Ecology

Biodiversity and classification

Biodiversity is the variety of life. Classification is how we organise that variety so a name means the same organism everywhere.

CAPS

Grade 10 · Life Sciences · Ecology

Life Sciences is two papers. Use the strand to know which one.

  • Where it is examined

    Grade 10 is the chemistry of life, cells, tissues, organs, support and transport, and the biosphere, biodiversity and the history of life.

  • How to write it

    Name the structure, then say what it does. A labelled diagram only scores if the labels are the biological names. “It helps the body” is not a function.

  • How a marker reads it

    A common mix-up is to place viruses in the kingdom of bacteria, or to treat the common name “lily” as a scientific name.

A 2-mark “explain” wants two facts, or one fact and its reason. Extra sentences that contradict the first one can cancel a mark.

sun

Diagram

Worked theory

Worked theory. Two beetles that look similar in a garden. If they cannot produce fertile offspring together, they are not one species, even if the colour matches. Their names would differ in the second word. A mushroom is a fungus, not a plant: it does not photosynthesise. An aloe is a plant. Grouping the aloe with the mushroom because both “sit still” ignores how they feed. Indigenous species evolved here. An alien species was brought in and can crowd local ones out.

More worked examples

  • Panthera leo and a garden aloe

    A lion is Panthera leo: genus Panthera, species leo. A leopard is Panthera pardus, same genus, different species. They do not produce fertile young together. An aloe is a plant. A mushroom on the same rock is a fungus: no chloroplasts, it feeds on dead matter. Calling both “plants” because neither walks is the wrong rank. The kingdom is decided by how the organism feeds and what its cells are.

  • Homo sapiens and a virus

    A human is Homo sapiens: genus Homo, species sapiens. Two people from different countries are the same species. A virus that gives one of them flu is not in any of the five kingdoms, because it is not a cell. It has no metabolism of its own. Calling it a very small bacterium puts it in a kingdom it does not belong to. The rank has to follow the structure, not the fact that it makes you ill.

In ordinary words

The ranks run from large to small: kingdom, phylum, class, order, family, genus, species. A species is a group that can interbreed and produce fertile young. Scientific names have two words, genus then species, written so the genus starts with a capital. The five kingdoms you meet are bacteria, protists, fungi, plants and animals. A virus is not in those kingdoms. It is not a cell.

In South Africa

Aloes, fynbos proteas and invasive wattles are the local picture of indigenous versus alien.

Part 1 / 4

What it is

Biodiversity is the variety of life. Classification is how we organise that variety so a name means the same organism everywhere.

Diagram
Diagram

More worked examples

Board walkthroughs on this topic. Open one, copy the working, then try the next.

Example 1 / 20

Write the scientific name of the lion correctly and identify its genus and species.

How we got there

Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

Explain in another language · 11

1. What is the question asking?

Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: Write the scientific name of the lion correctly and identify its genus and species.

In other words — as if you have never seen this before

If you have never seen this before: Binomial nomenclature. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

2. What do we already know?

Lion: Panthera leo.

3. Which method — and why this one?

Binomial nomenclature.

4. Step-by-step working

  1. 01 / 07

    Step A — Read the question twice

    Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.

    Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

  2. 02 / 07

    Step B — Write the given in a column

    Lion: Panthera leo.

    Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.

  3. 03 / 07

    Step C — Name the method in words

    Binomial nomenclature.

    Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.

  4. 04 / 07

    Identify the given

    Genus Panthera (capital letter), species leo (lower case); underline when handwritten or italicise when typed.

    Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.

  5. 05 / 07

    Step G — Sense-check the size

    Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.

    Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.

  6. 06 / 07

    Step F — Box the answer with its unit

    Panthera leo — genus Panthera, species leo.

    Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.

  7. 07 / 07

    Step H — What the marker is looking for

    On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.

    Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

5. The answer

Panthera leo — genus Panthera, species leo.

Copy onto your answer sheet — in this order

Answer: Panthera leo — genus Panthera, species leo.

6. Check it like a marker

The genus is shared with the leopard, Panthera pardus.

7. A trap first-timers fall into

First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

Ntsako · fx-991ZA PLUS. Tap to calculate.