Chapter 2. Here you get easy solutions of Lakhmir Singh and Manjit Kaur Biology solution Chapter 2. Here we have given Chapter 2 all solution of Class 10. Its help you to complete your homework.

Board – CBSE
Text Book – Biology
Class – 10
Chapter – 02

Lakhmir Singh Manjit Kaur Class 10 Biology 2nd Chapter Solution

Part A

Very Short Answer Type Questions

1.) What is the general name of chemical substances which bring about control and coordination in plants?

ANS-

The general name of chemical substance, which bring about control and coordination in plants is called plant hormones also we called them phytohormones example- auxins,gibberellins.

2.) Which plant hormone is responsible for the wilting and falling of leaves?

ANS-Abscisic acidacid is responsible for the wilting and falling of leaves.

3) Which plant hormone makes a stem (or shoot) bend towards light?

ANS-auxin is the plant hormone which is responsible for bend stem towards light.

4.) Where is the auxin hormone made in a plant stem?

ANS-Auxin hormone is produced in the apex of stem.

5.) What is the scientific name of sensitive plant?

ANS- Mimosa pudica is a sensitive plant which isalso called humble plant.

6.) Name one plant hormone that promotes growth and another plant hormone which inhibits growth.

ANS-Auxin is the plant hormones which promotes growth. It also promoted stem elongation. Abscisicacid inhibits plant growth.

7.) Name one example of the movement of a plant part which is very quick and can be observed easily.

ANS-Thigmonasty is the Movement of the plant part which is very quick and can be observed easily.

8.) Name the type of chemical substances that control the growth in plants.

ANS-Phytohormonesare the chemical substances that control growth in plants. Auxin, gibberellins, cytokinins and abscisic acid are examples of plant hormones.

9) What is the stimulus in: (a) phototropism ? (b) geotroprism ? (c) chemotropism ?

(d) hydrotropism ? (e) thigmotropism ?

ANS-

The stimulus for phototropism is light.

The stimulus for geotropism is gravity.

The stimulus for chemotropism is chemical compounds.

The stimulus for hydrotropism is water.

the stimulus for thigmotropism is Touch.

10.) Give the scientific terms used to represent the following:

(a) Bending of shoot towards light.

(b) Growing of roots towards the earth.

(d) Bending of roots towards water

(e) Winding of tendril around a support.

ANS-

Bending of shoot towards light – phototropism

Growing of roots towards earth – geotropism.

Growing of pollen tube towards ovule –chemotropism

Bending of roots towards water – hydrotropism

Winding of tendril around a support – thigmotropism.

11.) Give on example of the movement of a plant part which is caused by loss of water

(or migration of water).

ANS-Thigmonasty

12.) Give one example each of a plant part:

(a) Which is positively hydrotropic as well as positively geotropic.

(b) Which is positively phototropic but negatively geotropic.

ANS-

a) it is roots

b) it is leaves

13.) Which of the following is growth movement and which is not?

(a) Folding up of leaves of sensitive plant on touching with hand.

(b) Folding up of petal of dandelion flower when light fades.

ANS-

Neither of them are growth movements. They are nastic movements

a) This is a thigmonastic movement so it is not a growth movement

b) This is a photonastic movement also it is a growth movement

14.) Name the plant part:

(a) Which bends in the direction of gravity but away from light?

(b) Which bends towards light but away from the force of gravity?

ANS-(a) Root

(b) Stem

15.) To which direction stimuli do:

(a) rootsrespond?

(b) shoots respond?

ANS-

(a) root responds towards gravity .

(b) shoot respond towards sunlight

Short Answer Type Questions

17.) Plant parts show two types of movements, one dependent on growth and other independent of growth.

Give one example of the movement in plant parts:

(a) Which depends on growth

(b) Which does not depend on growth

ANS-

(a) Bending of stem towards light.

(b) sensitive plant are folds up there leaves after it experiences touch.

18.) What is a plant hormone? Name four plant hormones. State one function of each.

ANS-

Plant hormones are also known as phytohormones they are nothing but signal molecules, produced within plants, which founds in extremely low concentrations.

1) Auxin: It is responsible for cell enlargement (growth of cell) and cell differentiation ( cell reproduce another cell and separate it) in plants. 2) Gibberelins: it promotes growth in fruits.It breaks the dormancy in seeds and buds. 3) Cytokinins: it helps to delay the aging in plants also it responsible for cell division in plants. 4) Abscisic acid: It is responsible for wilting and falling of leaves and helps to closing of stomata.

19.) (a) What does a root do in response to gravity? What is this phenomenon known as?

(b) What does a stem (or shoot) do in response to light? What is this phenomenon known as?

