Biology

Control and Coordination

Question:

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

Answer:

Hormones secreted by pituitary gland alongwith their functions are:

  1. Grpwth hormone: It regulates growth and development ofbones and muscles.
  2. Trophic hormone: It regulates secretion of hormones from other endocrine glands.
  3.  Prolactin hormone: It regulates the function of mammary glands in females.
  4.  Vasopressin hormone: It regulates water and electrolyte balance in the body,
  5. Oxytocin hormone : It regulates ejection of milk during lactation.
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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.

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 4.

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

Q 5.

(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 6.

Mention the function of adrenaline hormone.

Q 7.

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

Q 8.

(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 9.

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

Q 10.

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

Q 11.

(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 12.

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

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.

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 15.

Name any two types of tropism.

Q 16.

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

Q 17.

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 18.

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

Q 19.

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

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.

(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 22.

Define reflex action with suitable examples.

Q 23.

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

Q 24.

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

Q 25.

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

Q 26.

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

Q 27.

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

Q 28.

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

Q 29.

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

Q 30.

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

Q 31.

What is the autonomic nervous system?

Q 32.

List the functions of testosterone and estrogen.

Q 33.

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 34.

(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 35.

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

Q 36.

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

Q 37.

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 ?

Q 38.

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

Q 39.

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

Q 40.

Write name of three hormones secreted by the pituitary gland.

Q 41.

What are phytohormones?

Q 42.

Mention the function of the hind-brain in humans.

Q 43.

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

Q 44.

Plant parts show two types of movements, one dependent on growth and the other independent of growth. Give one example of the movement in plant parts :
which depends on growth
which does not depend on growth

Q 45.

(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 46.

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 47.

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

Q 48.

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

Q 49.

(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 50.

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