General Science Botany Questions

General Science Botany Questions

1. Match column A (Types of fruits) with column B (Examples) then select the correct answer from the options given below—
Column A
a. Lomentum
b. Samara
c. Achene
d. Amphisacra
Column B
1. Aegle
2. Mirabilis
3. Acacia
4. Acer
a b c d
(A) 3 4 1 2
(B) 3 1 2 4
(C) 3 2 1 4
(D) 3 4 2 1

2. Phototropic and geotropic movements in plants have been traced to be linked with—
(A) Auxin
(B) Gibberellin
(C) Both (A) and (B)
(D) Specific enzymes

3. The first case of polyembryony was reported in certain orange seeds by—
(A) Brawn
(B) Nawaschin
(C) Maheswari
(D) None of the above

4. When the change from sol into gel is reversible, the colloid is called—
(A) Gelation
(B) Solation
(C) Suspension
(D) Reversible colloid

5. The nuclear spindle consists of—
(A) One type of fibre
(B) Two types of fibres
(C) Three types of fibres
(D) Four types of fibres

6. Which of the following types of RNA takes a message from DNA in the nucleus to the
ribosomes in the cytoplasm ?
(A) m-RNA
(B) r-RNA
(C) t-RNA
(D) All of the above

7. ‘The imbibition theory of ascent of sap’ was first suggested by—
(A) Strasburger
(B) Bose
(C) Fischer
(D) Sachs

8. The maximum transpiration occurs in—
(A) Mesophytic plants
(B) Hydrophytic plants
(C) Xerophytic plants
(D) All algae except cyanobacteria

9. The transfer of minerals from top soil to subsoil through soil-water is called—
(A) Percolation
(B) Conduction
(C) Leaching
(D) Transpiration

10. One of the important evolutionary features of alternation of generation from algae to
flowering plants is—
(A) Gradual elaboration of sporophyte
(B) Gradual elaboration of gametophyte
(C) Gradual elaboration of both sporophyte and gametophyte
(D) Elimination of sporophyte

11. Circular DNA is found in—
(A) Chloroplasts
(B) Mitochondria
(C) Bacteria
(D) All of the above

12. Which of the following respiratory substrates has the highest value of respiratory quotient ?
(A) Glucose
(B) Protein
(C) Fats
(D) Malic acid

13. Who described mitochondria as bioplast ?
(A) Altmann
(B) Waldayer
(C) Kollikar
(D) Hanstein

14. Which of the following statements is/are correct regarding microtubules ?
(A) They are about 200 A° to 270 A° in external diameter having an electron dense wall some 50A° to 70A° thick
(B) They can be considered as the universal components of eukaryotic cells
(C) They are usually found in rotating conditions
(D) All of the above statements are correct

15. The term ‘chromatophore’ was coined by—
(A) Garner and Allard
(B) W. Pfeffer
(C) Nawaschin
(D) Schmitz

16. Phytotron is a device by which—
(A) Plants are grown in controlled environment
(B) Leaf fall occurs on abscission layer
(C) Mutations are produced in plants especially during spores formation
(D) Protons are liberated after photosynthesis

17. Annual (growth) rings are formed by the activity of—
(A) Xylem
(B) Phloem
(C) Both (A) and (B)
(D) Cambium

18. The chief components of Hill’s reaction used in Blackmann’s reactions are—
(A) ATP and ADP
(B) ATP and NADPH2
(C) NADP and ADP
(D) ATP and NADH2

19. The process of the escape of liquid from the tip of uninjured leaf is called—
(A) Transpiration
(B) Osmosis
(C) Guttation
(D) Evaporation

20. The primitive type of stomata are found in—
(A) Leaves of moss plants
(B) Xerophytic leaves
(C) Apophysis of capsule
(D) Dorsiventral leaves of monocot

21. Long dark periods of short day plants (SDPs), if interrupted by a brief exposure of red light (660 μ) the flowering is—
(A) Inhibited
(B) Vigorous
(C) Promoted
(D) None of the above

22. Number of chromatids per chromosome complex at metaphase is—
(A) Two in mitosis and one in meiosis
(B) Two in mitosis and four in meiosis
(C) Four in mitosis and two in meiosis
(D) Two in both mitosis and meiosis

