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Biodiversity and Classification: SPI Biology

Biodiversity and Classification has 6 questions in the SPI bank, four of them EASY, and one is from the 2022 paper: who gave the five kingdom system. Every question asks where something belongs: a scientist to his system, a rank to its place in the order, an organism to its group. The options are real names from nearby groups (a moss beside a protist, a reptile beside a fish), and some use Latin genus names, so learn each group with two or three examples it is known by.

The handout has every subtopic, worked example, formula and trap with answers shown. The formula sheet is the chapter’s formulas and traps alone, on one page.

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Subtopic notes

Formula & revision sheet

0 formulas · 4 reference tables · 7 gotchas across all subtopics — the exam-eve cheat-sheet

Five Kingdoms and the Ranks of Classification

Reference tables (2)

Whittaker's five kingdoms and the ranks5 rows

Kingdom	Cell	Body	Example
Monera	No true nucleus	One cell	Bacteria, blue green algae
Protista	True nucleus	One cell	Amoeba, Euglena, diatoms
Fungi	True nucleus, cell wall of chitin	Mostly many cells, cannot make food	Yeast, mushroom, Rhizopus
Plantae	True nucleus, cell wall of cellulose	Many cells, make their own food	Moss, fern, mango
Animalia	True nucleus, no cell wall	Many cells, eat food	Earthworm, fish, human Whittaker's system covers all living things, not just animals.

Ranks top down: kingdom, phylum or division, class, order, family, genus, species.

Protists: Euglena, diatoms and their relatives5 rows

Protist	Moves by	Known for
Euglena	Flagellum	Link between plants and animals Euglena has chloroplasts; Paramecium has none.
Diatoms	Drift in water	Silica walls, deposits on the seabed
Amoeba	False feet (pseudopodia)	Changes its shape
Paramecium	Cilia	Slipper shape
Plasmodium	Carried by mosquitoes	Causes malaria

Watch out for (4)

Putting class below order
→ Whittaker's five kingdoms and the ranks
Robert Hooke for classification
→ Whittaker's five kingdoms and the ranks
Calling a moss a protist
→ Protists: Euglena, diatoms and their relatives
Protozoa or bacteria for seabed silica
→ Protists: Euglena, diatoms and their relatives

Plant and Animal Groups

Reference tables (2)

The plant groups5 rows

Group	Vascular tissue	Seeds	Examples
Thallophyta	No	No	Spirogyra, Chara
Bryophyta	No	No	Funaria (moss), Marchantia
Pteridophyta	Yes	No (spores)	Ferns, horsetails, Marsilea First plants with vascular tissue, but still no seeds.
Gymnosperms	Yes	Naked	Pine, cycas
Angiosperms	Yes	Inside a fruit	Mango, wheat

The five vertebrate classes and their hearts5 rows

Class	Heart chambers	Circulation	Examples
Pisces	Two	Single	Labeo, Hippocampus, Exocoetus, Anabas Only the fishes have single circulation.
Amphibia	Three	Double	Rana, Hyla, Salamander
Reptilia	Three (crocodile four)	Double	Draco, chameleon, turtle
Aves	Four	Double	Pigeon, sparrow
Mammalia	Four	Double	Whale, dolphin, bat

Sea horse, flying fish and climbing perch are all true fishes; whale and dolphin are mammals.

Watch out for (3)

Ferns as mosses
→ The plant groups
Whales and dolphins as fishes
→ The five vertebrate classes and their hearts
Sea horse and flying fish as not fish
→ The five vertebrate classes and their hearts

Question weightage by concept

4 concepts · 6 questions — where the marks actually sit, so you know what to drill first

Five Kingdoms and the Ranks of Classification4 questions · 67%

Concept	Qs	Share
Whittaker's five kingdoms and the ranks	2	33%
Protists: Euglena, diatoms and their relatives	2	33%

Plant and Animal Groups2 questions · 33%

Concept	Qs	Share
The plant groups	1	17%
The five vertebrate classes and their hearts	1	17%

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