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Question 1
Plants contain cells with the ability to differentiate into specialised cells. Specialised cells in plants include palisade cells, guard cells, and root hair cells. |
a) | What is the name given to cells that can differentiate into several types of specialised cells? A root cells B stem cells C young cells D special cells
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b) | State the name given to plant tissue that contains these undifferentiated cells.
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c) | What is the function of this plant tissue in the growth of a plant?
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d) | Explain why root hair cells are considered specialised cells.
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e) | The shape of the root hair cell is an adaptation. Explain how this adaptation helps the root hair cell to absorb water and mineral ions from the soil more effectively.
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Question 2
Type 1 diabetes is caused by the destruction of pancreatic beta cells. Beta cells are responsible for producing and releasing insulin, a hormone essential for regulating blood sugar levels. Scientists are using embryonic stem cells to grow new beta cells in order to treat type 1 diabetes. |
a) | Explain why stem cells could be used as a treatment for this condition.
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b) | Explain why scientists use embryonic stem cells rather than adult stem cells.
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c) | Why is it an advantage to use stem cells from the patient rather than from a donor?
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d) | In 2012, Professor Shinya Yamanaka of Kyoto University won a Nobel Prize. Professor Yamanaka discovered that adult cells can be reprogrammed to become induced pluripotent stem cells (iPSCs). iPSCs are stem cells with the same properties as embryonic stem cells. Describe the possible benefits of Professor Yamanaka's discovery.
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Question 3
Mitosis is a process of cell division in eukaryotic cells. During mitosis, a parent cell divides to produce two identical daughter cells. |
a) | Give two reasons why new cells need to be produced throughout an organism's life.
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b) | Which cells, found in the early stages of embryonic development, have the potential to differentiate into specialised cells?
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c) | Complete the diagram to depict the levels of organisation found within a multicellular organism. Cell → → Organ → → Organism Tissue Organ system
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d) | Name the organ in the human body responsible for pumping blood around the body.
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Question 4
Mitosis is a fundamental process of cell division that occurs in eukaryotic organisms. During mitosis, a single cell divides into two identical daughter cells. The picture below shows a stage of mitosis. |
a) | Name structure X.
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b) | Describe what happens immediately before mitosis.
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c) | How many cells are produced from one fertilised egg, after three cell divisions by mitosis?
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d) | Following mitosis, which process causes the divided cells to become specialised? A meiosis B cloning C differentiation D cytokinesis
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Question 5
a) | A student is trying to map out the sequence of events that occur during mitosis. Put the following statements about mitosis in the correct order by writing the numbers1 to 6 into the table. |
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Question 6
Plant cells divide by mitosis. Before mitosis can take place, the cell prepares for cell division by obtaining nutrients, synthesising molecules, and replicating its DNA. |
a) | Which two cell components are duplicated before plant cells start to divide? A cytoplasm B mitochondria C plasmids D chloroplasts E cell wall
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b) | Plant cells divide by mitosis so that the plant can grow. Give one other reason plant cells divide by mitosis.
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c) | Describe the process of mitosis from when the parent cell's chromosomes become visible to the production of two identical daughter cells.
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Question 7
In the human body, stem cells can differentiate into many different types of cells, including:
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a) | Which of the cells above are referred to as gametes?
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b) | Gametes have adaptations to increase the chances of fertilisation and therefore successful reproduction of the organism. Explain how the adaptations of the male and female gametes allow them to carry out their job.
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c) | Which of these statements about red blood cells are correct? A they carry carbon dioxide to the cells B they contain haemoglobin C they are biconcave, so they have a large surface area D they have a large nucleus E they are large and rigid so they cannot travel through capillaries
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Question 8
The image below shows a cell going through the different stages of the cell cycle. Assign numbers from 1 to 6 to each figure to arrange them chronologically.
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Question 9
Bacteria use cell division to reproduce. |
a) | What is the name of the process that bacteria use to carry out cell division? A meiosis B mitosis C binary fission D binary fusion
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b) | A scientist wants to compare the effectiveness of an antibiotic on two different species of bacteria. The scientist collected the following equipment:
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Describe how the scientist can use the equipment above to determine the effectiveness of the antibiotic on the two species of bacteria. Your answer should address the measures taken to minimise the risk of contamination when working with bacteria.
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Question 10
The most common type of bacteria associated with dental cavities is Streptococcus mutans. A scientist used aseptic techniques to investigate how effective different mouthwashes are at killing Streptococcus mutans.
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a) | Number the sentences below so that the steps followed by the scientists are in the correct order. - Incubate the Petri dishes in an incubator... - ... using sterile forceps. 8 - ... with a ruler. - Place filter paper discs soaked in different mouthwashes in the Petri dish... - ... using a sterile pipette. - Measure the inhibition zone around the discs... 1 - Add a Streptococcus mutans solution to a Petri dish... - ... for 24 hours at 37 °C. 5 4 3 2 7 6
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b) | Give two aseptic techniques the scientist should use when taking samples from the Streptococcus mutans bacterial culture.
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c) | After the bacteria were spread on the plates, both plates were incubated for 24 hours at 37 °C. Give a reason why the plates were incubated at 37 °C.
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d) | The image below shows the agar plate immediately after it was set up, and after 24 hours. Which mouthwash is the least effective? Give a reason for your answer.
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e) | The radius of the zone of inhibition of mouthwash A is 8 mm. The area of a circle is calculated using πr2. Calculate the area of the zone of inhibition for mouthwash A. Use π = 3.14. Give your answer to 3 significant figures.
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