Plant Physiology most important questions for competitive exams – Part 1

Plant Physiology most important questions for competitive exams – Part 1

  1. ‘Plant Physiology’ book was written by

(a) Singh & Purohit

(b) Salisbury & Ross

(c) Wiebe

(d) Albert

  1. Enzyme for conversion of ammonia to amino acid is

(a) Nitrate reductase

(b) Nitrite reductase

(c) Alanine transferase

(d) Glutamine synthetase

  1. Important function of leghaemoglobin in root nodules

(a) O₂ regulation

(b) N₂ fixation

(c) Water regulation

(d) All of these

  1. The externally thin strands of cytoplasm is termed as

(a) Primary cell wall

(b) Secondary cell wall

(c) Middle lamella

(d) Plasmodesmata

  1. In plants, the genetic material is present in

(a) Nucleus and mitochondria

(b) Nucleus only

(c) Mitochondria and chloroplast

(d) Nucleus, chloroplast & mitochondria

  1. The main function of endoplasmic reticulum (rough ER) is

(a) Fat synthesis

(b) Protein synthesis

(c) Disease resistance

(d) Chlorophyll synthesis

  1. An enzyme associated. with decarboxylation reaction in photosynthetic reaction of C, plants is

(a) Pyruvate dikinase

(b) Malic acid dehydrogenase

(c) PEP carboxylase

(d) Malic enzyme

  1. Golgi bodies was discovered in 1898 by

(a) Camillio Golgi

(b) Stanley

(c) Farmer and Moori

(d) Fleming

  1. RNA synthesis in nucleus participate in protein synthesis in

(a) Nucleus

(b) Cytosol

(c) Chloroplast

(d) Spherosome

  1. Which cell organells is the site of chemical activity in cells, perhaps over half of the cell’s metabolism?

(a) Chloroplast

(b) Nucleus

(c) Mitochondria

(d) ER

  1. Photorespiration is high in

(a) Maize

(b) Sugarcane

(c) Pineapple

(d) Rice

  1. Spherosomes are related with

(a) Chlorophyll

(b) Red pigments

(c) Power

(d) Fat

  1. Theoretically possible quantum yield in photosynthesis is

(a) 0.12

(b) 0.9

(c) 0.8

(d) 0.4

  1. Ribosomes are produced in

(a) ER (rough)

