Extra Questions for Class 10th: Ch 7 Control and Coordination Science

Extra Questions for Class 10th: Ch 7 Control and Coordination (Science) Important Questions Answer Included

Very Short Answer Questions (VSAQs): 1 Mark

Q1. Name any two types of tropic movement in plants.
Answer
(i) Geotropism (ii) Chemotropism

Q2.  Name the plant hormone that inhibits growth and also help in wilting of leaves.
Answer
The plant hormone that inhibits growth and also helps in wilting of leaves in abscisic acid.

Q3. Which hormone is responsible for the secondary sexual characters in male human beings? 
Answer
Testosterone is responsible for the secondary sexual characters in male human beings.

Q4. Name the sensory receptors found in the nose and the tongue.
Answer
Olfactory receptors and gustatory receptors are the sensory receptors found in nose and on the tongue respectievely.

Q5. . How do the shoot and roots of a plant respond to  the pull of earth's gravity ? 
Answer
Roots grow downwards, towards gravity while  shoot usually grow upwards and away from earth.

Short Answer Questions-I (SAQs-I): 2 Marks

Q1. Name one plant hormone which inhibit growth. Write its one more function.

Answer

Abscisic acid is a plant hormone which inhibits growth. 
It’s one more function is that it helps in closure of stomata to decrease loss of water.

Q2.(i) Name the part of brain which controls 
(a)Voluntary actions
(b)Involuntary actions
(ii) What is the significance of the peripheral nervous system? Name the components of nervous system?

Answer

(i) Voluntary actions: are controlled by cerebellum
(ii) Involuntary actions: are controlled by medulla

Q3. How does feedback mechanism regulate the hormone secretion?

Answer

The feedback mechanism regulates the timing and amount of hormone to be secreted. For example, if a person has more sugar in his blood, it is detected by cells of pancreas. As a result, more insulin will be secreted to oxidise the sugar. In opposite case, the secretion of insulin will be depleted.

Q4. Explain the cause of shoots of the plant bending towards light. 

Answer

Stems are positively phototrophic and bend towards the direction of light. The movement is due to occurrence of more auxin on the darker side and lesser auxin on the illuminated side. As a result, there is more growth on the darker side which causes the stem to bend towards light.

Short Answer Questions-II (SAQs-II): 3 Marks


Q1. How do auxins promotes the growth of a tendril around a support. Describe in berief?

Answer

Auxins produced in the shoot tip move downwards in the plant. These auxins cause cell elongation in the growing tissues.
In the tendrils, auxins move away from the point of contact with the supporting object. More growth occurs on the side away from the support. As a result of unequal growth on the two sides, the tendril coils around the support.


Q2. (a) State the function of plant hormones. Name a plant hormone which is essential for cell division. (b) Name the hormone which is involved in phototropism. Explain its role.

Answer

(a) Plant hormones are the chemicals secreted by the plants which helps to co-ordinate growth, development and responses to the environment.
Cytoldnin is hormone involved in phototropism.
(b) Auxin  
When growing plant detects light, auxin is synthesized at the shoot tip and helps the cell to grow longer. When light comes from other side of the plant, auxin diffuses to shady side of the shoot.

Q3. Hormones are needed by our body in an appropriate amount, slightly more or less secretion causes disorder in our body. Illustrate this by using three example.

Answer

(a)    Hypersecration (more secration) and hyposecration (less secration) of different hormones may cause certain disorders.
They are
(i)   Gigantism and dwarfism: Hypersecration of growth hormone can cause gigantism. Hyposecration  of growth harmone can cause dwarfism.
(ii)  Goitre: Iodine acts as the necessary component for the synthesis of thyroxin harmone from thyroid gland.
(iii)   Diabetis mellitus: Insuline secrated from pancreas helps to lower the blood glucose level. When secrated in lower amount, body suffers from diabetes.

Q4. List  three differences in the movement of leaves of a Touch-me-not plant (the plant of Mimosa family) when touched and movement of a tendril towards a support.


Answer

Mimosa Leaves Tendril
(i) Growth independent response,. (i) Growth dependent.
(ii) It is a fast process. (ii) It is a slow process.
(iii) It is non-directonal. (iii) It is directional.

Long Answer Questions (LAQs): 5 Marks

Q1. Why we call pituitary gland as master gland? Where is it located and what are the functions?

Answer

The pituitary glands in our body is meant to control various activities of other glands. Hence called the master glands. 
It is located just below the hypothalamus at the base of the brain.
It secretes five important hormones which are:
(i) Growth Hormone: It regulates the growth and development of bones and muscles. 
(ii) Tropic Hormone: It regulates the secretion  from other endocrine glands.
(iii) Prolactin Hormone: It regulates function of mammary glands in females. 
(iv) Vasopressin Hormone: It regulates water and electrolyte balance of the body.
(v) Oxytocin hormone: It regulates ejection of milk during lacation.

Q2. (a) Write the names and one function of each of any three growth hormones in plants. (b) In the absence of muscle cells, how do plant cells show movement?

Answer

(a) Three growth hormones in plants are:
(i) Auxin—It is synthesised in the young tip of roots and shoots. It promotes elongation and division of cell and root formation.
(ii) Gibberellins—They help in the growth of the stem.
(iii) Cytokines—They promote cell division and delay leaf ageing

(b) The ability of a plant to detect change and respond to that change is termed as the sensitivity of the plant. Yet plants have no nervous system and no muscle tissue, they use electrical and chemical means to convey the information from one cell to another cell. The leaves of the sensitive plant (Mimosa  pudica) folds up in response to touch. These leaf movements are independent of growth whereas, the directional movement of the shoot of a germinating seedling breaking through the soil is growth dependent. 


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