Objective NCERT at your FINGERTIPS: Biology

NCERT

Chapter 15

Plant Growth and Development - all with Video Answers

Educators

Chapter Questions

Problem 1

An irreversible or permanent increase in size, mass or volume of a cell, organ or organism is called as ____.
(a) growth
(b) differentiation
(c) dedifferentiation
(d) development

Narayan Hari

Narayan Hari

Numerade Educator

Problem 2

_________during includes all the changes that an organism undergoes its life cycle, from seed germination to senescence.
(a) Growth
(b) Differentiation
(c) Dedifferentiation
(d) Development

Narayan Hari

Numerade Educator

Problem 3

Identify the different regions of root and select the correct option.
$\begin{array}{lll}\mathrm{A} & \text { B } & \text { C }\end{array}$
(a) Meristematic zone Maturation Differentiation zone zone
(b) Meristematic zone Elongation Maturation zone zone
(c) Elongation zone Maturation Differentiation zone zone
(d) Elongation zone Differentiation Maturation zone zone

Narayan Hari

Numerade Educator

Problem 4

Increased vacuolation, cell enlargement and new cell wall deposition are the characteristics of cells in of growth.
(a) meristematic
(b) elongation
(c) maturation
(d) differentiation

Narayan Hari

Numerade Educator

Problem 5

Read the following statements regarding arithmetic growth and select the correct answer.
(i) Rate of growth is constant
(ii) One daughter cell remains meristematic while the other one differentiates and matures
(iii) Mathematical expression is $L_{t}=L_{0}+m$
(a) Statements (i) and (ii) are correct
(b) Statements (ii) and (iii) are correct
(c) Statements (i) and (iii) are correct
(d) All statements are correct

Narayan Hari

Numerade Educator

Problem 6

Select the incorrect statement among the following
(a) Increase in growth per unit time is growth
(b) A sigmoid growth curve is a characteristic of wirg organisms in their natural environmen. living organisms in their natural environment
(c) Rate of growth is constant during growth.
(d) Exponential phase is also called as log phase

Narayan Hari

Numerade Educator

Problem 7

The given figure shows development of an embryo that undergoes two phases $A$ and $B$. Select the correct option regarding it.
A
(a) Geometric phase
(b) Arithmetic phase
(c) Arithmetic phase
(d) Exponential phase
B Arithmetic phase Geometric phase Exponential phase Stationary phase

Narayan Hari

Numerade Educator

Problem 8

The exponential growth can be mathematically expressed as
(a) $L_{t}=L_{0}+r t$
(b) $W_{1}=W_{0}+e^{n}$
(c) $W_{1}=W_{0} e^{r t}$
(d) $L_{t}=L_{0}-r t$

Narayan Hari

Numerade Educator

Problem 9

Fastest phase of S-shaped growth curve is
(a) lag phase
(b) log phase
(c) stationary phase
(d) both (a) and (b).

Narayan Hari

Numerade Educator

Problem 10

Growth at cellular level, is pirncipally a consequence of increase in the amount of
(a). protoplasm
(b). DNA
(c). cell wall
(d). cell organelles.

Narayan Hari

Numerade Educator

Problem 11

Read the given statements and select the correct option.
(a). Statement (i) and (ii) are correct
(b). Statement (iii) and (iv) are correct
(c). Statement (i) and (iii) are correct
(d). Statement (i), (ii), (iii) and (iv) are correct

Parvati Devi

Numerade Educator

Problem 12

Which one is the correct graph for arithmetic growth?

Narayan Hari

Numerade Educator

Problem 13

The given figure shows growth of two leaves over the period of one day. If, $A G=$ absolute growth and $R G R=$ relative growth rate, then select the correct option.

Narayan Hari

Numerade Educator

Problem 14

Growth in plants is
(a) only determinate
(b) only indeterminate
(c) mostly determinate
(d) both determinate and indeterminate.

Narayan Hari

Numerade Educator

Problem 15

Given graph is drawn on the parameters of growth versus time. Here $A, B$ and $C$ respectively represent
(a) exponential phase, log phase and steady state phase
(b) steady state phase, lag phase and log phase
(c) log phase, steady state phase and logarithmic phase
(d) log phase, lag phase and steady state phase.