(b) Nucleolus

(c) Mitochondria

(d) Chloroplast

  1. The pigments which produce the colour of many flowers or the red of red maple leaves are generally stored in

(a) Vacuole

(b) Chromoplast

(c) Lysosome

(d) Dictyosome

  1. Ultimate electron donor in mitochondrial e- transport chain is

(a) Cytochrome A

(b) Cytochrome B

(c) Ubiquinon

(d) Plastoquinone

  1. The hydrogen atoms on the surface of the oxygen atom are distributed apart at a right angle of

(a) 90°

(b) 105°

(c) 120°

(d) 180°

  1. The strongest bond is

(a) Ionic bond

(b) Covalent bond

(c) Hydrogen bond

(d) Van der Waals

  1. The weakest bond is

(a) Covalent bond

(b) Van der Waals

(c) Ionic bond

(d) Hydrogen bond

  1. Latent heat of vaporization (water to vapour) is

(a) 80 cal

(b) 540 cal

(c) 586 cal

(d) 620 cal

  1. Latent heat of fusion (ice to water) is

(a) 540 cal (c) 80 cal

(b) 620 cal (d) 40 cal

  1. Important radiant generated in pentose phosphate pathway of glucose degradation is

(a) NADH

(b) ATP

(c) Ferridoxin


  1. Glyoxysomes functions in breakdown of

(a) Acetyl CoA

(b) Amino acids

(c) Sugars

(d) Fatty acids

  1. The Brownian discovered in 1827 by the Scottish was botanist

(a) Tyndall

(b) Robert Brown

(c) Murrfy

(d) Statyer

  1. Water potential of soil at field capacity is

(a) -0.3 bars

(b) -4 bars

(c) – 6 bars

(d) – 8 bars

  1. Calcium is an important constituent of

(a) Protein

(c) Chloroplast

(b) Cell wall

(d) Nucleic acid

  1. Maximum free radicals production is take place in

(a) Germination

(b) Flowering

(c) Fruiting

(d) Senescence

  1. Precursor for ethylene biosynthesis is

(a) Methionine

(b) Alanine

(c) Ornithine

(d) Tryptophan

  1. In a rapidly transpiring plant the water column in xylem will be in

(a) Positive pressure

(b) Negative pressure

(c) High root pressure

(d) No pressure

  1. Transpiration is measured by

(a) Lysimeter

(b) Potometer

(c) Tensiometer

(d) Auxanometer

  1. Stomata are regulated by

(b) P

(d) Ca

(a) N

(c) K

  1. Maximum density of water exists at

(a) 0°C

(c) 40°C

(b) 4°C

(d) 100°C

  1. Plant lost water in transpiration upto the extent of

(a) 80%

(c) 95%

(b) 90%

(d) 99%

  1. The world tallest tree is

(a) Sequoia sempervirens

(b) Eucalyptus regans

(c) Psendotsuga menziesii

(d) Alianthus excelsa

  1. Proteins that bind to TATA box in promoters region are

(a) Coactivators

(b) Coregulators

(c) Enhancers

(d) Transcriptional factors

  1. The chemical nature of GA, is

(a) Phenolic

(b) Terpene

(c) Purine

(d) Indole

  1. Site of oxidative electron transport in cell is

(a) Mitochondria

(b) Chloroplast

(c) Nucleus

(d) Cytoplasm

  1. Guttation is not favoured under

(a) Low humidity

(b) High humidity

(c) Low root pressure

(d) High humidity and low root pressure

  1. The basic elements of the cohesion theory for the ascent of sap are

(a) Driving force

(b) Hydration

(c) Cohesion of water

(d) All of these

  1. The xylem and phloem elements in the plant are surrounded by a layer of living cells called

(a) Casparian strips

(b) Pericycle

(c) Stele

(d) Endodermis

  1. Which part of root absorb water and minerals?

(a) Root cap

(b) Root hairs

(c) Epidermis

(d) Endodermis

  1. Fluid mosaic model of cell membrane is given by

(a) Daniel and Davson

(b) Robertson

(c) Robercook

(d) Singer and Nicholson

  1. The stage of seeds showing no germination because of internal conditions of seed is termed as

(a) Dormancy

(b) Quinscence

(c) Recalcitrant

(d) Longevity

  1. A plant hormone, which is primary regulator of abscission process is

(a) Ethylene

(b) Auxin

(c) ABA

(d) Gibberellins

  1. Growing of plant in soilless nutrient solution is referred as

(b) Hydroponics

(a) Aeroponics

(c) Xeroponics

(d) None of these

  1. Most of the wheat cultivars are

(a) Day neutral

(b) Short day plants

(c) Qualitative long day plants

(d) Quantitative long day plants

  1. Rice grain is deficient in

(a) Lysine

(b) Glysine

(c) Isoleucine

(d) Alanine

  1. The critical concentration of micronutrients needed in tissue is equal to or less than

(b) 10 ppm

(a) 1 ppm

(c) 100 ppm

(d) 1000 ppm

  1. Storage of elements in vacuoles occurs under

(a) Deficient zone

(b) Critical zone

(c) Luxury consumption

(d) Toxic zone

  1. Chelate are

(a) Organic in nature

(b) Inorganic in nature

(c) Both (a) and (b)

(d) None of these

  1. Siderophores produced by fungi and bacteria in soil are the source of

(a) Zn

(c) Cu

(b) Fe

(d) Mn

  1. The young leaves of terminal bud at first typically hooked, finally dying back at tips and margins are the deficiency symptoms of

