topic 5 Flashcards
What does being healthy mean in biology?
Being healthy means having good physical and mental well-being, not just the absence of disease.
What is a non-communicable disease?
A disease that can’t be passed from person to person (e.g. cancer, diabetes).
How can the transmission of malaria be prevented?
Use insecticide-treated mosquito nets and control mosquito populations.
What bacterium causes stomach ulcers?
Helicobacter pylori.
What is the lysogenic pathway in a virus life cycle?
Viral DNA is inserted into the host genome and remains inactive before entering the lytic cycle.
How can the spread of chlamydia be reduced?
Use condoms and regular screening.
Why does HIV eventually lead to AIDS?
HIV destroys white blood cells, weakening the immune system over time.
Why do plants produce antiseptic chemicals?
To protect themselves against pathogens and pests.
Name a medicine extracted from plants.
Aspirin (from willow bark).
Name four ways to identify plant diseases.
Visual symptoms, lab testing, microscopy, and testing soil or plant tissue.
Give two chemical human defences against pathogens.
Lysozymes in tears and hydrochloric acid in stomach.
What is an antigen?
A molecule on the surface of a pathogen that triggers an immune response.
What do B-lymphocytes do when they detect a pathogen?
They produce antibodies to target the pathogen.
How do vaccines protect against diseases?
They stimulate the immune system to produce memory cells against the pathogen.
What is herd immunity?
When a large portion of the population is immune, it helps protect those who aren’t.
What are monoclonal antibodies?
Identical antibodies produced from a single clone of B cells, targeting one specific antigen.
Why are tumour cells used in monoclonal antibody production?
They divide quickly and are fused with B-cells to create hybridomas.
How do pregnancy tests work with antibodies?
Antibodies bind to hCG in urine, showing a positive result with a visible line.
How can monoclonal antibodies identify cancer cells?
They bind to tumour markers and can carry fluorescent dyes or radioactive tags.
Why attach a radioactive element to an antibody for detecting blood clots?
So the location of the clot can be seen with imaging techniques.
What pathogens do antibiotics kill?
Bacteria (not viruses).
What is the placebo effect?
A change in condition caused by the patient’s belief in treatment, not the treatment itself.
How can you test antibiotic effectiveness?
Use agar plates with bacteria and antibiotic-soaked discs to see inhibition zones.
Why are aseptic techniques used in microbiology?
To prevent contamination from unwanted microbes.
How do you calculate inhibition zone size?
Measure diameter and use Area = π × (radius)².
How does smoking increase heart attack risk?
It damages arteries and increases blood pressure and cholesterol.
Give one lifestyle-related risk factor for liver disease.
Excessive alcohol consumption.
What is the BMI formula?
BMI = weight (kg) ÷ height² (m²)
Name three lifestyle changes to prevent cardiovascular disease.
Eat less saturated fat, stop smoking, and exercise regularly.
