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Botany

Plant Growth and Development

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In photoperiodism, critical day length refers to:

Minimum light period

Maximum light period

Minimum dark period

Exact duration of light or dark required

Senescence is delayed by:

Ethylene

ABA

Cytokinin

Auxin

Removal of apical bud results in growth of lateral buds. Which plant hormone suppresses the growth of lateral buds?

Auxin

Gibberellin

Cytokinin

Ethylene

Grass stem elongates by the activity of-

Primary meristem

Secondary meristem

Intercalary meristem

Apical meristem

Bolting is promoted by:

Auxin

Cytokinin

Gibberellin

ABA

Which hormone breaks seed dormancy?

ABA

Auxin

Cytokinin

Gibberellin

Which of the following is NOT correctly matched?

Auxin – Cell elongation

Cytokinin – Apical dominance

Gibberellin – Bolting

ABA – Dormancy

You are given a tissue with the potential for differentiation in an artificial culture. Which of the following pairs of hormones would you add to the medium to secure shoots as well as roots ?

Gibberellin and abscisic acid

IAA and gibberellin

Auxin and cytokinin

Auxin and abscisic acid

Plant growth regulators (PGRs) are:-

Small, simple substances of different chemical composition

Complex organic substances of different chemical composition

Simple and complex organic substances of same chemical composition

Small organic substances of same chemical composition

Phytochrome Pfr is:

Inactive form

Active form

Stable form

Dark form

Two leaves A and B have surface area 50 cm² and 100 cm², respectively. They both increase their surface area by 5 cm² in a day. The absolute growth rate;

of A is more than B.

of B is more than A.

is 5 cm² per day.

is 0.1 and 0.05 for leaf A and B, respectively.

How many among the following statements are incorrect ?
(a) Plant growth is defined as reversible increase in size or dry weight.
(b) Ethylene promotes fruit ripening and leaf senescence.
(c) Process by which cell lose their ability to divide and acquire specific functions is called differentiation.
(d) Abscisic acid promotes stomatal opening during water stress.
(e) Gibberellin induces bolting in rosette plants.

Three

Four

Five

Two

Which hormone is primarily responsible for delaying senescence?

Auxin

Cytokinin

Gibberellin

ABA

The phytohormone that is a carotenoid derivative is;

auxin.

gibberellin.

cytokinin.

abscisic acid.

Triple response is due to:

Auxin

Ethylene

ABA

Cytokinin

Apical dominance is due to:

Cytokinin

Auxin

ABA

Ethylene

Phytochrome exists in:

One form

Two interconvertible forms

Three forms

Four forms

Maximum growth occurs in:

Lag phase

Log phase

Stationary phase

Decline phase

The "bakanae" (foolish seedling) disease of rice seedlings is caused by a:

Virus

Bacterium

Fungus

Viroid

Vernalization can be reversed by:

Auxin

Cytokinin

High temperature

ABA

Assertion: Auxin promotes apical dominance Reason: It inhibits growth of lateral buds

A true R false

A false R true

Both true correct explanation

Both true wrong explanation

Florigen is:

Hormone

Protein complex

Hypothetical flowering hormone

Pigment

Abscisic acid causes:

Growth promotion

Stomatal opening

Dormancy

Cell elongation

Dedifferentiation refers to:

Cell death

Reversion to meristematic state

Growth stop

Differentiation

Match Column I and II:

Column I	Column II
AAuxin	iDerivative of indole compounds
BCytokinin	iiDerivative of terpenes
CGibberellin	iiiDerivative of adenine
D.	ivDerivative of carotenoids

A – i, B – iii, C – ii

A – ii, B – iv, C – i

A – i, B – iii, C – ii

A – iii, B – i, C – ii

Which hormone promotes synthesis of α-amylase in germinating seeds?

Auxin

Cytokinin

Gibberellin

ABA

Photoperiodism is mediated by:

Chlorophyll

Phytochrome

Auxin

Cytokinin

The given kind of growth will observed during:-

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Early embryo development

Shoot apex

Fruit ripening

Seasonal activities

Which is NOT a long day plant?

Wheat

Radish

Spinach

Tobacco

Given below are two statements; one is labelled as Assertion and the other is labelled Reason.

Assertion: In arithmetic growth, mitotic cell division occurs in which, only one daughter cell continues to divide, while other differentiate and matures.

Reason: The simplest expression of arithmetic growth is exemplified by zygote elongating at a constant rate.

If both assertion and reason are true and reason is the correct explanation of assertion.

If both assertion and reason are true but reason is not the correct explanation of assertion.

If assertion is true but reason is false.

If both assertion and reason are false.

Ethylene is:

Liquid hormone

Solid hormone

Gaseous hormone

Protein hormone

Differentiation means:

Increase in size

Increase in number

Specialisation

Death

Assertion (A) : During arithmetic growth, there is growth at constant rate.
Reason (R) : In arithmetic growth the two only one daughter cell continues to divide while the other differentiates and matures.

Both (A) and (R) are true and (R) is the correct explanation of (A)

Both (A) and (R) are true and (R) is not the correct explanation of (A)

(A) is true but (R) is false

(A) is false but (R) is true

Which hormone promotes lateral bud growth?

Auxin

Cytokinin

ABA

Ethylene

Growth rate curve is:

Linear

Sigmoid

Circular

Random

Redifferentiation is:

New cell formation

Specialisation again

Cell death

Growth stop

The curly top virus spreads through a plant via the tissue that is;

made of similar type of cells.

made of only dead cells.

responsible for carbon assimilation.

a part of conducting tissue system.

Which hormone is known as stress hormone?

Auxin

Cytokinin

Gibberellin

ABA

IAA is essential in all except

Apical hook formation

Apical dominance

Parthenocarpy in tomatoes

Xylem differentiation

Question Palette

Unattempted

Correct

Incorrect

Column I

Column II

AAuxin

iDerivative of indole compounds

BCytokinin

iiDerivative of terpenes

CGibberellin

iiiDerivative of adenine

ivDerivative of carotenoids