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 Q_b

 

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.