0654 Transport in Plants

The diagram below shows a potted plant and the same plant 48 hours later.

What has caused the plant’s appearance to change?

• Water loss by translocation is greater than water uptake.

• Water evaporating from the leaves by translocation.

• Water loss by transpiration is greater than water uptake.

• Water loss from the leaves by osmosis.

Which order below is correct in describing the pathway of water as it travels from the roots through a plant?

• Root hair cell → xylem → mesophyll cells → air spaces → stomata

• Root hair cell → xylem → air spaces → mesophyll cells → stomata

• Root hair cell → mesophyll cells → phloem → stomata

• Root hair cell → mesophyll cells → xylem → stomata

Which of the following is a correct explanation of the process of translocation in a plant?

• The movement of mineral ions through the xylem of a plant.

• The movement of sucrose and amino acids through the phloem from a source to a sink.

• The one-way movement of sucrose and amino acids through the phloem.

• The movement of sucrose and amino acids through the phloem from a sink to a source.

Which of the process would be involved in the movement of nutrients and amino acids through phloem?

Which of the process would be involved in the loss of water from the tree?

Which of the processes listed below would be involved in the loss of water from the tree?

• Respiration

• Photosynthesis

• Translocation

• Evaporation

A potometer can be used to measure the rate that a piece of plant transpires under various conditions. Part of a potometer is shown in the diagram below.

Which statement, relating to how a potometer works, is false?

• A potometer uses the transpiration stream to produce movement of an air bubble that can be measured.

• In a potometer, an air bubble moves away from the piece of plant tissue that is under investigation.

• In order to determine the rate of transpiration, the movement of the bubble must be measured alongside the time taken.

• The leaves of the plant in the potometer must be dry during the experiment.

A dicot plant is placed into a bowl of water coloured with red dye.

After 1 hour, a cross section of one of the roots is cut.

After 4 hours, a cross section is cut from the stem.

Which labelled regions would be stained red in each case?

• 1 and 3

• 1 and 4

• 2 and 4

• 2 and 3

Which of the following is a correct explanation of the effect of root hairs on absorption?

• Provide a large surface area, maximising the rate of absorption of water and ions by osmosis.

• Provide a large surface area, maximising the rate of absorption of water by osmosis and ions by active transport.

• Increase the surface area, maximising the uptake of water by osmosis and ions by diffusion.

• Provide a surface area, increasing the rate of absorption of water and ions by active transport.

Which of the following processes is/are involved in the loss of water from the leaves of plants?

1. diffusion

2. osmosis

3. condensation

4. evaporation

• 1 and 3

• 1 only

• 4 only

• 1 and 4