Skip to content
Dabour HubLEARN · PRACTICE · EXPLORESign inStudent

18.1.417-18 · Selection, Evolution, Classification and Conservation

Kingdoms — Cambridge AS & A Level Biology 9700 Revision Notes & Topical Questions

5 min read 10 parts Lesson 23 of 36 1 quiz

📚 Cambridge AS & A Level Biology 9700 Hub / Topical Revision
🩺
100% Curriculum Specification Match Lesson Doctor Verified
The only platform with 100% curriculum specification match and verified interactive question banks.
0%read
Lesson summary

18.1.4 Kingdoms — CAMBRIDGE AS & A LEVEL BIOLOGY 9700 — REVISION NOTES notes: Describe the features of the four kingdoms of the domain Eukarya.The domain Eukarya is divided into Protoctista, Fungi, Plantae and Animalia.Each kingdom has distinct features but they share common ones…

  • Plant groups
  • Animal groups
  • Binomial name
  • Heterotroph
  • Classification
  • Compartmentalisation by other organelles

Section 1 of 10Four kingdoms of Eukarya

Four kingdoms of Eukarya
The domain Eukarya is divided into Protoctista, Fungi, Plantae and Animalia.
Each kingdom has distinct features but they share common ones:
  • Cells with membrane-bound nuclei that separate genetic material from the cytoplasm.
  • Compartmentalisation by other organelles.
Placing an organism uses diagnostic features: cell wall composition, mode of nutrition, organisation and storage carbohydrate.

Section 2 of 10Kingdom Protoctista

Protoctista
  • Protoctista all eukaryotes that do not belong to the other three kingdoms.
They show great diversity in structure, life cycle, feeding, trophic level and locomotion.
They exist as single cells or groups of similar cells.
Protozoa
  • Protozoa cells similar to animal cells, with no cell wall.
Algae
  • Algae cells similar to plant cells, with cellulose walls and chloroplasts.
Examples
  • Plasmodium, Amoeba, Chlorella and Euglena.
    • (malaria parasite)

Section 3 of 10Kingdom Fungi

1
All fungi are eukaryotic and have non-cellulose walls, often chitin and glucans.
2
Cells lack cilia.
3
Fungi are heterotrophs:
  • They use organic compounds made by other organisms for energy and molecules.
  • They digest dead or decaying matter extracellularly, or are parasites on living organisms.
4
They reproduce with spores dispersed onto the ground nearby.
5
Body form is simple.
  • Some are unicellular, e.g. baker's yeast (Saccharomyces cerevisiae).
  • Others have long threads called hyphae growing from the mycelium.
  • Larger fungi have fruiting bodies that release many spores.

Section 4 of 10Kingdom Plantae

Kingdom Plantae
Plants are multicellular eukaryotes.
Plant cells have cellulose walls and large, usually permanent, vacuoles for support.
They differentiate into specialised cells forming tissues and organs.
They have chloroplasts for photosynthesis (not every cell has them) and sometimes flagella.
Plants are autotrophs, making organic compounds from inorganic compounds.
Plants have complex body forms with branching systems above and below ground.
Plant groups
  • Plant groups bryophytes, ferns, gymnosperms (naked seeds) and angiosperms.
    • (seeds in fruits; monocots and dicots)

Section 5 of 10Kingdom Animalia

Kingdom Animalia
Animals are multicellular eukaryotes.
Animal cells differentiate into many specialised types that form tissues and organs.
They have small temporary vacuoles (e.g. lysosomes), no cell walls and sometimes cilia.
Animals are heterotrophs with a wide range of feeding mechanisms.
They have a wide range of body forms and communicate through a nervous system and chemical signals.
Animal groups
  • Animal groups arthropods, molluscs, annelids, nematodes and chordates (vertebrates).
    • (jointed legs, chitin exoskeleton)

Section 6 of 10Comparing the kingdoms

FeatureProtoctistaFungiPlantaeAnimalia
OrganisationMostly unicellular or colonialHyphae (yeast single-celled)MulticellularMulticellular
Cell wallVaries (cellulose in algae, none in protozoa)ChitinCelluloseNone
NutritionAuto- or heterotrophicHeterotrophic, absorptivePhotosynthetic autotrophHeterotrophic, ingestive
ChloroplastsSomeNoYesNo
Carbohydrate storeVariesGlycogenStarchGlycogen

Section 7 of 10Identifying the kingdom

1
A single-celled eukaryote with chloroplasts but no cellulose wall, e.g. Euglena, is a protoctist.
2
A multicellular organism with a chitin wall and hyphae is a fungus.
3
No cell wall, multicellular and ingesting food means Animalia.
4
Molecular evidence shows protoctists are several lineages and fungi are closer to animals than to plants.

Section 8 of 10More from the specification

More from the specification
Archaea
  • Prokaryotes with ether-linked membrane lipids and no peptidoglycan.
Bacteria
  • Single-celled microorganisms, much smaller than plant or animal cells.
Classification
  • Grouping organisms by shared features and relationships.
Lipids
  • Concentrated energy, insulation, cell membranes.
Ribosome
  • The site where proteins are made.
Peptidoglycan
  • The cell wall material of bacteria.
Binomial name
  • Binomial name a species' Latin name gives its genus and species, the last two ranks after kingdom, phylum, class, order and family.

Section 9 of 10Key terms

TermMeaning
ProtoctistaKingdom of eukaryotes that are not fungi, plants or animals.
HyphaThread-like part of a fungus.
MyceliumNetwork of fungal hyphae forming the main body.
AutotrophOrganism that makes its own organic compounds from inorganic ones.
HeterotrophOrganism that obtains organic compounds from other organisms.
ChitinPolysaccharide forming fungal cell walls.

Section 10 of 10Exam technique

1
Saying fungi are plants — they have chitin walls, no chloroplasts and are heterotrophs.
2
Saying all protoctists are single-celled with the same features — the kingdom is very diverse.
3
Saying plant cells lack vacuoles or animal cells have large permanent vacuoles — it is the reverse.
4
Giving cellulose as the wall component of fungi — it is chitin and glucans.

Last updated: