1. Adrenaline is also known as ‘fight or flight’ hormone. It prepares the body for emergency situations. Increased secretion of adrenaline in the blood increases the blood supply to limbs and to the facial area. It increases the heart rate and breathing rate so that more oxygen could be supplied to theRead more

    Adrenaline is also known as ‘fight or flight’ hormone. It prepares the body for emergency situations. Increased secretion of adrenaline in the blood increases the blood supply to limbs and to the facial area. It increases the heart rate and breathing rate so that more oxygen could be supplied to the limbs. Slight precipitation also occurs on the temple and in palms. All of this shows readiness for a fight or; if need be; a flight from the scene.

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  2. Iodine is an important constituent of the hormone thyroxine. Iodine deficiency leads to a disease called goiter. Iodised salt is advised to prevent chances of goitre.

    Iodine is an important constituent of the hormone thyroxine. Iodine deficiency leads to a disease called goiter. Iodised salt is advised to prevent chances of goitre.

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  3. Chemical coordination in animals takes place through hormones. There are several endocrine glands which secrete various kinds of hormones. These hormones regulate different functions in the body. For example; insulin is a hormone which regulates the blood sugar level.

    Chemical coordination in animals takes place through hormones. There are several endocrine glands which secrete various kinds of hormones. These hormones regulate different functions in the body. For example; insulin is a hormone which regulates the blood sugar level.

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  4. Following things are required for this experiment: Seeds of bean, a deep tray, sand, a porous flower pot   Procedure: (i) The tray should be big enough to accommodate the porous pot. (ii) Fill the tray with sand and insert some seeds in it. (iii) Make a pit in the sand and insert the porous potRead more

    Following things are required for this experiment:
    Seeds of bean, a deep tray, sand, a porous flower pot

     

    Procedure:
    (i) The tray should be big enough to accommodate the porous pot.
    (ii) Fill the tray with sand and insert some seeds in it.
    (iii) Make a pit in the sand and insert the porous pot in it.
    (iv) Fill the porous pot with water.
    (v) Leave the set up for about a week.

    Observation: After a week when seeds are taken out, it is observed that roots grow in the direction of the porous pot. This shows hydrotropic movement in roots.

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  5. Auxin increase in concentration in the part of the tendril which is away from the support. This results in increased cell division in that part. The part which is nearer to the support has lesser rate of cell division. As a result, the external part of the tendril grows more than the internal part aRead more

    Auxin increase in concentration in the part of the tendril which is away from the support. This results in increased cell division in that part. The part which is nearer to the support has lesser rate of cell division. As a result, the external part of the tendril grows more than the internal part and the tendril coils around the support.

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