Human immunodeficiency virus (HIV) is a pathogen - AQA - GCSE Biology - Question 7 - 2022 - Paper 1
Question 7
Human immunodeficiency virus (HIV) is a pathogen.
Give one way HIV can spread from one person to another person.
Table 8 shows information about new cases of HIV d... show full transcript
Worked Solution & Example Answer:Human immunodeficiency virus (HIV) is a pathogen - AQA - GCSE Biology - Question 7 - 2022 - Paper 1
Step 1
Give one way HIV can spread from one person to another person.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
One way HIV can spread is through sexual contact or intercourse.
Step 2
Describe the trends shown in Table 8 between 2010 and 2018.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The number of new HIV cases in women shows a decreasing trend from 376 in 2010 to 242 in 2018, with fluctuations seen in some years. Conversely, the number of new HIV cases in men initially increased from 2266 in 2010, peaking at 2370 in 2014, before significantly decreasing to 1288 in 2018.
Step 3
Suggest one reason for the change in the number of new HIV cases between 2014 and 2018.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
One reason for the change could be increased awareness and usage of protection methods, such as condoms, leading to reduced transmission rates.
Step 4
Calculate the ratio of new cases of HIV in women to new cases of HIV in men in 2018.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
In 2018, the number of new cases of HIV in women was 242 and in men was 1288. The ratio is calculated as follows:
Ratio=1288242=0.188
Thus, the ratio to 3 significant figures is 0.188 : 1.
Step 5
Suggest how the data could be presented differently so that a more valid comparison can be made.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The data could be presented as a percentage of new cases per population size for both men and women, allowing for a more accurate comparison of the rates of infection.
Step 6
Explain how a vaccine for HIV could work to prevent a person developing HIV infection.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A vaccine for HIV could work by introducing an inactive or weakened form of the virus into the body, prompting the immune system to produce antibodies. This immune response would prepare the body to fight off a real HIV infection in the future.
Step 7
Describe how the monoclonal antibody for HIV can be produced.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Monoclonal antibodies for HIV can be produced by injecting inactive HIV into a mouse. This stimulates the mouse's immune system to produce lymphocytes that specifically recognize HIV. These lymphocytes are then harvested and fused with tumor cells to create hybridoma cells, which can multiply indefinitely and produce the specific antibody.
Step 8
Suggest how the monoclonal antibody for HIV helps to prevent a person infected with HIV developing AIDS.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The monoclonal antibody can bind to the HIV antigens, blocking the virus from entering the human cells. This action helps to neutralize the virus and prevents it from replicating, thereby slowing down or preventing the progression to AIDS.
