Specialised cells

Figure 3 shows a sperm cell.

Name the part labelled R.

Draw one straight line from each part of the sperm cell to its function.

Animal and plant cells are both eukaryotic.

State one structure found in a plant cell that is not found in an animal cell.

DNA is found in cells.

Figure 4 shows part of a DNA molecule.

Which type of large molecule is DNA?

Describe how the bases of a DNA molecule are held together.

Explain why a person’s heart rate increases when they are running compared with when they are at rest.

Figure 16 shows a diagram of mucus‑producing goblet cells and ciliated epithelial cells in the airways of the lungs.

(Source: © K.K.T Madhusanka/Shutterstock)

Figure 16

Describe how pathogens are removed from the airways by ciliated epithelial cells.

During a race, athletes respire aerobically and anaerobically.

Figure 17 shows an athlete after a race.

Explain how aerobic respiration provides energy for running.

The rate of respiration of maggots was investigated using the equipment shown in Figure 18.

State the reason why the soda lime is placed in the test tube.

The drop of liquid in Figure 18 is at 20 mm.

The drop of coloured liquid moved at a mean rate of 2 mm per minute.

Draw, on Figure 19, the new position of the bubble after the five minutes.

The investigation was repeated with two maggots.

Explain how the movement of the drop of coloured liquid would be affected if the investigation was repeated using fewer maggots.

State one way this investigation can be improved to obtain more reliable results.

Figure 2 shows a diagram of mucus‑producing goblet cells and ciliated epithelial cells in the airways of the lungs.

(Source: © K.K.T Madhusanka/Shutterstock)

Figure 2

Describe how pathogens are removed from the airways by ciliated epithelial cells.

During a race, athletes respire aerobically and anaerobically.

Figure 3 shows an athlete after a race.

Explain how aerobic respiration provides energy for running.

The rate of respiration of maggots was investigated using the equipment shown in Figure 4.

State the reason why the soda lime is placed in the test tube.

The drop of liquid in Figure 4 is at 20 mm.

The drop of coloured liquid moved at a mean rate of 2 mm per minute.

Draw, on Figure 5, the new position of the bubble after the five minutes.

The investigation was repeated with two maggots.

Explain how the movement of the drop of coloured liquid would be affected if the investigation was repeated using fewer maggots.

State one way this investigation can be improved to obtain more reliable results.

Figure 8 shows a diagram of a mouse sperm cell.

Which row of the table shows the functions of structure A and structure B?

The diploid chromosome number for a mouse is 40.

State the number of chromosomes in a mouse sperm cell.

After a mouse egg cell is fertilised, cell division produces a ball of genetically identical stem cells.

Which is the correct order for the stages of one cell division?

The genetically identical stem cells produce the cells that develop into an embryo.

Describe how stem cells produce the cells of an embryo.

Scientific research has made many discoveries and developments allowing stem cells to be used in medical treatments.

Figure 9 shows a timeline for some of these discoveries and developments.

2006 cells with
2014 cells that make 1963 discovery 1981 mouse embryonic stem cell insulin produced by of stem cells in embryonic stem properties produced generating stem cells bone marrow
cells isolated from adult body cells from skin cells

1968 bone marrow 1998 human 2009 embryonic transplant from a
embryonic stem stem cells used to sister to her brother
cells isolated treat spinal injury

Figure 9

Give one scientific reason why the bone marrow transplant in 1968 was from a sister to her brother.

Give one scientific reason why some people are opposed to the isolation of human embryonic stem cells.

Stem cells, with the properties of embryonic stem cells, can be produced from a patient’s own skin cells.

Discuss the benefits of using these stem cells to treat the patient.

Figure 12 shows a height percentile chart for boys.

The numbers on the right-hand side of the graph show the percentiles of the population for each growth curve.

A 10-year-old boy has a height of 140 cm.

Which is the percentile range for height for this boy?

State how percentile charts are used.

As we grow, we make new cells by mitosis and meiosis.

The cells that are made can become specialised.

Figure 13 shows a diagram of a sperm cell.

Describe two ways that the sperm cell is specialised.

Complete the table to show the results when a cell divides by mitosis or meiosis in humans.

Human body cells, except gametes, have 23 pairs of chromosomes.

The tips of plant roots are where many cells are dividing by mitosis.

Which term describes the area of a root where many cells are dividing by mitosis?

Plant root cells contain an enzyme that joins glucose molecules together to make starch.

Devise a plan to investigate the effect of pH on the activity of this enzyme.

9 (a) Figure 13 shows a sperm cell.

Figure 13

Describe how structure A and structure B enable fertilisation.

structure A

structure B

(b) Figure 14 shows a human egg cell, magnified ×700.

(Source: © Pascal Goetgheluck / Science Photo Library)

Figure 14

Calculate the actual width of the region indicated by the line on Figure 14. Give your answer in millimetres, in standard form.

* (c) A student investigated the movement of water. Hens’ eggs were placed in vinegar for two days to dissolve the shell. This makes the eggs permeable to water. The eggs were then weighed and placed in different solutions. After 24 hours the eggs were weighed again. Figure 15 shows the results.

Figure 15

Evaluate the results of this investigation. You should include calculations using the data in Figure 15.

Figure 18 shows ciliated epithelial cells from the airways of a human as seen using a light microscope.

Draw the cell labelled A in the box below.

Label three parts of this cell on your diagram.

State the function of the ciliated epithelial cells in the airways of the human breathing system.

Figure 19 shows equipment used to investigate the rate of respiration in maggots.

As the maggots respire, the drop of coloured liquid moves towards the test tube.

Figure 20 shows the position of the drop of coloured liquid after ten minutes.

Use information from Figures 19 and 20 to calculate the mean rate of respiration of the maggots in mm per minute.

*(c) Explain how alveoli in human lungs are adapted for gas exchange.

Include the names of the gases that are being exchanged.

Figure 4 shows ciliated epithelial cells from the airways of a human as seen using a light microscope.

Draw the cell labelled A in the box below.

Label three parts of this cell on your diagram.

State the function of the ciliated epithelial cells in the airways of the human breathing system.

Figure 5 shows equipment used to investigate the rate of respiration in maggots.

As the maggots respire, the drop of coloured liquid moves towards the test tube.

Figure 6 shows the position of the drop of coloured liquid after ten minutes.

Use information from Figures 5 and 6 to calculate the mean rate of respiration of the maggots in mm per minute.

Describe a control for this investigation.

A karyogram is a picture of the chromosomes found in the nucleus of a single cell.

Figure 8 shows a human karyogram.

State two reasons why this karyogram cannot be from a gamete (sex cell).

State the gender shown by this karyogram.

Complete the Punnett square to show how gender is inherited.

State the probability that a child will be male.

Figure 9 shows two sperm cells.

Name structure Z.

Sperm B has a larger middle section than sperm A.

Explain why sperm B will be more likely to fertilise an egg than sperm A if they were both released at the same time.