Which would be an adaptation of xerophytes?

• Large air spaces

• Large numbers of stomata

• Hairs on the leaves

• Reduced roots

When a farmer sprays a chemical on to crop plants, how does the chemical travel to the roots of the plants?

• In the phloem, by active translocation

• In the phloem, by transpiration pull

• In the xylem, by transpiration pull

• In the xylem, by active translocation

What conditions will cause the highest rate of transpiration in a well-watered plant?

• Hot, humid with bright sunshine and still air

• Low humidity, hot, bright sunshine and windy

• Windy, hot, cloudy and humid

• Windy, bright sunshine, humid and cool

Which direction does the phloem transport materials?

• Up the plant at night and down the plant during the day

• Up and down the plant all the time

• Up the plant only

• Down the plant only

What process creates the low pressures needed for the movement of water upwards in the xylem?

• Active translocation

• Active transport

• Evaporation of water from mesophyll of leaves

• Evaporation of water from guard cells

The diagram below shows a cross section of a stem.

What is the structure labelled Y and one of its functions?

• Y = phloem; Function = storage of water and starch

• Y = xylem; Function = mechanical support

• Y = phloem; Function = transport of sugars

• Y = xylem; Function = gas exchange

What part of the human body is most similar in function to the spongy mesophyll layer in a leaf?

• Alveoli in the lungs

• Erythrocytes in the blood

• Villi in the small intestine

• Sweat glands in the skin

How are fluids transported in the xylem and the phloem?

• A

• B

• C

• D

Tags

NGSS.MS-LS2-3

Which is the best definition for transpiration?

• Diffusion of water through mesophyll cells followed by its evaporation from stomata

• Diffusion of water through stomata followed by its evaporation from mesophyll cells

• Evaporation of water at the mesophyll cells followed by its diffusion through stomata

• Evaporation of water at the stomata followed by its diffusion through mesophyll cells

Which of the following are part of the cohesion-tension hypothesis?

I. evaporation of water causes a negative pressure in xylem vessels

II. water is drawn out of the xylem cell walls by cohesion

III. hydrogen bonds cause water molecule to stick together by cohesion

• I and II only

• I and III only

• II and III only

• I, II and III