Physiology of Plants MCQs Part 9

1) The Eustachian tube connects the
a) Pharynx to the middle ear
b) Middle ear to the external ear
c) Left ventricle to the right ventricle
d) Left atrium to the right atrium

2) Vaccination against small pox means the introduction of … into our body
a) leucocytes taken from animals
b) antibodies produced in other animals
c) antibiotics
d) actual weakened germs

3) the peritoneal membrane surrounds the
a) lungs
b) heart
c) vestigial organs
d) viscera

4) Phlebotomus argentipes
is a vector for

a) trypanosoma evansi
b) t. gambiense
c) leishmania donovani
d) T. cruzi

5) Which of the following provides three important ingredients
of our food namely carbohydrates, fat and proteins?

a) Gram
b) Castor
c) Mango
d) Groundnut

6) Many vegetables and pulses belong to the families?
a) Solanaceae and Liliaceae
b) Malvaceae and Compositae
c) Compositae and Leguminosae
d) Cucurbitaceae and Leguminosae

7) Which of the following plants seeds are used as jeweller’s weights?
a) Glycine max
b) Abrus precatorius
c) Cajanus cajan
d) Lens culinaris

8) Hashish, marijuana and LSD are
a) stimulants
b) toxic
c) hallucinogens
d) None of these

9) The water inside a coconut is the
a) Degenerated liquid endosperm
b) Liquid endocarp
c) Liquid mesocarp
d) Liquid nucellus

10) Plants are known as purifiers of air due to the process

a) Respiration
b) Photosynthesis
c) Transpiration
d) Dessiccation

11) Nodules with nitrogen fixing bacteria are present in the roots of
a) Wheat
b) Gram
c) Cotton
d) Mustard

12) Conversion of organic nitrogenous compound into ammonium compounds is called
a) Denitrification
b) Aminization
c) Nitrification
d) Ammonication (Ammonification)

13) Plants absorb nitrogen in the form of
a) Nitrate
b) Nitrogen gas
c) Nitrogen dioxide
d) All of the above

14) Which of the following can fix atmospheric nitrogen ?
a) Alkaloids
b) Fats
c) Alcohols
d) Anabaena

15) Which pigment is essential for nitrogen fixation by leguminous plants ?
a) Phycocyanin
b) Leghaemoglobin
c) Phycoerythrin
d) Anthocyanin

16) The bacteria that change proteins to ammonia in the nitrogen cycle are
a) Nitrogen fixing bacteria
b) Nitrate bacteria
c) Decay bacteria (Ammonifying bacteria)
d) Denitrifying bacteria

17) The bulk of nitrogen in nature is fixed by
a) Symbiotic bacteria
b) Chemical industries
c) Lightning
d) Denitrifying bacteria

18) Peptide linkages are formed among
a) Amino acids
b) Glucose molecules
c) Sucrose molecules
d) Glycerol molecules

19) In the nitrogen cycle, which of the following plays an important role ?
a) Rhizopus
b) Mucor
c) Nitrobacter
d) Spirogyra

20) In nature, the main organisms which take part in the nitrogen cycle are
a) Parasitic fungi
b) Legume plants
c) Bacteria
d) Saprophytic flowering palnts

21) Rotation of crops is practised because
a) It decreases the nitrogen content of the soil
b) It increases the nitrogen content of the soil
c) It kills harmful bacteria of the soil
d) It increases the water content of the soil

22) Even without adding nitrogenous manures a good yield of rice crop can be obtained because
a) Their roots have nitrogen fixing bacteria
b) There are nitrogen- fixing algae in rice fields
c) Rice plants do not require nitrogen
d) They require minute quantities of nitrogen

23) Which of the following does not help in adding nitrogen to soil?
a) Bacterial decay of animal remains
b) Electric lightning
c) Addition of lime in soil
d) Nitrogen fixing bacteria

24) Proteins are synthesized on the
a) Mitochondria
b) Centrosome
c) Golgi bodies
d) Ribosomes

25) Proteins are made up of
a) Amino acids
b) Nucleic acids
c) Sugars
d) Fatty acids

