Chapter 11

Out of the following, which one is the most common type of transpiration? (a) Foliar (b) Stomatal (c) Lenticular (d) Cuticular

In a hot summer day, a plant cools itself due to (a) Loss of water vapours from leaf (b) Transport of water in plant (c) Loss of liquid water (d) Loss of water from entire plant

Guard cells are surrounded by (a) Epidermal hairs (b) Mesophyll cells (c) Palisade cells (d) Subsidiary cells

Which of the following is an adaptation to reduce water loss? (a) Presence of thick cuticle (b) Change of leaf into spine (c) Change of leaf into phylloclade (d) All of these

Which of the following plants economizes the transpirational loss of water? (a) \(C_{3}\) (b) \(C_{4}\) (c) Both equally (d) \(C_{2}\)

The condition under which transpiration would be most rapid is (a) High humidity (b) Excess of water in soil (c) Low humidity, high temperature, guard cells are turgid (open) and moist soil (d) Low velocity of wind

The transpiration in plants will be the lowest (a) When there is high humidity in the atmosphere (b) High wind velocity (c) There is excess of water in the cell (d) Environmental conditions are very dry

Under what conditions the rate of transpiration increases? (a) Increase of humidity (b) Increase of atmospheric pressure (c) Decrease of temperature (d) Decrease of humidity

Transpiration increases with an increase in (a) Humidity (b) Temperature (c) Minerals (d) Soil moisture

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

Stomata opens because of (a) Oxygen in the air (b) Increased turgidity of the guard cells brought about by the cxposure to light (c) Vacuoles in guard cells (d) All the above

The transpiration is regulated by the movements of (a) Subsidiary cells of the leaves (b) Guard cells of the stomata (c) Mesophyll tissue cells (d) Epidermal cells of the leaves

Guttation is caused due to (a) Imbibitions (b) Osmosis (c) Positive root pressure (d) Transpiration

Guttation usually occurs when the plant is put in a (a) More saturated atmosphere (b) More humid soil (c) Dry condition (d) Desert

Guttation is the process of elimination of water from plants. It occurs from the pores in leaves through which water comes out in the form of droplets or a specialized multicellular structure in leaves which excretes water droplets. The pores are called (a) Stomata (b) Hydathodes (c) Lenticels (d) Wounds

Guttation is found mostly in (a) Herbaceous plants (b) Shrubs (c) Wood plants (d) None of these

Water lost by guttation is (a) Pure (b) Mixed with salts (c) Sometimes pure and sometimes impure (d) None of these

Guttation occurs in (a) Morning (b) Night (c) Evening (d) Morning 10 a.m.

Select from the following (in numbers) the correct function which are performed by transpiration. (1) Creates transpiration pull for absorption and transport of water in plant. (2) Transport minerals from the soil to all parts of the plant. (3) Cools the leaf surface (sometime \(10-15^{\circ} \mathrm{C}\) ). (4) Supplies water for photosynthesis. (5) Maintains the shape and structure of plants by keeping the cells turgid. (a) 1 (b) 3 (c) 4 (d) 5

\(\mathrm{C}_{4}\) plants are more evolved than \(\mathrm{C}_{3}\) plants because (a) \(\mathrm{C}_{4}\) plants are twice efficient in terms of carbon fixing. (b) \(\mathrm{C}_{4}\) plants loose only half of its water as \(\mathrm{C}_{3}\) plants for same amount of \(\mathrm{CO}_{2}\) fixed. (c) Both (a) and (b) (d) None of these

Plants obtain most of its carbon from (a) Atmosphere (b) Water (c) Soil (d) All of these

Mincrals are mostly absorbed by (a) Active transport (b) Facilitated diffusion (c) Simple diffusion (d) All of these

Ions are absorbed from soil by (a) Active transport (b) Passive transport (c) Both (a) and (b) (d) None of these

Where is the control point for minerals, where a plant adjusts the quantity and types of solutes that reach the xylem? (a) Epidermal cell (b) Cortical cell (c) Endodermal cell (d) Pericycle cell

Endodermis actively transports ion in one direction because (a) It is inner to epidermis (b) Cell wall is suberized (c) Cell wall is lignified (d) Its cell membrane has special transport proteins

Chief sink of minerals are (a) Apical and lateral meristem (b) Young leafs and storage organs (c) Developing flower, fruits and seeds (d) All of these

Unloading of mineral occurs at the fine vein endings through (a) Diffusion (b) Active uptake (c) Both (a) and (b) (d) None of these

Which of the following helps in the transportation of minerals? (a) Xylem (b) Phloem (c) Both (a) and (b) (d) None of these

Sink and source in sucrose transport may be reversed depending on (a) Plant's need (b) Season (c) Both (a) and (b) (d) None of these

Phloem sap is mainly composed of (a) Water + Glucose (b) Water + Fructose (c) Water + Cellulose (d) Water + Sucrose

Which of the following is translocated through phloem? (a) Sugar (b) Amino acid (c) Hormone (d) All of these

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)

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

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

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.

Assertion: Phloem is the principal food conducting tissue. Reason: It has been recognized by girdling or ringing experiment.

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.

Assertion: Imbibition is also diffusion. Reason: The movement of water in the above process is along a concentration gradient.

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.

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.

Assertion: The more the solute molecules in solution, the lower (more negative) is the solute potential of solution. Reason: For a solution at atmospheric pressure, water potential = solute potential.

Assertion: In apoplast, the water movement is through mass flow. Reason: The apoplast does not provide any barrier to water movement.

Assertion: Transport saturates in facilitated diffusion. Reason: Facilitated diffusion occurs through protien molecule.

Assertion: Light is a very important factor in transpiration. Reason: It induces stomatal opening and darkness closing. Therefore, transpiration increases in light and decreases in dark.

Assertion: Guttation liquid is found on the margins of leaves of herbaceous plants. Reason: Hydathodes are found on the margins of herbaceous plant.

Assertion: Transpiration occurs when stomata are open. Reason: Transpiration occurs only through stomata.

Assertion: Transport of sucrose from leaf to root is called translocation. Reason: This is long distance transport through vascular system of plant.

Assertion: Movement by diffusion is passive process. Reason: No energy expenditure takes place during diffusion.

Assertion: Molecules up to small size of protein can pass through outer membrane of plastids. Reason: Outer membrane of plastids contain porins

Assertion: Water is often the limiting factor for plant growth and productivity. Reason: Large amount of water is required by plants.