Topic 5 - Human Diseases & The Immune System Flashcards
State the term used to describe the rapid growth of a bacterial population. (1)
Exponential growth
Children can be immunised against whooping cough. Suggest why outbreaks of whooping cough still occur in the UK. (2)
Not everyone has been immunised (1)
Immigration introduces people who are not immunised (1)
Immunisation isn’t fully effective (1)
Immunity can decrease with age (1)
Describe the response of the human body to immunisation. (3)
Immunisation introduces an antigen/causes an immune response (1)
B-lymphocytes (1)
Produce antibodies (1)
Memory lymphocytes also produced (1)
Houseflies can be the animal vector for the disease dysentery.
The disease dysentery is caused by (1)
A bacterium
B fungus
C protozoan
D virus
Bacterium
Houseflies can be the animal vector for the disease dysentery.
Describe how a housefly can cause a person to become infected with dysentery. (2)
Housefly carries a pathogen (1)
Housefly lands on contaminated faeces/animal waste (1)
Transfers dysentery onto food (1)
Food is eaten (1)
Explain how a chemical defence mechanism of the human body can reduce the chance of dysentery. (3)
Hydrochloric acid (1)
In stomach (1)
Kills bacteria (1)
Explain Anopheles mosquito can spread the disease malaria. (2)
Mosquito is a vector (1)
Carries plasmodium/protozoan (1)
Pierces skin (1)
Transfers plasmodium/protozoan to blood (1)
Suggest have a change in body mass may cause a person to develop type 2 diabetes. (2)
Increasing body mass leads to overweight/obesity (1)
Doesn’t respond to insulin/insulin resistance (1)
Describe how the human body acts in response to low glucose levels in the blood. (3)
Glucagon is released (1)
From the pancreas (1)
Glycogen to glucose (1)
In liver/muscle cells (1)
Which acts to raise blood glucose levels (1)
A scientist is planning to test a new diet for weight loss. She selects 40 obes people to take part in the test. They’re all between 20 & 30yrs. State 2 other factors the scientist should control when selecting the people. (2)
Similar BMI (1)
Same gender profile (1)
Similar amount/type of exercise (1)
A scientist is planning to test a new diet for weight loss. She selects 40 obes people to take part in the test. They’re all between 20 & 30yrs. Devise a plan the scientist could use to test the effectiveness of the new diet using the 40 obese people. (3)
Weigh all 40 (obese) people (1)
Half follow the new diet and the other half keep their own diet (1)
Re-weigh the 40 people after a fixed time period (1)
Some STI’s can be diagnosed by testing urine samples. These tests use monoclonal antibodies that bind to an antigen on the pathogen. Describe how a monoclonal antibody can be developed and used to detect an STI using a urine sample. (6)
• isolate an antigen from the pathogen which causes the STI
• inject the antigen into a mouse/rodent collect lymphocytes producing an antibody to the STI antigen
• fuse the B-lymphocyte with a myeloma cell • production of a hybridoma
• hybridoma produces a monoclonal antibody against the antigen of the STI
• attach the monoclonal antibody to coloured bead/indicator
• incorporate into a test strip.
The antigens on pathogens can be proteins with a specific amino acid sequence. Explain how the order of amino acids in a protein is determined by the sequence of the gene. (4)
a single strand of messenger RNA is transcribed from the gene in the nucleus (1)
messenger RNA molecule binds to the ribosome (1)
the triplet code from the mRNA is matched by a complementary tRNA anticodon at the ribosome (1)
tRNA transfers amino acids to the polypeptide chain in a specific order (1)
An athlete miscalculated his carbohydrate intake to be greater than his actual intake. Explain how the increase in the number of units of insulin injected would affect his blood glucose concentrations. (2)
an increase in the units of insulin injected would cause more blood glucose to be converted to glycogen and stored in the liver/muscles (1)
leading to blood glucose levels becoming critically low/person would become hypoglycemic (1)
A doctor diagnosed a person with an underactive thyroid gland. Explain why an underactive thyroid gland cause this patient to have an increased body mass. (6)
• the thyroid gland produces thyroxine
• thyroxine helps to regulate metabolic rate
• low levels of thyroxine should stimulate the production of TRH
• TSH being produced and more thyroxine being released
• an underactive thyroid would cause less thyroxine to be produced
• metabolic rate to drops
• less energy (calories) are available for tasks
• more fat storage so the person gains body mass