26) One of the following is a sulphur containing amino acid:
a) Valine
b) Methionine
c) Tryptophan
d) Phenylalanine

27) Members of the bean family are of particular importance in crop rotation programmes primarily because
a) They add nitrates to the soil
b) They manufacture nitrogenous compounds
c) They have nitrogen-fixing bacteria associated in their roots
d) They provide green manure

28) The process by which proteins are synthesized in a cell is called
a) Translation
b) Transduction
c) Translocation
d) Transcription

29) A free living anaerobic bacterium capable of nitrogen fixation in soil is
a) Azotobacter
b) Streptococcus
c) Clostridium
d) Rhizobium

30) The simplest amino acid is
a) Alanine
b) Glycine
c) Leucine
d) Aspartic acid

31) Which of the following elements is involved in nitrogen metabolism in
reduction of nitrates ?

a) Zinc
b) Molybdenum
c) Boron
d) Manganese

32) Organisms which fix atmospheric nitrogen in the soil are found among
a) Mosses
b) Green algae
c) Soil fungi
d) Bacteria

33) Symbiotic nitrogen fixing bacteria occur in the genus
a) Xanthomonas
b) Pseudomonas
c) Rhizobium
d) Azotobacter

34) The production of nitrates from ammonia through Nitrosomonas is called
a) Nitrification
b) Ammonification
c) Nitrogen fixation
d) Denitrification

35) Atmospheric nitrogen in the soil is fixed by
a) Cereals
b) Pulses
c) Sugarcane
d) Cotton

36) The small rootless aquatic herb in which a portion of the leaf forms
a tiny sack or bladder which trap water insects is

a) Dionaea
b) Utricularia
c) Sarracenia
d) Drosera

37) In Nepenthes, the pitcher is a modified part of the leaf part called
a) Leaf apex
b) Leaf base
c) Leaf petiole
d) Leaf blade

38) Plants such as the “sundew” and the “pitcher plant ” are
a) Carnivorous
b) Parasitic
c) Symbiotic
d) Autotrophic

39) In the “sundew” (Drosera) the part of the plant which attracts the insects
is the

a) Leaf blade
b) Leaf apex
c) Leaf base
d) Leaf petiole

40) Obligate saprophytes are plants which can live
a) On living hosts as well as dead material
b) On living hosts only
c) Only on dead and decaying organic matter
d) On dead material as well as living hosts

41) The Dodder (Cuscuta ) plant is a
a) Total stem parasite
b) Total root parasite
c) Partial stem parasite
d) Partial root parasite

42) Which of the following is an example of an insectivorous plant ?
a) Brassica
b) Cuscuta
c) Mucor
d) Nepenthes

43) In some insectivorous plants there is secretion of an acidic enzyme by
which trapped insects are killed and digested. This enzyme is

a) Erepsin
b) Trypsin
c) Strypsin
d) Amylopsin

44) Heterotrophic nutrition is found in
a) Pistia
b) Opuntia
c) Drosera
d) Vallisneria

45) By trapping insects the insectivorous plants get

a) Sugar
b) Protein
c) Water
d) Vitamins

46) In Orobanche which is a root parasite, germination of the seed is dependent on
a) Auxins released by the roots of the host
b) Exudates from the roots of the host
c) Exudates released from the parasite
d) Gibberellins released by the parasitic roots

47) In the nitrogen cycle, nitrite is converted to nitrate

a) Azotobacter
b) Rzhizobium
c) Nitrosomanas
d) Nitrobacter

48) The insects captured by the insectivorous plants partially fulfill their
requirement of

a) Enzymes
b) Oxygen
c) Nitrogen
d) Water

49) Dionaea muscipula is commonly known as
a) Butterwort
b) Venus fly-trap
c) Water fly-trap
d) Bladderwort

50) An example of a photosynthetic anaerobic non-symbiotic nitrogen fixing bacterium is
a) Aztobacter
b) Bacillus
c) Rhizobium
d) Rhodospirillum

51) The Orobanche plant is a
a) Partial parasite
b) Total root parasite
c) Symbiont
d) Total stem parasite