(a) Potassium

(c) Calcium

(b) Iron

(d) Copper

  1. The young leaves chlorotic, principal veins remain typically green, stalks slender and short are the deficiency symptoms of

(a) Fe

(b) Cu

(d) Boron

(c) Mn

  1. Iron stored in chloroplast protein complex is called

(a) Calmodulin

(c) Chloroferritin

(b) Phytoferritin

(d) Chromoferritin

  1. Initiation of protein synthesis in eukaryotic mRNA requires

(a) (c) a 5′ cap a 3′ poly-A tail

(b) a 5′ poly-A tail

(d) a 3′ cap

  1. The first sign of switch over from vegetative stage to reproductive stage in wheat is

(a) Ear emergence stage

(b) Double ridge stage

(c) Terminal spikelet stage

(d) Anthesis stage

  1. Abundant phosphorus in plants is related with

(a) Early maturity

(b) Delay maturity

(c) Accumulation of anthocyanin pigments

(d) Both (b) and (c)

  1. Increase in temperature at anthesis stage in wheat results in

(a) Increased grain size

(b) Decreased grain size

(c) Increased duration of grain growth

(d) No effect

  1. An ideal type of rice with small, thick and erect leaf was proposed by

(a) Tsunoda

(b) Tanaka

(c) Yoshida

(d) Murata

  1. Increase in wheat yield potential so far results from

(a) Increase in HI

(b) Increase in dry matter

(c) Increase in stem weight production.

(d) Increase in leaf weight

  1. Acetylene reduction measured as to ethylene is

(a) Nitrate reduction

(b) Glutamate synthase activity

(c) Nitrite reduction

(d) N₂ fixation

  1. The grey speck of oats, ‘marsh spot’ of peas, and speckled yellows of sugar beets are the deficiency symptoms of

(a) Cu

(b) Mn

(c) Fe

(d) Zn

  1. The ‘heart rot’ of beets, ‘stem crack’ of celery, ‘water core’ of turnip and ‘drought spot’ of apples are the deficiency symptoms of

(a) B

(b) Ca

(d) Cu

(c) Zn

  1. Optimum temperature for maximum crop development in wheat is

(a) 10-15°C

(b) 20-25°C

(c) 25-30°C

(d) 30-35°C

  1. Water potential of chemically pure water is

(a) -0.1 MPa

(b) -0.5 MPa

(c) -1.0 MPa

(d) Zero

  1. ‘Little leaf’ and ‘rosette’ of apple, ‘white bud’ of maize are the deficiency symptoms of

