Answers · Kingdoms and animal groups

Supplement: five kingdoms, plant groups and viruses — answer key

Check meaning, not exact wording. These are teaching points, not official Cambridge marks.

1. XQ1 · Practice

Options as numbered on the pupil sheet: 1 — Many cells with no cell walls and no chloroplasts; feed on other living things; 2 — Many cells with cell walls and chloroplasts; make their own food by photosynthesis; 3 — Cell walls but no chloroplasts; digest dead or living matter outside the body; most are thread-like hyphae; 4 — Cells with a nucleus; most are a single cell; some are like animals, some like plants; 5 — Single cells with no nucleus: a loop of DNA in the cytoplasm, and a cell wall.

Model answer. Animals are many cells with no walls and no chloroplasts, and feed on other living things. Plants are many cells with walls and chloroplasts, and make their food by photosynthesis. Fungi have walls but no chloroplasts, digest dead or living matter outside the body, and most are made of hyphae. Protoctists have cells with a nucleus, and most are a single cell. Prokaryotes are single cells with no nucleus, a loop of DNA and a cell wall.

A full answer includes

Animals: many cells with no cell walls and no chloroplasts; feed on other living things.
Plants: many cells with cell walls and chloroplasts; photosynthesis.
Fungi: cell walls but no chloroplasts; digest matter outside the body; most are hyphae.
Protoctists: cells with a nucleus; most are a single cell.
Prokaryotes: single cells with no nucleus, a loop of DNA and a cell wall.

Also accept

animals: no walls, no chloroplasts, feed on others; plants: walls, chloroplasts, photosynthesis; fungi: walls, no chloroplasts, digest outside, hyphae; protoctists: nucleus, mostly one cell; prokaryotes: no nucleus, loop of DNA, wall

Watch for

“Fungi are plants because they have cell walls.” — Fungal walls are not made of cellulose, and fungi have no chloroplasts: they cannot photosynthesise.
“Prokaryotes have a nucleus, because they have DNA.” — Prokaryote DNA is a loop lying in the cytoplasm, not inside a nucleus.

2. XQ2 · Practice

Model answer. b. The mushroom is made of hyphae with walls that are not made of cellulose, it has no chloroplasts, and it digests dead material outside its body: it is a fungus. Growing out of the ground does not make it a plant (a). Every kingdom except the prokaryotes has a nucleus (c), and prokaryotes are single cells (d).

A full answer includes

b: hyphae with cell walls, no chloroplasts and digesting food outside the body are fungus features.

Also accept

Watch for

“Mushrooms are plants.” — A mushroom has no chloroplasts and cannot make its own food; it digests dead material outside its body. It is a fungus.
“It has a nucleus, so it is a protoctist.” — Animals, plants and fungi have a nucleus too; only prokaryotes have none.

3. XQ3 · Practice

Model answer. c. Paramecium is a single cell with a nucleus and no cell wall: a protoctist. It swims and feeds like an animal, but animals are made of many cells (a). Prokaryotes have no nucleus (b). It has no cell wall, so it is not a fungus (d): yeast is also a single cell with a nucleus, but it has a cell wall and is a fungus.

A full answer includes

c: a single cell with a nucleus and no cell wall is a protoctist; yeast, also one cell with a nucleus, has a cell wall and is a fungus.

Also accept

Watch for

“Paramecium is an animal, because it moves and feeds like one.” — Animals are made of many cells; Paramecium is one cell with a nucleus: a protoctist.
“Every single-celled organism is a prokaryote.” — Prokaryotes have no nucleus; Paramecium has one.

4. XQ4 · Practice

Model answer. a, b, c and d. The cells of animals, plants, fungi and protoctists all have a nucleus. Prokaryotes (e) have no nucleus: their DNA is a loop in the cytoplasm.

A full answer includes

a, b, c and d: animals, plants, fungi and protoctists all have a nucleus; prokaryotes do not.

Also accept

a, b, c, d

Watch for

“Only protoctists have a nucleus.” — Animals, plants and fungi have a nucleus too; only prokaryotes have none.
“Prokaryotes have a nucleus, because they have DNA.” — Prokaryote DNA is a loop lying in the cytoplasm, not inside a nucleus.

5. XQ5 · Practice

Model answer. b. It is a protoctist, like Chlorella. Plants have walls and chloroplasts too, but plants are made of many cells (a). Prokaryotes have no nucleus (c). Fungi have no chloroplasts (d), so a single cell with chloroplasts cannot be a fungus such as yeast.

A full answer includes

b: one cell, so not a plant; a nucleus, so not a prokaryote; chloroplasts, so not a fungus: a protoctist.