ANS-

(a) Root bends downwards in the direction of gravity is the positive geotropism.

(b)A stem follows the light path, hence it moves in direction of source of light. This phenomenon is called positive phototropism.

20.) (a) What does a stem (or shoot) do in response to gravity? What is this phenomenon known as?

(b) What does a root do in response to light? What is this phenomenon known as?

ANS-

(a) Stem (or shoot) grows upwards which is opposite direction of gravity hence it is Negative geotropism

(b) Root bends away from light; Negative phototropism

They both (root and shoot) have showing movements against stimulus hence here we use negative as a prefix.

21.) (a) What does a Mimosa pudica plant do in response to touch? What is this phenomenon known as?

(b) What happens to the dandelion flower (i) during daytime, and (ii) at night? What is this phenomenon known as?

ANS-

a) If we touch leaf of mimosa plant then it shows shy behaviour by folding its own leaves. Mimosa plant responses towards touch hence its phenomenon is known as thigmonasty.

b) Dandelion flowers behave according to light intensity.

c) When light is bright (morning time)-petals of flowers get open

d) When light intensity is less (at evening)- petals of dandelion flowers get close

22.) (a) What does a plant root do in response to water? What is this phenomenon known as?

(b) What happens to a moonflower (i) during daytime, (ii) at night? What is this phenomenon known as?

ANS-

(a) Roots shows hydrotropism phenomenon because it has its own function to survive plant life by absorbing water from soil for photosynthesis. Hence it grows towards water.

(b) (i) During the daytime –its petalsget close during day time.

(ii) At night time- its petals get opens up.

Above these types of phenomenon is known asphotonasty.

23.) What is a tendril? Name the two types of tendrils. What does a tendril do in response to the touch of a support? What is this phenomenon known as?

ANS-

Tendrils are always positively thigmotropic which is thin thread-like extension observed on stems or leaves of a climbing plant. Tendrils are not easily grown up by its own strength it need support hence it starts grow where ever it get support. Any plants who responses towards touch that shows a special type of phenomenon known as thigmotropism. Generally two types of tendrils are found one is stem tendrils and another one is leaf tendrils.

24.) Name the five types of tropisms. How are tropic movements helpful to plants? Explain with examples.

ANS-

Tropic movement takes place in the presence of stimulus. The different types of stimulus are:

Phototropism: It is the movement of plants which mainly shows in presence of light. For example, shoot bends towards the light.

Geotropism – It is movement of plant part,towards the soil. For example, root grows into soil.

Hydrotropism– It is the movement of a plant part towards the water is nothing but hydrotropism. For example, plant root growing in oil where it feels water.

Chemotropism – It is the movement of plants part which responses in the presence chemical stimulus. For example, growing pollen tube towards ovule.

Thigmotropism – It is a action of plants in response to touch. For e.g. mimosa plant closes its leaves after it experience any type of touch.

25.) Define chemotropism. Give one example of chemotropism. State whether this example is of positive chemotropism or negative chemotropism.

ANS- The growth of a plant part observed in the presence chemical stimulus is known as chemotropism. For example- When sugary substance gets secreted, that time pollen tube shows movement towards ovule is the example of positive chemotropism. In this case sugary chemical substance is act as stimulus.

26.) Distinguish between tropic movements and nastic movements in plants. Give examples to illustrate your answer.

ANS-

Tropic movements	Nastic movements
1. it is the growth movement of plant part showing at which the directions of stimulus determine. This type of response towards stimulus called tropism.	1. Nastic movement’s means non directional movement happened in plant parts which responses towards external stimulus. But, its response is not determined by the direction of stimulus from which it experiences.
2. Tropical movements are directional movement.	2. Nastic movement is not directional movement
3. Tropic movements are happened in all parts of a plant. 4. For example, movement of shoot towards the light	3. Nastic movements are found In flat organs like leaves and petals of flowers. 4. For example-the closing and opening of petals in moonflower plants with respect to bright light and dark light.

27.) (a) What is meant by nastic movements in plants? Give one example of nastic movements in plants.

(b) What is the difference between photonasty and thigmonasty?

ANS-

a)Plant parts shows movement where it responses towards external stimulus.But, its response is not determined by the direction of stimulus Example: Dandelion flowers opens up its petals in the presence of bright light (daytime) but it get close its petals at night time.

Photonasty

Thigmonasty

1. It is non-directional movement where the plant part get stimulates in the presence of light.

2. In photonasty light act as stimulus.

3. Dandelion flowers shows opening and closing of petals which responses with the light intensity.

1. It is non-directional movement of plant parts which shows movement after it experiences touch.

2. Inthigmonasty touch is the stimulus.

3. Mimosa pudica folds up its leaves by sensing touch.

28.) A potted plant is kept horizontally for a considerable time. The three positions of the parts A and B of the potted plant are shown in the following figures:

(a) Which figure shows the correct position taken by the parts A and B of the plant?

