Grouping organisms by observable features, the five kingdoms, the taxonomic hierarchy, binomial names and dichotomous keys.
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.
Why does a bat belong with humans, not with birds? Let’s find out how biologists sort millions of species.
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.
Arranging organisms into groups based on shared features. Shows relationships and makes identification easier. Modern classification also uses DNA sequences.
Prokaryotae (bacteria), Protoctista (Amoeba, algae), Fungi, Plantae, Animalia.
Kingdom, Phylum (Division in plants), Class, Order, Family, Genus, Species — each lower rank shares more features.
Organisms that can interbreed under natural conditions to produce fertile offspring.
Genus species — capital G, lower-case s, italics (underline when writing).
Three body parts (head, thorax, abdomen), six jointed legs, one pair of antennae, usually two pairs of wings.
Fish (gills, fins), amphibians (moist skin), reptiles (dry scales), birds (feathers), mammals (hair, milk).
Series of paired, contrasting statements based on observable, constant features that leads to an organism’s name.
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.
| Couplet | Feature | Go to |
|---|---|---|
| 1a | Body covered in fur or hair | Agouti |
| 1b | No fur or hair | 2 |
| 2a | Body covered in feathers | Hummingbird |
| 2b | No feathers | 3 |
| 3a | Has fins | Parrotfish |
| 3b | No fins | 4 |
| 4a | Dry skin covered in scales | Anole lizard |
| 4b | Moist skin, no scales | Frog |
Try it in your notebook first, then reveal the solution one step at a time.
Try it in your notebook first, then reveal the solution one step at a time.
| Class | Body covering | Body temperature | Breathes with | Reproduction |
|---|---|---|---|---|
| Fish | Scales, fins | Varies with surroundings (ectotherm) | Gills | Eggs laid in water |
| Amphibians | Moist skin, no scales | Ectotherm | Gills as larvae; lungs and skin as adults | Jelly-coated eggs in water |
| Reptiles | Dry scaly skin | Ectotherm | Lungs | Leathery-shelled eggs on land |
| Birds | Feathers; scales on legs | Constant (endotherm) | Lungs | Hard-shelled eggs |
| Mammals | Hair or fur | Endotherm | Lungs | Most give birth to live young; feed them milk |
Learn the features in columns: one feature at a time across all five classes is easier to remember than five separate lists.
The ranks in order: King Philip Came Over For Good Soup — Kingdom, Phylum, Class, Order, Family, Genus, Species.
Local names change from island to island: the fruit called chennette in Trinidad is guinep in Jamaica and kenep in Haiti. Its scientific name, Melicoccus bijugatus, is the same everywhere — that is why scientists use binomial names.
Photograph or sketch eight organisms around your home or school. Construct your own dichotomous key for them, then ask a friend to test it on one organism without telling them which one.
3 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 (15 marks in total). Your answers are saved on this device.
Question 1 [8 marks]
A student photographs six different fish (A–F) on a Caribbean coral reef. Some have stripes, some have spots; some have a forked tail and some a rounded tail.
(a) Apart from the animal kingdom, name THREE kingdoms into which living organisms are classified. [3]
(b) List THREE visible characteristics that could be used to classify the fish. [3]
(c) Explain why colour alone is a poor feature to use when classifying organisms. [2]
Question 2 [7 marks]
The following animals were found in a school garden: earthworm, spider, grasshopper, snail, millipede, butterfly.
(a) Construct a dichotomous key to identify the six animals. [5]
(b) State TWO features that show the grasshopper is an insect. [2]
Find these in your own past-paper booklets for extra timed practice. The practice above is adapted from them.