(a) Fe

(c) Cl

(b) Zn

(d) Mo

  1. Under an excessive light level the synthesis of which of the following is found to be increased ?

(a) Antheraxanthin

(b) Violaxanthin

(c) Zeaxanthin

(d) All of these

  1. In citrus plant, die back disease is the result of deficiency of

(a) N

(b) P

(c) Boron

(d) Copper

  1. Which micronutrient is essential for the synthesis of ‘auxin’ ?

(a) Cu

(c) Zn

(b). Mn

(d) Silicon

  1. ‘Whiptail’ disease of cauliflower is due to deficiency of

(a) Copper

(b) Chlorine

(c) Calcium

(d) Molybdenum

  1. Direct reduction of O, by photosystem I leads to the formation of

(a) H₂O₂

(b) Superoxide anion radical

(c) Singlet oxygen

(d) Singlet exited state of O₂

  1. Which of the following is not a colligative property?

(a) Depression of freezing point

(b) Refractive index

(c) Lowering of vapour pressure

(d) Elevation of boiling point

  1. The optimum pH of nutrient solution in nutrient solution culture is

(a) 4


(b) 6

(d) 9

  1. Acid rains are due to which of the following gases ?

(a) CO, and CO

(b) Ozone and CO2

(c) NO, and SO,

(d) NH, and CO₂

  1. Tumor inducing principle Agrobacterium is in

(a) T-DNA

(c) t-RNA

(b) T,-plasmid

(d) None

  1. Mycorrhiza (association of fungi with roots of higher plants) increased the availability of

(a) Fe

(b) N

(c) P

(d) B

  1. VAM (vesicular arbuscular mycorrhiaze) is mostly used in

(a) Perennial trees

(b) Annual crops

(c) Biennial crops

(d) All of these

  1. If the accumulation ratio in absorption of nutrients is greater than one then it is known as

(a) Active absorption

(b) Passive absorption

(c) Adsorption

(d) None of these

  1. Which one of the following is a most harmful pollutant by automobiles ?

(a) SO2

(b) CO

(c) N₂O

(d) CO₂

  1. 14 C has a half life of

(a) 14 days

(b) 100 years

(c) 5730 years

(d) 6000 years

  1. Mass flow mechanism was proposed by

(a) Darwin

(b) Munch

(c) Hugo de Vries

(d) Banda

  1. hn RNA stands for

(a) Homogeneous nuclear RNA

(b) Heterogenous nuclear RNA

(c) Heterocyclic nuclear RNA

(d) All of these

  1. Isotopes differs in

(a) Electrons and protons

(b) Protons and neutrons

(c) Neutrons only

(d) Electrons and neutrons

  1. The process in sugars (carbohydrates) are raised to high concentration in phloem cells close to a which source is known as

(a) Xylem loading

(b) Phloem loading

(c) Phloem concentration

(d) Phloem deloading

  1. is the break down of large molecules to small molecules, and this process often releases energy

(a) Anabolism

(b) Catabolism

(c) Both (a) and (b)

(d) None of these

  1. One curie of activity is equivalent to

(a) 3.7 x 104 disintegration per sec.

(b) 3.7 x 10¹ disintegration per sec.

(c) 3.7 x 1010 disintegration per sec.

(d) 3.7 x 107 disintegration per sec.

  1. Climatric rise in respiration is observed in

(a) Mango

(c) Grapes

(b) Citrus

(d) Cherries

  1. Callus is induced to form roots in the medium of

(a) Auxin only

(b) Cytokinins only

(c) More cytokinins than auxin

(d) More auxin than cytokinins

  1. Sulphur containing amino acids is/are

(b) Methionine

(a) Cysteine

(c) lysine

(d) Both (a) and (b)

  1. 100 of enzymes form double 92. Which group bonds by elimination of a chemical group?

(b) Lyases

(a) Kinases

(c) Polymerases

(d) Ligases

  1. Electrophoresis was developed to separate

(a) Fats

(c) Vitamins

(b) Carbohydrates

(d) Proteins

  1. Ripening is delayed by synthesis of antisense ACC synthetase RNA in which fruit?

(a) Tomato

(c) Citrus

(b) Grapes

(d) Cherries

  1. Blue light is always less efficient in photosynthesis than

(a) White

(b) Red

(c) Orange

(d) Violet

  1. Recognition site of t- RNA is

(a) Anticodon

(b) Loop I

(c) Loop IV

(d) 3′ OH end

  1. Chlorophyll are green because they

(a) Reflect green light

(b) Absorb green light

(c) Transmit green light

(d) None of these

  1. RNA-DNA hybridization to quantify gene expression at mRNA level is called as

(a) Southern blotting

(b) Slot – blot technique

(c) Western blotting

(d) Northern blotting

  1. Wavelength of visible light is

(a) 260 350 nm

(b) 360 – 760 nm

(c) 390 760 nm

(d) 400

  1. Plastocyanin protein contains

(a) Fe

(c) P

(b) Cu

(d) Mo

  1. Z-scheme of electron transport was first proposed by

(a) Hill and Bendall

(b) Hatch and Boardman

(c) Haliwell

(d) Calvin

  1. How many photons are required to produce one molecule of oxygen ?

(a) 4

(b) 8

(c) 12

(d) 16

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