Biology

Control and Coordination

Question:

Name the five types of tropisms. How are tropic movements helpful to plants ? Explain with an example.

Answer:

The five types of tropisms are: Phototropism, Geotropism, Chemotropism, Hydrotropism and Thigmotropism. The various types of tropic movements help the plants to survive. Example even if a seed is planted upside down, its root will grow downwards into earth because it is positively geotropic.

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Control and Coordination

Q 1.

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

Q 2.

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

Q 3.

(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 4.

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

Q 5.

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

Q 6.

(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 7.

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

Q 8.

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

Q 9.

Name the hormones secreted by thyroid, parathyroid and pancreas.

Q 10.

(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 11.

What are hormones?

Q 12.

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

Q 13.

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 14.

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

Q 15.

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

Q 16.

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

Q 17.

What is the function of thyroxine hormone in our body ?

Q 18.

What are 'nastic' and 'curvature' movements? Give one example of each.

Q 19.

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

Q 20.

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

Q 21.

Name one plant hormone that promotes growth and another plant hormone which inhibits growth.

Q 22.

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

Q 23.

Name the type of chemical substances that control the growth in plants.

Q 24.

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 25.

Which of the following is a growth movement and which is not ?
(a) folding up of leaves of sensitive plant on touching with hand.
(b) folding up of petals of dandelion flower when light fades.

Q 26.

(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 27.

(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 28.

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 29.

Define chemotropism. Give one example of chemotropism. State whether this example is of positive chemotropism or negative chemotropism.

Q 30.

(a) What is meant by ‘tropisms’ (or tropic movements) ? Explain with an example.
(b) What are the different types of tropisms ? Define each type of tropism. Write the name of stimulus in each case.
(c) How do tropisms differ from nasties (or nastic movements) ?

Q 31.

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

Q 32.

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

Q 33.

Name the most important part of the human brain.

Q 34.

Name one hormone secreted by the pituitary gland.

Q 35.

Which gland secretes the growth hormone ?

Q 36.

Name the hormones secreted by (a) testes, and (b) ovaries

Q 37.

What are the scientific names for the following receptors in animals ?
(a) receptors for light
(b) receptors for heat
(c) receptors for sound
(d) receptors for smell
(e) receptors for taste

Q 38.

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

Q 39.

Why are some patients of diabetes treated by giving injections of insulin ?

Q 40.

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 41.

Name one gland each :
(a) which acts only as an endocrine gland.
(b) which acts only as an exocrine gland.
(c) which acts both as an endocrine gland as well as an gxocrine gland.

Q 42.

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

Q 43.

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

Q 44.

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 45.

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

Q 46.

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

Q 47.

Compare the nervous system and endocrine system (hormonal system) for control and coordination in humans.

Q 48.

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

Q 49.

Write the names of all the major endocrine glands present in the human body. Which of these glands also function as exocrine glands ?

Q 50.

In what ways are puberty and adolescence result of the activity of some glands in the human body ?