Short Question For Plant Physiology
1) What turgor
pressure?
In plant cells the pressure
component arises from the force exerted out wardly against the cell wall by
expanding protoplast is called Turgor pressure.
2) What are diffusion and
diffusion pressure deficit?
Diffusion is the net movement of molecules or
atoms from a region of high concentration(or high chemical potential) to a
region of low concentration (or low chemical potential).This is also referred
to as the movement of a substance down a concentration gradient.
The difference in the diffusion pressure between a solution
and its solvent is called diffusion
pressure deficit (DPD).It
was coined by B.S Meyer in 1938.The DPD of a solution is always lesser than its
pure solvent.
3) What is
plasmolysis? Give an example.
The shrinkage of protoplast of
cells due to exosmosis when the cell is placed
in hypertonic solution is called plasmolysis.
When a living
plant cell is placed in a sufficiently concentrated solution of a suitable
agent (e.g. cane sugar), plasmolysis occurs.
4) What is water
potential?
Water potential is a measure of the potential energy in water as well as the
difference between the potential in a given water sample and
pure water. Water potential is represented by the equation Ψ system = Ψ total=
Ψ s + Ψ p + Ψ g + Ψ m.
5) What is diffusion
pressure gradient?
6) What incipient plasmolysis?
The initial
stage of plasmolysis in plant cell
when the protoplasm just begins to separate from cell wall is called incipient plasmolysis.
7) What is suction
pressure?
The
actual pressure with which
cell absorbs water is called "suction
pressure”.
8)What is the difference between semi-permeable and a selectively permeable membrane?
Semi
permeable membrane permits the entry of solvent through it but Selectively
permeable membrane permit the entry of
solvent as well as some low molecular weight solute particle through it.
9) What is a saturation
vapour pressure?
Vapor
pressure is a measurement of the amount of moisture in the air.
It is technically the pressure of water vapor above a surface of water.When air reaches the saturation vapor pressure, the water vapor
in it will condense. At this time, the dew point temperature is the same as the
air temperature. A solute has a lower saturation vapor pressure than pure
water, which means that there is a wider range of air pressures for which the
solute can condense than for the pure water. It is easier for the solute cloud
droplet to grow.
The
saturation vapor pressure is
the pressure of a vapor when it is in equilibrium with the liquid phase. It is
solely dependent on the temperature. As temperature
rises the saturation vapor pressure rises as well.
10) What are active
and passive absorption?
The
intake of water by plantwith the use of wnergy is called active
absorption.The intake of water by plants
due to transpiration pull from the top of the plant and without using energy is
called passive absorption.
11) What is meant by
physiologically dry soil?
Physiologically dry soil is
that kind of soil in which, concentration of salts are very high. That's why
halophytes grow in that kind of soil. It is found in coastal area like Sunderbans area, India.
12) What is wilting
coefficient?
Wilting coefficient is defined as the ratio
of amount of transpired water and of
absorbed water by a plant kept in optimum condition.
13) What is root
pressure?
Root pressure is osmotic pressure within the cells of a root system that
causes sap to rise through a plant stem to the leaves. Root pressure occurs
in the xylem of some vascular plants when the soil moisture level is high
either at night or when transpiration is low during the day.
14) What are apoplast
and symptast?
15) What are
peristomatal and lenticular transpiration?
Peristomatal transpiration: Peristomatal transpiration is defined as the
relative high local rate of cuticular water loss from external and internal
surfaces around the stomatal pore.
Lenticular transpiration Sometimes water may evaporate through certain other
openings present on the older stems. These openings are called Lenticels and
the transpiration that takes place through term is known as Lenticular
Transpiration.
16)Which hormone is
responsible for hydroactive stomatal closure?
Abscisic acid
(ABA) is an isoprenoid plant hormone, which
is is responsible for
hydroactive stomatal closure.
17) What is
antitranspitant? Give two examples.
Antitranspirants are compounds applied to the leaves of plants to reduce
transpiration.They are used on Christmas trees,on cut flowers, on newly
transplanted shrubs, and in other applications to preserve and protect plants
from drying out too quickly.Eg: ABA, Phenylmercuric acetate.
