Transport in & out of cells

This question is about the transport of substances into and out of organisms.

Glucose moves from an area with a high concentration of glucose to an area with a low concentration of glucose.

Name the process that moves the glucose.

Figure 7 shows a salamander.

The species of salamander shown in Figure 7 does not have lungs.

Gas exchange between the air and the blood of the salamander occurs through the skin.

Humans have lungs for gas exchange.

Figure 8 shows the lungs.

Describe how human lungs are adapted for efficient gas exchange.

Figure 7 shows part of a food web from one ecosystem.

Define the term ‘ecosystem’.

Describe the difference between a population and a community in one habitat.

Humans kill narwhals for meat and skin.

Killing more narwhals can cause the number of seals to increase or decrease.

Explain why killing more narwhals can have two different effects on the number of seals.

The algae in Figure 7 store a mass of 68 arbitrary units of carbon in 1 year.

8.4% of the carbon in each stage of the food web is passed to the next stage.

Calculate the mass of carbon stored in tertiary consumers in 1 year.

Mass of carbon = _____________________ arbitrary units

Mineral ions are at: a low concentration in sea water

a high concentration in algae.

Name the process algae use to absorb mineral ions from sea water.

Algae and plants are producers.

Explain how not having enough magnesium ions and nitrate ions can limit the mass of carbon stored in producers.

Figure 5 shows a green pepper growing on a pepper plant.

Figure 6 shows a drawing of a cell from a pepper.

Cell part A contains a green pigment.

Label parts A, B and C on Figure 6.

Choose answers from the box.

Water can move into cells and out of cells.

A student investigated how different concentrations of sugar solution affect the mass of pepper tissue.

This is the method used.

1. Cut three pieces of pepper 1 cm wide and 1 cm long.

2. Dry each piece.

3. Record the mass of each piece.

4. Leave each piece in sugar solution for 1 hour.

5. Remove the pieces from the sugar solution and dry each piece.

6. Record the mass of each piece.

7. Repeat steps 1 to 6 using different concentrations of sugar solution.

Before the investigation, the pepper was wrapped in plastic and kept at 5 °C.

Which are two reasons for keeping the pepper wrapped in plastic at 5 °C?

Tick (✓) two boxes.

To change the colour of the pepper

To decrease the size of the pepper

To increase growth of the pepper

To reduce water loss from the pepper

To slow down decay of the pepper

The student calculated the mean percentage change in mass at each concentration of sugar solution.

Figure 7 shows the results.

Figure 7

Concentration

–10

–20

In some concentrations of sugar solution, the mass of the pieces of pepper increased.

The mass increased because water moved into the cells.

What process moved water into the cells?

What concentration of sugar solution would cause a mean percentage change in mass of 0%?

Use Figure 7.

Concentration of sugar solution = __________________ arbitrary units

The cells of the pepper have wrinkled cell walls.

What is the advantage of wrinkled cell walls to the pepper plant?

Tick (✓) one box.

The cells can expand

The cells contain less cellulose

The surface area is smaller

Tobacco mosaic virus (TMV) can infect pepper plants.

Infected plants have yellow patches on the leaves.

Explain why plants with TMV grow slower than plants that do not have TMV.

Figure 6 shows a green pepper growing on a pepper plant.

The cells of the green pepper contain water.

Water cannot enter the cells through the waxy waterproof coating on the outside of the pepper fruit.

Describe how water reaches the green pepper cells.

A pepper cell was viewed using a microscope.

The image of a pepper cell had a width of 32 mm.

The magnification of the image was × 400

Calculate the real width of the cell in micrometres.

Real width = __________________ micrometres

A student investigated how different concentrations of sugar solution affect the mass of pepper tissue.

This is the method used.

1. Cut three pieces of pepper 1 cm wide and 1 cm long.

2. Dry each piece.

3. Record the mass of each piece.

4. Leave each piece in sugar solution for 1 hour.

5. Remove the pieces from the sugar solution and dry each piece.

6. Record the mass of each piece.

7. Repeat steps 1 to 6 using different concentrations of sugar solution.

8. Calculate the mean percentage change in mass at each concentration of sugar solution.

Before the investigation, the pepper was kept at 5 °C.

Suggest why.

Describe why calculating the percentage change in mass is more valid than only calculating the change in mass.

Figure 7 shows the results.

Figure 7

Mean

Concentration

–10

–20

Determine the concentration of the solution inside the pepper cells before the investigation.

