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PLANT GROWTH AND DEVELOPMENT

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Section-A

1.In the exponential phase of geometric growth, the

Progeny cells stops dividing
Both progeny cells follow mitotic division
Both Progeny cells stops dividing and follow mitotic division
Only one progeny cell follows mitotic division graphs
In the exponential growth, there is geometric increase of organism (cell, mass, etc.) because both the cell follows the mitosis. This type of growth can be seen in microorganism and embryo stage of animals and plants

2.Which hormone is responsible for apical growth?

IAA
ABA
GA
All of these
IAA (auxin) is responsible for apical growth (apical dominance) in which presence of apical bud does not allow the nearby lateral buds to grow.

3.Arithmetic growth is linear because

One daughter cell remains meristematic and other differentiates and mature
Both daughter cell remains meristematic
Both daughter cells gets matured
All of the above
Arithmetic growth is linear because in this growth, there is a sequential adding of the new cell. One daughter cell remains meristematic (dividing) while the other becomes mature and gets differentiated

4.S-shaped or sigmoid growth curve have
I. lag phase
II. log phase
III. stationary phase
IV. diminishing growth phase
Select the correct option

All except IV
All except III
All except II
I, II, III and IV
Geometric growth curve shows ‘S’-shaped curve. ‘S’-shaped have has following phases
(i) Lag phase
(ii) Log phase
(iii) Stationary phase
(iv) Diminising of growth phase.
Geometrical Growth In most system the initial growth is slow (lag phase), and it increases there after at a exponential rate (log or exponential phase). Both the progeny cells following mitotic cell division retains the ability to divide and continue to do so. However due to the limited nutrient supply, the growth slows down leading to stationary phase. If we plot the parameter of growth against time, a typical sigmoid curve is obtained.
It has following stages
1. During lag phase, organism adapt themselves to growth conditions. It is the period where the individual organism are maturing and not yet able to divide. During the lag phases of the bacterial growth cycle, synthesis of RNA, enzyme and other molecules occurs
2. The log phase (sometimes called the logarithmic phase or the exponential phase) is a period characterised by cell doubling. The number of new organism appering per unit time is proportional to the present population.
3. The stationary phase is often due to a growth-limiting factor such as the depletion of an essential nutrient, and/or the formation of an inhibitory product such as an organic acid. Stationary phase results from a situation in which growth rate and death rate are equal
4. Death phase, organism run out of nutrients and die

5.The coiling of tendril around some base in response to touch, is called

Hydrotaxis
Chemotaxis
Thigmotropism
Geotaxis
Contact or touch stimulus that induced growth movements are called ‘thigmotropism’. E.g., binding of tendril, twisting of twinner around a solid support, stem of Ciscuta, root of Vanilla

6.Name the process when dedifferentiated cells again loss the ability to divide and get mature?

Cell-enlargement
Redifferentiation
Dedifferentiation
Differentiation
Redifferentiation as the name suggest indicates again differentiation. When dedifferentiated cell again get differentiated, the phenomena is called redifferentiation. e.g., secondary cortex

7.‘Bakane’ disease is related to (hormone and plant)

Auxin & Wheat
Cytokinin & Corn
Gibberellin & Rice
Ethylene & Tomato
Gibberellins were named after the fungus Gibberella fujikuroi which causes disease in rice plants. A Japanese plant pathologist, Elichi Kurosawa investigated it as the bakane (foolish seedling) disease

8.Which of the PGR induces parthenocarpy in tomatoes?

Auxin
Gibberellin
Cytokinin
Ethylene
Auxin induces perthenocarpy in tomatoes.

9.Which hormone (PGR) encounters the apical dominance induced by auxin?

IAA
Cytokinin
$C_2 H_4$
NAA
Cytokinin encounter the apical dominance by promoting the cell division in lateral shoots. It is also used to increase the growth of lateral buds in short plants

10.The problem of necrosis and gradual senescence, while performing tissue culture can be overcome by

Spraying auxins
Spraying cytokinins
Suspension culture
subculture
The ageing process of the leaves usually accompanies with loss of chlorophyll and repid breakdown of proteins called as senescence. Spraying of cytokinin delays senescence and increases the rate of chlorophyll formation.

