Cambridge Syllabus Notes

IGCSE Biology 0610 – Features Used to Place Animals and Plants into Kingdoms

Objective

State the main features used to place animals and plants into the appropriate kingdoms and recognise the principal groups within each kingdom, as required by the Cambridge IGCSE (0610) syllabus.

Core vs. Supplement

Core (required for all candidates): the seven classification features listed below, the five‑kingdom framework, and the principal groups of Animalia and Plantae.
Supplement (useful for extended study): detailed examples of protist and fungal groups, additional historical classification systems, and extra ecological notes.

Why Kingdoms Are Used

Kingdoms give a broad, systematic way of grouping organisms that share fundamental characteristics. For the IGCSE syllabus the five‑kingdom system (Monera, Protista, Fungi, Plantae, Animalia) is the reference model.

First Decision Point – Prokaryote or Eukaryote?

The syllabus expects you to begin classification by deciding whether the organism’s cells have a true nucleus.

Prokaryotic cells – no membrane‑bound nucleus; DNA free in the cytoplasm (e.g., bacteria).
Eukaryotic cells – nucleus enclosed by a nuclear membrane; usually contain membrane‑bound organelles (e.g., algae, fungi, plants, animals).

This decision immediately separates Monera (prokaryotes) from the other four kingdoms (eukaryotes).

The Seven Classification Features (exactly as required by the syllabus)

Cell type (Prokaryote / Eukaryote) – determines the first split between Monera and the remaining kingdoms.
Cell‑wall composition – distinguishes plants (cellulose), fungi (chitin), bacteria (peptidoglycan), and many protists (none or cellulose).
Presence of chloroplasts (or other photosynthetic pigments) – indicates a photosynthetic (autotrophic) organism such as plants and many algae.
Mode of nutrition – autotrophic (self‑feeding) vs. heterotrophic (feeding on others); important for separating plants, algae, fungi and animals.
Multicellularity – unicellular versus multicellular; helps to separate many protists (unicellular) from fungi, plants and animals (multicellular).
Level of tissue differentiation – no tissues, simple tissues, or complex tissues & true organs; this separates fungi (filamentous hyphae) from plants (true tissues & organs) and animals (complex tissues & organs).
Reproductive structures – spores, seeds, fruits, or specialised gametes; key for distinguishing non‑vascular plants, seed plants, and animal reproductive strategies.

Each feature is asked about in exam questions because it provides a clear, observable difference between kingdoms.

Five‑Kingdom Overview (Core Information)

Kingdom	Typical members	Cell type	Cell‑wall composition	Chloroplasts	Nutrition	Multicellularity	Tissues / Organs	Reproductive structures	Principal groups (core)
Monera	Bacteria, cyanobacteria	Prokaryotic	Peptidoglycan (some lack a wall)	Absent (photosynthetic pigments in cyanobacteria)	Heterotrophic or autotrophic (photosynthetic)	Usually unicellular	None	Binary fission; some form spores	–
Protista	Algae, protozoa, slime moulds	Eukaryotic	None or cellulose (e.g., some algae)	Present in algae; absent in protozoa	Both autotrophic & heterotrophic	Mostly unicellular; colonial forms exist	Simple tissues in some multicellular forms	Sexual & asexual spores, cysts	Algae, Protozoa, Slime moulds
Fungi	Mushrooms, yeasts, moulds	Eukaryotic	Chitin	Absent	Heterotrophic (absorptive)	Multicellular (except yeasts)	Filamentous hyphae, mycelium, fruiting bodies	Spore production (sexual & asexual)	Moulds, Yeasts, Mushrooms (basidiomycetes & ascomycetes)
Plantae	Algae, mosses, ferns, conifers, flowering plants	Eukaryotic	Cellulose	Present	Autotrophic (photosynthetic) – some parasitic	Multicellular	True tissues (parenchyma, collenchyma, sclerenchyma) & organs (roots, stems, leaves, flowers)	Spore‑based (non‑vascular) or seed‑based (vascular)	Bryophytes, Pteridophytes, Gymnosperms, Angiosperms
Animalia	Sponges, insects, mammals, fish, etc.	Eukaryotic	Absent	Absent	Heterotrophic (ingestive)	Multicellular	Complex tissues (muscle, nerve, epithelial) & organs	Gametes → fertilisation; some asexual methods	Sponges, Invertebrates (e.g., insects), Vertebrates (see table below)

Principal Groups Within the Core Kingdoms

Animalia – Vertebrate Groups (1.3.1)

Group	Defining features	Examples
Mammals	Hair/fur, mammary glands, three middle‑ear bones	Human, rabbit, whale
Birds	Feathers, beak, hard‑shelled eggs, hollow bones	Eagle, penguin, sparrow
Reptiles	Dry scaly skin, shelled eggs (most), ectothermic	Snake, turtle, crocodile
Amphibians	Aquatic larvae with gills → terrestrial adult with lungs; moist skin	Frog, salamander, newt
Fish	Gills throughout life, fins, usually scales	Goldfish, shark, salmon

Plantae – Major Groups (1.3.2)

Group	Key characteristics	Examples
Non‑vascular (Bryophytes)	Lack true roots, stems, leaves; reproduce by spores; dominant haploid (gametophyte) stage	Mosses, liverworts
Seedless vascular (Pteridophytes)	True vascular tissue (xylem & phloem); reproduce by spores; dominant diploid (sporophyte) stage	Ferns, horsetails
Gymnosperms	Vascular; naked seeds often in cones; usually woody	Conifers (pine, spruce), cycads
Angiosperms	Vascular; seeds enclosed in fruits; flowers are the reproductive organs	Rose, wheat, oak

Fungi – Principal Groups (Supplement)

Group	Typical members	Key traits
Moulds (filamentous fungi)	Penicillium, Aspergillus	Hyphae form a mycelium; reproduce by conidia or sporangia
Yeasts (unicellular fungi)	Saccharomyces cerevisiae	Single cells; reproduce by budding or fission
Mushrooms (basidiomycetes & ascomycetes)	Agaricus bisporus, morels	Fruiting bodies; sexual spores on basidia or asci

Protista – Principal Groups (Supplement)

Group	Typical members	Key traits
Algae	Chlamydomonas, kelp	Photosynthetic, may be unicellular or multicellular
Protozoa	Amoeba, Paramecium	Heterotrophic, usually motile, no cell wall
Slime moulds	Physarum polycephalum	Amoeboid cells that aggregate to form a fruiting body

Quick Checklist – Placing an Organism into a Kingdom

Are the cells prokaryotic or eukaryotic?
Is a cell wall present? If so, what is it made of (peptidoglycan, cellulose, chitin, none)?
Are chloroplasts (or other photosynthetic pigments) present?
What is the mode of nutrition – autotrophic or heterotrophic?
Is the organism unicellular or multicellular?
Does it have specialised tissues or true organs?
What reproductive structures are produced (spores, seeds, fruit, gametes)?
Match the combination of answers to the table above to select the correct kingdom, then to the relevant sub‑group (e.g., vertebrate class or plant group).

Suggested diagram: A flow‑chart beginning with “Prokaryotic or Eukaryotic?” and proceeding through cell‑wall type, chloroplasts, nutrition, multicellularity, and tissue differentiation to reach one of the five kingdoms. From Plantae and Animalia the chart branches to the sub‑groups listed in the tables.

State the main features used to place animals and plants into the appropriate kingdoms.