Biology Class 10 Chapter 2 – Control and Coordination

Chapter 2 of Biology class 10 is very interesting and scoring. Students who have strong knowledge of this chapter can achieve desired marks in Biology. NTSE Guru Experts have designed the important questions that are most likely to appear in exams. Control and Coordination chapter of class 10 carries some fixed amount of marks in the examination. Students are strongly suggested to solve and learn these questions and answers to score good grades in the boards. This sheet contains a point-wise explanation and theoretical questions and answers. Start practicing them now.

Important Questions of Control and Coordination:

 

1. What is ‘synapse’?

Ans. Synapse is a microscopic functional gap between the nerve ending of one neuron and dendrite of another neuron, through which nerve impulses pass. Neurotransmitter (chemical released by pre-synaptic neuron) helps to transfer nerve impulses from one neuron to another.

2. What is reflex action? Give a suitable example.

Ans.  A reflex action is defined as a spontaneous, unconscious and involuntary response of body to a stimulus.

In reflex action, a message from receptors is passed by sensory nerves to the spinal cord, which then sends signals for response through motor neurons to effectors.

Examples:

 (a)   If we unknowingly touch a hot object, our hand immediately moves away automatically. We do not need to think about moving our hand away.   (b)  Knee-jerk, coughing, sneezing, yawning, blinking of eyes, swallowing, movement of diaphragm, etc.

3.  How is the brain and spinal cord protected?

Ans.  Brain: 

(i) By three layers of Meninges

(ii) By skull

(iii) By cerebrospinal fluid   

Spinal Cord:  

(i) By three layers of meninges

(ii) By backbone or vertebral column

(iii) By cerebrospinal fluid.

4. Label the diagram of human brain:

Brain diagram

 

Ans.     A  ->   Cerebrum                                B ->   Mid brain

             C  ->       Cranium                               D  ->  Spinal cord

             E  ->       Medulla Oblongata             F ->   Cerebellum

             G  ->       Pons                                       H  ->    Pituitary gland

             I  ->      Hypothalamus                        J ->    Fore brain

5.  These functions are performed by which part of brain?

a) Solving tricky question         b)  Memorizing concepts

c) Listening music                        d) Breathing deeply       

e) Dancing                                       f)  Riding on a horse      

g) Improving handwriting         h) Vomiting & Sneezing centre

Ans.     a)  Cerebrum                          b)  Cerebrum 

c) Cerebrum                           d) Pons                                                    

e) Cerebellum                        f) Cerebellum                                         

g) Cerebellum                         h) Medulla oblongata

6.  How control and coordination is performed by plants?

Ans: Control and co-ordination in plants is performed by the chemical substances called plant hormones.

7.  Fill the types of tropic movements done by plants.

a) Movement of shoot towards light.

b) Movement of roots towards soil.

c) Movement of pollen tube towards ovule under the influence of certain chemical sugary substance.

d) Movement of roots of the plants towards water.

e) Movement of tendrils of bitter gourd (Karela) and bottle gourd (Lauki) to help them to climb on supports.

Ans.  a)  Positive Phototropism         b)  Positive Geotropism

   c) Chemotropism                        d) Positive Hydrotropism

   e) Thigmotropism

8. What are phytohormones? Name five plant hormones and state one function of each.

Ans: Chemical substances which have the function of control and co-ordination in plants are called phytohormones.

Plant Hormone

Function

(a) Auxins

Cell enlargement and cell differentiation

(b) Gibberellins

Shoot elongation, lateral growth

(c) Cytokinins

Cell division

(d) Abscisic acid (ABA)

Growth inhibitor

(e) Ethylene

Ripening of fruits

9. Which plant hormone is called ‘growth inhibitors’? Why it is called so? Write its functions.

Abscisic acid’ is called growth inhibitor. It is called so because it inhibits flowering process and fruit and seed development.

Functions of ABA are:

  • It promotes closing of stomata.
  • It is a growth inhibitor which keeps plant growth under check.
  • It inhibits the flowering process. It also inhibits fruit and seed development.
  • It initiates falling of leaves (abscission).

10. Compare Tropic and Nastic movement.

Tropic Movement

Nastic Movement

Tropic movement is that movement in which the plants move towards the stimuli or away from the stimuli.

In Nastic movement, movement of plant body part is neither towards the stimulus nor away from the stimulus.

It is directional movement.

It is non-directional movement.

It occurs in every plant.

It occurs in certain plants like Mimosa or chhuimui.

It affects plant for longer time.

It affects plant for short time.

 

11.  What are hormones? They are secreted by which part of your body? Name endocrine glands and hormones secreted by them.

Ans: Hormones are the chemical substances secreted in very small amount by endocrine glands.

Endocrine glands

Hormones

(a) Hypothalamus

i.          Releasing Hormones

ii.         Inhibitory Hormones

(b) Pituitary

i.          Growth hormone (GH)

ii.         Prolactin

iii.        Thyroid stimulating hormone (TSH)

iv.        Adrenocrticotropic hormone (ACTH)

v.         Follicle stimulating hormone (FSH)

vi.        Oxytocin

vii.       Vasopressin/ADH

viii.      Luteinising hormone (LH)

(c) Pineal gland

Melatonin

(d) Thyroid

Thyroxine, Calcitonin

(e) Parathyroid

Parathormone

(f) Thymus

Thymosine

(g) Pancreas

i.          Insulin

ii.         Glucagon

(h) Adrenal gland

Adrenaline, Corticoids

(i) Testis

i.          Testosterone

(j) ovaries

ii.         Oestrogen

 

iii.        Progesterone

12.  How the timing and amount of hormone released by various glands is controlled in our body?

Ans.     The timing and amount of hormone released by various glands is controlled in our body by feedback mechanism.

13. What are heterocrine glands? Give one example.

Ans.     Glands which have both endocrine and exocrine tissues are called heterocrine glands or mixed glands.

  Example:  Pancreas.

(Releases both pancreatic juice and hormones: Insulin and glucagon).

14. A gland X located just below brain in human head secretes a chemical substance Y which controls the development of bones and muscles in the body of a person. Secretion of too little as well as too much of Y leads to abnormal development of the body of a person.

a) Name the gland X.

b) What is chemical substance Y?

c) What will happen if too little of Y is secreted?

d) What will happen if too much of Y is secreted?

e) Name the system of body of which gland X is a part.

Ans.     a) Pituitary gland                      b) Human growth hormone

      c) Dwarfism                               d) Gigantism

      e) Endocrine system

15. Dinesh kept a potted plant horizontally for considerable amount of time. The position of the part A and B are shown here in figures.

 

Plants

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

b) What type of phenomenon is exhibited by A and B parts in figure chosen by you.

Ans.  a)  Figure (c)                                

b) Geotropism by part (B), Phototropism by part (A)

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