11.The cells proximal (just next away from the tip) to the meristematic zone represents the phase of

Division
Maturation
Elongation
Meristematic division
The cells proximal (just next, away from tip) to the meristematic zone represents the phase of elongation. Increased vacuolation, cell enlargement and new cell wall deposition are the characteristics of the cells in this phase

12.Heterophylly can be observed in
I. cotton
II. coriander
III. larkspur
Select the right option

I, II and III
I and II
II and III
I and III
Heterophylly can be observed in cotton, coriander, and larkspur

13.One set of a plant was grown at 12 hours day 12 hours night period cycles and it flowered, while in the other set night phase was interrupted by flash of light and it did not produce flower. Under which one of the following categories will you place this plant?

Long day
Darkness neutral
Day neutral
Short day
The conditions show that the plant requires photoperiod shorter than the critical day length.
This plant needs uninterrupted dark period for flowering.
Therefore, it is a short day plant and these plants do not flower if the dark period is interrupted with flashes of light.

14.Decapitation (shoot tip removal) is widely used in

Blotting
Hedge making
Tea plantation
Both Hedge making and Tea plantation
In most of the higher plants, the growing apical bud inhibits the growth of the lateral (axillary) buds, a phenomenon called apical dominance. Removal of shoot tips (decapitation) usually result in the growth of lateral buds. It is widely applied in tea plantation, hedge-making

15.Which hormone is called the dormancy hormone?

IAA
NAA
ABA
GA
Firstly, the ABA was discovered and named dormin because this hormone induce dormancy in seeds. Hence, it is also called dormancy hormone

16.Cytokinins are mostly

Glucosides
Amino purines
Acidic
phenolic
Cytokinins are amino purines which are derived from autoclaving sperm DNA

17.In geometrical growth, lag phase is represented by

Initial rapid growth
Latter rapid growth
Initial slow growth
Latter slow growth
Lag phase is represent by initial slow growth rate

18.Growth in plants is measured by the increase in
I. fresh weight
II. dry weight
III. length, area and volume
IV. cell number
Choose the correct option

All except I and II
All except III
All except IV
I, II, III and IV
Growth is measured by variety of parameters like
(i) increase in fresh weight
(ii) increase in dry weight
(iii) increase in length, area and volume,
(iv) increase in cell number

19.The natural plant hormone isolated from corn kernels and coconut milk is

Florigen
$GA_3$
Free auxins
Zeatin
This first natural cytokinin was obtained from unripe maize grains or kernels by Lenthan et al. it is known as zeatin (6-hydroxy 3-methyl trans2-butenyl amino –purine). It also occurs in coconunt milk.

20.Opening and closing of flowers represent a kind of

Opening and closing of flowers represent a kind of
Tropic movement
Mutation
Autonomic movement
pening and closing of flowers is a case of photonasty. Flowers of certain plants open in light and close down in dark.

21.The following statements are given about plant growth hormones:
I. Kinetin is a degradative substance from DNA molecule.
II. ABA is present, in all the plants.
III. Low ratio of cytokinins to auxins favours root formation only.
IV. ABA is synthesized catabolically through mevalonate pathway.
The correct combination is

I and II
II and III
I and III
III and IV
Abscisic acid (ABA) is produced in many parts of the green plants. It is formed from mevalonic acid

22.Which one is an example of redifferentiation?

Cork cambium
Secondary cortex
Meristems
Interfasicular cambium
Redifferentiation as the name suggest, indicates again differentiation. When dedifferentiated cell again get differentiated, the phenomena is called redifferentiation. e.g., secondary cortex

23.Growth of an organism is characterised by

An irreversible permanent increase in size of an organ
An irreversible permanent increase in size of a cell
Both irreversible permanent increase in size of an organ and cell
Reversible permanent changes
Growth is regarded as one of the most fundamental and conspicuous characteristics of a living being. Growth can be defined as the irreversible permanent increase in the size of an organ or its part or even of an individual cell. Generally growth is accompanined by metabolic process (both anabolic and catabolic), that occurs at the expanse of energy

24.The phytohormone that helps in germination of seed, is

ABA
Auxin
Gibberellin
cytokinin
During seed germination especially of cereals, gibberellin stimulates the production of hydrolytic enzymes like amylases, proteases and lipases. These enzymes solubilize the reserve food of seed.

