NCERT Exemplar solutions for Biology [English] Class 11 chapter 15 - Plant Growth and Development [Latest edition]

Ethylene is used for ______.

Coconut water contains ______.

The affect of apical dominance can be overcome by which of the following hormone ______.

Match the following:

Apples are generally wrapped in waxed paper to ______.

Growth can be measured in various ways. Which of these can be used as parameters to measure growth ______.

The term synergistic action of hormones refers to ______.

Plasticity in plant growth means that ______.

To increase sugar production in sugarcanes, they are sprayed with ______.

ABA acts antagonistic to ______.

Monocarpic plants are those which ______.

The photoperiod in plants is perceived at ______.

Fill in the places with appropriate word/words.

A phase of growth which is maximum and fastest is ______.

Fill in the places with appropriate word/words.

Apical dominance as expressed in dicotyledonous plants is due to the presence of more ______ in the apical bud than in the lateral ones.

Fill in the places with appropriate word/words.

In addition to auxin, a ______ must be supplied to culture medium to obtain a good callus in plant tissue culture.

______ of a vegetative plants are the sites of photoperiodic perception.

Plant growth substances (PGS) have innumerable practical applications. Name the PGS you should use to

Increase yield of sugar cane

Plant growth substances (PGS) have innumerable practical applications. Name the PGS you should use to

Promote lateral shoot growth

Plant growth substances (PGS) have innumerable practical applications. Name the PGS you should use to

Cause sprouting of potato tuber

Plant growth substances (PGS) have innumerable practical applications. Name the PGS you should use to

Inhibit seed germination

A primary root grows from 5 cm to 19 cm in a week. Calculate the growth rate and relative growth rate over the period.

Gibberellins were first discovered in Japan when rice plants were suffering from bakane (the foolish seedling disease) caused by a fungus Gibberella fujikuroi.

Give two functions of this phytohormone.

Gibberellins were first discovered in Japan when rice plants were suffering from bakane (the foolish seedling disease) caused by a fungus Gibberella fujikuroi.

Which property of Gibberellin caused foolish seedling disease in rice?

Gibberellins promote the formation of ______ flowers on genetically _____ plants in Cannabis whereas ethylene promotes formation of _______ flowers on genetically ______ plants.

Classify the following plants into Long-Day Plants (LDP), Short Day Plants (SDP) and Day Neutral Plants (DNP) Xanthium, Henbane (Hyoscyamus niger), Spinach, Rice, Strawberry, Bryophyllum, Sunflower, Tomato, Maize.

A farmer grows cucumber plants in his field. He wants to increase the number of female flowers in them. Which plant growth regulator can be applied to achieve this?

Where are the following hormones synthesized in plants?

IAA

Where are the following hormones synthesized in plants?

Gibberellins

Where are the following hormones synthesized in plants?

Cytokinins

In botanical gardens and tea gardens, gardeners trim the plants regularly so that they remain bushy. Does this practice have any scientific explanation?

Light plays an important role in the life of all organisms. Name any three physiological processes in plants which are affected by light.

In the figure of Sigmoid growth curve given below, label segments 1, 2 and 3.

Growth is one of the characteristic of all living organisms? Do unicellular organisms also grow? If so, what are the parameters?

The rice seedlings infected with fungus Gibberlla fujikuroi is called foolish seedlings? What was the reason behind it?

Nicotiana tabacum, a Short Day Plant, when exposed to more than critical period of light fails to flower. Explain.

What are the structural characteristics of meristematic cells near root tip

What are the structural characteristics of the cells in the elongation zone of the root

Does the growth pattern in plants differ from that in animals? Do all the parts of plant grow indefinitely? If not, name the regions of plant, which can grow indefinitely.

Explain in 2-3 lines the following terms with the help of examples taken from different plant tissues.

Differentiation

Explain in 2-3 lines the following terms with the help of examples taken from different plant tissues.

De-differentiation

Explain in 2-3 lines the following terms with the help of examples taken from different plant tissues.

Redifferentiation

Auxins are growth hormones capable of promoting cell elongation. They have been used in horticulture to promote growth, flowering and rooting. Explain the meaning of the following terms related to auxins.

Auxin precursors

Auxins are growth hormones capable of promoting cell elongation. They have been used in horticulture to promote growth, flowering and rooting. Explain the meaning of the following terms related to auxins.

Anti-auxins

Auxins are growth hormones capable of promoting cell elongation. They have been used in horticulture to promote growth, flowering and rooting. Explain the meaning of the following terms related to auxins.

Synthetic auxins

The role of ethylene and abscisic acid is both positive and negative. Justify the statement.

While experimentation, why do you think it is difficult to assign any affect seen to any single hormone?

What is the mechanism underlying the phenomenon by which the terminal/apical bud suppresses the growth of lateral buds? Suggest measures to overcome this phenomenon.

In animals there are special glands secreting hormones, whereas there are no glands in plants. Where are plant hormones formed? How are the hormones translocated to the site of activity?

Many discoveries in science have been accidental. This is true for plant hormones also. Can you justify this statement by giving an example? Also what term is used for such accidental findings?

To get a carpet like grass lawns are mowed regularly. Is there any scientific explanation for this?

In a slide showing different types of cells can you identify which type of the cell may be meristematic and the one which is incapable of dividing and how?

A rubber band stretches and reverts back to its original position. Bubble gum stretches, but it would not return to its original position. Is there any difference between the two processes? Discuss it with respect to plant growth (Hint: Elasticity (reversible) Plasticity (irreversible))

Label the diagram

1. This is which part of a dicotyledonous plant?
2. If we remove part 1 from the plant, what will happen?

Both animals and plants grow. Why do we say that growth and differentiation in plants is open and not so in animals? Does this statement hold true for sponges also?

Define parthenocarpy. Name the plant hormone used to induce parthenocarpy.

While eating watermelons, all of us wish it was seedless. As a plant physiologist can you suggest any method by which this can be achieved.

A gardener finds some broad-leaved dicot weeds growing in his lawns. What can be done to get rid of the weeds efficiently?

On germination a seed first produces shoot with leaves, flowers appear later, Why do you think this happens?

On germination a seed first produces shoot with leaves, flowers appear later, How is this advantageous to the plant?

Fill in the blanks:

Maximum growth is observed in ______ phase.

Fill in the blanks:

Apical dominance is due to ______.

Fill in the blanks:

______ hormone initiate rooting.

Fill in the blanks:

Pigment involved in Photoperception in flowering plants is ______.

Some varieties of wheat are known as spring wheat while others are called winter wheat. Former variety is sown, and planted in spring and is harvested by the end of the same season. However, winter varieties, if planted in spring, fail to flower or produce mature grains within a span of a flowering season. Explain, why?

It is known that some varieties of wheat are sown in autumn but are harvested around next mid summer.

What could be the probable reason for this?

It is known that some varieties of wheat are sown in autumn but are harvested around next mid summer.

What term is used for this promotion of flowering under low temperature?

It is known that some varieties of wheat are sown in autumn but are harvested around next mid summer.

Which plant hormone can replace the cold treatment?

Name a hormone which is gaseous in nature

Name a hormone which is responsible for phototropism

Name a hormone which induces femaleness in flowers of cucumber

Name a hormone which is used for killing weeds (dicots)

Name a hormone which induces flowering in long day plants