Translocation

Different parts of a plant have different functions.

Draw one line from each part of a plant to the function of that part.

Oranges are grown on farms.

Oranges grow on trees that can become infected with bacteria.

The bacteria enter the trees when an insect feeds on the leaves.

The tree responds to the infection by blocking phloem tissue.

Why does blocking phloem tissue decrease the rate of spread of bacteria in a tree?

Tick (✓) one box.

Blocking phloem increases the rate of photosynthesis.

Blocking phloem reduces the transport of substances in the tree.

Blocking phloem weakens the cell walls of the tree.

What can farmers do to reduce the spread of the bacteria from one tree to another tree?

Tick (✓) two boxes.

Destroy infected orange trees immediately.

Plant infected orange trees closer together.

Transport trees to another orange tree farm.

Wash hands after touching infected orange trees.

Water the infected orange trees more often.

Orange juice contains sugar.

Benedict’s solution is used to test for sugar.

Figure 7 shows some of the equipment used for the Benedict’s test.

Describe a method a student could use to test if a drink contains sugar.

You should refer to the equipment in Figure 7.

Plant diseases often reduce the rate of plant growth.

Meristem tissue is found at the tips of shoots and roots in plants.

Which process happens in meristem tissue?

Tick (✓) one box.

Fertilisation

Meiosis

Mitosis

Transpiration

Oranges are grown on farms.

Oranges grow on trees that can become infected with bacteria.

The bacteria enter the trees when an insect feeds on the leaves.

The tree responds to the infection by blocking phloem tissue.

Suggest one advantage to the infected tree of blocking phloem tissue.

Blocking phloem tissue causes oranges to contain a lower concentration of sugar than oranges from trees that are not infected.

Explain why.

Eventually, the blocked phloem tissue causes the tree to die.

Explain why blocked phloem tissue causes the tree to die.

Farmers want to reduce the spread of the bacteria between orange trees.

Explain one way farmers can reduce the spread of bacteria between orange trees.

Oranges can be made into fruit juice.

A student used the test for sugar to compare the concentration of sugar in five types of fruit juice.

The test for sugar produces a range of colours depending on the concentration of sugar present.

Figure 6 shows the colour chart for the test for sugar.

Describe a method the student could have used to compare the concentration of sugar in the different fruit juices.

The student’s results will not accurately show the concentration of sugar in juice from oranges.

Explain why.

This question is about plants.

Meristem is a specialised tissue found at the tips of shoots and roots.

What is the function of meristem tissue?

Tick (✓) one box.

Cell division

Fertilisation

Transpiration

Xylem tissue and phloem tissue are found in plants.

Cells in phloem tissue contain sugars.

Table 1 shows some features of xylem tissue and phloem tissue.

Complete Table 1.

Put one tick (✓) in each row to show if the feature is true for:

both xylem and phloem.

Stomata are tiny holes in the surface of leaves.

Guard cells surround the stomata.

Figure 2 shows the shape of guard cells around stomata at different times of the day.

Figure 2

Guard cells control water loss from the leaf.

Explain what happens to the guard cells to increase water loss from the leaf.

Use Figure 2.

Xylem tissue and phloem tissue are found in plants.

Compare the structure and function of xylem tissue and phloem tissue.

Plants have different tissues that are adapted for special functions.

One plant tissue is meristem tissue.

Meristem tissue:

is made of meristem stem cells

is found in the growing areas of a plant

contains the cells that divide as a plant grows.

Figure 12 shows how specialised leaf cells are produced from meristem cells.

Meristem cells divide and then form specialised cells.

Cells become specialised during process X.

Name process X.

Describe two changes that can happen in a plant because meristem cells divide.

Scientists used a microscope to investigate cell division in a plant shoot.

Figure 13 shows the plant shoot.

The percentage of cells dividing by mitosis was estimated.

This is the method used.

1. Take a tissue sample from section A of the plant shoot and view 100 cells.

2. Count how many of the 100 cells are dividing by mitosis.

3. Repeat steps 1 and 2 for sections B, C and D of the plant shoot.

Table 8 shows the results.

Explain the results in Table 8.

Phloem tissue and xylem tissue are part of a plant’s transport system.

What is the name of the process that transports dissolved sugars around a plant?

Figure 14 shows a section of phloem tissue in a leaf.

Describe two ways the structure of phloem cells is different from the structure of xylem cells.

Dissolved sugar moves from the leaf cell into the phloem cell.

In Figure 14:

the concentration of sugar in the leaf cell is 4 mg per dm³

the concentration of sugar in the phloem cell is 118 mg per dm³.

The companion cell is needed to move sugar from the leaf cell into the phloem cell.

Explain why.

Sugars and water are transported in plants.

Name the tissue that water is transported in from the roots to the leaves.

Students investigated the rate of water uptake by a plant shoot.

Figure 7 shows the equipment used.

The air bubble moves when the plant shoot loses water by transpiration.

The movement of the air bubble shows the rate of water uptake by the plant shoot.

Why is the tap needed below the reservoir?

Tick (✓) one box.

To keep air out of the glass tube

To move the air bubble to zero

To stop water reaching the plant shoot

Students used the equipment in Figure 7 to investigate the effect of temperature on water uptake by the plant shoot.

Draw one line from each variable to the type of variable it is.

Figure 8 shows the results.

Explain the effect of temperature on the rate of water uptake by the plant shoot.

Use Figure 8.

The investigation was repeated with a fan to move the air around the plant shoot.

Predict how an increase in air movement would cause the results to be different.

In one test, the water in the tube moved 3 mm in one minute.

The radius of the tube was 0.5 mm.

The volume of water taken up can be calculated using the equation:

volume = π × r² × h

where: π = 3.14 r is the radius h is the distance moved by the water

Calculate the volume of water taken up in one minute.