IGCSE · Practice questions · Features of organisms

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Six original Cambridge-style questions on kingdoms, vertebrates and arthropods, classifying from a table of features, and (Extended) fungi, prokaryotes, viruses, ferns, monocots and dicots.

Original questions All questions on this page are original work, written in the Cambridge IGCSE style. They are not from past papers. They test the same concepts and skills the syllabus rewards.

Keep these straight

Features, not habitat.

Plant v animal cells: cellulose cell wall and chloroplasts in plants only.
Vertebrates: scales and gills (fish), moist skin (amphibians), dry scales (reptiles), feathers (birds), fur and milk (mammals).
Arthropods: count pairs of legs, body parts and antennae: 3/3/1 insect, 4/2/0 arachnid, >4 pairs with 2 pairs of antennae crustacean, many segments myriapod.
Extended: fungi have chitin walls; prokaryotes no nucleus; viruses only genetic material in a protein coat.

Recall

[3 marks]

State three features that are used to place an organism in the plant kingdom rather than the animal kingdom.

Cells have cellulose cell walls. ✓
Cells contain chloroplasts. ✓
They make their own food by photosynthesis (both kingdoms are multicellular, so this does not separate them). ✓

Recall

[4 marks]

State two visible features of (a) birds and (b) mammals that are used to classify them.

(a) Birds: feathers; a beak. ✓
(Also accept: front limbs are wings; eggs with hard shells.) ✓
(b) Mammals: fur or hair; external ears (pinnae). ✓
(Also accept: whiskers; mammary glands.) ✓

Data

[4 marks]

Classify each arthropod into its group. P: 8 legs, 2 body parts, no antennae. Q: 6 legs, 3 body parts, 1 pair of antennae. R: about 60 segments with 2 pairs of legs on each, 1 pair of antennae. S: 10 legs, 2 pairs of antennae, hard shell containing calcium.

P: arachnid (4 pairs of legs, no antennae). ✓
Q: insect (3 pairs of legs, 3 body parts). ✓
R: myriapod (many segments, legs on each). ✓
S: crustacean (more than 4 pairs of legs, 2 pairs of antennae). ✓

Explain

[3 marks]

Dolphins live in the sea and have a streamlined body and fins. Explain why they are classified as mammals and not as fish.

Classification uses the features of the organism, not where it lives. ✓
Dolphins breathe air with lungs, not gills. ✓
They have mammary glands and feed their young on milk (and have a few hairs), which are mammal features. ✓

Recall

[4 marks]

Extended. (a) State two features of fungi that are different from plants. (b) State two features of viruses, and explain why viruses are not placed in any of the five kingdoms.

(a) Fungal cell walls are made of chitin, not cellulose; fungi have no chloroplasts and feed by secreting enzymes onto organic matter and absorbing the products. ✓
(b) A protein coat; ✓
genetic material (DNA or RNA). ✓
Viruses are not made of cells, so they cannot be placed in a kingdom of cellular organisms. ✓

Analysis

[4 marks]

Extended. A student finds three plants. X has fronds with brown spots underneath and no flowers. Y has broad leaves with branching veins and flowers with five petals. Z has long narrow leaves with parallel veins and flowers with parts in threes. Identify the group of each plant, and state how Y and Z differ in their seeds.

X: fern (fronds, spores made in sori, no flowers). ✓
Y: dicotyledon (net veins, flower parts in fives). ✓
Z: monocotyledon (parallel veins, flower parts in threes). ✓
Seeds of Y have two cotyledons; seeds of Z have one. ✓

Mark this once you have attempted all six and checked your working. It records a Practiced badge on the topic and adds a one-time bonus. Revealing the solutions alone does not count.