Cell Division & Stem Cells (WJEC GCSE Biology): Exam Questions

In 2019, it was reported that an individual who had received a kidney transplant had survived for 19 months without taking drugs to suppress their immune response.
Before the transplant, this individual had a small number of stem cells taken from their bone marrow. The stem cells were grown and multiplied in the lab and then reinjected into the individual the day before the transplant.
Some scientists suggested that the injection of stem cells from the bone marrow caused the body to accept the foreign antigens on the transplanted kidney.

Not all scientists were confident that the stem cells were responsible, because a second person given the same treatment was not able to survive without drugs to suppress their immune response.

(i) State what is meant by the term stem cell.

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(ii) I. Name the type of cell division that occurs when stem cells are grown in the laboratory.

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II. Give one feature of this type of cell division which is important in the production of stem cells.

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(iii) State one benefit to the patient of using stem cells from their own bone marrow rather than stem cells from the bone marrow of another individual.

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(iv) Adult stem cells were used in this procedure. Name one other source of stem cells.

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Suggest one way in which the scientific community could increase their confidence that the injection of stem cells was responsible for the result observed

The photograph shows a koala (Phascolarctos cinereus). These animals live in trees in Australia. Their chromosome number is 16.

(i) Complete Table 5 about cell division in the koala

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Table 5

(ii) State:

I. one function of mitosis;

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II. the scientific name for the daughter cells produced by meiosis.

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Another Australian animal, the grey kangaroo (Macropus giganteus) also has 16 chromosomes but its appearance is very different from the koala.

Underline which one of the following statements explains what causes the appearance of these two species to be different.

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They live in different habitats.

The genes on their chromosomes are different.

Their diet consists of different types of plants.

In 2018, scientists announced they had produced a laboratory grown oesophagus using a rat oesophagus and human adult stem cells. This was part of on-going research by scientists into different ways of producing organs for transplants.

Image 5 outlines the procedure.

Image 5

(i) State the meaning of the term stem cell.

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(ii) State the name of the type of cell division which occurs during Step 4.

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(iii) Suggest one advantage of using adult stem cells rather than embryonic stem cells in the process shown in Image 5.

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(iv) Suggest two variables which need to be controlled in the bioreactor.

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State one reason why animal-rights groups might oppose this type of research.

Female ants have a chromosome number of 34 and produce gametes through the process of meiosis.

(i) State how many gametes are produced from each mother cell.

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(ii) Males develop from female eggs which have not been fertilised. Conclude the chromosome number in males and explain your answer.

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(iii) State one function of mitosis in adult ants.

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