Control and Coordination


(a) How is brain protected from injury and shock?
(b) Name two main parts of hind brain and state the functions of each.


(a) Brain is covered by a three layered membrane called meninges. In between the layers of meninges and brain, cavity fluid named Cerebro Spinal Fluid (CSF) is filled. The hard skull covers the meninges.  Thus Meninges, CSF and Skull protects our brain for a certain extent.
(b) Two main parts of hind-brain are — Medulla and Cerebellum. Their functions are:
Medulla : Involuntary actions such as blood pressure, salivation and vomiting.
Cerebellum : It is responsible for precision of voluntary actions and maintaining the posture and balance of the body.



Control and Coordination

Q 1.

Label the parts (a), (b), (c) and (d) and show the direction of flow of electrical signals in the given figure.

Q 2.

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

Q 3.

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

Q 4.

What is a tropic movement? Explain with an example.

Q 5.

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

Q 6.

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 7.

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

Q 8.

What is the scientific name of sensitive plant ?

Q 9.

If we happen to touch a hot object unknowingly, we immediately pull back our hand. What is this type of action known as ?

Q 10.

Where are hormones made in the human body ?

Q 11.

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

Q 12.

(a) Write the names of five endocrine glands found in the human body. Name the hormones secreted by each gland.
(b) How do hormones reach the organs they control ?
(c) Name the gland which controls the secretion of hormones from the pituitary.
(d) How does our body respond when adrenaline is secreted in large amounts into the blood ?
(e) Name the disease which occurs in adults due to the deficiency of iodine in the diet. What is the main symptom of this disease ?

Q 13.

Answer the following:
(a) Which hormone is responsible for the changes noticed in females at puberty?
(b) Dwarfism results due to deficiency of which hormone?
(c) Blood sugar level rises due to deficiency of which hormone?
(d) Iodine is necessary for the synthesis of which hormone?

Q 14.

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

Q 15.

What is a neuron?

Q 16.

Mention the receptors for light and sound in animals.

Q 17.

What is coordination?

Q 18.

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

Q 19.

Name any two phytohormones, which are growth promoters.

Q 20.

Name any growth inhibiting phytohormone.

Q 21.

Mention the function of adrenaline hormone.

Q 22.

Name the hormone secreted by human testes. State its functions.

Q 23.

List the components of reflex arc in correct sequence. State in brief the role of brain in reflex action.

Q 24.

What are plant hormones? Write two important functions of auxin.  

Q 25.

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

Q 26.

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

Q 27.

Fill in the following blanks :
(a) A plant’s response to light is called…………..
(b) A plant’s response to gravity is called…………..
(c) Plant shoot grows upward in response to…………….
(d) Plant roots grow downward in response to…………..
(e) Tendrils wind around a support in response to……………
(f) Plant roots grow towards…….. and in the direction of force of……………
(g) A root of a plant grows downward. This is known as…………..
(h) ……….is the hormone that causes phototropism in plants
(i) The response of leaves to the sunlight is called……………

Q 28.

(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 29.

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

Q 30.

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

Q 31.

(a) What is spinal cord ? What is its main function ?
(b) Give the functions of medulla.

Q 32.

(a) How does chemical coordination take place in human beings ?
(b) Why is the use of iodised salt advisable ?

Q 33.

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

Q 34.

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

Q 35.

(a) Name two systems which taken together perform the functions of control and coordination in human beings.
(b) What does the central nervous system in humans consist of ? What is the job of the central nervous system ?
(c) Give the various functions of brain.

Q 36.

What makes a stem bend towards sunlight?

Q 37.

What is synapse ? In a neuron cell how is an electrical impulse created and what is the role of synapse in this context ?

Q 38.

(a) Name the hormone which is released into the blood when its sugar level  rises. Explain the need of Chemical communication in multicellular organisms the organ which produces this hormone and its effect on blood sugar level. Also mention the digestive enzymes secreted by this organ with one function of each.
(b) Explain the need of Chemical communication in multicellular organisms.

Q 39.

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

Q 40.

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

Q 41.

State the functions of plant hormones. Name four different types of plant hormones.

Q 42.

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

Q 43.

Mention the function of the hind-brain in humans.

Q 44.

A young green plant receives sunlight from one direction only. What will happen to its shoots ?

Q 45.

Which one of the following actions on touch is an example of chemical control?
(i) Movement on the touch-sensitive plant.
(ii) Movement in human leg.

Q 46.

(a) Name the two main constituents of the Central Nervous System in human beings.
(b) What is the need for a system of control and coordination in human beings?

Q 47.

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

Q 48.

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

Q 49.

Give one example each of a plant part:
(a) which is positively hydrotropic as well as positively geotropic.
(b) which is positively phototropic but negatively geotropic.

Q 50.

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.