18) Name two
commercial antitransirants.
Phenylmercuric
acetate and Silicone oil.
19)What is guttation?
Name one plant where guttation is observed.
Guttation is the exudation of
drops of xylem sap on the tips or edges of leaves of some vascular plants, such
as grasses. Guttation is not to be confused with dew, which
condenses from the atmosphere onto the plant surface. It is common in Lycopersicon esculentum.
20) What is the
function of hydathode?
A hydathode is a type
of secretory tissue in leaves, commonly found in Angiosperms, that secretes
water through pores in the epidermis or leaf margin, typically at the tip of a
marginal tooth or serration.
21) What is bleeding
of plant?
Bleeding is leakage of sap from
a wound or pruning cut on a tree, shrub or woody climber. Sometimes this may be
a gentle seeping, other times a copious flow.Bleeding occurs due to the pressure
of sap within the tissues that conduct water and sugars around the plant.
22)What sunken stomata?
Where is it observed?
A sunken stomata is a
stomata in a small pit, which protects the escaping water vapor from air
currents, decreasing water loss from the leaf. Sunken stomata are commonly found in plants in arid
environments as one of their adaptations to preserve water. Plants with sunken
stomata often have fewer stomata in general than plants in moister
environments.
24)Which ion
predominantly regulates guard cell opening and closing?
K+ Ion.
25) What is ascent of
sap?
The upward movement
of water
and minerals from the root to
aerial parts of the plant body is called ascent of sap or often called
translocation of water. It occurs in the xylem
tissue of plants from the root to the crown.
26)What is evapotransanspiration?
Evapotranspiration (ET) is the sum of evaporation and plant transpiration from
the Earth's land and ocean surface to the atmosphere. Evaporation accounts for
the movement of water to the air from sources such as the soil, canopy
interception, and water bodies.
27) What type of
chlorophyll is found in higher plants?
Mainly chlorophyll-a and chlorophyll-b.
28) Where do
chlorophyll-c and chlorophyll-d occur?
29) What is the basic
chemical difference between phycobillin and chorophyll?
Phycobilins are water
soluble tetrapyrrol pigment whreas
Chlorophylls are water insoluble
tetrapyrrol pigment.
30) Mention the basic chemical
difference between chlorophyll-a and
chlorophyll-b.
31) Which part of the spectrum is absorbed by phycocyanin and
phyeoerythrin?
Phycocyanin is a pigment-protein complex from the light-harvesting phycobiliprotein absorbing orange and red light, particularly near
620 nm (depending on which specific type it is), and emits fluorescence at
about 650 nm (also depending on which type it is)
32) What is red drop?
Wavelengths
beyond 700nm are apparently of insufficient energy to drive any part of
photosynthesis. So a huge drop in efficiency has been noticed at 700nm i.e.,
the red zone of visible spectrum. Thus this phenomenon is called as Red Drop
Effect.
33) Name two mobile
electron carriers in photosynthetic electron transport system.
Ferredoxin
NADP Reductase (FNR) and Plastoquinone Qb
34) What are
absorption and action spectra?
35) What is Hill reaction?
When
leaf extract containing chloroplasts are
supplemented with hydrogen acceptor and then illuminated, reduction of hydrogen
acceptor take place and subsequently release of oxygen takes place.This
reaction was discovered by Robin Hill and thus the reaction is named as Hill
reaction.
36) Name one inhibitor of
non-cyclic photophosphoryation.
DCMU
37) What is meant by macronutrient? Give two examples.
Macronutrients are nutrients that provide calories or energy. Nutrients are
substances needed for growth,metabolism and for other body functions.Since
“macro” means large, macronutrients are nutrients needed in large amounts.
Example: Nitrogen, Phosphorous
38) What is meant by micronutrient? Give two examples.
Micronutrients are dietary components, often referred to as vitamins and
minerals, which although only required by the body in small amounts, are vital
to development, disease prevention, and well being. Example: Zinc, Molybdenum
39)Name two nutrient
which is responsible for chlorosis?