25.Search for natural cytokinin lead to the

Isolation of zeatin from corn kernels
Isolation of zeatin from coconut milk
Isolation of zeatin from sugarcane
Isolation of zeatin from both corn kernels and sugarcane
Natural cytokinin was first obtained from corn kernels and coconut milk

26.Which plant hormone is found in gaseous form?

Auxin
Cytokinin
Ethylene
ABA
Ethylene is a simple gaseous PGR. It is synthesised in large amounts by tissues undergoing senescence and ripening fruits

27.Which is used as weedicide?

2,4-D
IBA
IAA
ABA
2, 4-D (2, 4-dichloro-phenoxy acetic acid) is a synthetic auxin. It is selective weedicide and kills broad-leaved dicot plants only.

28.Process of vernalization can be induced by

Cytokinin
Auxin
Phototropin
GA
Vernalization is a process of shortening of the juvenile or vegetative phase and hastening flowering by a previous cold treatment. Vernalization or low temperature requirement of some plants can be replaced by gibberellins.

29.Primary growth of plants is contributed by

Root apical meristem
Shoot apical meristem
Intercalary meristem
All of these
Root Apical Meristem (RAM), Shoot Apical Meristem (SAM) and intercalary meristem are responsible for the primary growth to the plants and they principally contributes to the elongation of the plants along their axis.
In the dicotyledons and gymnosperms, the lateral meristems, vascular cambium and cork cambium appear later in life. These are the meristems that causes increase in the girth of the organ in which they are active. This is known as the secondary growth of the plant

30.Parthenocarpy in tomatoes is induced by

Cytokinin
Auxin
Gibberellin
$CH_2-CH_2$
Functions of Auxin
(i) Auxin helps to initiate rooting in stem cuttings, an application widely used for plant propagation
(ii) Auxin promotes flowering, e.g., in pineapples
(iii) It helps to prevent fruit and leaf drop at early stages
(iv) They promote the abscission of older mature leaves and fruits
(v) Apical dominance
(vi) Induce parthenocarpy in tomatoes
(vii) Controls xylem differentiation and helps in cell division

31.One hormone helps in ripening of fruits, while the other stimulates closure of stomata. These are respectively

Abscisic acid and auxin
Ethylene and abscisic acid
Auxin and ethylene
Ethylene and gibberellic acid
Ethylene helps in ripening of climacteric fruits, while abscisic acid stimulates closure of stomata.

32.The terms auxin is applied to
I. IAA
II. IBA
III. NAA
IV. 2-4-D
Select the correct option

I, II and III
II, III and IV
I, III and IV
I, II, III and IV
The term ‘auxin’ is applied to the indole-3 acetic acid and to other natural and synthetic compound having certain growth regulating properties

33.Apple’s elongation and improvement of its shape is performed by

Auxin
Ethylene
$C_2 H_4$
GA
Gibberellins causes fruit like apple to elongate and improve its shape. They also delay senescence

34.Cytokinins are formed in

Roots
Leaves
Fruits
Stems
Roots seem to be the major source of cytokinin synthesis. From roots, the cytokinins pass upwardly through xylem.

35.Short day plant is

Xanthium
Pisum
Cucumis
Avena
Xanthium is a short day plant.

Section-B

36.Mobilization of stored food in germinating seed is triggered by

ABA
GA
Cytokinin
Ethylene
One of the most dramatic effect of GA is its induction of α-hydrolytic enzymes like proteases, αamylases, lipases, which help to mobilise stored nutrients in the aleurone layer of endosperm of germinating barley seeds and cereal grains.

37.In geometrical growth, log phase is represented by

Rapid consumption of nutrient
Rapid increment of cell number
Highest growth rate
All of the above
In the exponential phase of growth (S-shaped), there is a rapid increase in size, cell number and mass of an organism, due to the rapid consumption of nutrients. Due to rapid consumption of nutrient, the growth rate is highest at this phase

38.Which of the following in incorrectly matched?

Explant – Excised plant part used for callus formation
Cytokinins – Root initiation in callus
Somatic embryo- Embryo produced from a vegetative cell
Anther culture- Haploid plants
Root initiation in callus is the function of auxin. Cytokinins delay the senescence of leaves and other organs and also induce shoot formation.

