Leaf Functions

The external structure of a green leaf consists of ___________?

• palisade mesophyll and spongy mesophyll

• lamina and petiole

• cuticle and epidermis

• stoma and guard cell

The rate of transpiration in plant TS A is 0.05 cm/second. The rate of transpiration in plant B is 0.015 cm/second. Which of the following factors could have caused the difference in the rate of transpiration between A and B?

I Air humidity

II Temperature

III Concentration of oxygen

IV Concentration of carbon dioxide

• I and II

• II and III

• III and IV

• I and IV

The rate of photosynthesis increases when the light intensity becomes higher. The rate of photosynthesis decreases in the middle of a hot sunny day for some plants.

Which of the following statement explains the above situation?

• Palisade cells undergo plasmolysis due to the loss of water.

• Stomatal pores close to reduce the loss of water from the leaves.

• Enzymes involved in photosynthesis are denatured.

The figure shows the structure of a leaf. Which can perform the most photosynthesis?

• P

• Q

• R

• S

Tags

NGSS.HS-LS1-5

NGSS.HS-LS2-5

Which of the following external features allow a leaf to absorb maximum energy from sunlight?

• Thin lamina

• Wide flat surface

• Abundant network of vessels all over a leaf

• Abundant stomata at the bottom side of a leaf

Tags

NGSS.MS-LS1-6

Which of the following characteristics of guard cells help in regulating the opening and closing of stomata?

• guard cells contain chloroplast

• guard cells are bean-shaped

• guard cells are only found at the underside of leaves

• guard cells can adjust its turgor pressure

What will happen to a plant if it does not have any stomata?

• it cannot photosynthesis

• gaseous exchange cannot be carried out between the plant and the atmosphere

• too much of water would be retain in the plant without transpiration

• the plant would die of heat stroke since it cannot cool down itself

Tags

NGSS.MS-LS1-6

The rate of transpiration can be increased if the potometer is placed in

• an open field

• a bathroom

• a greenhouse

• a shady area under the tree

Which of the following does not effect the rate of transpiration?

• light intensity

• carbon dioxide concentration

• temperature

• relative humidity

Which of the following changes would likely to decrease the rate of transpiration?

I Decreasing the humidity of the atmosphere

II Increasing the water potential of the atmosphere

III Increasing the water potential of the soil IV Placing the plant in the total darkness area

• I and II

• I and IV

• II and III

• III and IV

Tags

NGSS.MS-LS2-3

NGSS.MS-LS2-4