11th class (FSc) Biology Unit 14 MCQs
26. Guttation occurs in plants through:
a. Lenticels
b. Cuticle
c. Stomata
d. Hydathodes
27. The dew drops on the tip of the grass leaves involves the phenomenon:
a. Guttation
b. Imbibition
c. Transpiration pull
d. Bleeding
28. The volume of dry seed may increase up to 200 times after absorbing water by:
a. Osmosis
b. Diffusion
c. Active transport
d. Imbibition
29. The mutual bolding of water molecules to form solid chain-like column in xylem is due to bonds:
a. Covalent
b. Ionic
c. Ester
d. Hydrogen
30. The structures involved in guttation are:
a. Stomata
b. Lenticels
c. Cuticle
d. Hydathodes
31. The normal pH of blood is:
a. 8.0
b. 7.4
c. 9.0
d. 6.0
32. 90% of total transpiration is:
a. Lenticular
b. Cuticular
c. Stomatal
d. Hydathodes
33. Transpiration takes place through cuticle is about:
a. 5-6%
b. 5-7%
c. 2-5%
d. 1-7%
34. Cuticular transpiration takes place at:
a. Evening
b. Morning
c. Night
d. Noon
35. __ is incorrect about guard cells.
a. Surrounding stomata
b. Have chloroplasts
c. Connected to surrounding cells by plasmodesmata
d. Bean shaped
36. The ions involved in the opening and closing of stomata are:
a. Potassium
b. Sodium
c. Magnesium
d. Calcium
37. Temperature causes closure of stomata:
a. 25-350C
b. 30-400C
c. 40-450C
d. 30-350C
38. A hormone is released by mesophyll cells at high temperature:
a. Hydrochloric acid
b. Amin acids
c. Sulphuric acid
d. Abscsic acid
39. The movement of ions cause opening and closing of stomata by:
a. K+
b. Ca++
c. Mg++
d. All of these
40. According to one hypothesis, stomata opens due to the active transport of:
a. Sulphur
b. Sodium
c. Nitrogen
d. Potassium
41. The rate of transpiration doubles by every rise of temperatusre.
a. 300C
b. 100C
c. 400C
d. 200C
42. According to pressure flow theory, which of the following serves as sink?
a. Roots
b. Leaves
c. Stem
d. None of the above
43. The cells of phloem that conduct sugars and organic material throughout the plant are known as:
a. Stylets
b. Xylem
c. Guard cells
d. Sieve cells
44. Which one contains companion cells:
a. Endodermis
b. Xylem
c. Cortex
d. Phloem
45. The cells which supply ATP and proteins to sieve tubes are:
a. Tracheids
b. Companion
c. Vessels
d. Epidermal
46. The pressure flow theory was first proposed in 1930 by:
a. Hemming
b. Ernst Hackle
c. Dixon
d. Ernst Munch
47. They process that most likely / directly enables a root hair cell to absorb minerals by active transport and enables a muscle cell to contract is:
a. Respiration
b. Circulation
c. Assimilation
d. Excretion
48. Which one of the following animals has closed blood circulatory system:
a. Insect
b. Snail
c. Spider
d. Octopus
49. The heart of fish works as:
a. Closed circuit heat
b. Double circuit heat
c. Single circuit heat
d. None of these
50. The pairs of lateral hearts in earthworms are:
a. 6 or 7
b. 4 or 5
c. 7 or 8
d. 5 or 6