Also accept

Watch for

“Anything with chloroplasts is a plant.” — Plants are made of many cells; a single cell with a nucleus and chloroplasts is a protoctist.

6. XQ6 · Practice

Model answer. (a) The yoghurt bacteria are prokaryotes. (b) Each one is a single cell with no nucleus: its DNA is a loop lying in the cytoplasm. Each cell also has a cell wall.

A full answer includes

(a) Prokaryotes.
(b) Any two: single cells; no nucleus; DNA is a loop in the cytoplasm; a cell wall.

Also accept

(a) prokaryotes; (b) two of: single cell, no nucleus, loop of DNA in the cytoplasm, cell wall

Watch for

“Bacteria are tiny animals, because they are alive and feed.” — Animals are made of many cells with a nucleus; a bacterium is one cell with no nucleus.

7. XQ7 · Practice

Options as numbered on the pupil sheet: 1 — Ferns; 2 — Monocotyledons; 3 — Dicotyledons; 4 — Both groups of flowering plants.

Model answer. Ferns reproduce by spores, with no flowers or seeds, and have leaves called fronds. Monocotyledons have one cotyledon in each seed and long, narrow leaves with parallel veins. Dicotyledons have two cotyledons and broad leaves with a branching network of veins. Both monocots and dicots have flowers that make seeds.

A full answer includes

Spores, no flowers or seeds: ferns.
Leaves called fronds: ferns.
One cotyledon: monocotyledons.
Parallel veins: monocotyledons.
Two cotyledons: dicotyledons.
Branching network of veins: dicotyledons.
Flowers that make seeds: both groups of flowering plants.

Also accept

spores: ferns; fronds: ferns; one cotyledon: monocots; parallel veins: monocots; two cotyledons: dicots; branching network: dicots; flowers and seeds: both flowering groups

Watch for

“Ferns make seeds.” — Ferns have no flowers and no seeds: they reproduce by spores.
“Grasses have no flowers.” — Grass flowers are small and green, but they make seeds: grasses are monocots.

8. XQ8 · Practice

Model answer. The brown spots are clusters of spore cases, not a disease. A fern has no flowers and makes no seeds: it reproduces by spores, made in these spore cases on the underside of its fronds.

A full answer includes

The spots are clusters of spore cases.
Ferns reproduce by spores; they have no flowers and no seeds.

Also accept

spots = clusters of spore cases; ferns reproduce by spores, no flowers or seeds

Watch for

“The brown spots under a fern frond are a disease.” — They are clusters of spore cases; a fern reproduces by spores.

9. XQ9 · Practice

Model answer. a and c. A virus is genetic material inside a protein coat (a), so it is not made of cells (c). It is not a bacterium (b), it has no cell wall, cytoplasm or ribosomes (d), its genetic material is not inside a nucleus (e), and it is not placed in any kingdom (f).

A full answer includes

a and c: a virus is genetic material inside a protein coat, so it is not made of cells.

Also accept

a, c

Watch for

“Viruses are bacteria.” — A bacterium is a living cell with a wall, cytoplasm and a loop of DNA; a virus is not a cell at all.
“A virus is a prokaryote, because it has no nucleus.” — A virus has no cells at all, so it is placed in no kingdom.

10. XQ10 · Practice

Model answer. The soil bacterium has no nucleus: 1 prokaryote. Yeast, bread mould and the mushroom have walls not made of cellulose, no chloroplasts and get their food from outside: 3 fungi. Amoeba and Chlorella are single cells with a nucleus: 2 protoctists. The oak tree and maize are many cells with cellulose walls and chloroplasts: 2 plants.

Checked automatically

Fungi: 3 (exact value)
- Common wrong answer 2 : Yeast is a single cell, but its wall is not made of cellulose and it has no chloroplasts: it is a fungus.
Protoctists: 2 (exact value)
- Common wrong answer 1 : Chlorella has chloroplasts, but it is a single cell: a protoctist, not a plant.
- Common wrong answer 3 : Yeast is a single cell with a nucleus, but its wall is not made of cellulose and it has no chloroplasts: a fungus.
Plants: 2 (exact value)
- Common wrong answer 3 : Chlorella is a single cell; plants are made of many cells.
Prokaryotes: 1 (exact value)

A full answer includes

Fungi: 3 (yeast, bread mould, mushroom).
Protoctists: 2 (Amoeba, Chlorella).
Plants: 2 (oak tree, maize).
Prokaryotes: 1 (soil bacterium).