23. The dark staining region in a chromosome is called—
(A) Euchromatin
(B) Heterochromatin
(C) Paracentric
(D) Pericentric

24. Plastids are not found in—
(A) Gram positive bacteria
(B) Gram negative bacteria
(C) Fungi
(D) All of the above

25. Bacterial nucleoid consists of—
(A) One double-stranded DNA
(B) Two double-stranded DNA
(C) Two single-stranded DNA
(D) One single-stranded DNA

26. The number of chromosomes in Pinus pollen grain in 12, the number of chromosomes in the endosperm of its own is—
(A) 6
(B) 12
(C) 24
(D) 36

27. During protein synthesis in prokaryotes, the initiation of polypeptide chain is induced
by—
(A) Serine
(B) Lysine
(C) Methionine
(D) Leucine

28. In Oxalis, the flowers open in the morning and close during evening because of—
(A) Phototropism
(B) Phototaxis
(C) Photonasty
(D) Nyctinasty

29. Conjoint, collateral, open and endarch vascular bundles are found in—
(A) Dicot root
(B) Dicot stem
(C) Monocot root
(D) Monocot stem

30. Spraying of DDT produces pollution of—
(A) Air only
(B) Airal water
(C) Air and soil
(D) Air, water and soil

31. The ‘first codon’ discovered by Nirenberg and Matthaei was—
(A) AAU
(B) GGG
(C) CCC
(D) UUU

32. The smallest unit of genetic material capable of undergoing mutation is—
(A) Cistron
(B) Muton
(C) Recon
(D) Proton

33. The least number of t RNA molecules for each of the twenty amino acids found in
protein is—
(A) One
(B) Two
(C) Three
(D) Four

34. Which of the following, plants is commonly known as ‘redwood’ ?
(A) Sequoia sempervirens
(B) Dacridium laxifolium
(C) Sequoia giganteum
(D) Polygalia hirsute

35. Epidermal tissue forms the outer protective covering of a herbaceous plant. It is modified in—
(A) Leaves
(B) Stems
(C) Roots
(D) All of the above

36. PCR based markers have been developed to—
(A) Create terminate codon
(B) Manufacture antibiotics
(C) Differentiate different biotypes of gall midge
(D) Obtain soil micro-organisms with the help of specific enzyme—reductase

37. The function of a root cap is to—
(A) Produce embryonic cell
(B) Protect the root apical meristem from damage
(C) Absorb minerals
(D) Absorb water

38. In a certain dicotyledonous stem the vascular cambium is a meristematic tissue referred to as—
(A) Apical
(B) Lateral
(C) Intercalary
(D) Secondary

39. In the phosphorus cycle, weathering makes phosphate available first to—
(A) Producers
(B) Consumers
(C) Tertiary consumers
(D) Decomposers

40. Petaloid staminode is seen in genus—
(A) Cassia
(B) Canna
(C) Solanum
(D) All of the above

41. A recessive pair of alleles at one locus sometimes prevents the expression of a dominant allele at another locus. This expression is termed as—
(A) Pleiotropy
(B) Polygenic inheritance
(C) Complementary gene
(D) Epistasis

42. Floridean starch is found in—
(A) Cyanophyceae
(B) Chlorophyceae
(C) Myxophyceae
(D) Rhodophyceae

43. Feathery stigma is present in—
(A) Ceasalpinia
(B) Pisum sativum
(C) Datura stramonium
(D) Triticum aestivum

44. Maximum transpiration occurs through/ from—
(A) Ground tissue of scale leaf
(B) Protoderm and procambium
(C) Periderm and lenticels
(D) Dermal tissue

45. Separation of components of a mixture based on their differential movements is called—
(A) Plasmolysis
(B) Dialysis
(C) Osmosis
(D) Chromatography

46. The free energy in breaking down of glucose into CO2 and H2O is—
(A) Negative and exergonic
(B) Positive and exergonic
(C) Negative and endergonic
(D) Positive and endergonic

47. A pome fruit is said to be false because—
(A) The fruit is present in fleshy edible thalamus
(B) The endocarp is cartilaginous
(C) The pericarp is inconspicuous
(D) The fruit is derived from inferior ovary

