Pathogenic, deficiency, hereditary and physiological diseases; the mosquito life cycle; vectors of dengue, malaria and more; control and impact of disease.
7 narrated scenes. Press play, listen and read along — the points appear as they are explained. Use ‹ Prev / Next › or the scene bar to jump to any scene.
The deadliest animal to humans isn’t a shark or a snake. It’s a mosquito weighing 2 milligrams.
Narration uses your device’s built-in voice. No sound? Switch to “Captions only” — the captions advance on their own.
Copy these into your notebook in your own words — that is how they stick.
Caused by pathogens: viruses (dengue, AIDS), bacteria (TB, cholera, gonorrhoea), fungi (ringworm), protoctists (malaria).
Lack of nutrient: anaemia (iron), scurvy (vit C), rickets (vit D), kwashiorkor (protein).
Inherited: sickle-cell anaemia, haemophilia, albinism.
Organ malfunction: diabetes, hypertension, heart disease, cancer, atherosclerosis.
Organism that transmits a pathogen without being harmed (female mosquito).
Egg → larva → pupa → adult; first three stages in still water.
Remove standing water, oil film, larvicides, guppies, insecticide spray (adults), nets, repellent, education.
WHO certified Suriname malaria-free (30 June 2025). PAHO: record dengue cases in the Americas in 2024.
The kind of support a teacher gives after the lesson: worked examples to attempt first, a board illustration, key terms, common misconceptions and memory aids.
Try it in your notebook first, then reveal the solution one step at a time.
| Month | Feb | Apr | Jun | Aug | Oct | Dec |
|---|---|---|---|---|---|---|
| Rainfall (mm) | 40 | 60 | 180 | 210 | 230 | 90 |
| Dengue cases | 6 | 8 | 25 | 70 | 95 | 30 |
Try it in your notebook first, then reveal the solution one step at a time.
| Group | Cause | Examples | Treatment / control |
|---|---|---|---|
| Pathogenic | Pathogens: viruses, bacteria, fungi, protozoa | Dengue, HIV/AIDS, tuberculosis, ringworm | Vaccines, antibiotics (bacteria only), vector control, hygiene |
| Deficiency | Lack of a nutrient | Scurvy (vitamin C), rickets (vitamin D), anaemia (iron) | Balanced diet; supplements |
| Hereditary | Inherited alleles | Sickle cell anaemia, haemophilia | Manage symptoms; genetic counselling |
| Physiological | An organ or system not working properly | Type 2 diabetes, hypertension | Diet, exercise, medication |
Learn one clear example for each group — examiners accept the common ones.
Mosquito life cycle: Every Little Pest Annoys — Egg, Larva, Pupa, Adult. The first three are in water.
Aedes aegypti also spread chikungunya (Caribbean outbreak 2014) and Zika (2016) through the region. Removing breeding sites around homes protects against all three viruses at once.
Do a breeding-site check around your home: look for anything holding still water (tyres, buckets, plant saucers, bottle caps, gutters). Empty, cover or remove each one and record what you found.
4 quick games on this lesson. Earn XP and badges as you play — your best score for each game is saved. Games are for practice and do not change your exam readiness.
8 items modelled on real CSEC Paper 1 questions. Choose one answer for each, then check. Aim for 80% or better.
Write full answers, then reveal the mark scheme and tick the points you earned (24 marks in total). Your answers are saved on this device.
Question 1 [11 marks]
In 2024 the World Health Organization confirmed persons in the Caribbean infected with West Nile virus, a disease spread mainly by mosquitoes.
(a) Suggest THREE implications for the Caribbean of the presence of this disease. [3]
(b) Draw (or list) the stages of the mosquito life cycle and suggest ONE control method for EACH. [8]
Question 2 [13 marks]
A new animal pathogen from a rainforest caused a large outbreak in a human population: cases rose rapidly (A), fell rapidly (B), then stayed near zero (C).
(a) Distinguish among the four main groups of disease, giving ONE example of each. [4]
(b) Describe the shape of the graph in regions A, B and C and suggest reasons. [3]
(c) Discuss THREE ways human activities may have contributed to the spread of the pathogen. [6]
Find these in your own past-paper booklets for extra timed practice. The practice above is adapted from them.