Stem cells

Plants and animals have stem cells.

These are cells that have not undergone changes to become specialised cells.

Which process do stem cells go through to become specialised cells?

Tick (✓) one box.

The table gives features of different types of stem cells.

Complete the table by putting one tick (✓) in each row.

One type of specialised cell in a plant is a root hair cell, shown in the diagram.

Give a function of a root hair cell and state how it is adapted for that function.

One role of a root hair cell is to move ions into the plant against the concentration gradient.

State the name given to this type of transport.

The diagram shows drawings of red blood cells.

Complete the sentences about red blood cells. Use words from the list.

biconcave chlorophyll haemoglobin helix

nitrogen oxygen water

Red blood cells are adapted to transport........ around the body.

One adaptation is the red pigment........ found inside the cells.

Another adaptation is their........ shape.

Bone marrow cells inside human bones differentiate to form red blood cells.

What name describes cells that can differentiate?

This diagram shows the human heart.

The table shows some information about the heart.

Use the diagram to complete the table.

Hormones are transported in the blood.

The graph shows the changes that occur to female hormone concentrations in the blood during the menstrual cycle.

Which day of the cycle does hormone X reach its peak?

Draw a line from each hormone to its correct name.

Which risk is decreased by using adult stem cells instead of embryonic stem cells in skin transplants?

A Fatty deposits forming below the skin

B Rejection of transplanted skin

C Skin becomes less waterproof

D Skin cancer developing

What is a difference between embryonic stem cells and adult stem cells?

A Adult stem cells are less likely to be rejected when used in transplants.

B Only embryonic stem cells can differentiate.

C Only embryonic stem cells produce a full range of different cell types.

D There are more ethical issues in the use of adult stem cells.

To function correctly, the brain needs to make a chemical called dopamine. Parkinson’s disease is where the brain does not make enough dopamine. Embryonic stem cells might be used to treat Parkinson’s disease.

What is an ethical consideration in this kind of treatment?

A The embryonic stem cells are obtained from a human fetus.

B The embryonic stem cells may not produce the correct type of dopamine.

C The embryonic stem cells may be rejected by the patient’s immune system.

D The embryonic stem cells will not have the same genome as the patient.

Which term describes cells that have the ability to differentiate into all types of body cells?

A Adult stem cells

B Bone marrow stem cells

C Embryonic stem cells

D Skin stem cells

The diagram shows the main components of the blood.

Complete the table to show which part of the blood is liquid and which helps blood to clot.

Put one tick (✓) in each row.

Describe two differences in the structure of red blood cells and white blood cells.

In which year were there the most number of transplants?

Describe the overall trend in the number of transplants shown in the graph.

The blood stem cells used in these transplants are adult stem cells from a donor.

Stem cells can also be taken from embryos.

Write down one benefit and one risk of using adult stem cells from a donor.

Benefit........

Risk........

Adult stem cells found in skin usually only form new skin cells.

• Scientists have developed adult skin cells that can be reprogrammed into ‘embryonic – like’ stem cells.

• These stem cells are called iPS cells and they can be used as a source of any human cell.

Which process turns stem cells into specialised skin cells?

Both embryonic stem cells and iPS cells are used in medical research.

The graph shows the number of scientific papers published by scientists who have used either embryonic stem cells or iPS cells in their research.

Give one reason why it is important for scientists to publish their research.

How many more scientific papers used iPS cells rather than embryonic stem cells in 2016?

Suggest two reasons for the difference in use between the two types of stem cells seen in 2016.

Which row correctly describes human stem cells?

Which statement is true of both adult and embryonic stem cells?

A They are in all adult and embryonic tissues.

B They are only used to make blood cells.

C They can divide by mitosis.

D They cannot differentiate.

The diagram shows the root tip of a plant.

Which label, A, B, C or D, identifies the position of stem cells in the root tip?

The diagram shows some crops that have been developed from a wild mustard plant.

The cauliflower crops grown today have taken many years to develop.

Name the process used by humans to develop cauliflower plants from wild mustard plants.

Put a tick (✓) next to the correct answer.

Some bacteria have genes which mean that they can produce a natural insecticide. Scientists have produced cauliflowers that contain these genes. This means the cauliflowers can now make their own natural insecticide.

What is modified inside the cauliflower so that it has the genes?

Suggest one reason for and one reason against producing cauliflowers with these genes.

Scientists can now treat blood disorders using gene therapy. To do this they need to obtain blood stem cells.

The blood stem cells are then modified before being placed into the patient.

Complete these sentences to explain the benefits of using modified stem cells.

The stem cells can be modified to stop the........ blood cells of the immune system detecting the stem cells.

This will reduce the chance of........