48. If mendel had studied the 7 traits using a plant with 12 chromosomes instead of 14 in what way would the interpretations have been different ?
(A) He would not have discovered the law of independent assortment
(B) He would have mapped the chromosome
(C) He would have discovered blending o r incomplete dominance
(D) He would have discovered sex linkage

49. Enzymes are absent in—
(A) Fungi
(B) Cyanobacteria
(C) Viruses
(D) Algae

50. Length of one turn of the helix in a B-form
DNA is approximately—
(A) 2 nm
(B) 20 nm
(C) 0•34 nm
(D) 3•4 nm

Answers with Explanation
1. (D)
2. (A) Auxin’s concentration toward nonilluminated side is greater than illuminated side. Thus, it shows phototropism. Auxin also shows geotropism in seed-ling, where due to gravitation it accumulates in the lower region of plumule or shoot.
3. (D) The first case of polyembryony was reported in certain orange seeds by Antoni Van Leeuwenhoek.
4. (D) The sol, under certain conditions, may change into another form called gel, the process being called gelation. When a gel is converted into sol, the process is called solation. When the change from sol into gel is reversible the colloid is called reversible.
5. (C) Nuclear spindle consists of three types of fibres—interzonal, continuous and discontinuous.
6. (A) m-RNA carries a message from DNA in the nucleus to the ribosomes in the cytoplasm.
7. (C) The imbibition theory of ascent of sap was first suggested by R. A. Fischer and supported by Sachs.
8. (A) 9. (C) 10. (A) 11. (D)
12. (D) 13. (A) 14. (D)
15. (D) The electron microscopic studies have revealed that in photosynthetic bacteria and blue-green algae some distinct lamellar structures meant for photosynthesis occur in protoplasm. These pigmented lamellae are named as chromatophores by Schmitz (1882).
16. (A) Phytotron—In glasshouses (green houses) when plants are kept on artificial light and temperature, the method is called phytotron and is applicable in tissue culture, horticulture and agriculture.
17. (D) The activity of cambium is often periodical, and as a result, distinct growth layers are formed in the xylem. In transverse view these growth layers appear as rings, and hence are referred to as growth rings or annual rings.
18. (B) The assimilatory power i.e., NADPH2 and ATP are formed in light or Hill’s reaction. They are utilized in the dark reaction or Blackmann’s reaction of photosynthesis in reducing CO2 to carbohydrates.
19. (C)
20. (C) In the stomata of apophysis of capsule only stomatal pores are reported (i.e., without guard cells). Guard-cell-lacking stomata are said to be primitive.
21. (A) 22. (B)
23. (B) Heterochromatin is a dark staining region which contains genetically inert or late replicating genes.
24. (D) 25. (A)
26. (B) Pinus is a member of gymnosperms and its endosperm develops before fertilization. Hence it is haploid and, therefore, there will be no change in its chromosome number.
27. (C) In protein synthesis of prokaryotes, the initiation of polypeptide chain is always brought about by an amino acid, methionine, which is coded by AUG.
28. (C) Photonasty or light-induced opening and closing of flower is seen in Oxalis.
29. (B) 30. (D) 31. (D)
32. (B) Muton is a unit of mutation.
33. (A) 34. (A) 35. (D)
36. (C) Polymerase chain reaction (PCR) based markers have been developed to differentiate different biotypes of gall midge.
37. (B)
38. (B) Lateral meristems are present along the lateral sides of stem and roots. Interstelar
cambium ring formed by intrafascicular, interfascicular cambium and cork cambium are
examples of lateral meristem.
39. (A)
40. (B) Canna belongs to family Cannaceae. Petaloid staminode is characteristic of this family.
41. (D)
42. (D) Floridean starch is a reserve food material of algal class-Rhodophyceae.
43. (D) Wheat (Triticum aestivum) belongs to family Gramineae (Poaceae) which has characteristic Feathery stigma.
44. (D) 45. (D) 46. (A) 47. (A) 48. (A)
49. (C) Viruses are metabolically inactive outside the host cell because they lack their own enzyme systems and protein synthesis machinery.
50. (D) The length of one turn of the helix in a Bform DNA is approximately 3•4 nm. The nucleotides are set in the planes at the right angles to the axis of the helix and spaced at an intervals of 3•4 A° or 0•34 nm.