Biology

Control and Coordination

Question:

(a) Explain any three directional movements in plants.
(b) How brain and spinal cord are protected in human ?
(c) Name the master gland present in the brain.

Answer:

(a) Stimuli is responsible for the movement of the plant parts towards or away from it. This movement is called as Tropic Movement.
Phototropism: movement of plant towards or away from the light. Geotropism: movement of plant parts towards the earth or away from it. Hydrotropism: movement of plant parts towards or away from any source of water.
(b) Both the brain and the spinal cord are protected by bone: the brain by the bones of the skull and the spinal cord is protected by a set of ring-shaped bones called vertebrae. They are both cushioned by layers of membranes called meninges as well as a special fluid called cerebrospinal fluid. This fluid helps to protect the nerve tissue to keep it healthy, and remove waste products.
(c) Pituitary gland present in the brain is known as the master gland.

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Control and Coordination

Q 1.

Why is the response of a plant to a stimulus not observed immediately?

Q 2.

(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.

Q 3.

What is the function of insulin hormone ? What type of patients are given insulin injections ?

Q 4.

Why is it advised to use iodised salt in our diet ?

Q 5.

Give an example of a plant hormone that promotes its growth. Where it is synthesized ?

Q 6.

Name the part of the brain which controls posture and balance of the body.

Q 7.

(a) Which plant hormone is present in greater concentration in the areas of rapid cell division?
(b) Give one example of a plant growth promoter and a plant growth inhibitor.

Q 8.

(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 ?

Q 9.

(a) What does a plant root do in response to water ? What is this phenomenon known as ?
(b) What happens to the moonflower (i) during daytime, and (ii) at night ? What is this phenomenon known as ?

Q 10.

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

Q 11.

Which halogen element is necessary for the making of thyroxine hormone by the thyroid gland ?

Q 12.

How are involuntary actions and reflex actions different from each other?

Q 13.

Name the hormones secreted by thyroid, parathyroid and pancreas.

Q 14.

How does control and coordination occur in single-celled animals?

Q 15.

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

Q 16.

State the functions of the following hormones :
(a) Thyroxine (b) Adrenaline (c) Growth hormone

Q 17.

(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.

Q 18.

What are hormones?

Q 19.

Name, the two main organs of our central nervous system. Which one of them plays a major role in sending command to muscles to act without involving thinking process? Name the phenomenon involved.

Q 20.

Give the scientific terms used to represent the following :
(a) Bending of a shoot towards light.
(b) Growing of roots towards the earth.
(c) Growth of a pollen tube towards ovule.
(d) Bending of roots towards water.
(e) Winding of tendril around a support

Q 21.

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

Q 22.

a) What are the short fibres of a neuron known as ?
What is the long fibre of a neuron known as ?

Q 23.

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

Q 24.

(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 ?

Q 25.

What is a neuron?

Q 26.

Describe the central nervous system in human beings.

Q 27.

Define reflex action with suitable examples.

Q 28.

Mention the part of the body where gustatory and olfactory receptors are located.

Q 29.

What is chemotropism? Give one example. Name any two plant hormones and mention their functions.

Q 30.

Name and explain the function of the hormone secreted by the pituitary gland in humans.

Q 31.

What is a reflex action? Describe the steps involved in a reflex action.

Q 32.

Name the plant hormones which help/promote (i) cell division (ii) growth of
the stem and roots?

Q 33.

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

Q 34.

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

Q 35.

Give one example of the movement of a plant part which is caused by the loss of water (or migration of water).

Q 36.

(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 (z) during daytime, and (ii) at night ? What is this phenomenon known as ?

Q 37.

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

Q 38.

Name the most important part of the human brain.

Q 39.

Which gland secretes the growth hormone ?

Q 40.

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

Q 41.

Which one term in each of the following includes the other three ?
(a) thyroid, ductless gland, thymus, pituitary, ovary
(b) adrenalin, insulin, hormone, thyroxine, estrogen

Q 42.

Explain the difference between each of the following pairs of terms :
(a) receptor and effector (b) cerebrum and cerebellum

Q 43.

Mention one function for each of these hormones:
(a) Thyroxin (b) Insulin (c) Adrenaline (d) Growth hormone (e) Testosterone.

Q 44.

Name various plant hormones. Also give their physiological effects on plant  growth and development.  

Q 45.

Mention the receptors for light and sound in animals.

Q 46.

Differentiate between tropic and nastic movements.

Q 47.

What is coordination?

Q 48.

What makes a stem bend towards sunlight?

Q 49.

(i) Name the hormones that are released in human males and females when they reach puberty.
(ii) Name a gland associated with brain. Which problem is caused due to the deficiency of the hormone released by this gland ?

Q 50.

Write one example each of the following tropic movements :
(i) Positive phototropism (ii) Negative phototropism
(iii) Positive geotropism (iv) Negative geotropism
(v) Hydrotropism (vi) Chemotropism