Stomata tends to close when CO2 increases. Answer : (c)

The apoplast is the space outside the plasma membrane within which material can disperse freely. It is broken up by the Casparian strip in roots, by air spaces between plant cells and by the plant cuticle. The apoplast route facilitates the transportation of water and solutes across a tissue or organ Answer : (c)

Water lost through transpiration is in the form of water vapour Answer : (a)

Plants exchange water with environment through structures by two cells Stomata guard cells are two bean-shaped cells that surround a stoma. Answer : (c)

Water absorption by root hairs occurs until Concentration of water in the cell sap is higher Water always moves from the system with a higher water potential to the system with a lower water potential. The internal water potential of a plant cell is more negative than pure water; this causes water to move from the soil into plant roots via osmosis. Answer : (d)

Chlorophyllous cells fewer in number, unique in shape with inner walls thicker are Guard cells Answer : (a)

Malate, K and Cl accumulated in vacuoles of guard cells during stomatal opening Answer : (d)

In osmosis, the volume of solvent ( in solution) will Increases Answer : (b)

Answer : (a)

Water will be absorbed by root hairs when the external medium is Hypotonic Answer : (a)

Underwater leaves (finely divided) can absorb carbon dioxide directly from the water. Water is abundant so there is no need for transpiration to help cool and transport water and minerals into the leaves Answer : (b)

Field Capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased. FORMS OF SOIL MOISTURE: Forms of soil moistures are i) Chemically Bound Water ii) Hygroscopic Water iii) Capillary Water iv) Gravitational Water Answer : (d)

Increase in the number of solute results in the decrease in the water potential, and therefore solute potential is always negative. Answer : (b)

Thus the osmotic potential of distilled water is zero, and becomes more and more negative on addition of solute Thus water always flow from lesser negative Osmotc potential to more more osmotic potential Answer : (a)

Answer : (b)

Ganong’s potometer is used to measure the transpirate rate a - ii Dry cobalt chloride paper that is blue in colour turns pink when it comes in contact with water. Using this property of cobalt chloride paper we can study the rate of transpiration from the two surfaces of a leaf by comparing the loss of water vapour from the two surfaces of the leaf b - iii An auxanometer is an apparatus for measuring increase or rate of growth in plants. c - i The Leaf Porometer is a device used to measure stomatal conductance in leaves d - iv Answer : (c)

Active absorption of water by roots from the soil is mainly affected by Osmotic concentration of cell sap Answer : (d)

Stomata are tiny pores found in the epidermis of leaves and other soft aerial parts. Stomata occur both on the upper and lower epidermal surfaces in mesophytic plants. Stomata are meant for gaseous exchange and are also the main source of transpiration. So an adaptation for better gaseous exchange in plant leaves is stomata are present on the lower surface which are away from direct sunlight are very much effective for gases exchange. Answer : (d)

For fully turgid cell the water potential becomes zero when solute potential becomes equal to the pressure potential A fully turgid cell has its Solute potential and pressure potential equal but with opposite sign Answer : (d)

A slice of Sugar Beet placed in concentrated salt solution would Lose water and become flaccid Answer : (b)

According to theory of ascent of sap by Dixon and Joly there is no use of energy or ATP for the ascent of the sap Answer : (d)

The guard cells contain chloroplasts, so they can manufacture food by photosynthesis (The epidermal cells do not contain chloroplasts) Guard cells are the only epidermal cells that can make sugar. Answer : (d)

water molecules tend to stick to one another, by strong mutual forces of attraction called cohesion and adhesion forces. That's why water column does not rupture during ascent in tracheary elements even though it translocate water and carries through the xylem vessels to all parts of the plant body. The xylem is composed of dead cells with thick, lignified secondary cell walls. These form a low resistance pathway for the movement of solution. Answer : (d)

In Bose’s Potometer A freshly cut twig is inserted in water bottele Answer : (b)

Transpiration often results in water deficit (capillary water) or development of water stress, which causes injury to the plants by desiccation. Answer : (a)

ranspiration is helpful to plants in Upward conduction/ascent of sap Answer : (c)

Answer : (d)

Maximum transpiration takes place from Leaves Answer : (b)

Guard cells line Stomata Answer : (a)

Answer : (b)