Narayan Hari

Numerade Educator

Problem 16

The given diagram shows different stages of seed germination. Identify $A, B, C$ and $D$ and select the correct option.
(a) Plumule Cotyledons Epicotyl Hypocotyl
(b) Radicle Cotyledons Epicotyl Hypocotyl
(c) Mesocotyl Cotyledons Epicotyl Hypocotyl
(d) Root hair Cotyledons Hypocotyl Epicotyl

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 17

Increase in girth (diameter) of plant as a result of the activities of lateral meristems is called
(a) primary growth
(b) secondary growth
(c) open form of growth
(d) diffuse growth.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 18

Vascular cambium and cork cambium are
(a) |ateral meristems
(b) intercalary meristems
(c) primary meristems
(d) apical meristems.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 19

Secondary growth generally occurs in
(a) monocots
(b) dicots
(c) gymnosperms
(d) both (b) and (c).

Narayan Hari

Numerade Educator

Problem 20

Meristematic cells are characterized by
(a) thin cellulosic cell walls
(b) dense protoplasm
(c) prominent nuclei
(d) all of these.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 21

Cells of tracheary elements (tracheids and vessels) become dead at maturity and lose their protoplasm due to the deposition of lignocellulosic cell wall thickenings. This is an example of
(a) growth
(b) differentiation
(c) dedifferentiation
(d) redifferentiation.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 22

Which of the following is an example of differentiation?
(a) Lignocellulosic wall thickenings of tracheids
(b) Loss of nudeus, vacuolisation and end wall perforations in sieve tube elements
(c) Elongation, thickening and emptying of sclerenchyma fibres
(d) All of these

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 23

Living differentiated cells which have otherwise lost the capacity to divide, can regain the power of division under certain conditions This phenomenon is termed as
(a) differentiation
(b) dedifferentiation
(c) redfferentiation
(d) development.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 24

______ are the examples of tissues, formed by dedfferentiation.
(a) Irterfacicuar cambium
(b) Cork cambium
(c) Both $(\mathrm{z})$ and $(\mathrm{b})$
(d) Tracheary elements

Narayan Hari

Numerade Educator

Problem 25

The dedfferentiated cells mature to form some specific cells to perfom specific functions, this is referred to as
(a) differentiation
(b) decffferentiation
(c) redfferentiation
(d) development.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 26

Examples of tissues that are formed by redifferentiation are -
(a) secondar xylem
(b) secondary phloem
(c) cork cell
(d) all of these.

Narayan Hari

Numerade Educator

Problem 27

If a part of pith from the stem of a plant is used as an explant and cultured on nutrient medium, which of the following processes is responsible for the formation of an undifferentiated mass of cells called callus?
(a) Growth
(b) Differentiation
(c) Dedifferentiation
(d) Redifferentiation

Narayan Hari

Numerade Educator

Problem 28

The factors which influence growth are
(a) nutrients
(b) water, oxygen
(c) light, temperature
(d) all of these.

Narayan Hari

Numerade Educator

Problem 29

Different kinds of structures develop in phases of growth or in response to envirolants is called
(a) plasticity
(b) elasticity
(c) heterophylly
(d) differentiation In aquatic plant Ranuncult

Narayan Hari

Numerade Educator

Problem 30

Idtion In aquatic plant Ranunculus flabellaris submerged leaves are highly dissected whereas the. leaves are broad and lobed. This is an
(a) heterophylly
(b) environmental plasticity
(c) phenology
(d) both (a) and (b).

Narayan Hari

Numerade Educator

Problem 31

Intrinsic heterophylly is found in all except
(a) Cotton
(b) Buttercup
(c) Coriander
(d) Larkspur.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 32

Larkspur. Growth is maximum in zone of
(a) cell elongation
(b) cell division
(c) cell maturation
(d) all of these

Narayan Hari

Numerade Educator

Problem 33

A primary root grows from $5 \mathrm{~cm}$ to $19 \mathrm{~cm}$ in Calculate the actual growth rate (AGR) and relatily rate (RGR) over the period. AGR $\quad$ RGR (a) $14 \mathrm{~cm} \quad 2.8$
(b) $14 \mathrm{~cm} \quad 3.8$
(c) $3.8 \mathrm{~cm} \quad 14$
$\begin{array}{ll}\text { (d) } 24 \mathrm{~cm} & 2.8\end{array}$

