Tag: biology

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Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Phytohormones are 

  1. Hormones regulating growth from seed to adulthood

  2. Growth regulators synthesised by plants that influence physiological processes

  3. Hormones regulating flowering

  4. Hormones regulating secondary growth
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Phytohormones are produced by plants, that regulate germination, growth, metabolism, or other physiological activities.

So the correct option is 'Growth regulators synthesized by plants that influence physiological processes.'

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

How does chemical coordination occur in plants?

  1. Phytohormones

  2. Blood

  3. Water

  4. Special chemicals
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Plants do not have a nervous system or blood; they use chemical messengers called phytohormones to coordinate growth and physiological responses.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Phytohormones are

  1. Chemicals regulating flowering

  2. Chemicals regulating secondary growth

  3. Hormones regulating growth from seed to adulthood

  4. Regulators synthesised by plants and influencing physiological processes
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Phytohormones are chemical substances synthesized by plants. 
These chemical substances regulate various physiological processes in plants.
So, the correct answer is 'Regulators synthesised by plants and influencing physiological processes'
Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Chemicals having profound effect on growth and development are

  1. Enzymes

  2. Phytohormones

  3. Catalytic agents

  4. Manure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Phytohormones are also called as plant hormones. These are chemicals which play important role in growth and development of plants. These are involved in various physiological processes of plants like growth, flowering, fruiting, shoot and root development, etc. Phytohormones liks auxin, cytokinin act as growth promoter whereas hormones like abscisic acid, ethylene act as growth inhibitor. 

Thus, the correct answer is option B.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Through their effect on phytohormones, temperature and light control

  1. Stomatal closure

  2. Apical dominance

  3. Flowering

  4. Fruit development
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Phytohormone is the plant hormone that is involved in various processes of plants. Hormones like gibberellin induce flowering and abscisic acid inhibits flowering in plants. In plants, flowering is controlled by light and dark periods (photoperiod) and temperature in specific environments. Plant generally requires either long day or cold condition for flowering.

Thus, the correct answer is option C.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Phytohormone is a naturally produced organic substance in ________________.

  1. Higher plants which controls growth and development in general

  2. Plants to control growth and physiological functions at the site of its production

  3. Higher plants controlling growth and development at a site for removed from the site of its production and is effectively only when present in large quantities

  4. Higher plant controlling physiological and growth functions at a site quite removed form the site of its production and is effective when present when in minute quantities
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

High concentration of hormone will

  1. Kill the plant

  2. Cause chlorosis in leaves

  3. Cause stunting in plants

  4. Show no effect on the plant
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When concentration of hormones in the plant body increases, growth of the plants decreases.

So, the correct option is cause stunting in plants’.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

State whether the following statements are true or false.
A hormone is produced in small amounts in a tissue, and it causes a physiological action within that same tissue soon after its production.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A hormone is not produced in tissue but instead in an organ. The effect caused by that by that hormone can be seen in various parts of the body including the site of production. For example, insulin produced by pancreas converts the glucose present in the bloodstream into the glycogen.  

So, the correct option is 'False'.

Multiple choice biology life processes: control and coordination control and coordination in plants growth in plants chemical coordination in plants animal senses sense organs in animals sense organs in humans

Identify the physiological process induced by two phytohormones having a common precursor which is formed due to catalytic activity of pyruvic dehydrogenase complex
(a) More female flowers in Cucumber
(b) $\alpha$-amylase production in Barley grains
(c) Acceleration of fruit ripening in Tomato
(d) Delay in sprouting of Potato tubers.

  1. a, b

  2. a, c

  3. c, d

  4. b, d
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ethylene is a plant hormone. It accelerates fruit ripening in tomato. Maleic hydrazide is a type of auxin, plant hormone. It delays sprouting of potato tubers. Both these hormones have common precursor that is formed due to the catalytic activity of pyruvic dehydrogenase complex.

Thus, the correct answer is option C.