(b) What type of phenomenon is exhibited by the figure chosen in (a) above?

ANS-

(b) Geotropism

29.) Name the plant hormones which are responsible for the following effects:

(a) Falling of leaves (b) opening of stomata

(c) Bending of stem towards light (d) closing of stomata

ANS-

(a) Abscisic acid

(b) Cytokinins

(d) Abscisic acid

30.) Name the plant organs which are:

(a) Positively phototropic (b) positively geotropic

(c) Negatively geotropic (d) positively hydrotropic

ANS-

(a) Stem

(b) Roots

(d) Roots

31.) Why is the folding up of the leaves of a sensitive plant on touching with a finger not a tropism?

ANS- The folding up of leaves in a sensitive plant when we touch them is the example of thigmonastic movement and it is non-directional movement where touch is the stimulus. thigmonastic movement. Tropism is a directional movement and it shows response only such directions where they get stimulus. Hence folding up leaves of sensitive plants on touching it is not tropism.

32.) Why is the closing of a dandelion flower at dusk (when it gets dark) not a tropism?

ANS-

The closing of a dandelion flower is always shows movement with respect to intensity of light. It is not a tropismmovement. On the contrary we sayit is nastic movement which non directional in nature. In this example petals of dandelion flowers responses for light but this response, is not in the direction of stimulus that means petals of dandelion flowers opens in bright light and get close at night.

Long Answer Type Questions

33.) (a) What is meant by ‘tropism’ (or tropic movements) ? Explain with an example.

(b) What are the different types of tropisms? Define each type of tropism.

Write the name of the stimulus in each case.

(c) How do tropisms differ from nasties (or nastic movements)?

ANS-

a)Tropism is the growth movement of plant part, showing at which the directions of stimulus determine. This type of response towards stimulus called tropism.Tropical movements are directional movement.Example – bending of plant stem towards sunlight is agood example of positive phototropism.

(b) Different types of tropisms (i) Phototropism – plant part shows response towards light is called phototropism. (ii) Geotropism – plant part shows response towards gravity is called geotropism. (iii) Chemotropism – The movement of a plant part in response towards chemical stimulus is called chemotropism. (iv) Hydrotropism – The plant parts responses in presence of water is hydrotropism. (v) Thigmotropism -by touching plant part it gives a response that type of stimulus is called thigmotropism. Its stimulus is touch.

(c) Tropisms: it is the growth movement, of plant part showing at which the directions of stimulus determine. This type of response towards stimulus is called tropism.Tropical movements are directional movement.Whereasnastic movement shown in response to an external stimulus in which the direction of response is not determined by the direction of stimulus.Means it is non-directional in nature.Above These main differences found in both types of movements.

34.) (a) Define phototropism. Give one example of phototropism.

(b) How does phototropism occur in a plant stem (or shoot)? Explain with the help of labeled diagrams.

(c) What is meant by positive phototropism and negative phototropism? Give examples of each type.

ANS-

(a) Phototropism-Phototropism means movement of plant part responses towards light.It only happens in presence of light. Example –shoot or stem bendand grows towards the light is the best example ofphototropism.

(b) Phototropism means any plant part shows movement or it responses towards light .growth of shoot or stem towards is the best example of phototropism. When stem grows at that time it get bends towards light. Main reason of this bending is auxin hormone promotes its growth. Auxin hormone prefers to stay at shady area of stem.when sunlight falls on stem that time it get concentrated to opposite side of light or shady area and this part of stem grows longer. Due to this uneven secreation of auxin hormone plant stem bends towards light.

(c) The movement or growth of plant parts shows in the presence of light stimulus is known as positive phototropism Example- Stemsor shoot of plant grows upwards(towards sunlight) is the positive phototropism, whereas the movement or growth of plant parts like roots, grows away from light is known as negative phototropism.

35.) (a) Define geotropism. Give one example of geotropism.

(b) What is meant by positive geotropism and negative geotropism? Give one example if each type. Draw a labeled diagram to illustrate your answer indicating the plant part which shows positive geotropism and the plant part which shows negative geotropism.

(c) Name one plant part which exhibits positive thigmotropism.

ANS-

(a) Geotropism means plant part responsestowards gravity. Here the stimulus is gravity.Example-root of plants grows down in earth with the force of gravity hence this movement of roots is shows geotropism.