Narayan Hari

Numerade Educator

Problem 34

Development in plants is influenced by both intros? ? extrinsic factors. Which of the following is induder.? intrinsic factors?
(a) Growth regulators
(b) Oxygen
(c) Water
(d) All of these

Narayan Hari

Numerade Educator

Problem 35

Functions of plant growth promoters and plart $\underline{x}$ inhibitors are given here in a jumbled up manners. Select the option that correctly segregates these funciors
(i) Cell division
(ii) Cell enlargemert
(iii) Pattern formation
(iv) Tropic growh
(v) Flowering
(vi) Fruiting
(vii) Seed germination
(viii) Response to wourt:
(ix) Response to stresses
(x) Dormancy of biotic and abiotic origin

Parvati Devi

Numerade Educator

Problem 36

Match the column - I with column - II and select the correct option from the codes given below.

Parvati Devi

Numerade Educator

Problem 37

Select the pair that consist of plant growth promoters only
(a) Auxins and cytokinins
(b) Gibberllins and ABA
(c) Ethylene and Aba
(d) all of these

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 38

Which of the following is both a growth promoter as well as a growth inhibitor?
a. Auxin
b. Gibberllic Acid
c. ABA
d. Ethylene

Narayan Hari

Numerade Educator

Problem 39

Who isolated auxins from tips of coleoptiles of oat seedlings?
a. Darwin and Darwin
b. Went
c. Skoog et al
d. Kurosawa

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 40

Match the column - I with column - II and select the correct option from the codes given below.
Column-I
A Natural auxin
B. Synthetic auxin
C Bakane disease of rice
D. Natural cytokinin
Column-Il
(i) NAA
(ii) Zeatin
(iii) IAA
(iv) GA
(v) Kinetin
(a) $A-(i i i), B-(i), C-(i v), D-(i i)$
(b) $A-(i), B-(i i i), C-(i v), D-(v)$
(c) $A-(i i i), B-(i), C-(i v), D-(v)$
(d) $A-(i v), B-(i), C-(v), D-(i i)$

Parvati Devi

Numerade Educator

Problem 41

Which of the following hormones is used in root formation On stem cuttings?
(a) Kinetin
(b) GA
(c) $A B A$
(d) $I B A$

Narayan Hari

Numerade Educator

Problem 42

Apical dominance in dicot plants is due to the presence of more _______ in the apical bud than in the lateral ones.
(a) auxins
(c) gibberellins
(b) cytokinins
(d) ethylene

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 43

In addition to auxins, medium to obtain a good callus in plant tissue culture.
(a) $\mathrm{ABA}$
(b) cytokinins
(c) gibberellins
(d) ethylene

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 44

Select the mismatched pair.
(a) Gibberellic acid - Increases yield of sugarcane
(b) Cytokinin - Promotes apical dominance
(c) Ethylene - Sprouting of potato tuber
(d) Abscisic acid - Inhibits seed germination

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 45

Read the given statements and select the correct option.
(i) Darwin and Darwin (1880) found that sensation of tip of canary grass.
(ii) IAA is universal natural auxin, discovered by Kogl et al.
(iii) IBA is both natural and synthetic auxin.
(iv) Auxins promote the growth of lateral shoots.
(a) Statements (i) and (ii) are correct
(b) Statements (ii) and (iii) are correct
(c) Statements (i), (ii) and (iii) are correct
(d) Statements (i), (ii), (iii) and (iv) are correct

Parvati Devi

Numerade Educator

Problem 46

The term 'auxin precursor' refers to
(a) raw material used in the synthesis of auxin
(b) compound which inhibits the action of auxin
(c) artificially synthesized auxin
(d) active form of auxin.

Parvati Devi

Numerade Educator

Problem 47

In the process of apical dominance, lateral buds are unable to grow in the presence of apical bud. This is due to
(a) less amount of auxin in apical bud
(b) more amount of auxin in apical bud
(c) less amount of cytokinins in lateral buds
(d) more amount of cytokinins in lateral buds.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 48

In plant tissue culture experiments, high auxin to cytokinin ratio favours _____ development and high cytokinin to auxin ratio favours _____ development.
(a) root, shoot
(b) shoot, root
(c) root, root
(d) shoot, shoot

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 49

Decapitation i.e. removal of shoot tips in a plant usually results in
(a) inactivation of lateral buds
(b) growth of lateral buds
(c) cessation of plant growth
(d) yellowing of leaves.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 50

Functions of auxins include
(a) promoting flowering in pineapple
(b) inducing parthenocarpy in tomato
(c) use as herbicides to kill dicot weeds
(d) all of these.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 51

The hormone responsible for apical dominance is
(a) IAA
(b) GA
(c) $\mathrm{ABA}$
(d) florigen.

