Biology Revision – B5 Communicable Diseases Notes

This collection of flashcards covers key concepts, definitions, and processes related to communicable diseases and health, as outlined in the student's lecture notes.

What is the definition of health?

A state of physical and mental wellbeing.

What is a communicable disease?

A disease caused by an infectious organism that can be transmitted from one individual to another.

What are the causes of ill health?

Disease (communicable and non-communicable), diet, stress, and life situations.

How do bacteria cause diseases?

By invading cells, reproducing to burst cells, and producing toxins.

What structures are found in bacteria?

Slime capsule, cell wall, cell membrane, cytoplasm, infold of cell membrane for feeding, pili, circular loop of DNA, plasmids, ribosomes, and flagellum.

How do viruses cause disease?

By hijacking cells’ replication machinery to make new virus particles that burst the cell.

What are ways pathogens spread?

Airborne transmission, droplet transmission, direct physical contact, fomites, faecal-oral, and vector borne.

What is an antibiotic?

A chemical substance used to kill bacteria in the body.

Why do communicable diseases spread rapidly after a natural disaster?

Due to poor sanitation, dirty water, and close living conditions among people.

What is the method for growing a culture in a lab?

1. Wash hands and disinfect surfaces, 2. Label Petri dish, 3. Light a Bunsen burner, 4. Sterilize inoculating loop, 5. Collect bacteria, 6. Make streaks on agar plate, 7. Close lid, 8. Secure with tape, 9. Incubate.

What is the role of phagocytes?

To engulf bacteria and viruses and destroy them through phagocytosis.

What is antibiotic resistance?

When bacteria survive against antibiotics due to overuse, incomplete courses, or agricultural use, leading to 'superbugs'.

What symptoms are associated with malaria?

Fever, headaches, muscle and joint fatigue, nausea, vomiting, diarrhea, and abdominal pain.

How do plants defend themselves against pathogens?

Through physical barriers like cellulose walls, chemical deterrents, and mechanical features like thorns.

What are some symptoms of nitrogen deficiency in plants?

Shorter growth than usual and fewer leaves.

What does a memory cell do?

Remains in the body after a pathogen is eliminated, allowing for a quicker response upon re-encountering the same pathogen.