Chapter-7. Control and Coordination

Q – what is dendrite ? Write its function.

A – specialised edges of neuron is called dendrite.

 Function of Dendrite;

(i)It recieves all informations.

Q – What is called the space between two neurons?

A – Synapse.

Q: Name the two substances which are responsible for the control and coordination in plants.

Ans: phytohormones.  

Q – write the function of sensory nerves?

A – It receives information from sensory organs.

Q – Write the function of motor nerves.

A – It sends impulses to muscles to take actions.

Q – How do informations travel into neurons?

A – Informations travel as electric impulse.

Q – What is the scientific name of following receptors in an animal?

(a)Receptors for light

(b)Receptors for sound

(c)Receptors for taste

(d)Receptors for Heat.

(e)Receptors for smell.

A –

(a)Photo receptor

(b)Phono receptor

(c)Gustatory receptor

(d)Thermo receptor

(e)Olfactory receptor.

Q – Write difference between involuntary actions and reflex actions.

A –

Q – What is reflex arc?

A – The pathway of reflex action is termed as reflex arc. When we touch a hot object the stimulus passes through sensory nerve to spinal cord. From here the motor nerve brings the message to the musles of hand to contract and hand is removed within a fraction of time from the hot object.

Q – Which organs forms central nervous system?

A – Brain and spinal cord.

Q – What is called that bone box which protects the brain?

A – Cranium.

Q – What is called the membrane which provides protection to the brain?

A – Menings.

Q – What is C.S.F? Write its function?

A –  Full name of C.S.F is Cerebro spinal Fluid. It is a fluid which found among three Menings. It prevents brain to Meningitis and internal injuries.

Q – Name the parts of hind-brain and mention their functions.

A – The hind-brain consists of three centers:

(i)Cerebellum – It maintains posture and adjusts movement.

(ii)Pons – It takes part in regulation of respiration.

(iii)Medulla oblongata – it is regulating center for swallowing, coughing, sneezing and vomiting. 

(i)Fore-brain –

(ii)Mid-brain – it controls the involuntary actions of body.

(iii)Hind-brain – It even controls the the involuntary actions of body. And all involuntary actions like blood pressure, salivary secretion and vomiting are controlled by medulla oblongata situated in hind-brain.

Q – Name the part of brain which is responsible for precision of voluntary actions and maintaining the posture and balance of the body.

A – cerebellum.

Q – Distinguish between Positive geotropisms and negative geotropisms.

A –

Q – What is phyto hormones (plant hormome)?

A – Phyto hormones are the substances which are responsible for coordinate and control in plants. These are five in number.

(i) Auxins –

(a) It is responsible for enlongation of plants.

(b) It enhances the growth of fruits.

(c) It enhances the growth of cell and cell division. 

(d) Auxin also influences rooting formations.

(ii)Gibberllin –

(a)  Gibberllin enhances the growth of cell and cell division in presence of Auxin

(b)  It enhaces the growth of fruits and stems.

(c) Gibberllin also enhances the transition to flowering, and the development of flowers, fruits, and seeds 

(iii) Cytokinins

(a) It stimulates the cell division in plants.

(b) It helps in blooming of fruits.

(iv) Abscisic Acid

(a)  It inhibits and controls the growth of plants.

(b)  It controls the water loss in plants.

(c)  It encourages the protein synthesis in plants.

(v)Athelin

(a) It promotes fruits for ripping.

(b) It increases the numbers of female flowers.

(c)  It helps in growth of stems.

Ques: What are glands? write it type.

Ans: Glands: Glands are the body organs which secretes hormones.

There are two types of glands.

(1)Endocrine glands: The glands which secretes their hormones directly through blood stream. Ex. Pituitary gland, thyroid gland, thymus gland etc.

(2)Exocrine glands: The glands which secretes their hormones through the duct. Ex. Liver, Lachrymal, Mammary gland etc.