This question is about diseases.

Complete the table to compare some different diseases.

Tick (✓) five boxes.

Tuberculosis has been done for you.

TB is a disease of the lungs. TB is transmitted by breathing in when an infected person near you coughs or sneezes.

One way to prevent the spread of TB is vaccination.

Describe two other ways you could prevent the spread of TB.

There are many diseases and disorders of the circulatory system.

Some blood cell disorders can affect the function of white blood cells or red blood cells.

Suggest two effects on the body if either white blood cells or red blood cells are prevented from working efficiently.

Cardiovascular diseases affect the heart.

Which lifestyle factor can increase a person’s chance of developing cardiovascular disease?

Tick (✓) one box.

*(c) The cornea is the front part of the eye that allows in light. The layers of cells in the cornea are similar to the cells in skin layers, the difference is that they have become transparent to allow the light through.

Scientists are now using stem cell technology for treating damage to the cornea to restore vision.

Describe how stem cells could be used in the treatment of damage to the cornea and any possible risks involved in this type of treatment.

The cornea is a part at the front of the eye that allows in light.

The cornea can be damaged by injury or disease. Treatment often requires a local anaesthetic. Local anaesthetics stop nerve impulses passing along the sensory neurone.

Use your knowledge of the structure of a reflex arc to explain why a person would not feel pain.

Pregnancy can affect the response of neurones to local anaesthetics.

The graph shows the effect of a local anaesthetic on nerve activity in women.

Time following local anaesthetic injection (minutes)

Look at the data over the first 10 minutes after injection.

Calculate the percentage decrease in nerve activity after 10 minutes when pregnant compared to not being pregnant.

The data in the graph has range bars plotted. These give the highest and lowest values at each point.

Why is this an improvement when presenting this data?

Explain why stem cells taken from embryos are more suitable than those from adult bone marrow.

* Scientists can use embryo stem cell technology for treating damage to the cornea to restore vision.

Read the information in the box.

• Corneal cells are transparent to allow light to pass through.

• Corneal tissue does not have blood vessels in order to remain transparent.

• Corneal transplants from donor tissue are one way to restore vision after damage to the cornea.

• Corneal transplants are at risk of tissue rejection when blood vessels develop in the cornea.

• Scientists are able to genetically engineer donor corneal cells to prevent new blood vessel formation following transplantation.

• The genetically engineered cells produce a protein which prevents the formation of blood vessels.

Describe the main steps involved in genetically engineering donor corneal cells and identify any improvements and risks from this type of treatment.

Stem cells are found in both animals and plants.

Fig. 11.1 shows the area where stem cells can be found in a plant.

What is the name of the area where stem cells are found?

Describe the difference between embryonic and adult stem cells in animals.

A group of people were asked if they were in favour of using embryonic stem cells for medical research.

The pie chart in Fig. 11.2 shows the results.

There were 254 people in the survey.

Calculate the total number of people who were against the use of embryonic stem cells.

Give your answer to the nearest whole number.

Suggest two reasons why some people may object to the use of embryonic stem cells.

Surface area is important for transport in plants.

Scientists investigate the relationship between surface area and volume.

Roots are important for transport in plants.

The diagram in Fig. 12.2 shows a root tip, with a root hair cell labelled.

The root hair cell is adapted for its function.

Explain why the adaptation is needed.

Look at the area of the root tip labelled X in Fig. 12.2.

Describe the type and function of the cells found in area X.

The diagram in Fig. 15.1 shows events that occur during human sperm production.

Cells in the germinal epithelium have the ability to turn into sperm cells.

Which term describes cells that have the ability to turn into specialised cells?

Compare the number of chromosomes in human germinal epithelium cells and human mature sperm cells.

Describe the events that occur at Stage 1 and Stage 2 in Fig. 15.1.

Sperm production occurs best at 35.0 °C due to the enzymes involved.

Explain why the testes are positioned outside of the body cavity.

Some children can inherit a rare kidney condition called ARPKD. It is caused by a recessive allele.

A pregnant woman has ARPKD. The baby’s father is heterozygous for ARPKD.

What is the probability of their baby having ARPKD?

Complete the genetic diagram to explain your answer.

Use the letters:

• R for the dominant allele

• r for the recessive allele.

It is estimated that 1 in 70 people in the UK is a carrier of ARPKD.

The estimated population of the UK in 2011 was 63.2 million.

Estimate the number of people in the UK in 2011 who were carriers.

Explain why this number is only an estimate and not the real number of carriers.

The kidneys in people with ARPKD have not developed normally.

Stem cells could be used to repair the damaged kidneys.

Discuss reasons for and against using stem cells to treat ARPKD.