(b) POSITIVE GEOTROPISMmeans plant parts growing downward in the soil with the force ofgravity. Example-in below diagram (c) root grows downward direction by showing positive phototropism phenomenon.

NEGATIVE GEOTROPISM means plant parts growing against the force of gravity. Example- in below diagram (c) stem grows upward direction (opposite to gravity) by showing negative phototropism phenomenon.

36.)

(a) How does control and coordination take place in plants? How does it differ from that in animals?

(b) Name five stimuli which act on plants. Name the type of tropism produced by each one of these stimuli.

(c) Define hydrotropism. Give one example of hydrotropism. State whether this example is of positive hydrotropism or negative hydrotropism. Illustrate your answer with the help of labeled diagram.

ANS-

a) Animal shows control and coordination by the help of nervous system and hormones which secreted by special type of glands called endocrine glands.

But, in plants there is no any special type of nervous system and glands. Although it has its own hormones like auxin, gibberellins. These hormones get released when plants experiences an external stimulus like light, touch, water etc. plant hormones develops coordination in plant body after experience stimulus from environment as a result they show growth in their body parts..

(b) (i) Light – Phototropism.

(ii) Gravity – Geotropism.

(iii) Chemical – Chemotropism.

(iv) Water – Hydrotropism.

(v) Touch – Thigmotropism.

The best Example of hydrotropism is shown in below diagram.

In diagram b) root get bent by the side of water get present also, it grows towards water. It means growing root shows hydrotropism or positive hydrotropism (root grows towards water).

37)

(a) What is meant by positive tropism and negative tropism? Explain with examples.

(b) Define thigmotropism. Give one example of thigmotropism.

(c) What is the difference between thigmotropism and thigmonasty? Name one plant which exhibits thigmotropism and one plant which exhibits thigmonasty. What behaviour(or response) of these plants make you think that they exhibit thigmotropism and thigmonasty respectively?

ANS-

(a) Positive tropism-If the movement of plant part is seen towards the stimulus, is known as positive tropism

Example-Roots grows downwardin the soil with the force of gravity is the positive geotropism.

Negative tropism-if the movement of the response is in the opposite direction of stimulus is known as negative tropism.

Example-Stem grows upward direction which is opposite to the force of gravity is negative geotropism.

(b) It is directional movement of plant parts, where the plant parts showsresponses towards touch is known as thigmotropism.

Example-tendril is the plant part which grows with the help of support. That means when it experiences touch it shows movement (in the form of growth)

(c)

Thigmotropism	Thigmonasty
Thigmotropism is directional movement where the plant part responses towards touch.	It is a non-directional movement of plant part where it shows responses towards touch.
Example: tendril grows with the help of support.	Example: Mimosa pudicaplant folds up its leaves after sensing touch.

PART -B

Very Short Answer Type Question

) Name the two systems of control and coordination in higher animals.

ANS- Nervous system and endocrine system.

2.) What are the two parts of the vertebrate nervous system?

ANS-The two parts of vertebrate nervous system are:-

(i) central nervous system – it made up of brain and the spinal cord.

(ii) Peripheral nervous system – it made up of cranial, spinal and visceral nerves.

3 ) If we happen to touch a hot object unknowingly, we immediately pull back our hand. What is this type of action known as?

ANS- After touching a hot object unknowingly, hand gets automatically pulled off back. This type of action is known as a reflex action.

4.) Name the three components of a neuron (or nerve cell).

ANS-A neuron has three main parts: dendrites, an axon, and a cell body or soma.

5.) (a) What are the short fibers of a neuron known as?

(b) What is the long fiber of a neuron known as?

ANS-

(a) Dendrites.

(b) Axon.

6.) Name the most important part of the human brain.

ANS- Cerebrum is the most important part of a human brain.

7.) Which part of the brain maintains posture and balance of the body?

ANS- cerebellum is the brain part which maintains posture and balance the body.

8.) State one function each of cerebellum and pons.

ANS- The pons helps for regulating respiration.

The cerebellum helps to maintain balance and posture of the body.

) Name one hormone made in the human body?

ANS-Endocrine glands

10.) Which are hormones secreted by the pituitary gland?

ANS- The gland is attached to a part of the brain (the hypothalamus) that controls its activity. Also it called growth hormones

11.) What is the name of the system of glands which produces hormones?

ANS-The endocrine system is made up of a gland which produces hormones.

12.) Which gland secretes the growth hormone?

ANS-The pituitary gland secrets growth hormone..

13.) Name the hormone secreted by (a) testes, and (b) ovaries

ANS-The hormone secreted by Testis is Testosterone. The hormones secreted by Ovaries are Estrogen and Progesterone.

14.) What are the scientific names for the following receptors in animals?

