AQA AS level biology
1. What are the three ways a pathogen can damage hosts cells?: 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
2. What are the two ways pathogens cause disease?: 1) production of toxins
2) cell damage
3. What are the lifestyle factors that can affect your chances of getting
can- cer?: 1) smoking
2) excessive exposure to sunlight
3) excessive alcohol intake
4. What are the three surfaces of contact- where pathogens enter our body?
and how do they get in?: 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
1/
,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.
5. Explain the process of phagocytosis.: 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.
6. What is the cellular and humoral response?: Cellular = The T-cells and
other immune system cells that they interact with e.g phagocytes ,
form the cellular response
2/
, Humoral - B cells and the production of antibodies form the humoral
response.
7. Explain what is meant by a primary response.: The primary response is
slow because there aren't many B-cells that can make the antibody
needed to bind to it.
3/
1. What are the three ways a pathogen can damage hosts cells?: 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
2. What are the two ways pathogens cause disease?: 1) production of toxins
2) cell damage
3. What are the lifestyle factors that can affect your chances of getting
can- cer?: 1) smoking
2) excessive exposure to sunlight
3) excessive alcohol intake
4. What are the three surfaces of contact- where pathogens enter our body?
and how do they get in?: 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
1/
,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.
5. Explain the process of phagocytosis.: 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.
6. What is the cellular and humoral response?: Cellular = The T-cells and
other immune system cells that they interact with e.g phagocytes ,
form the cellular response
2/
, Humoral - B cells and the production of antibodies form the humoral
response.
7. Explain what is meant by a primary response.: The primary response is
slow because there aren't many B-cells that can make the antibody
needed to bind to it.
3/
