Biology AQA AS Level 7401/1 Paper 1 –
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• The human cell then makes a complementary strand to the HIV
DNA.
The complementary strand is made in the same way as a
new complementary
strand is made during semi-conservative replication of
human DNA. Describe how the complementary strand of HIV
DNA is made. - ANS ---- there are complementary
nucleotides/bases pair
- DNA polymerase used
- Nucleotides join together (to form new strand)/phosphodiester
bonds form;
Contrast the structures of DNA and mRNA molecules to give
three differences. - ANS ---- DNA is double stranded/double
helix and mRNA single-stranded; -
DNA (very) long and RNA short;
-Thymine/T in DNA and uracil/U in RNA; -
Deoxyribose in DNA and ribose in RNA;
This fat substitute cannot be digested in the gut by lipase.
Suggest why. - ANS ---- (Fat substitute) is a different/wrong
shape/not complementary
, - Unable to fit/bind to (active site of) lipase/no ES complex
formed;
Despite being a lipid, the substitute cannot cross the cell-surface
membranes of cells lining the gut.
Suggest why it cannot cross cell-surface membranes. -
ANS ---It is hydrophilic/is polar/is too large/is too
big;
Cells constantly hydrolyse ATP to provide energy. Describe
how ATP is resynthesised in cells. - ANS ---- From ADP
and
phosphate;
- By ATP synthase;
- During respiration/photosynthesis;
Give two ways in which the hydrolysis of ATP is used in cells. -
ANS ---- To provide energy for other reactions/named
process;
- To add phosphate to other substances and make them
more reactive/change their shape
What is the evidence from Figure 2 that a scanning electron
microscope was used to take this photograph? - ANS ---
(Can see) 3D image
name the part of the mitochondrion labelled X in Figure 2
- ANS ---Crista/cristae
Y is a protein. One function of Y is to transport
cellulose molecules across the phospholipid bilayer.
Latest Exam with Well-Verified Questions
and Correct Answers | Expert Reviewed &
A+ Graded Study Guide 2025
• The human cell then makes a complementary strand to the HIV
DNA.
The complementary strand is made in the same way as a
new complementary
strand is made during semi-conservative replication of
human DNA. Describe how the complementary strand of HIV
DNA is made. - ANS ---- there are complementary
nucleotides/bases pair
- DNA polymerase used
- Nucleotides join together (to form new strand)/phosphodiester
bonds form;
Contrast the structures of DNA and mRNA molecules to give
three differences. - ANS ---- DNA is double stranded/double
helix and mRNA single-stranded; -
DNA (very) long and RNA short;
-Thymine/T in DNA and uracil/U in RNA; -
Deoxyribose in DNA and ribose in RNA;
This fat substitute cannot be digested in the gut by lipase.
Suggest why. - ANS ---- (Fat substitute) is a different/wrong
shape/not complementary
, - Unable to fit/bind to (active site of) lipase/no ES complex
formed;
Despite being a lipid, the substitute cannot cross the cell-surface
membranes of cells lining the gut.
Suggest why it cannot cross cell-surface membranes. -
ANS ---It is hydrophilic/is polar/is too large/is too
big;
Cells constantly hydrolyse ATP to provide energy. Describe
how ATP is resynthesised in cells. - ANS ---- From ADP
and
phosphate;
- By ATP synthase;
- During respiration/photosynthesis;
Give two ways in which the hydrolysis of ATP is used in cells. -
ANS ---- To provide energy for other reactions/named
process;
- To add phosphate to other substances and make them
more reactive/change their shape
What is the evidence from Figure 2 that a scanning electron
microscope was used to take this photograph? - ANS ---
(Can see) 3D image
name the part of the mitochondrion labelled X in Figure 2
- ANS ---Crista/cristae
Y is a protein. One function of Y is to transport
cellulose molecules across the phospholipid bilayer.