(a) Receptors for light (b) receptors for heat (c) receptors for sound

(d) Receptors for smell (e) receptors for taste

ANS- a) Receptors for light (eyes)-Photoreceptors

b) Receptors for heat (skin)-Thermoreceptors

c) Receptors for sound (ear)-Phonoreceptors

d) Receptors for smell (nose)- Olfactory receptors

e) Receptors for taste (tongue)-Gustatory receptors

15.) Name the disease caused by deficiency of insulin hormone in the body.

ANS-Diabetes

16.) Name the disease caused by deficiency of thyroxin hormone in the body.

ANS-Goiter

17.) Which halogen element is necessary for the making of thyroxin hormone by the thyroid gland?

ANS-Iodine

18.) Why are some patients of diabetes treated by giving injections of insulin?

ANS- The peoples who’s suffered from diabetes are treated by giving injections of insulin.

19.) What is the name of in-built ‘arrangement’ in our body which controls the timing and amount of hormones released by various endocrine glands in the body?

ANS- Feedback mechanism.

20.) Name one gland each:

(a) Which acts only as an endocrine gland?

(b) Which acts only as an exocrine gland?

ANS-

(a) Thyroid gland.

(b) Salivary glands.

21.) What part does the diet play in helping us to have a healthy thyroid gland?

ANS-

Iodine is very necessary for proper functioning of thyroid glands. When adequate amount of iodine is not present in our body then thyroxin hormone deficiency get observed.

22.) If sugar is detected in the urine of a person, name the disease he is suffering from.

ANS-Diabetes.

23.) Name two parts of the body which contain receptors of chemical stimuli.

ANS-The nose and the tongue contain receptors of chemical stimuli.

24.) Which part of the eye contains cells which are sensitive to light?

ANS-Retina is the part of the eye which cells are sensitive when light present.

25.) What are the two main communications systems in an animal’s body?

ANS- nervous system and endocrine system is main two communication systems in animal body

26.) Which one term in each of the following includes the other three?

(a) Thyroid, ductless gland, thymus, pituitary, ovary

(b) Adrenalin, insulin, hormone, thyroxin, estrogen

ANS-

(a) Ductless gland

(b) Hormone

27.) Which parts of the body form the central nervous system?

ANS-The central nervous system is made up of the brain and spinal cord.

28.) Give three examples of reflex actions.

ANS-

1.) Coughing

2.) When bright light falls on eyes it gets close up

3.) Pull our hands when we touch hot cup

4.) Sneezing

5.) Reshape our eye size when any object feels far or near to us.

29.) Why do you need iodine in your diet?

ANS- Our body uses iodine to make thyroxin hormone. Hence iodine is very essential in our diet.

30.) State whether coughing is a voluntary action or reflex action.

ANS- Coughing is a reflex action.

Short Answer Type Questions

32.) (a) What are the various sense organs in our body?

(b) What is meant by receptors and effectors? Give two examples of each

ANS-

(a) Eyes, ears, nose, tongue and skin are the five sense organ generally found in our body.

(b) In our body many types of receptors and effectors present. But their functions and existence in our body are different.

Receptor-it is a special type of cells present in the sense organ. They are very sensitive towards particular type of stimulus and also it senses environmental change. Example- phonoreceptors, thermo receptors.

Effectors-it is body part can responses towards stimulus and it get monitored by nervous system. Example-glands, muscles

33.) (a) What is spinal cord? What is its main function?

(b) Give the functions of medulla.

ANS-

(a) Spinal cord is the cylindrical tube like structure which is always present in bundles and it starts from medulla, then get further elongate to down side.

Function-1.) It helps to transfer nerve impulse from lower body to brain.

2.) It works in nerve impulse for reflex action

(b) Medulla-

1.) All involuntary actions controlled by medulla. For example-riding walking, dancing etc.

2.) It also play vital role to control centre for reflexes likecoughing, sneezing, secretion of saliva etc.

34.) (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)?

ANS-

(a) The three types of nerves which made up of peripheral nervous system are: spinal nerves, cranial nerves and visceral nerves.

(b)

Reflex action

Walking

1. reflex action are not controlled by brain

2. Reflex action is comes under involuntary actions and it originated by spinal cord.

3. Reflex action is quick action hence it does not based on thinking.

1. It is voluntary action which is always monitored by our brain.

2. Walking is the action for which we have to think hence it instructed from brain.

(c) In our body there are many receptor takes a stimulus from environment and makes some chemical reaction in our body for further process. When agarbatti burns, that time it produces a nice smells which can detected by olfactory receptor. It is present in our nose. These type of receptors did some chemical reactions and produces chemical impulse which carry by sensory neuron and passes them to cerebrum it has own capacity to sense impulse hence it called sensory area of brain which sense smell of agarbatti.

