A Level Biology FINAL EXAM with valid questions and answers
What are the three ways a pathogen can damage hosts cells? - ANSWER -1) rupturing
them to release nutrients inside them
2) breaking down nutrients inside the cell for their own use. This starves and eventually
kills the cell.
3) replicating inside the cells and bursting them when they're released
What are the two ways pathogens cause disease? - ANSWER -1) production of toxins
2) cell damage
What are the lifestyle factors that can affect your chances of getting cancer? - ANSWER
-1) smoking
2) excessive exposure to sunlight
3) excessive alcohol intake
What are the three surfaces of contact- where pathogens enter our body? and how do
they get in? - ANSWER -1) gas-exchange system = if you breathe in air that contains
pathogens, most of them will be trapped in mucus lining the lung epithelium. Some
pathogens are able to reach the alveoli where they can invade cells and cause damage.
2) Skin = if you damage your skin, pathogens on the surface can enter your
bloodstream. blood clots prevent pathogens from entering.
3) Digestive system = if you eat or drink food that contains pathogens. Some will survive
from the acidic conditions of the stomach, and invade cells of the gut wall and cause
disease.
Explain the process of phagocytosis. - ANSWER -1) A phagocyte recognises the
antigens on a pathogene
2) The cytoplasm of the phagocyte moves round the pathogen, engulfing it.
3) The pathogen is now contained in a vacuole or a vesicle in the cytoplasm of the
phagocyte.
4) A lysosome fuses with the phagocytic vacuole and the lytic enzymes break down with
the pathogen
5) The phagocyte presents the pathogens antigens, it sticks the antigens on its surface
to activate other immune system cells.
What is the cellular and humoral response? - ANSWER -Cellular = The T-cells and
other immune system cells that they interact with e.g phagocytes , form the cellular
response
Humoral - B cells and the production of antibodies form the humoral response.
, Explain what is meant by a primary response. - ANSWER -The primary response is
slow because there aren't many B-cells that can make the antibody needed to bind to it.
The infected person will show symptoms of the disease while the body produces
enough of the right antibody to overcome the infection.
T-cells and B-cells produce memory cells. Memory T-cells remember the specific
antigen and will recognise it second time round. Memory B-cells record the specific
antibodies needed to bind the antigen.
The body is now immune.
Explain what is meant by the secondary response. - ANSWER -If the same pathogen
enters the body again, the immune system will produce a quicker, stronger immune
response.
Memory B-cells divide into plasma cells that produce the right antibody to the antigen.
Memory T-cells divide into the correct type of T cells to kill the cell carrying the antigen.
The secondary response often gets rid of the pathogen before you begin to show any
symptoms.
Explain how monoclonal antibodies target cancer - ANSWER -1) Cancer cells have
antigens called tumour markers that are not found on body cells.
2) Monoclonal antibodies can be made that will bind to the tumour markers.
3) You can also attach anti-cancer drugs to the antibodies
4) Antibodies come into contact with the cancer cells and bind to the tumour markers
5) This means the drug will acuumulate in the body where there are cancer cells.
6) side effects of an antibody based drug are lower than other drugs because they
accumulate near specific cells
how do monoclonal cells work in pregnancy tests? - ANSWER -1) The application area
contains antibodies for hCG bound to a coloured bead
2) when urine is applied to the application area any hCG will bind to the antibody on the
beads, forming an antigen-antibody complex.
3) the urine moves up the stick to the test strip, carrying any beads with it
4) the test strip contains antibodies to hCG that are stuck in place.
What are the three ways a pathogen can damage hosts cells? - ANSWER -1) rupturing
them to release nutrients inside them
2) breaking down nutrients inside the cell for their own use. This starves and eventually
kills the cell.
3) replicating inside the cells and bursting them when they're released
What are the two ways pathogens cause disease? - ANSWER -1) production of toxins
2) cell damage
What are the lifestyle factors that can affect your chances of getting cancer? - ANSWER
-1) smoking
2) excessive exposure to sunlight
3) excessive alcohol intake
What are the three surfaces of contact- where pathogens enter our body? and how do
they get in? - ANSWER -1) gas-exchange system = if you breathe in air that contains
pathogens, most of them will be trapped in mucus lining the lung epithelium. Some
pathogens are able to reach the alveoli where they can invade cells and cause damage.
2) Skin = if you damage your skin, pathogens on the surface can enter your
bloodstream. blood clots prevent pathogens from entering.
3) Digestive system = if you eat or drink food that contains pathogens. Some will survive
from the acidic conditions of the stomach, and invade cells of the gut wall and cause
disease.
Explain the process of phagocytosis. - ANSWER -1) A phagocyte recognises the
antigens on a pathogene
2) The cytoplasm of the phagocyte moves round the pathogen, engulfing it.
3) The pathogen is now contained in a vacuole or a vesicle in the cytoplasm of the
phagocyte.
4) A lysosome fuses with the phagocytic vacuole and the lytic enzymes break down with
the pathogen
5) The phagocyte presents the pathogens antigens, it sticks the antigens on its surface
to activate other immune system cells.
What is the cellular and humoral response? - ANSWER -Cellular = The T-cells and
other immune system cells that they interact with e.g phagocytes , form the cellular
response
Humoral - B cells and the production of antibodies form the humoral response.
, Explain what is meant by a primary response. - ANSWER -The primary response is
slow because there aren't many B-cells that can make the antibody needed to bind to it.
The infected person will show symptoms of the disease while the body produces
enough of the right antibody to overcome the infection.
T-cells and B-cells produce memory cells. Memory T-cells remember the specific
antigen and will recognise it second time round. Memory B-cells record the specific
antibodies needed to bind the antigen.
The body is now immune.
Explain what is meant by the secondary response. - ANSWER -If the same pathogen
enters the body again, the immune system will produce a quicker, stronger immune
response.
Memory B-cells divide into plasma cells that produce the right antibody to the antigen.
Memory T-cells divide into the correct type of T cells to kill the cell carrying the antigen.
The secondary response often gets rid of the pathogen before you begin to show any
symptoms.
Explain how monoclonal antibodies target cancer - ANSWER -1) Cancer cells have
antigens called tumour markers that are not found on body cells.
2) Monoclonal antibodies can be made that will bind to the tumour markers.
3) You can also attach anti-cancer drugs to the antibodies
4) Antibodies come into contact with the cancer cells and bind to the tumour markers
5) This means the drug will acuumulate in the body where there are cancer cells.
6) side effects of an antibody based drug are lower than other drugs because they
accumulate near specific cells
how do monoclonal cells work in pregnancy tests? - ANSWER -1) The application area
contains antibodies for hCG bound to a coloured bead
2) when urine is applied to the application area any hCG will bind to the antibody on the
beads, forming an antigen-antibody complex.
3) the urine moves up the stick to the test strip, carrying any beads with it
4) the test strip contains antibodies to hCG that are stuck in place.