_ Concentration = __________________ mol/dm³

Explain the mean percentage change in mass of pepper when the concentration of sugar solution was 0.5 mol/dm³.

As peppers develop, the vacuoles of the cells increase in volume.

Figure 8 shows the shape of a pepper cell before it is fully developed.

Suggest two reasons why the cell walls of pepper cells are wrinkled.

Figure 7 shows part of the human breathing system.

Label structures A, B and C on Figure 7.

Choose answers from the box.

Describe one way that lungs are adapted for gas exchange.

A student investigated the effect of surface area to volume ratio on diffusion.

The student used gel cubes with different surface area to volume ratios.

The gel cubes: were pink at the start of the investigation became colourless as acid diffused into the cube.

This is the method used.

1. Cut the gel into a cube with sides that are 1 cm long.

2. Place the cube in a beaker.

3. Cover the cube with acid.

4. Keep the beaker at 20 °C.

5. Record the time taken for the cube to go colourless.

6. Repeat steps 2 to 5 with cubes of different sizes.

Draw one line from each type of variable to that variable in the investigation.

Table 2 shows the results.

Describe the effect of increasing the size of the cube on the time taken for the cube to go colourless.

What would be an improvement to the investigation?

Tick (✓) one box.

Repeat the method three times and calculate a mean for each size cube.

Repeat the method with 5 cubes all of the same size.

Repeat the method with a different size beaker for each size cube.

All living organisms are made of cells.

Figure 15 shows two types of cell.

Calculate how many times longer the liver cell is than the bacterial cell.

Compare the structure of cell A with the structure of cell B.

You should include similarities and differences in your answer.

Do not refer to cell size.

In multicellular organisms, cells are organised into tissues.

What is meant by a ‘tissue’?

A scientist investigated the effect of different concentrations of sugar solution on red blood cells.

Figure 16 shows the effect of placing a red blood cell into a sugar solution.

What conclusion can be made from the result in Figure 16 ?

Tick (✓) one box.

The sugar solution was less concentrated than inside the cell.

The sugar solution was the same concentration as inside the cell.

The sugar solution was more concentrated than inside the cell.

A student investigated the effect of different concentrations of sugar solution on the change in mass of plant tissue.

The student used pieces of potato.

Describe a method the student could use to produce valid results.

The student used a valid method.

The student calculated the percentage change in mass of the pieces of potato.

Table 5 shows the results.

Complete Figure 17.

You should:

plot the data from Table 5

draw a line of best fit.

Some of the results have been plotted for you.

Determine the concentration of sugar solution that would cause no change in the mass of a piece of the potato.

Use Figure 17.

Concentration of sugar solution = _________________________ mol/dm³

All living organisms are made of cells.

Figure 1 shows two types of cell.

Calculate how many times longer the liver cell is than the bacterial cell.

Compare the structure of cell A with the structure of cell B.

You should include similarities and differences in your answer.

Do not refer to cell size.

In multicellular organisms, cells are organised into tissues.

What is meant by a ‘tissue’?

A scientist investigated the effect of different concentrations of sugar solution on red blood cells.

Figure 2 shows the effect of placing a red blood cell into a sugar solution.

What conclusion can be made from the result in Figure 2 ?

Tick (✓) one box.

The sugar solution was less concentrated than inside the cell.

The sugar solution was the same concentration as inside the cell.

The sugar solution was more concentrated than inside the cell.

A student investigated the effect of different concentrations of sugar solution on the change in mass of plant tissue.

The student used pieces of potato.

Describe a method the student could use to produce valid results.

The student used a valid method.

The student calculated the percentage change in mass of the pieces of potato.

Table 1 shows the results.

Complete Figure 3.

You should:

plot the data from Table 1

draw a line of best fit.

Some of the results have been plotted for you.

Determine the concentration of sugar solution that would cause no change in the mass of a piece of the potato.

Use Figure 3.

Concentration of sugar solution = _________________________ mol/dm³

Students investigated the effect of different concentrations of salt solution on the mass of pieces of potato.

This is the method used.

1. Cut three pieces of potato, each with a mass of 2.00 g.

2. Place the pieces of potato into a salt solution with a concentration of 0.2 mol/dm³

3. After 30 minutes, measure the mass of each piece of potato.

4. Calculate the change in mass.

5. Repeat steps 1 to 4 for five other concentrations of salt solution.

Table 3 shows the results.

Give two control variables the students should have used in the investigation.