35) (a) What substances are made by endocrine gland?

(c) What is the function of receptors and effectors in our body?

ANS

(a) Endocrine glands made a chemical substances and secrets them called hormones which mainly responsible for many chemical change happened in our body.

(b) Receptors means object who receives something.in our body there are many receptors present in form of cell with their particular organs. Like photoreceptor (eyes), phonoreceptors( nose) etc..

It receives stimuli from surrounding and transfer that massage to sensory area of the brain through sensory neuron it is its main function.

Effectors is the body organ or gland which receives stmuli.it responds to electrical impulse which get it from nervous system through motor neuron( which always carry massage and give it to concern body part).

36.) (a) Name the hormones secreted by the following endocrine glands:

(i) Thyroid gland (ii) Parathyriod glands (iii) Pancreas (iv) Adrenal glands

(b) Write the functions of testosterone and oestrogen hormones.

ANS-

(i) Thyroxine

(ii) Parathromone

(iii) Insulin

(iv) Adrenaline.

b) Oestrogen is the female sex hormone.

Oestrogen hormone secrets in female body for control development of female sex organ and female secondary sexual character such as narrow voice, development of breast (mammary gland)

Testosterone is the male sex hormone.

Testosterone hormone secrets in male body. It controls the development of male sex organs and male secondary sexual character such as broad throat, deep voice, and beard.

37.) (a) Write the names of the regions in hindbrain. Give one function of each region.

(b) Name the function of cerebrum.

ANS-

(a) Hindbrain has 3 regions:

(i) Pons: 1. It helps in regulating respiration in our body.

(ii) Medulla: 1.it is part of hind brain which controls various involuntary actions (not depends on our will) like heartbeat, breathing etc.

2.) it helps to control reflexes such as coughing, sneezing etc

(iii) Cerebellum: 1. It is helps in coordination for smooth movement accurs in body parts.

2.) it helps to maintain posture and balance body parts.

(b) Function of cerebrum: 1. It is main part of fore brain.

It is main thinking part of forebrain hence it controls thinking and memory reserved in our brain.
it has many sensory areas who receives information from sensory organs.

38.) (a) The human brain can be broadly divided into three regions. Name these three regions.

(b)What is cranium? What is its function?

ANS-

(a) The 3 regions of human brain are (i) Forebrain- it consists of cerebrum (ii) Midbrain-it has no any sub-part (iii) Hindbrain it consists of pons, cerebellum, medulla

(b) Brain is always present in cranium. It is very hard in nature because it made up bones hence it also called bony box. Brain is vital organ of our body hence cranium gives protection to it.

39.) (a) How does chemical coordination take place in human beings?

(b) Why is the use of iodized salt advisable?

ANS-

a) In our body there is two major systems does work for coordination one is nervous system and another one is endocrine system. Many glands is present in the endocrine system which secrets chemical called as hormones. These hormones directly entered in our blood stream. It acts as messenger between nervous system and targeted organ.

b) Iodised salt is full of iodine element. Iodized salt is very necessary to fulfil iodine deficiency in our body. Due, to deficiency person my get suffer from goitre.

40.) What is the function of insulin hormone? What types of patients are given insulin injections?

ANS-

Insulin hormone controls sugar level. if sugar level is uncontrolled by body then the person get suffers from diabetes disease for that reason insulin injection is very necessary to control it.

41.) Compare the nervous system and endocrine system (hormonal system) for control and coordination in humans.

ANS-

Difference between nervous system and endocrine system

Nervous system

Endocrine system

1. It consists of brain, spinal cord, nerves

2. It coordinate various activity done in the body

3. This system generates electrical impulse for coordination which passes through nerve cells.

4. The major parts of this system is spinal cord and brain get connected to the other body parts through millions of nerve system

1. Emdocrine system is consists of endocrine gland and hormones.

2. Endocrine glands produces varius types of chemicals called hormones.

3. Hormones act as messenger between the nerve system and organs

4. It generates chemical signal for coordination

42.( State the functions of the following hormones:

(a) Thyroxin (b) Adrenaline (c) Growth hormone

ANS-

(a) Thyroxin – The function thyroxin hormone is to control the rate of metabolism of carbohydrates, fats and proteins in the body.

(b) Adrenaline – Adrenaline plays major role in the regulation of heart rate, breathing rate, blood pressure as well metabolism of carbohydrate.

43.) Write the names of all major endocrine glands present in the human body. Which of these glands also function as exocrine glands?

