Gas exchange, transport and support in plant

The indicator solution changes from red to purple when it becomes less acidic. In which of the tubes does the indicator solution change from red to purple most rapidly?

• P

• Q

• R

• S

Which of the following elements in plants are obtained from the air through the leaves?

• carbon and oxygen

• carbon and nitrogen

• nitrogen and oxygen

• carbon, nitrogen and oxygen

Water is used by the plants for

(1) Cell enlargement

(2) Breaking down glucose to release energy

(3) producing organic food from inorganic substances

• (1) and (2) only

• (1) and (3) only

• (2) and (3) only

• (1), (2) and (3)

Which of the following correctly describes the plant at 1200 hour?

• It carried out photosynthesis, but not respiration.

• It carried out photosynthesis at the maximum rate.

• The rate of photosynthesis was equal to the rate of respiration.

• The rate of photosynthesis was lower than the rate of respiration.

The leaf carried out photosynthesis during the period

• P to S only

• P to T only

• Q to R only

• Q to S only

When the light intensity is 6 units, what is the actual rate of photosynthesis of the plant in terms of the rate of carbon dioxide uptake?

• 1 unit

• 2 units

• 3 units

• 4 units

Which of the following is a correct interpretation of the graph?

• Plant X has a lower respiratory rate than plant Y.

• Plant X has a higher maximum photosynthetic rate than plant Y.

• Plant X reaches its maximum photosynthetic rate at a lower light intensity than plant Y.

• When the light intensity is below 5 arbitrary units, plant X has a higher photosynthetic rate than plant Y.

Which element is not normally obtained by the roots of a plant from the soil?

• carbon

• nitrogen

• hydrogen

• phosphorus

Leaves of the water lily floating on water have stomata found on

• the upper side only

• the lower side only

• both sides

• neither side

Which region is made up of cells with the thickest cell wall?

• 1

• 2

• 3

• 4