Root hair cells

Figure 9 shows a stoma on the lower epidermis of a leaf as seen using a

Draw the stoma and two cells around it in the box.

Give the name of the two cells around the stoma.

A student observed that a plant in a room had grown towards the light.

Name the plant hormone that causes the plant to grow towards the light.

Name the type of tropism that causes the plant to grow towards the light.

Figure 10 compares the root hair cells of two plants.

Plant A is adapted to growing in wet soil.

Plant B is adapted to growing in dry soil.

Compare the root hair cells of Plant A with the root hair cells of plant B.

Figure 11 shows sections of a leaf from plant A and a leaf from plant B.

plant A (wet soil)
plant B (dry soil)

Figure 11

State two differences in the leaf structure shown in Figure 11 that help plant B to survive in a dry environment.

In 2018, all the plants were removed from the soil in a 1000 m² area.

A wall was built around this area to keep people out.

In 2019, three species of plants were recorded growing in this area.

Two of these species were indigenous.

State what is meant by the term ’indigenous’.

Name one piece of equipment that could be used to sample the number of indigenous plants in this area.

The area was surveyed every year and the number of plants of each species (A to H) was estimated.

Figure 6 shows the results.

State the trend shown by the data in Figure 6 for plant species C from 2019 to 2023.

A scientist suggested that the decrease in the number of plants of species B in 2021 was caused by competition from one of the other species of plant.

Which species is most likely to have out-competed species B in 2021?

Explain one way that this species could have out‑competed species B.

Give one way that species H could have moved into the area.

Plants also need water to grow.

Explain how water is absorbed into the plant.

Figure 13 shows a root hair cell from a plant.

Name the part labelled X.

State one way that the structure of the root hair cell increases the volume of substances it absorbs.

Explain why root hair cells do not contain chloroplasts.

*(c) The arrows in Figure 15 show the direction of water movement through a tree.

Explain how water is moved from the soil, through the plant and into the air.

3 (a) Figure 2 shows a root hair cell from a plant.

(i) Name the part labelled X.

(ii) State one way that the structure of the root hair cell increases the volume of substances it absorbs.

(iii) Explain why root hair cells do not contain chloroplasts.

from the Elodea cells in tap water.

(ii) Explain why placing the Elodea cells in the 10% salt solution causes the changes seen in Figure 3.

8 (a) Figure 14 shows a diagram of a plant root hair cell.

Figure 14

(i) Name the part labelled R.

(ii) Explain one adaptation of a root hair cell that increases the absorption of water and mineral ions.

(b) Figure 15 shows xylem and phloem from the stem of a plant.

Figure 15

(i) Living cells in phloem use energy to transport sucrose. Which organelles release energy in living cells?

(ii) Describe two features of the structure of xylem vessels that can be seen in Figure 15.

(c) A scientist investigated how the flow of air affected the rate of transpiration in a plant. A fan was used to change the flow of air. The volume of water taken up by the plant was measured. Figure 16 shows the results of this investigation. fan switched on

time in minutes

Figure 16

(i) Explain why switching on the fan caused a change in the volume of water taken up by the plant.

(ii) Give one reason why the volume of water taken up by the plant was also measured when the fan was not switched on.

(iii) Calculate the rate of water uptake from 8 minutes to 10 minutes when the fan was switched on. Use the equation

_{..............................................................}mm³ per minute

Figure 6 shows a root hair cell from a strawberry plant.

Label the cell vacuole in Figure 6.

Explain how the structure of root hair cells increases water absorption from the soil.

Figure 7 shows fungus growing on strawberries.

The fungus is decomposing the strawberries.

A scientist investigated the effect of temperature on the decomposition of strawberries.

The scientist spread fresh strawberries on six trays.

Each tray was kept at a different temperature.

After five days the scientist measured the area of fungus that had grown on each tray of strawberries.

The results are shown in Figure 8.

The mean rate of growth of fungus at 25C was 12 cm² per day.

Calculate the mean rate of growth of fungus at 30C.

_........ cm² per day

State the effect of temperature on the growth of fungus on strawberries from 5C to 30C.

Decomposition of strawberries can be prevented by boiling the strawberries with sugar to make jam.

Enzymes in the fungus caused decomposition.

Explain how boiling stops the enzymes from working.

Cells from a fungus can land on jam.

The sugar solution inside the jam is more concentrated than the sugar solution inside the fungus cells.

State how osmosis causes the fungus cells to die.

(a) (i) Water enters a plant through root hair cells.

Root hair cells have

Explain how water in the root is transported to the leaves of the plant.

How is sucrose transported from the leaves to other parts of the plant?

Figure 7 shows the average size of stomata in a leaf during one day.

Name the cells that change the size of stomata.

Describe the trend shown in Figure 7.

The temperature increased from 8 am to 1 pm.

Explain why this affected the size of the stomata.

(a) Plants use nitrate ions to make proteins and chlorophyll.

What effects will a low nitrate ion concentration in soils have on plants?

Which organisms convert nitrogen to nitrate ions during the nitrogen cycle?

Figure 8 shows part of a root as seen using a light microscope.

Figure 9 shows information about the two types of cell labelled in Figure 8.

Calculate the surface area to volume ratio of the root hair cell.

Explain the benefit to the plant of having root hair cells.

Algae are green plants.

Figure 10 shows the number of algae in a lake in the United Kingdom during one year.

Explain the changes in the number of algae in the lake from February to June.

(a) A student investigated the effect of nitrate ion concentration on plant growth. She placed barley seedlings in three test tubes containing different concentrations of nitrate fertiliser.

Test tube 1 contained distilled water with 1 pellet of nitrate fertiliser. Test tube 2 contained distilled water with 2 pellets of nitrate fertiliser. Test tube 3 contained distilled water with 3 pellets of nitrate fertiliser.

After 7 days, the lengths of the seedlings were measured.

Figure 13 shows an example of the apparatus used.

Describe a control for this investigation.

The nitrate fertiliser contains the chemical compound potassium nitrate. The hazard symbol on the bag of potassium nitrate fertiliser is shown in Figure 14.

Which hazard does this symbol represent?

Give a method, other than measuring the change in length, that would show the growth of the seedlings.

Figure 15 shows the results of this investigation.

Explain why there are differences in the change in the lengths of the seedlings.

Explain how nitrate ions were absorbed by the seedling in test tube 3.

Farmers use crop rotation to reduce the need to add nitrate fertilisers to the soil.

Plants such as peas and beans have a mutualistic relationship with nitrogen-fixing bacteria.

Explain why farmers use these plants in their crop rotation cycle.