ANS-

The major endocrine glands present in the human body are hypothalamus gland, pituitary gland, thyroid gland, parathyroid glands, thymus gland, pancreas, adrenal glands, and testes in males and ovaries in females. But pancreas, testes and ovaries also function as exocrine glands.

) Match the hormones given in column I with their functions given in column II:

Hormones Functions

(i) Thyroxin (a) Causes breasts to develop in females

(ii) Adrenaline (b) Causes the male to start producing sperms

(iii) Insulin (c) Prepares the body for an emergency

(iv) Estrogen (d) Controls the metabolic rate

(v) Testosterone (e) Regulates the amount of sugar in blood

ANS-

(i) d

(ii) c

(iii) e

(iv) a

(v) b

45.) A person walks across a room in barefeet and puts his foot on a drawing pin lying on the floor. He lets out a cry. Explain what happens in his nervous system in bringing about this response.

ANS-

When any person walk with bare feet and pin get hit then sensory cells which present In skin receives sense. This type of sense is always present in the form of impulse which are travelled through sensory neuron and passes to spinal cord. Impulses are nothing but massage which gets instructed already. It comes back to concern muscles through motor neuron. Such ways muscles get massage that pull away feet from pins.

46.) In what ways are puberty and adolescence result of the activity of some glands in the human body?

ANS-at the age 13-14 male gender experiences puberty with sexual secondary characters .testes secrets male hormone called testosterone which is responsible for hormonal change ( sexual) happen in the male body.

At the age of 10-12 female experiences puberty. Ovary is the female gamete who produces ovaries by monthly called menstruation cycle for that change oestrogen is responsible. At the puberty phase many physical as well chemical (hormonal) change occurs in the body.

47.) List thee ways in which neurons are similar to other cells.

ANS-Neurons and other cells have a cell membrane, cytoplasm and a nucleus.

48.) Explain the difference between each of the following parts of terms:

(a) Receptor and effector (b) cerebrum and cerebellum

Receptor- (a)

1.) A receptor is the sets of cell present in a sense organ. Whereas effector is the gland or organs.

2.) The receptors detect stimuli and then it converts in the form of impulse whereas effectors is convert the impulse into action.

3.) Example of receptors- Photoreceptors (eyes) and Phonoreceptors (ears)

Example of effectors- salivary gland ( due to action of muscles saliva get secret)

(b)

Cerebrum

(i) It is a part of forebrain.

Function:

(ii) Our memory and thinking get controlled by cerebrum.

Cerebellum

(i) It is a part of hindbrain.

Functions:

(ii) It helps to maintain body posture and balance of the body.

(iii)) it is helps in coordination for smooth movement occurs in body parts.

49.) What is the difference between a voluntary and an involuntary action? Which kind of action is digestion? Explain your choice.

ANS-

Voluntary Action – Some actions get completed after thinking. The actions who did by willingly called voluntary action. These actions are monitored by brain. Example: singing, dancing, exam writing

Involuntary actions-The actions who did not need thinking but it get happened automatically are called involuntary action. . Example: Digestion, respiration. Respiration etc.

50.) What does CNS stand for? Which part of CNS: (a) consists of two hemispheres, and (b) has spinal nerves attached to it?

ANS-

CNS stands for Central Nervous System.

(a) Cerebrum

It is part of the forebrain, consists of two cerebral hemispheres.

51.) Which hormone:

(a) prepares the body for action ?

(b) controls the amount of glucose in blood?

(c) gives boys deep voice?

(d) gives girls soft skin?

ANS-(a) Adrenaline (b) Insulin (c) Testosterone (d) Oestrogen.

52.) When you smell a favorite food your mouth begins to water (that is, you secrete saliva). Write down what the following are examples of:

(a) the smell of the food

(b) the cells in your nasal passages which perceive the smell

(c) the gland which is stimulated to secrete saliva.

ANS-

(a) Stimulus. (b) Receptors (Olfactory). (c) Effector (Salivary glands).

Long Answer Type Questions

53.) (a) Name the structural and functional unit of nervous system.

(b) Draw a flow chart to show the classification of nervous system into various parts.

(c) What is autonomic nervous system? What is its function?

(d) What is voluntary nervous system? Explain the working of voluntary nervous system with an example.

ANS-

(a) The structural and functional unit of nervous system is neuron.

Function- 1.) It control and sustain the function of internal organs which happened automatically in the body.

2.) Autonomic nervous system generate nerve network which controls the processes like breathing, heart beat digestion etc.

(d) Voluntary actions controlled by our own thinking which concern with voluntary nervous system.

Function-this system controls voluntary actions, for that brain induces conscious control on it.

Example- thinking, dancing, reading etc.

54.) (a) What is a reflex action? Explain with the help of an example.