Mg and Mn
40)
Name two nutrient solutions for plants.
1. The Hoagland solution is a hydroponic nutrient
solution that was provides every nutrient necessary for plant growth and is
appropriate for the growth of a large variety of plant species.
2. M.S Medium
41)
Name two enzymes where Mg acts as an activator.
Hexokinase
42)
Name two enzymes where Zn acts as an activator.
Carboxy
peptidase
43)
Name two enzyme where copper is present.
Ascorbic acid oxidase and Polyphenol oxidase
44) Name one metal, which play important
role in biological nitrogen fixation
Zinc
45)From which wavelength red drop is
observed?
Beyond 700nm
46) Give examples of two plants
having C4 pathway.
47)
How much moles of ATP and NADPH are required for the formation of one mole of
hexose sugar in a CAM plant?
48)
Name the cell organelle where photorespiration is occured.
Chloroplast,
Peroxisome and Mitochondria.
49)
What is rubisco?
Ribulose bisphosphate carboxylase/oxygenase,commonly known by
the abbreviation RuBisCO, is an enzyme involved in the
first major step of carbon fixation, i.e., fixation of atmospheric carbon
dioxide.
50)
What is C2 cycle?
51)
What is photo-inhibition?
Photoinhibition is
light-induced reduction in the photosynthetic capacity of a plant, alga,or
cyanobacterium. Photosystem-II (PSII) is more sensitive to light than the rest of the
photo-synthetic machinery,and most researchers define the term as light-induced
damage to PS-II.
52)
What is krantz anatomy’? Where is it found?
53) In
which pathway CO2 is fixed at night?
Crassulacean
Acid Metabolism cycle
54)
Which enzyme reduces nitrate to nitrite?
55)
What is the full form of GOGAT?
GOGAT
stands for Glutamine oxoglutarate
aminotransferase.It is also known as Glutamate synthase.
56)
What is the function of glutamine synthase?
Major role of glutamine synthetase (GS) in plant nitrogen
metabolism. GS functions as the major assimilatory enzyme for ammonia produced
from N fixation, and nitrate or ammonia nutrition. It also reassimilates
ammonia released as a result of photorespiration and the breakdown of proteins
and nitrogen transport compounds. GS is distributed in different subcellular
locations (chloroplast and cytoplasm) and in different tissues and organs.
57)
Name two non-leguminous nitrogen-fixing angiosperms.
Casuarina
58)
What is leghemoglobin?
Leghemoglobin is
a nitrogen or oxygen carrier, because naturally occurring oxygen and nitrogen
interact similarly with this protein; and a hemoprotein found in the
nitrogen-fixing root nodules of leguminous plants.
59)
Which phyto-hormones are responsible for callus formation in plant tissues?
Auxins,Gibberelin
and Cytokinin
60)
What are bound auxins and free auxins?
Auxins
which remain conjugated with sugars,
sugar alcohol or proteins are called bound auxin.They remain inactive in cells.
Auxin which
exist as a free soluble auxin are called
as free auxin.They remain active in cell and tissue.
61)
Name the precursor of auxin in plants.
The
major precursor of Auxin is most likely the amino acid
Tryptophan.
62)
What is basipetal ant acropetal transport
of auxin?
In shoot system
auxins move downwards from the apex to the base of the tem.Such transport of auxin is called basipetal polar transport.
In root system
auxins move up wards from the root tip to the base of stem.Such transport of auxin is called acropetal polar transport.
63)Write
the auxin transport pattern in
root?
In root system
auxins move up wards from the root tip to the base of stem.Such transport of auxin is called acropetal polar transport.
64)
What is anti-auxin?
Any
substance that inhibits auxin by competing for the same receptors
are known as antiauxin.
65)
Name two synthetic auxins.
Indole Butyric Acid and 2,4-Dichloro acetate
66)
Name one hormone which delays leaf abscission.
Auxin/ cytokinin
67)Name one fungus which produces
gibberellin.
