Control And Coordination, Class 10th Notes

THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE  PATTERN

Unit Summary: 

Nervous system: (System that helps in control and coordination among body parts)	Parts: I. Central Nervous system: Brain and Spinal Cord II. Peripheral Nervous System: Nerves that arise from Spinal cord (31 pairs in Humans and other mammals)
Neuron: (Cells that make up Nervous system)	There are 100 billion neurons in brain. Neuron has many parts: Cyton > Axon > Dendrites > Synapse
Reflex Action	Quick, Involuntary and automatic action against the stimuli. Occurs via Reflex Arc which consists of: Sensory neuron > Relay neuron > Motor Neuron > Effector Muscles
Human Brain: (Soft, whitish Coordinating centre of the body)	Parts: I. Forebrain (Prosencephalon): Contains Cerebrum, Olfactory Lobes & Diencephalon II. Mid Brain (Mesencephalon) III. Hind Brain (Rhombencephalon) Contains Cerebellum, Pons Varolii, Medulla Oblongata
Plant Movement	I. Nastic Movements: Non directional movements that occur due to turgor change. They include Seismonastic & Nyctinastic movements II. Tropic Movements: Directional movements that occur in response to stimuli They include Geotropic, Phototropic, Hydrotropic, Chemotropic movements
Phyto hormones (Def: Chemical compounds secreted by plants in low concentration that help to regulate their growth)	I. Auxins: e.g. IAA, IBA. Help in cell enlargement, Fruit growth, parthenocarpy etc II. Gibberellins: e.g. GA1, GA2, GA3. Help in cell enlargement, Stem growth etc III. Cytokinins: e.g.  Kinetin, Zeatin. Help in cell division, Morphogenesis etc IV. Abscisic Acid: Helps to induce dormancy, wilting of leaves etc V. Ethylene: Helps in fruit ripening etc
Glands and Hormones in Human beings (Def: Hormones are chemical messengers secreted in small amounts. They carry various body functions)	I. Pituitary Gland: FSH > TSH > LH > ACTH > GH > Melanin > Oxytocin > Vassopressin II. Thyroid Gland: Thyroxine > Calcitonin III. Adrenal Glands: Adrenaline > Noradrenaline > Cortisol > Aldosterone IV. Pancreas: Insulin > Glucagon V. Ovary: Estrogen > Progesterone > Relaxin VI. Testes:  Testoserone VI. Thymus: Thymosin

 

Q. Discuss the structure of Neuron? 

Ans: The neuron is structural and functional unit of nervous system. 

Neuron has three parts; 

I. Cyton   II. Axon    III. Dendrites

I. Cyton: It is cell body. It contains nucleus and has nissl granules. 

II. Axon: It is long tail like nerve fibre arising from cyton. 

It has nodes of Ranvier and is covered by myelin sheath. 

III. Dendrites: They are branch like fibres which extend from cyton. They help in signalling. 

The two neurons are separated by synapse.

Q. What is Reflex action? Explain the process of reflex action. 

Ans: Reflex action is set of quick, automatic and spontaneous responses against stimuli. The reflex action occurs by reflex arc. 

Example withdrawing of hand upon touching hot object. 

Upon recieving stimuli, the sensory nerve sends signal to spinal cord via relay nerve. 

The signal is passed on to motor nerve which causes effector muscle to respond. 

Q. Discuss the structure of human brain? 

Ans: The human brain is soft, whitish organ inside cranium. 

It is sorrounded by three membranes called meninges  filled with cerebrospinal fluid. 

The human brain is divided into three parts. 

I. Fore Brain: It includes olfactory lobes, Cerebrum and Diencephalon 

Olfactory lobes: They help in sense of smell. 

Cerebrum: It is largest part of brain. It has two cerebral hemispheres. It has gyri and sulci to increase surface area. 

Cerebrum governs most body functions. 

Diencephalon: It is centre of glandular activity. 

II. Mid Brain: It connects Forebrain to Hindbrain. 

III. Hind Brain: It includes Pons varolli, cerebellum and medula oblongata. 

Cerebellum: It is second largest part of brain. It  mantains posture and equilibrium of body.. 

Medula oblongata: It acts as reflex and respiratory centre. 

Q. What are Phyto-Hormones? Discuss their functions.  Or 

How does chemical co ordination take place in plants? 