(b) Define reflex arc. Give the flow chart of a spinal reflex arc.

(c) How are involuntary actions and reflex actions different from each other?

ANS-

(a) The quick and automatic response towards stimulus which is happened automatically in fraction of second called reflex action. Example: pull our hand away from hot plate. In this action, receptors present in the skin (thermoreceptor) experiences hotness. This massage monitored by spinal cord with send command, which get returned towards concern muscles that pull out hand.

Reflex Action

Involuntary Action

1. Reflex action is automatic, quick response towards stimulus.

2. Reflex action is not comes under voluntary control.

3. Reflex generates in this action is originated from spinal cord.

4. example-pull our hand by experiencing thorn.

1. The actions which do not need thinking.It happened without conscious control of brain.

2.It monitored by medulla.

3. Example: Digestion, respiration. Respiration is an involuntary action. T

55.) (a) What is the function of our nervous system?

(b) What are the main organs of human nervous system? Draw a labeled diagram to show the main organs of the human nervous system?

(c) How does the human nervous system work? Explain.

ANS-

a) The function of the nervous system –

It responsible for coordination occurs in the human body.

It receives information from surrounding and responds according to situation

It passes information from internal system to another body parts

It helps in all systems for body work together

b) The main organs of the nervous system are; brain, spinal cord and nerves.

(c) When the sense organ founds any problem, thensensory organ sends message to the brain. Massage is always in the form of electrical impulses. This electrical impulse is always passes through the sensory neurons. Brain rectify problem or decides which instruction have to transfer then it send command to the concern organ or muscles through motor neuron. Whenever body need to respond for complicated situations that time brain and spinal cord both wok together.

Brain does not take part in the simple responses it handled by only spinal cord.

56.) (a) What is a neuron? Draw a labeled diagram of a neuron.

(b) What is a synapse? What happens at the synapse between two neurons? How are the messages carried across a synapse? Explain with the help of a labeled diagram.

ANS-

a) Neuron is the smallest functional unit of nervous system.

b) Electrical nerve impulse is always travelled through a microscopic gap between two adjacent nerves cells that gap is nothing but synapse.

In below diagram A is the part of first nerve cell and B is the part of second nerve cell.

Mechanism- receptor a cell receives the massage and passes to dendrites of sensory neuron where the chemical reaction occurs and chemical impulse get originate. These electrical impulses travelled through the first nerve cell then it gets reaches to synapse where it produces chemical substance in it. This chemical substance easily travelled through the gap (synapse) and reach to next nerve cell (part B in above diagram) then it further regenerate same impulse. Above process can happen continuously in adjacent cells.

57.) (a) Name two systems which taken together perform the functions of control and coordination in human beings.

(b) What does the central nervous system in humans consist of? What is the job of the central nervous system?

(c) Give various functions of the brain.

ANS-

(a) Nervous system and endocrine system.

(b) The central nervous system is made up of brain and spinal cord.

It is responsible for coordination and control present found the body.The central nervous system (CNS) controls most of the body functions. This system collects information from all types of receptors and passes this information to effectors and then action happens. This is the main job do by central nervous system.

(c)

1.) Brain is the main controlling part of nervous system.

2.) Coordination between various internal activities is happened due to brain

3.) Brain controls all the voluntary actions like singing, speaking, writing etc

4.) Brain has three main parts forebrain, midbrain, and hindbrain. And they did various types of functions. Like stores memory, balance the body, to control involuntary actions etc.

58.) (a) Write the names of five endocrine glands found in the human body. Name the hormones secreted by each gland.

(b) How do hormones reach the organs they control?

(c) Name the gland which controls the secretion of hormones from the pituitary.

(d) How does our body respond when adrenaline is secreted in large amounts into the blood?

(e) Name the disease which occurs in adults due to the deficiency of iodine in the diet. What is the main symptom of this disease?

ANS-

(i) Pituitary – Growth.

(ii) Thyroid – Thyroxin.

(iii) Pancreas – Insulin.

(iv) Adrenal – Adrenaline.

(v) Testes – Testosterone.

b) Endocrine glands can secret hormones at the concerned body part through the blood because they have no own duct to release those hormones. Hormones get releases via blood stream.

(d) Adrenaline is the hormone which prepares our body for action. If our body faces any type of physical or mental stress that time it releases more. It enhances speed of heart rate, breathing etc.. Results, more glucose entered into blood stream and give us more energy to tackle this type of adverse situations.

e) Goitre is the disease which cause due to iodine deficiency. Symptoms of this disease-neck are getting swollen. Reason is deficiency of iodine affects the thyroid gland. Hence the area of thyroid gland (neck region) gets swollen.

For more Chapter solution, click below