Also accept

fungi 3; protoctists 2; plants 2; prokaryotes 1

Watch for

“Yeast is a protoctist, because it is a single cell.” — Yeast is one cell, but its wall is not made of cellulose and it has no chloroplasts: it is a fungus.
“Chlorella is a plant, because it has chloroplasts.” — Chlorella is a single cell; plants are made of many cells.

11. XT1 · Apply

Model answer. (a) Euglena is a protoctist. (b) Plants and animals are both made of many cells, and Euglena is a single cell with a nucleus. Some protoctists are like plants and some like animals; Euglena is like a plant in the light and like an animal in the dark, but it is still one cell, so it is a protoctist.

A full answer includes

(a) Protoctists.
(b) Plants and animals are made of many cells; Euglena is a single cell with a nucleus. Protoctists include some that are like plants and some like animals, and Euglena is like both.

Also accept

(a) protoctist; (b) plants and animals have many cells; Euglena is one cell with a nucleus; protoctists can be plant-like or animal-like

Watch for

“Anything with chloroplasts is a plant.” — Plants are made of many cells; a single cell with chloroplasts and a nucleus is a protoctist.
“Anything that takes in food is an animal.” — Animals are made of many cells; some single-celled protoctists take in food too.

12. XT2 · Apply

Model answer. (a) Having no nucleus is not enough. A prokaryote is a living cell with a cell wall, a membrane, cytoplasm and a loop of DNA. The virus is not made of cells: it is only genetic material inside a protein coat, and it can make copies of itself only inside the living cells of the tobacco plant. (b) Because it is not made of cells, it is not placed in any of the five kingdoms.

A full answer includes

(a) A prokaryote is a cell (cell wall, membrane, cytoplasm, a loop of DNA); a virus is not made of cells at all: only genetic material inside a protein coat.
(b) None: viruses are not placed in any of the five kingdoms.

Also accept

(a) prokaryotes are cells with a wall, membrane, cytoplasm and DNA; a virus is not a cell, only genetic material in a protein coat; (b) no kingdom

Watch for

“A virus is a prokaryote, because it has no nucleus.” — A virus has no cells at all; prokaryotes are cells.
“Viruses are bacteria.” — A bacterium is a living cell; a virus is genetic material inside a protein coat.

13. XT3 · Apply

Model answer. (a) The mould is a fungus. (b) It is made of hyphae, not leaves, stems and roots; its walls are not made of cellulose; and it has no chloroplasts (the blue-green colour comes from its spores), so it cannot photosynthesise. Making spores does not make it a plant: fungi make spores too. (c) The hyphae release enzymes onto the bread, digest it outside the mould and absorb the dissolved food.

A full answer includes

(a) Fungi.
(b) Any two: it is made of hyphae, not leaves, stems and roots; its walls are not made of cellulose; it has no chloroplasts (the colour comes from its spores), so it cannot photosynthesise.
(c) Its hyphae release enzymes onto the bread, digest it outside the mould and absorb the dissolved food.

Also accept

(a) fungus; (b) two of: hyphae; walls not cellulose; no chloroplasts, so no photosynthesis; (c) enzymes from the hyphae digest the bread outside, then the food is absorbed

Watch for

“Mushrooms and moulds are plants.” — Fungi have no chloroplasts and cannot make their own food; their walls are not made of cellulose.
“Anything green has chloroplasts.” — The colour of this mould comes from its spores; it has no chloroplasts.

14. XT4 · Apply

Model answer. (a) Bracken is a fern; the bluebell is a monocotyledon. (b) Bracken has fronds and makes spores in spore cases, with no flowers or seeds: fern features. The bluebell has flowers that make seeds, so it is a flowering plant, and its long, narrow leaves with parallel veins place it with the monocotyledons. Both these plants are green and have leaves, so being green and having leaves cannot separate their groups. (c) One cotyledon: monocotyledons have one cotyledon in each seed.

A full answer includes

(a) Bracken: ferns. Bluebell: monocotyledons.
(b) Bracken: fronds, spore cases, no flowers or seeds. Bluebell: flowers and seeds, with long, narrow leaves and parallel veins.
(c) One: parallel veins place it with the monocotyledons, which have one cotyledon in each seed.

Also accept

(a) bracken fern, bluebell monocot; (b) fronds, spores, no flowers vs flowers, seeds, parallel veins; (c) one cotyledon, because it is a monocot

Watch for

“Every plant with leaves is in the same group.” — Ferns and flowering plants both have leaves; flowers, seeds, spores and the veins decide the plant group.
“Ferns are flowering plants.” — Ferns have no flowers and no seeds: they reproduce by spores.