39.Gibberellin was first discovered from

Algae
Fungi
Bacteria
Roots of higher plants
Gibberellin was first discovered from fungi Gibberella fujikuroi.

40.Growing season is the season of plants in which there is

Maximum vegetative growth
Minimum vegetative growth
Moderate vegetative growth
Maximum reproduction occurs
Parts of the year when maximum vegetative growth occurs is known as growing season

41.The living differentiated cells, regain capacity of division under certain condition which called

Redifferentiation
Dedifferentiation
Differentiation
Reverse division
Dedifferentiation is regaining the capacity to divide of by differentiated cells. For example, formation of meristems in interfascicular cambium and cork cambium from fully differentiated parenchyma cells

42.Growth curve is the

Pictorial representation of total growth/space
Graphical representation of total growth/space
Graphical representation of total growth/time
All of the above
Growth Curve is the graphical representation of total growth against time

43.Which one of the following is not a effect of gibberellin?

Increase grapes stalk
Delay senescence of fruit
Induce dormancy
Increase sugarcane stem
Functions of Gibberellin are
(i) Increase in the length of axis (used to increase the length of grapes stalk)
(ii) Causes fruit like apple to elongate
(iii) Delay senescence of fruits
(iv) Used to speed up the malting process in brewing industry
(v) Spraying on sugarcane increases the stem height
(vi) Early seed production
(vii) Promotes blotting

44.In expression, $L_t=L_0+rt$, of arithmetic growth rate, $ L_t,L_0$ and r respectively represents

Length at time zero, Length at time 't', Elongation per unit time
Length at time 't', Length at time zero, Elongation per unit time
Length at time 't', Length at time zero, Growth rate
Length at time 't', Length at time zero, Growth rate & Elongation per unit time
Arithmetic Growth Rate The expression of arithmetic growth is exemplified by roots (or organ) elongating at constant rate. On plotting the length of an organ against time, a linear curve is obtained. Mathematically it is expressed as
Constant linear growth, a plot of length L against time
$L_t=L_0+rt$
$L_t =$ Length of time ‘t’
$L_0 =$ Length of time to
r = Growth rate or elongation per unit time

45.Differentiation in plants is open because

Cells/tissue arising out of meristem regain the capacity of division under certain conditions
Cells/tissue arising out of different meristem have different structures at maturity
Cells/tissue arising out of different meristem have same structures at maturity
All of the above
The differentiation in plants is open, because cells/tissue arising out of the same meristem have different structure at the maturity. The cells tissues arising out of meristem region the capacity of division under certain condition

46.Abscisic acid is primarily synthesized in

Lysosomes
Golgi complex
Chloroplast
ribosomes
Abscisic acid (ABA) or stress hormone or dormin is present in all vascular plants as well as in some mosses, some green algae and some fungi. They completely absent in bacteria. This is commonly formed inside chloroplast either from mevalonic acid or xanthophyll like violaxanthin. Chloroplasts in leaves contain the cartenoids from which ABA arises, whereas in certain other parts like roots, fruits, seeds, etc, necessary carotenoids are in chromoplasts, leucoplasts or proplastids.

47.Permanent localised qualitative change in size, biochemistry, structure and function of cells or organs is called

Cell division
Meristematic division
Differentiation
Dedifferentiation
Permanent localised qualitative change in size, biochemistry, structure and function of cells or organs is called differentiation

48.Treatment of seed at low temperature under moist conditions to break its dormancy, is called

Scarification
Vernalization
Chelation
Stratification
Stratification involves the treatment of seed at low temperature (5℃-10℃) under sufficiently moist condition to break its dormancy and to induce germination.

49.For cryopreservation, plant materials are frozen at

-196℃
-150℃
-80℃
-40℃
In cryopresservation, plant materials are frozen at -196℃.

50.Plant hormones are

Growth regulators
Growth promoters
Growth inhibitors
All of these
Plant hormones or phytohormones can be defined as a chemical substance produced naturally in plants, which is translocated to another region for regulating (by inhibitory or enhancing effect) one or more physiological reactions when present in low concentration.
1. Growth promoter -Auxins, gibberellins and cytokinins
2. Growth inhibitor -Ethylene, ABA, etc.