Narayan Hari

Numerade Educator

Problem 52

The term 'antiauxin' refers to
(a) raw material used in the synthesis of auxin
(b) compound which inhibits the action of auxin
(c) artificially synthesized auxin
(d) active form of auxin.

Narayan Hari

Numerade Educator

Problem 53

Which of the following effects of auxins on plants is the basis for their commercial application?
(a) Callus formation
(b) Curvature of stem
(c) Induction of root formation in stem cuttings
(d) Induction of shoot formation

Narayan Hari

Numerade Educator

Problem 54

The phenomenon of apical dominance can be overcome by exogenous application of
(a) auxins
(b) gibberellins
(c) cytokinins
(d) ethylene.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 55

A plant hormone used for inducing morphogenesis in plant tissue culture is
(a) abscisic acid
(b) gibberellin
(c) cytokinin
(d) ethylene.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 56

Artificial ripening of fruits is caused by the treatment of
(a) $\mid \mathrm{AA}$
(b) $\mathrm{NAA}$
(c) ethylene
(d) kinetin.

Narayan Hari

Numerade Educator

Problem 57

Induction of cell division activity and delay in senescence is caused by
(a) gibberellin
(b) auxin
(c) cytokinin
(d) ethylene.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 58

Cytokinins are mostly
(a) glucosides
(b) phenolics
(c) amino purines
(d) organic acids.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 59

The hormone which reduces transpiration rate by inducing stomatal closure is
(a) $\mathrm{ABA}$
(b) ethylene
(c) cytokinin
(d) gibberellin.

Narayan Hari

Numerade Educator

Problem 60

High concentration of auxin is present in
(a) root apex
(b) stem apex
(c) node
(d) petiole.

Narayan Hari

Numerade Educator

Problem 61

Match Column-I with Column-II and select the correct option from the codes given below. Column-I $\quad$ Column-II
Column-I
A. Auxins
B. Gibberellins
C. Cytokinins
D. Ethylene
Column-II
(i) Breaking seed dormancy
(ii) Inducing fruit ripening
(iii) Formation of abscission layer
(iv) Root initiation
(v) Chloroplast development in leaves

Parvati Devi

Numerade Educator

Problem 62

The activity of $\alpha$-amylase in the endosperm of a seed of barley is induced by
(a) ethylene
(b) cytokinin
(c) $\mathrm{IAA}$
(d) gibberellin.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 63

Hormone involved in phototropism is
(a) $\mathrm{IAA}$
(b) gibberellin
(c) kinetin
(d) $2,4-D$.

Narayan Hari

Numerade Educator

Problem 64

Artificial application of auxins like IAA, IBA unpollinated pistils can form
(a) fruits with much flesh
(b) larger fruits
(c) sweet fruits
(d) seedless fruits.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 65

Which of the following physiological effects plants by gibberellic acid?
(a) Shortening of genetically tall plants.
(b) Elongation of genetically dwarf plants.
(c) Rooting in stem cuttings.
(d) Yellowing of young leaves.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 66

To get a carpet like grass, lawns are mowed requlth; is done to
(a) remove the shoot apical meristem
(b) remove the axillary buds
(c) accelerate the growth of terminal bud
(d) both (b) and (c).

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 67

Gibberellin was first extracted from
(a) Gibberella fujikori
(b) Gelidium
(c) Gracilaria
(d) Aspergillus.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 68

Dwarfness can be controlled by treating the plant with
(a) cytokinin
(b) gibberellic acid
(c) auxin
(d) antigibberellin.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 69

Hormone responsible for ageing is
(a) GA
(b) $\mathrm{IAA}$
(c) $\mathrm{ABA}$
(d) cytokinin.