Ans: Phytohormones are chemical substances produced in plants which help in control and coordination in plants. 

They are plant growth regulators. They include: 

I. Auxins: They are found in shoot apex and young leaves. 

They help in cell division and cell elongation. E.g. IAA, IBA 

II. Gibberlins: They help in cell elongation and cell differentiation. E.g GA2, GA3 

III. Cytokinins: They are found in endosperms and roots. 

They help in cell division, cell elongation and breaking of dormancy. 

IV. Abscisic acid: It acts as growth inhibitor. 

It helps in promotion of dormancy, ageing of leaves. 

Q. Write note on various nastic movements in plants? 

Ans: Nastic movements are those plant movements which do not involve growth. 

Nastic movement occur due to turgor changes. They include: 

I. Nyctinastic movement: It are sleep movements. It occurs by change in shape of leaves and flowers during day and night. 

It can be photonastic i.e due to light stimuli or Thermonastic i.e. due to temperature. 

II. Seismonastic movement: It occurs in response to touch e.g. Chui Mui plant. 

Q. Write a note on tropic movements in plants? 

Ans: Tropic movements are growth movements. They occur due to differential growth and are slow. E.g. 

Phototropism: This movement of plant part towards or away from light. 

Shoot is positively phototropic and root is negatively phototropic. 

Geotropism: The movement of plant part towards or away from gravity. 

Shoot is negatively geotropic and root is positively geotropic. 

Hydrotropism: The movement of plant part towards or away from water. 

Shoot is negatively hydrotropic and root is positively hydrotropic. 

Chemotropism: The movement of plant part in response to chemical stimuli. 

Q. Table containing glands, their hormones and disease associated with them.

Ans: Hormones are chemicals produced in small quantities to carry out various body functions.

They are secreted by endocrine glands. 

Q. Which animal or plant hormone is associated with following:

i. Develop secondary sexual characters at puberty in boys

ii. Inhibits growth in plants

iii. Goitre

Ans:

i. Develop secondary sexual characters at puberty in boys: Ans: Testosterone

 ii. Inhibits growth in plants Ans: Abscisic Acid

iii. Goitre  Ans: Thyroxine

Important textual questions: 

Q. Differentiate between reflex action and walking? 

Ans: 

Q. What happens at synapse of two neurons? 

Ans: Synapse is gap between two neurons. The neurotransmitters are secreted at the synapse. E.g dopamine, serotonin, GABA.

Q. Which part of brain mantains posture and equilibrium of body? 

Ans: Cerebellum maintains posture and  equilibrium of body. 

Q. How do we sense the smell of agarbatti? 

Ans: As the scent molecules pass through nose, the cells send electric signal to olfactory lobes which help in smell detection. 

Q. How is movement of leaves in sensitive plant different from movement of shoot? 

Ans: The movement of leaf is nastic movement where as movement of shoot is tropic movement. 

Q. Why is use of iodised salt advisable? 

Ans: The use of iodised salt is advisable because iodine is essential for synthesis of thyroxine by thyroid glands. 

Q. How does our body respond when adrenaline is secreted into blood? 

Ans: Adrenaline is a rush hormone. It results in increase in heart beat, blood sugar and heavy breathing. It also dilates our blood vessels. 

Q. Why are patients with diabetes given insulin injections? 

Ans: The diabetic patients are not able to secrete insulin to regulate blood sugar. 

Hence they are given insulin injections which helps them to lower blood sugar level.

Q. What is difference between involuntary action and reflex action? 

Ans: Reflex actions are spontaneous whereas involuntary actions are non spontaneous. 

Reflex actions are controlled by Spinal cord where as involuntary actions are controlled by brain. 

Q. Which signal will get disrupted in case of spinal cord injury? 

Ans: In case of spinal cord injury, the reflex actions and voluntary action will get disrupted. 

Q. Differentiate between endocrine system and nervous system? 

Ans:

Q. Why Pituitary gland is called Master gland?

Ans: The pituitary gland is called the "master gland" because it produces hormones that regulate many bodily functions.

It releases many hormones such as FSH, TSH, GH, LH, Vasopressin, Melanin, Oxytocin. 

Q. Which hormone regulates blood sugar level in humans?

Ans: Insulin is the hormone which regulates the blood sugar level in humans. It is secreted by Pancreas.