Do not refer to mass or time in your answer.

Calculate value X in Table 3.

Figure 14 shows a potato cell.

Explain why the mass of the pieces of potato increased in the 0.2 mol/dm³ salt solution.

You should refer to the cell parts labelled in Figure 14.

The image in Figure 14 was made using an electron microscope and not a light microscope.

Give one piece of evidence to support this.

Starch is digested in the gut.

Why is digestion of starch needed?

Tick (✓) one box.

Starch is a carbohydrate.

Starch molecules are insoluble.

Starch molecules are small.

Describe the process of starch digestion.

Students investigated the effect of different concentrations of salt solution on the mass of pieces of potato.

This is the method used.

1. Cut three pieces of potato, each with a mass of 2.00 g.

2. Place the pieces of potato into a salt solution with a concentration of 0.2 mol/dm³

3. After 30 minutes, measure the mass of each piece of potato.

4. Calculate the change in mass.

5. Repeat steps 1 to 4 for five other concentrations of salt solution.

Table 1 shows the results.

Give two control variables the students should have used in the investigation.

Do not refer to mass or time in your answer.

Calculate value X in Table 1.

Figure 2 shows a potato cell.

Explain why the mass of the pieces of potato increased in the 0.2 mol/dm³ salt solution.

You should refer to the cell parts labelled in Figure 2.

The image in Figure 2 was made using an electron microscope and not a light microscope.

Give one piece of evidence to support this.

Starch is digested in the gut.

Why is digestion of starch needed?

Tick (✓) one box.

Starch is a carbohydrate.

Starch molecules are insoluble.

Starch molecules are small.

Describe the process of starch digestion.

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.

Heart tissue is made of cardiac muscle cells.

Figure 2 shows a cardiac muscle cell.

Cardiac muscle needs to contract and relax continuously.

Cardiac muscle cells contain a large number of the structures labelled A.

Name structure A.

Oxygen moves from the cytoplasm into structure A by the process of diffusion.

Why does the oxygen move by diffusion?

Which change would cause the rate of diffusion of oxygen across an exchange surface to decrease?

Tick (✓) one box.

An increase in the surface area of the exchange surface

An increase in the temperature of the cell

An increase in the thickness of the exchange surface

The cardiac muscle cells in humans can respire aerobically and anaerobically. Aerobic respiration uses oxygen. Anaerobic respiration does not use oxygen.

Compare the processes of aerobic respiration and anaerobic respiration.

Do not refer to oxygen in your answer.

Figure 3 shows a diagram of a human heart.

What is the name of blood vessel X ?

Tick (✓) one box.

Aorta

Pulmonary artery

Pulmonary vein

Vena cava

Give one difference in the composition of the blood in the right ventricle compared with the blood in the left ventricle.

When the walls of the atria and ventricles contract, the pressure increases.

Table 4 shows information about the pressure during one contraction of the heart.

The left ventricle has the highest pressure.

Why does the left ventricle need to have the highest pressure?

What is the most likely maximum pressure in the right atrium?

Use Table 4.

Tick (✓) one box.

< 25 = 25 > 25

Some people have a medical condition called a ‘hole in the heart’.

A ‘hole in the heart’ is a small hole between the right ventricle and the left ventricle.

Some blood flows from the right ventricle to the left ventricle.

Explain why a ‘hole in the heart’ causes a person to feel tired.

Table 1 shows the concentration of some substances outside a cell and inside a cell.

Why do sodium ions move into the cell?

Use information from Table 1.

Calculate how many times greater the potassium ion concentration is inside the cell compared with outside the cell.

Name the process that releases energy in cells.

Which process needs energy to move a substance into a cell?

Tick (✓) one box.

Give two factors that affect the rate of diffusion.

Students investigated the change in mass of potato pieces in different concentrations of sugar solution.

Figure 7 shows some of the equipment used.

Describe a method to investigate the effect of different concentrations of sugar solution on the change in mass of potato pieces.

Plant leaves contain chlorophyll.

Nitrate ions are needed to produce chlorophyll.

Name one other mineral ion needed to produce chlorophyll.

Do not refer to nitrate in your answer.

Some mineral ions are in a lower concentration in the soil compared with inside plant root hair cells.

Name the process that moves mineral ions from a lower concentration in the soil into plant root hair cells.

Explain how mineral ions move from root hair cells to the leaves.

Which two factors increase the rate of movement of mineral ions through the plant?

Tick (✓) two boxes.