Narayan Hari

Numerade Educator

Problem 70

Hormone primarily connected with cell division is
(a) $\mathrm{IAA}$
(b) NAA
(c) cytokinin
(d) gibberellic acid.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 71

Avena Curvature test is a bioassay for examining the activity of
(a) auxins
(b) gibberellins
(c) cyokinins
(d) ethylene.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 72

Bud dormancy is induced by
(a) IAA
(b) GA
(c) $A B A$
(d) ethylene.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 73

Hormone that promotes growth of lateral buds and has negative effect on apical dominance is
(a) cytokinin
(b) gibberellin
(c) auxin
(d) both (b) and (c).

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 74

in tea plantations and hedge making, gardeners trim the plants regularly so that they remain bushy. Scientific explanation behind this is
(a) removal of apical dominance
(b) growth of lateral buds
(c) suppression of lateral buds
(d) both (a) and (b).

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 75

Intemodal elongation is stimulated by
(a) auxin
(b) $\mathrm{ABA}$
(d) otokinin
(d) gibberellin.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 76

Which one is paired incorrectly?
(a) Auxin- Isolated from human urine
(b) Zeatin- Isolated from corn kernels and coconut milk
(c) Gibberellins - Isolated from fungus G. fujikori
(d) Abscisic acid - Isolated from ripened oranges

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 77

Removal of auxin source demonstrates that leaf abscission is _________ by auxin, and apical dominance is _________ auxin.
a) promoted, promoted
b) inhibited, inhibited
(c) promoted, inhibited
(d) inhibited, promoted

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 78

The fruits can be left on the tree longer using GA so as to extend the market period. This is due to which function of GA?
(a) Bolting
(b) Delaying senescence
(c) Internodal elongation
(d) Inducing parthenocarpy

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 79

Spraying sugarcane with gibberellins increases the yield by as much as 20 tonnes per acre. GA performs it by
(a) improving the quality of fruit
(b) increasing sugar content
(d) internodal elongation
(d) delaying senescence.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 80

Auxin and cytokinin are antagonistic in which of the following functions?
(a) Cell division
(b) Phototropism
(c) Apical dominance
(d) Geotropism

Parvati Devi

Numerade Educator

Problem 81

Natural cytokinins are synthesized in regions where rapid cell division occurs. Such regions are
(a) root apices
(b) developing shoot buds
(c) young fruits
(d) all of these.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 82

Kinetin, a modified form of adenine was discovered from
(a) autoclaved herring sperm DNA
(b) coconut milk
(c) corn kernel
(d) fungus.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 83

Cytokinins help to produce all except
(a) new leaves
(b) chloroplast in leaves
(c) lateral shoot growth and adventitious shoot formation
(d) rooting on cut stem.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 84

Seed dormancy is caused by
(a) $\mathrm{C}_{2} \mathrm{H}_{4}$
(b) $\mathrm{ABA}$
(c) $\mathrm{IAA}$
(d) $\mathrm{GA}_{3}$.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 85

Read the given statements and select the option that correctly identifies the incorrect ones.
(i) Cytokinin is primarily concerned with cell division.
(ii) $\mathrm{C}_{2} \mathrm{H}_{4}$ breaks seed and bud dormancy
(iii) ABA stimulates the opening of stomata.
(iv) $\mathrm{C}_{2} \mathrm{H}_{4}$ initiates germination in peanut seeds, sprouting of potato tubers.
(v) $\mathrm{ABA}$ is synergistic to GA.
(a) (i), (ii) and (iv)
(b) (iii) and (ii)
(c) (iii) and (v)
(d) (iv) and (v)

Parvati Devi

Numerade Educator

Problem 86

Read the given statements and identify the plant hormones $X, Y$ and $Z$.
(i) Hormone $Y$ induces flowering in mango and also promotes rapid internode/petiole elongation in deep water rice plants and hence helping leaves or upper part of shoot to remain above water.
(ii) Hormone $X$ promotes root growth and root hairs formation.
(iii) Hormone Z inhibits the seed germination, increases the tolerance of plant to various stresses, play important role in seed development, maturation and dormancy.
(a) $\mathrm{Y}-\mathrm{ABA}, \mathrm{X}-$ Auxin, $\mathrm{Z}-\mathrm{GA}$
$=$
(b) $Z-G A, X-A u x i n, Y-C_{2} H_{4}$
(c) $\mathrm{Y}-\mathrm{Auxin}, \mathrm{X}-\mathrm{C}_{2} \mathrm{H}_{4}, \mathrm{Z} \cdot \mathrm{GA}$
(d) $\mathrm{Y}-\mathrm{C}_{2} \mathrm{H}_{4}, \mathrm{X}-\mathrm{C}_{2} \mathrm{H}_{4}, \mathrm{Z}-\mathrm{ABA}$

