This question is about stem cells - AQA - GCSE Biology Combined Science - Question 6 - 2018 - Paper 1
Question 6
This question is about stem cells.
0 6 . 1 Give one place in a plant where stem cells are found.
0 6 . 2 What is one economic use of plant stem cells?
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Worked Solution & Example Answer:This question is about stem cells - AQA - GCSE Biology Combined Science - Question 6 - 2018 - Paper 1
Step 1
Give one place in a plant where stem cells are found.
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Answer
One place in a plant where stem cells are found is in the meristem.
Step 2
What is one economic use of plant stem cells? Tick one box.
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Answer
The economic use of plant stem cells is to produce large numbers of identical plants.
Step 3
Convert 6 picograms to grams. Give your answer in standard form.
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Answer
The mass of DNA at the start of the cycle is given as 6 picograms. To convert this into grams:
6extpicograms=6imes10−12extgrams
Step 4
Calculate how many hours the cell spent in mitosis.
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The total time of the cell cycle is 15 hours. From Figure 9, mitosis occupies 28% of the cycle. To calculate the time spent in mitosis:
extTimeinmitosis=0.28imes15exthours=4.2exthours
To three significant figures, the time spent in mitosis is 4.20 hours.
Step 5
Describe what happens in each of the three stages of the cell cycle.
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Stage 1 (Interphase): During this stage, the cell grows and increases its number of organelles. The DNA also replicates, meaning the two copies of each chromosome are formed.
Stage 2 (Mitosis): In this stage, one set of chromosomes moves to each end of the cell as the nucleus divides. The nucleus splits into two, and during this stage, the cytoplasm divides, resulting in two genetically identical cells.
Stage 3 (Cytokinesis): This is the final phase where the cell membrane divides, completing the process of cell division and producing two daughter cells that are genetically identical.
Step 6
Give two advantages and two disadvantages of therapeutic cloning in medical treatments.
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Advantages:
Therapeutic cloning may be used to cure or treat genetic diseases, offering potential solutions for conditions like diabetes or paralysis.
Stem cells produced can differentiate into various cell types, allowing for tailored treatments and replacements for damaged tissues or organs.
Disadvantages:
Ethical concerns arise as the process may involve the destruction of embryos, which some people believe has a right to life.
There are risks of immune rejection since the body may recognize transplanted cells as foreign, leading to complications.
