A Level Key Knowledge Flashcards
Define “emphysema”
A disease in which the walls of the alveoli break down, reducing the area for gaseous exchange, thereby causing breathlessness in the patient
Define “carcinogenic”
A chemical, form of radiation or other agent that causes cancer
Define “cancer”
A disease resulting from mutations that leads to uncontrolled cell division
Define “antioxidants”
Chemicals which reduces or prevents oxidation. Often used as an additive to prolong the shelf life of certain foods
Define “saturated fats”
Fat molecules in which there are no double bonds between the carbon atoms
Define “tumour”
A swelling in an organism that is made up of cells that continue to divide in an abnormal way
Define “mutation”
A sudden change in the amount or the arrangement of the genetic material in the cell
What is a Pathogen?
A microorganism that causes infectious disease
Distinguish between the terms infection and disease
An infection is the growth of pathogenic micro organisms in the body, whether or not the body function is impaired. A disease is any change from a state of health or an impaired body function.
When is a disease recognised? What is causing this?
The manifestation of symptoms such as fever, pain or aches. This is due to failure of immune system to control in the first round of the growth of infectious organisms.
Give three ways in which bacteria cause disease
Bacteria can cause disease directly by actually attacking and digesting human cells and tissues. They can cause disease indirectly by producing harmful by-products that harm surrounding tissue. They can produce toxins that harm or destroy tissue.
How does a virus cause disease?
Viruses insert their DNA into body cells and commands it to produce more of the same virus. The body cells are then destroyed.
What happens in the mitochondria?
Respiration
What is the equation for magnification when using microscopes?
Magnification = size of image / actual size of the object
How many micrometers are there in a millimetre ?
1000