Gibberella
fujikuroi , an endophytic
fungi produce
gibberellins.
68)Name
one hormone which is able to
break seed and bud dormancy.
Gibberellins
69)
Name the hormones which help in development of partheno-carpic fruits.
Auxin
70) Which plant hormone is
required during malting of barley?
Gibberelin
71)
Name one gibberellin biosynthetic inhibitor.
Auxin
72)
Name two naturally occuring cytokinins.
Zeatin and Kinetin
73)Name
one synthetic compound that antagonizes cytokinin.
74)Which
hormones are synthesized from Agrobacterium Ti plasmid?
Auxin and
Cytokinin
75)
Which plant hormones regulate cell division?
Cytokinin
76)Name
one plant hormone which promotes ethylene biosynthesis.
Gibberelin
77)
Which is the immediate precursor of ethylene? Mention its two physiological functions.
ACC (1-Aminocyclopropane-1-Carboxylic
acid) is the immediate precursor of ethylene.
(i) It helps in
fruit ripening. (ii)It also helps in
leaf abscission.
78)Which
hormone induces leaf senescence?
Ethylene
79)Mention
two commercial uses of ethylene.
80)Name
the hormones which control vivipary.
Gibberelin and
ABA
81)Which
hormones help in stomatal opening and closing?
ABA
82)What
is coat imposed dormancy?
Testa
83)What
are photohiasne and quiescent seeds?
When a seed fails
to germinate due to the unfavourable environmental conditions like extreame dry
or warm or cold for germination.Such seeds are called quiescent seeds.
84)
What are microbiotic ,mesobiotic and macrobiotic seeds?
The
seeds which have life span 3 years are called microbiotic seeds.The seeds
which have life-span ranges from 3–15 years are called mesobiotic seeds.The seeds which have life-span from 15 to more
than 100 years are called macrobiotic seeds.
85)Name
two synthetic hormone which is used as weed killer.
2,4-D and 2,4,5-T
86)
What is the chemical name of kinetin?
6-Furfurylamino-purine
87)
Give two examples of long day plants.
Solanum
tuberosum
and Gossypium hirsutum
88)
Give two examples of short day plants.
Nicotiana tabacum and Xanthium pennsylvanicum
89)
What is critical day length?
The
photoperiod(relative
length of day and night)required to induce flowering
is referred to as the critical day length.
90)
Why does cytochromc act as a good electron carrier?
Cytochrome
contain Iron ion which appear as both reduced and oxidized form.Due to the
inter convertion of Iron cytochromc act as a good electron carrier.
91)
What are florigen and antiflorigen?
Florigen is
the hypothesized hormone-like molecule responsible for controlling or
triggering flowering in plants.Florigen is produced in the leaves, and acts in
the shoot apical meristem of buds and growing tips.It is known to be
graft-transmissible,and even functions between species.
Substances which counteract florigen or inhibit the activity
of florigen, are known as antiflorigen.
92)
What is phytochrome?
Phytochrome is a blue proteinaceous plant pigment which
perceive light stimuli and controls flowering responses in plants.
93)
Name two phytochrome mediated photoresponses in plants.
(i)Flowering and
(ii)Crop yield are two important phytochrome mediated photoresponses
.
94)What
is climacteric fruit?
The climacteric is a stage of fruit ripening
associated with increased ethylene production and a rise in cellular
respiration. Apples, bananas, melons, apricots, tomatoes (among others) are climacteric fruit. Citrus, grapes, strawberries are non-climacteric (they ripen without ethylene and
respiration bursts).
95)Define
bolting?
Bolting is
the term applied to vegetable crops when they prematurely run to seed, usually
making them unusable. A cold spell or changes in day length initiates this
behaviour. It can affect a wide range of vegetables including lettuce, spinach
and fennel.
96)Name
the plant hormone having least molecular weight.
Ethylene
97)What
is dormin?
Dormin is a hypothetical plant hormone which is thought to be responsible for dormancy .
98)What
is vernalin
Vernalin is a hypothetical plant hormone which is thought to be responsible for vernalization.
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