Figure 2 shows part of a DNA molecule - Edexcel - GCSE Biology Combined Science - Question 2 - 2018 - Paper 1
Question 2
Figure 2 shows part of a DNA molecule.
(a) (i) What is the shape of a DNA molecule?
A single helix
B double helix
C complementary helix
D triple helix
(ii)... show full transcript
Worked Solution & Example Answer:Figure 2 shows part of a DNA molecule - Edexcel - GCSE Biology Combined Science - Question 2 - 2018 - Paper 1
Step 1
What is the shape of a DNA molecule?
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Answer
The shape of a DNA molecule is the B double helix. This structure consists of two long strands twisted around each other, resembling a spiral staircase.
Step 2
Which molecules are present in the DNA backbone?
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Answer
The molecules present in the DNA backbone are sugars and phosphates. These form the structural framework of the DNA molecule, connecting the nucleotide bases.
Step 3
Describe how cells are broken down to release DNA.
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Cells can be broken down to release DNA by first homogenising the cells, which involves crushing or grinding the fruit tissue to break down cell walls. After this, the homogenised mixture is treated with a salt/detergent solution that disrupts the cell membranes, allowing the DNA to be released into the solution.
Step 4
State two benefits that the Human Genome Project could have for medicine.
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Answer
The Human Genome Project can help locate genes associated with diseases, enabling better understanding and diagnosis.
It can assist in treating genetic disorders by informing genetic counselling and development of new treatments.