Q. Write down the functions of the following human hormones: (i) Thyroxin (ii) Adrenaline

Ans: Thyroxine: It regulates metabolism of the body and helps maintain Body Mass Index

Adrenaline: Adrenaline is a rush hormone. It results in increase in heart beat, blood sugar and heavy breathing. It also dilates our blood vessels

Objective Type Questions: 

Q. Which of the following helps in maintaining posture and balance of the human body ?

a. Cerebellum     b. Cerebrum     c. Medulla    d. Pons

Ans: a. Cerebellum    

Q. The number of pairs of nerves which arise from the spinal cord is :

a. 21     b. 41    c. 31     d. 51

Ans: c. 31    

Q. The spinal cord originates from:

a. Cerebrum     b. Cerebellum    c. Medulla     d. Pons

Ans: c. Medulla    

 

Q. The involuntary actions in the body are controlled by:

a. Medulla in Forebrain      B. Medulla in hind brain

c. Medulla in Spinal cord    D. Medulla in Mid brain 

Ans: B. Medulla in hind brain

 

 Q. Cerebellum, Medulla and Pons are parts of

a. Mid brain    b. Hind brain     c. Fore brain     D. Spinal Cord

 Ans: b. Hind brain

Q. Which of following is Plant hormone

A. Insulin          B. Thyroxin
C. Estrogen      D. Cytokinin


Ans: Cytokinin

Q. The gap between two neurons is called:

A. Axon        B. Dendrite   
C. Synapse    D. Impluse

Ans: C. Synapse



Q. The brain is responsible for:

A. Thinking      B. Regulate heartbeat
C. Balance       D. All of above

Ans: All of above


Q. Iodine is necessary for synthesis of which hormone?

A. Adrenaline        B. Thyroxine
C. Insulin               D. Auxin


Ans: B. Thyroxine



Q. Posture and equilibrium of body is mantained by;

A. Cerebrum      B. Cerebellum
C. Medula oblongata   D. All of above


Ans: B. Cerebellum


Q. Cell division in plants is promoted by,

A. Auxins       B. Gibberellins
C. Cytokinins   D. None of these


Ans: C. Cytokinins

Q. Sense of hearing, smell and sight are recieved from various receptors in

A. Forebrain    B. Mid brain
C. Hind brain   D. All of above

Ans: A. Forebrain

Q. The hormone secreted directly in blood and carried to different parts of body is

A. Endocrine     B. Exocrine
C. Heterocrine    D. Halocrine

Ans: A. Endocrine


Q. Hormone responsible for wilting of leaves is

A. Auxins     B. Gibberlins  
C. Cytokinins   D. Abscisic acid

Ans: D. Abscisic acid

Q. Name the plant hormone which helps in the ripening of fruits.

Ans: The plant hormone which helps in ripening of fruit is ethylene.

Q. Name the plant hormone which helps in the ripening of fruits.

Ans: The plant hormone which helps in ripening of fruit is ethylene.

Q. Draw a flow chart depicting a reflex action.

Ans:

Q. Name two types of Tropism.
Ans: The different types of Tropism are Phototropism, Geotropism, Hydrotropism, Chemotropism etc.

Q. Which is the correct sequence of the components of a reflex arc?

a. Receptors > Muscles > Sensory neurons > Motor Neurons > Spinal Cord

b. Receptors > Motor neuron > Spinal cord > Sensory neuron > Muscles

c. Receptors > Spinal cord > Sensory neuron > Motor Neuron > Muscles

d. Receptors > Sensory neuron > Spinal cord > Motor neuron > Muscle

Ans: d. Receptors > Sensory neuron > Spinal cord > Motor neuron > Muscle



Q. Involuntary actions in a body are controlled by:

a. Medulla in forebrain b. Medulla in Midbrain

c. Medulla in Hindbrain d. Medulla in Spinal cord

Ans: c. Medulla in Hindbrain


Q. Which part of the brain regulates the body temperature?

a. Hypothalamus b. Thalami c. Pituitary c. Medulla oblongata

Ans: a. Hypothalamus

Q. Which plant hormone inhibits (stops) growth in plants ?

(A) Cytokinin (B) Auxin  (C) Abscisic acid   (D) Gibberellins

Ans: (C) Abscisic acid   

 

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