Parvati Devi

Numerade Educator

Problem 87

The most widely used compound as a source of $\mathrm{C}_{2} \mathrm{H}_{4}$ is
(a) kinetin
(b) zeatin
(c) $\mathrm{IBA}$
(d) ethophen.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 88

Which of the following statements regarding gibberellins is incorrect?
(a) $\mathrm{GA}_{3}$ was one of the first gibberellins to be discovered.
(b) All GA are acidic.
(c) They increase the length of plant axis as in grapes, sugarcanes etc.
(d) They promote senescence.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 89

Bolting i.e. internode elongation just prior to flowering in beet, cabbage and many rosette plants, is promoted by
(a) auxins
(b) gibberellins
(c) cytokinins
(d) ethylene.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 90

Select the correct statement(s) regarding auxins.
(a) Auxins promote root growth only at extremely low concentrations and they inhibit root growth at higher concentrations.
(b) Concentration of auxins which is inhibitory to root growth causes initiation of adventitious roots from the nodes or basal regions of stem.
(c) Auxins such as NAA and IBA are used to induce rooting in stem cuttings.
(d) All of these.

Parvati Devi

Numerade Educator

Problem 91

Which among the following is not a function of cytokinins?
(a) Essential for cytokinesis during cell division
(b) Delays the senescence of leaves
(c) Helps in fruit ripening
(d) Helps to overcome apical dominance

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 92

Match Column-I with Column-II and select the correct option from the codes given below.
Column-I (Phytohoromne)
A. $\mathrm{IAA}$
B. Cytokinins
C. Ethylene
Column-II (Plant part where it is synthesized)
(i) Tissues undergoing senescence
(ii) Shoot apices
(iii) Root apices
(a) $\mathrm{A}-(\mathrm{ii}), \mathrm{B}-(\mathrm{iii}), \mathrm{C}-(\mathrm{i})$
(b) $\mathrm{A}-(\mathrm{iii}), \mathrm{B}-(\mathrm{ii}), \mathrm{C}-(\mathrm{i})$
(c) $\mathrm{A}-(\mathrm{i}), \mathrm{B}-(\mathrm{ii}), \mathrm{C}-(\mathrm{iii})$
(d) $\mathrm{A}-(i i), \mathrm{B}-(i), \mathrm{C}-(\mathrm{iii})$

Parvati Devi

Numerade Educator

Problem 93

Read the given statements to identify the phytohormone that performs these functions.
(i) Horizontal growth of seedlings, swelling of the axis and apical hook formation in dicot seedlings.
(ii) Promoting senescence and abscission lro flowers.
(iii) Breaking seed and bud dormancy. (iv) Initiating germination in peanut seeds.
(v) Sprouting of potato tubers.
(a) $\mathrm{ABA}$
(b) Ethylene
(c) GA
(d) Cytokinins

Parvati Devi

Numerade Educator

Problem 94

Gibberellins promote the formation of $A$ flowe, genetically $\underline{\text { B }}$ plants in Cannabis whereas ethylenepor plants.
(a) male female female male
(b) male male female female
(c) female male male female
(d) female female male male

Parvati Devi

Numerade Educator

Problem 95

A farmer grows cucumber plants in his field, He nirg increase the number of female flowers in them. Which growth regulator can be applied to achieve this?
(a) $\mathrm{ABA}$
(b) Ethylene
(c) $G A$
(d) Cytokinins

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 96

The hormone ' $X$ ' does the following functions.
(i) Induces seed dormancy.
(ii) Inhibits seed germination.
(iii) Prepares plants to cope with stress.
(iv) Stimulates closure of stomata. The hormone ' $X$ ' should be
(a) $\mathrm{ABA}$
(b) ethylene
(c) GA
(d) cytokinins.

Parvati Devi

Numerade Educator

Problem 97

Phytohormone A causes apical dominance w phytohormone $\mathrm{B}$ overcomes the same. Select the our that correctly identifies $\mathrm{A}$ and $\mathrm{B}$.
(a) Auxin Cytokinin
(b) Cytokinin Auxin
(c) Gibberellin Cytokinin
(d) Auxin Gibberellin

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 98

Which phytohormone would you use if you are aset! 'bolt'a rosette plant?
(a) Auxins
(b) Gibberellins
(c) Cytokinins
(d) Any of these.

