Biology

Control and Coordination

Question:

Mention the function of adrenaline hormone.

Answer:

Adrenaline hormone is released into the blood from the adrenal gland during stimulation of the nervous system on seeing any adverse situation of fight or fright, it:

  1. increases the blood pressure.
  2. increases heart beat rate.
  3. increases breathing rate.
  4. diverts blood to essential organs including the heart, brain and skeletal muscles by dilating their blood vessels and constricting those of less essential organs, such as the skin and digestive system.
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Control and Coordination

Q 1.

Mention the names of various phytohormones.

Q 2.

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

Q 3.

(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 4.

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

Q 5.

Which part of the brain maintains posture and balance of the body ?

Q 6.

What are 'hormones'? State one function of each of the following hormones:
(i) Thyroxine (ii) Insulin

Q 7.

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

Q 8.

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

Q 9.

(a) Explain how auxins help in bending of plant stem towards light.
(b) State the objective of the experiment for which experimental set-up is shown in the given diagram.

Q 10.

A potted plant is made to lie horizontally on the ground. Which part of the plant will show
(i) positive geotropism?
(ii) negative geotropism?

Q 11.

Mention the function of adrenaline hormone.

Q 12.

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 13.

(a) The human brain can be broadly divided into three regions. Name these three regions.
(b) What is cranium ? What is its function ?

Q 14.

What are the major parts of the brain? Mention the functions of different parts.

Q 15.

Name any two types of tropism.

Q 16.

Define reflex action with suitable examples.

Q 17.

What is the stimulus in : (a) phototropism ? (b) geotropism ? (c) chemotropism ? (d) hydrotropism ? (e) thigmotropism ?

Q 18.

(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 19.

State the function of:
(i) gustatory receptors, and
(ii) olfactory receptors.

Q 20.

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

Q 21.

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

Q 22.

(a) Write the names of the regions in hindbrain. Give one function of each region.
(b) Name the functions of cerebrum.

Q 23.

When you smell a favourite 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.

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.

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

Q 26.

To which directional stimuli do :
(a) roots respond ?
(b) shoots respond ?

Q 27.

Name, the disease caused by the deficiency of thyroxine hormone in the body.

Q 28.

What will happen if intake of iodine in our diet is low?

Q 29.

List the functions of testosterone and estrogen.

Q 30.

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

Q 31.

What are phytohormones?

Q 32.

List in tabular form three differences between nervous control and chemical control.

Q 33.

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

Q 34.

Write name of three hormones secreted by the pituitary gland.

Q 35.

What are meanings? What are their functions? Name the fluid, which is filled in between meanings.

Q 36.

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

Q 37.

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 38.

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

Q 39.

(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 40.

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

Q 41.

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 ?

Q 42.

(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 43.

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

Q 44.

How does phototropism occur in plants?

Q 45.

Write the functions of any one part of the hind – brain.

Q 46.

What is the autonomic nervous system?

Q 47.

State the structural and the functional unit of the nervous system. Draw its neat labelled diagram and write two functions.

Q 48.

(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.

Q 49.

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

Q 50.

Smita's father has been advised by a doctor to reduce his sugar intake.

  1. Name the disease he is suffering from and name the hormone whose deficiency is? ,
  2. Identify the gland that secretes it and mention the function of this hormone.
  3.  Explain how the time and amount of secretion of this hormone is regulated in human system.