Problem 145
Which of the following is translocated through phloem? (a) Sugar (b) Amino acid (c) Hormone (d) All of these
Problem 146
The accepted mechanism for the translocation of sugar from source to sink is called (a) Pressure flow hypothesis (b) Mass flow hypothesis (c) Transpiration pull hypothesis (d) Both (a) and (b)
Problem 147
What is the means of transport through which sucrose moves into sieve tube of source and out of sicve tube at sink? (a) Simple diffusion (b) Facilitated diffusion (c) Active transport (d) Passive transport
Problem 149
Which of the following experiment showed that food in plant is transported through phloem? (a) Avena curvature experiment (b) Girdling experiment (c) Bell-jar experiment (d) None
Problem 150
Select the incorrect statement from the following: (a) The portion of bark above the ring in girdling experiment gets swollen after few weeks. (b) Translocation in phloem is bidirectional. (c) Phloem tissue is composed of sieve tube cells, which form long coloumns with holes in the walls called sieve plates. (d) The process of loading at the source which produces a hypotonic condition in the phloem.
Problem 151
Assertion: Phloem is the principal food conducting tissue. Reason: It has been recognized by girdling or ringing experiment.
Problem 152
Assertion: The water and mineral uptake by root hairs from the soil occurs through apoplast until it reaches the endodermis. Reason: Casparian strips in endodermis are suberized.
Problem 153
Assertion: Imbibition is also diffusion. Reason: The movement of water in the above process is along a concentration gradient.
Problem 154
Assertion: Pinus seeds cannot germinate and established without the presence of mycorrhaizae. Reason: Mycorrhiza is a symbiotic association of a fungus with a root system.
Problem 156
Assertion: Most of the minerals must enter the root by active transport. Reason: The concentration of minerals in the soil is usually lower than the concentration of minerals in roots.