Parvati Devi

Numerade Educator

Problem 99

If a rotten fruit gets mixed with unripe fruits, the of fruits will
(a) also be rotten
(b) ripe quickly
(c) remain unchanged
(d) none of these.

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 100

What would happen if you forget to add cytokinin to the culture medium?
(a). Callus will not develop shoot buds
(b). Callus will not develop root buds
(c). Callus will stop differentiating
(d). both (a) and (b)

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 101

Read the given statements and select the correct option.
statement 1: Ethylene is a gaseous hormone.
statement 2: Ethylene causes climacteric ripening of fruits
(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statements 1.
(b) Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statements 1.
(c) statements 1 is correct and statements 2 are incorrect .
(d) Both statements 1 and 2 are incorrect and

Parvati Devi

Numerade Educator

Problem 102

Read the given statements and select the correct option.
statement 1: Elongation of reduced stem is possible due to application of gibberellin hormone.
statement 2: Gibberellin stimulates cell division and cell elongation.
(a) Both statements 1 and 2 are correct and statement 2 is the correct explanation of statements 1.
(b) Both statements 1 and 2 are correct but statement 2 is not the correct explanation of statements 1.
(c) statements 1 is correct and statements 2 are incorrect .
(d) Both statements 1 and 2 are incorrect and

Parvati Devi

Numerade Educator

Problem 103

Match the column - I with column - II and select the correct option from the codes given below.
Column-I
A. Auxin
B. Cytokinins
C. Abscisic acid
D. Ethylene
Column-Il
(i) Fruit ripening
(ii) Phototropism
(iii) Antagonist to GAs
(iv) Growth of lateral buds
(a) $A-(\mathrm{iv}), \mathrm{B}-(\mathrm{ii}), \mathrm{C}-(i i i), \mathrm{D}-(\mathrm{i})$
(b) $A-(i i), B-(i v), C-(i i i), D-(i)$
(c) $A \cdot(i i) ; B-(i i i), C-(i v), D-(i)$
(d) $A-(i i i), B-(i v), C-(i i), D-(i)$

Parvati Devi

Numerade Educator

Problem 104

Which plant hormone induces the phenomenon of phototropism in plants?
(a) Auxins
(b) Ethylene
(c) Cytokinin
(d) Gibberellin

Nikhil Choudhary

Nikhil Choudhary

Numerade Educator

Problem 105

To speed up the malting process in brewing industry the growth hormone used is
(a) auxin
(b) gibberellin
(c) kinetin
(d) ethylene.

Parvati Devi

Numerade Educator

Problem 106

Plants which require an exposure to light for a period greater than critical day length are
(a) long day plants
(b) short day plants
(c) long-short day plants
(d) short-long day plants.

Parvati Devi

Numerade Educator

Problem 107

Which of the following is correct about phytochrome?
(a) $\mathrm{P}_{\mathrm{r}}$ absorbs red light and becomes $\mathrm{P}_{\mathrm{fr}}$.
(b) $P_{f}$ absorbs yellow light and becomes $P_{f r}$.
(c) $\mathrm{P}_{\mathrm{ff}}$ absorbs yellow light and becomes $\mathrm{P}_{\mathrm{r}}$.
(d) $P_{f f}$ absorbs red light and becomes $P_{r}$.

Parvati Devi

Numerade Educator

Problem 108

Photoperiod stimulus is perceived by_____ pigment.
(a) cryptochrome
(b) cytochrome
(c) phytochrome
(d) monochrome

Parvati Devi

Numerade Educator

Problem 109

The given figure shows flowering responses of three plants $A, B$ and $C$ to the photoperiod. Select the correct option regarding this.
(a) Long day plant Day neutral plant Short day plant
(b) Short day plant Day neutral plant Long day plant
(c) Long day plant Short day plant Day neutral plant
(d) Short day plant Long day plant Day neutral plant

Parvati Devi

Numerade Educator

Problem 110

Maryland mammoth tobacco is a short day plant. Its critical duration of darkness is 10 hours. Under which of the following conditions will it not flower?

Parvati Devi

Numerade Educator