52) All the following contribute to the available nitrogen compounds in
the soil except

a) Thunderstorm
b) Animal remains
c) Plant remains
d) Liming

53) Which of the following is an insectivorous plant ?
a) Cuscuta
b) Orobanche
c) Drosera
d) Rafflesia

54) Epiphytes are the plants which are dependent on other plants for
a) wateronly
b) water and food
c) food only
d) shelter (support)

55) The insectivorous plant which has a rosette of prostrate leaves with winged petioles, the lamina consisting of two rounded halves having teeth like
margins devised for catching prey is

a) Dionaea
b) Drosera
c) Nepenthes
d) Utricularia

56) Nitrogen is present in the atmosphere upto the extent of 78% but plants cannot use it directly because
a) Nitrogen is present in gaseous form
b) Gaseous nitrogen is toxic to plants
c) Concentration of nitrogen is too high
d) None of the above

57) Protein essentially contains
a) Carbon, nitrogen, hydrogen and sulphur
b) Carbon, nitrogen, hydrogen and oxygen
c) Carbon, nitrogen, oxygen and sulphur
d) Nitrogen, hydrogen, sulphur and oxygen

58) Nitrogen can be fixed in soil economically by
a) Growing leguminous plants
b) Adding humus
c) Adding nitrogen fixing bacteria
d) Increasing bacteria by ploughing

59) Insectivorous plants grow on
b) Humus
d) Clay

60) A tree which is a partial root parasite is
a) Loranthus
b) Viscum
c) Santalum
d) Balanophora

61) Which of the following is a total root parasite ?
a) Loranthus
b) Rafflesia
c) Viscum
d) Cuscuta

62) Which of the following is a total root parasite ?
a) Orobanche
b) Viscum
c) Cuscuta
d) Loranthus

63) Which of the following phenomenon is exhibited by Loranthus and Orobanche

a) Parasitism
b) Epiphytism
c) Commensalism
d) Insectivory

64) Which one of the following statements is correct ?
a) Legumes fix nitrogen only through speciallzed bacteria that live in their leaves
b) Legumes are incapable of fixing nitrogen
c) Legumes fix nitrogen only through the specialized bacteria that live in their roots
d) Legumes fix nitrogen independently of the specialized bacteria that live in their roots

65) Organisms which fix atmospheric nitrogen in the soil come under the
category of

a) Soil fungi
b) Mosses
c) Bacteria
d) Green algae

66) Which one of the following species does not have the ability to fix
atmospheric nitrogen ?

a) Nostoc
b) Spirogyra
c) Azotobacter
d) Anabaena

67) Which bacteria convert nitrate into nitrogen ?
a) Nitrifying bacteria
c) Denitrifying bacteria

68) The term nitrogen fixation includes the
a) Change of nitrates into nitrogen
b) Conversion of nitrogen into ammonia
c) Conversion of nitrite into ammonia
d) Use of nitrogen containing salts

69) The microbial conversion of ammonia to nitrate is called
a) Ammonification
b) Nitrification
c) Denitrification

70) Which of the following animals is crepuscular?
a) Rabbit
b) Owl
c) Deer
d) Bat

71) Food reserve is hydrolysed in seeds even at relatively low temperatures because of
a) Enzymes
b) Hormones
c) Proteins
d) Auxins

72) Which of the following is a typical example of ‘feedback Inhibition” ?
a) Allosteric inhibition of hexokinase by glucose-6-phosphate
b) the reaction between succinic dehydrogenase and succinic acid
c) Cyanide and cytochrome reaction
d) Sulpha drugs and folic acid synthesizer bacteria

73) Starch and cellulose are compounds formed of many units of
a) Amino acids
b) Glycerol
c) Simple sugars
d) Fatty acids

74) Sugar contains
a) Hydrogen, oxygen and carbon
b) Carbon, nitrogen and oxygen
c) Hydrogen, carbon and sulphur
d) Carbon, phosphorous and oxygen

75) The number of ‘floating ribs’ in the human body is
a) 2 pairs
b) 5 pairs
c) 3 pairs
d) 6 pairs

76) The shortest contraction of any muscle is seen in the
a) Jaws
b) Eye lids
c) Heart
d) Intestine

