AQA A LEVEL BIOLOGY EXAMPREP
MATERIAL SOLVED QUESTIONS AND VERIFIED
SOLUTIONS PREMIUM COLLECTION
◉ How does HIV replicate in helper T cells? Answer: 1. attachment
proteins attach to a receptor molecule (CD4) on the membrane of
helper T-cell
2. capsid is released into the cell, where it uncoats and releases the
genetic material into cells cytoplasm
3. reverse transcriptase is then used to make a complementary strand
of DNA from the viral RNA template
4. from this, double-stranded DNA is made and inserted into human
DNA
5. host cell enzymes are used to make viral proteins from viral DNA
found within the human DNA
6. viral proteins are assembled into new viruses
7. they bud from the cell and go on to infect other cells
◉ How does HIV cause the symptoms of AIDS? Answer: 1. HIV
reduces number of T-helper cells in blood
2. Th-cells cannot stimulate B-cells to produce antibodies or the Tc-
cells that kill infected cells.
MATERIAL SOLVED QUESTIONS AND VERIFIED
SOLUTIONS PREMIUM COLLECTION
◉ How does HIV replicate in helper T cells? Answer: 1. attachment
proteins attach to a receptor molecule (CD4) on the membrane of
helper T-cell
2. capsid is released into the cell, where it uncoats and releases the
genetic material into cells cytoplasm
3. reverse transcriptase is then used to make a complementary strand
of DNA from the viral RNA template
4. from this, double-stranded DNA is made and inserted into human
DNA
5. host cell enzymes are used to make viral proteins from viral DNA
found within the human DNA
6. viral proteins are assembled into new viruses
7. they bud from the cell and go on to infect other cells
◉ How does HIV cause the symptoms of AIDS? Answer: 1. HIV
reduces number of T-helper cells in blood
2. Th-cells cannot stimulate B-cells to produce antibodies or the Tc-
cells that kill infected cells.