77) When released from the ovary, a human egg contains
a) One Y chromosome
b) Two X chromosomes
c) One X chromosome
d) X Y chromosomes

78) When yeast ferments glucose the products are
a) Methanol and CO2
b) Ethanol and CO2
c) Water and CO2
d) Ethanol and water

79) In cheese manufacture micro-organisms are important for
a) The souring of milk only
b) The ripening only
c) The development of resistance to spoilage only
d) Both the souring and the ripening processes

80) The production of nitrates from ammonia through Nitrosomonas is called
a) Nitrification
b) Ammonification
c) Nitrogen fixation
d) Denitrification

81) Plants are similar to animals because
a) They respire during the night
b) They respire during the day and night
c) They respire when it is required
d) They respire during the day only

82) In Chlamydomonas chlorophyll is found in the
a) Pyrenoids
b) Grana
c) Stigma
d) Thylakoids

83) Agaricus cannot manufacture its own food because
a) They do not have leaves
b) They lack chlorophyll
c) They do not need food
d) They have no roots

84) Minerals are absorbed by a plant from the soil by the process
a) Independent of water absorption
b) Dependent on water absorption
c) Dependent on the strength of solutions
d) Dependent on osmosis

85) Plants require two metallic compounds (minerals) for chlorophyll synthesis, which are
a) Fe and Ca
b) Fe and Mg
c) Cu and Ca
d) Ca and K

86) There is a possibility of the incidence of infectious diseases increasing due to an increased supply of
a) Potassium
b) Magnesium
c) Copper
d) Nitrogen

87) The transfer of minerals from the topsoil to the subsoil through soil water is called
a) Transpiration
b) Conduction
c) Percolation
d) Leaching

88) Deficiency of mineral nutrition is not responsible for
a) Shortening of internodes
b) Necrosis
c) Chlorosis
d) Etiolation

89) Seeds swell when placed in water due to
a) Osmosis
b) Imbibition
c) Hydrolysis
d) Plasmolysis

90) Absorption of water by roots is increased when
a) Transpiration rate is less
b) Salt absorption is increased
c) Transpiration rate increases
d) Photosynthetic rate increases


A soil is physiologically dry when

a) Soil temperature is 4oC

b) There is excess of CO2 in soil

c) the concentration of the soil solution is higher than that of the cell
d) It has no hygroscopic water

92) The direction and rate of water movement from cell to cell is based on
a) W.P.
b) T.P.
c) D.P.D
d) Incipient plasmolysis

93) During transport of sugar or amino acids through the cell membrane
a) Na+ ions move against the direction of
concentration gradient

b) Na+ ions move in both directions irrespective
of its concentration gradient

c) No net Na+ ions movement

d) Na+ ions move in the direction of the
concentration gradient

94) “Osmosis is the flow of a solution from higher concentration to a solution of lower concentration through a semi-permeable membrane.” What is incorrect in this statement?
a) The exact concentration of the solution is not given
b) The character of the semi-permeable membrane is not given
c) The flow of solution is not possible through a semi permeable membrane
d) All are incorrect

95) Prolonged water-logging causes death of plants because
a) Root respiration stops
b) Cell sap in the plants becomes very dilute
c) Nutrients leach down due to excess water
d) Soil nutrients become very dilute

96) Stomata in Angiosperms open and close due to
a) Their genetic constitution
b) the effect of hormones
c) Changes of turgor pressure in the guard cells
d) Pressure of gases inside the leaves

97) The apparatus generally used for studying the rate of transpiration stream is the
a) Potometer
b) Evaporimeter
c) Atmometer
d) Perimeter

98) Spraying of phenyl mercuric acetate (PMA)
a) Increases the rate of guttation
b) Increases the rate of transpiration
c) Decreases the rate of transpiration
d) Increases the rate of water absorption

99) In guard cells when sugar is converted into starch, the stomatal pore
a) Opens partially
b) Opens completely
c) Closes completely
d) Remains unchanged

100) An effective adaptation for better gas exchange in plants is the
a) Large number of hairs on the lower epidermis
b) Presence of stomata on the lower surface of the leaf
c) Multiple epidermis
d) Waxy cuticle


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