Practice Flashcards
Flip to reveal answersWhat is an identifying feature of a group?
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 15 Flashcards — Recognising the major groups
Sign up free to track progress and get spaced-repetition review schedules.
Question
What is an identifying feature of a group?
Answer
A feature that **tells the group apart** from others (e.g. feathers for birds), not just any feature the organism has.
Question
Two identifying features of mammals?
Answer
**Fur/hair** and **feeding young on milk** (from mammary glands).
Question
Two identifying features of birds?
Answer
**Feathers** and a **beak** (no teeth); they also lay hard-shelled eggs.
Question
Three identifying features of fish?
Answer
**Scales**, **gills** and **fins**; they live in water.
Question
Identifying feature of amphibians?
Answer
**Moist smooth skin**; they live partly in water and lay jelly-covered eggs in water.
Question
How do flowering plants differ from mosses?
Answer
Flowering plants have **true roots, vascular tissue and flowers/seeds**; mosses have **none** and reproduce by **spores**.
Question
How do mosses (bryophytes) reproduce?
Answer
By **spores** — they have no flowers or seeds.
Question
Which phylum has stinging cells and a single gut opening?
Answer
**Cnidarians** (e.g. jellyfish, sea anemones).
Question
Identifying feature of a mollusc?
Answer
A **soft body**, often protected by a **shell** (e.g. snail, octopus).
Question
Identifying feature of an arthropod?
Answer
A hard **exoskeleton** and **jointed legs** (e.g. insects, spiders, crabs).
Question
Identifying feature of an annelid?
Answer
A long body built from many similar **ring-like segments** (e.g. earthworm).
Question
Define vertebrate.
Answer
An animal with a **backbone** (a column of bones along its back).
Question
What does each branch point (node) on a cladogram represent?
Answer
A **common ancestor**. Groups meeting at a **more recent node** are **more closely related**.
Question
What evidence are modern classifications and cladograms built from?
Answer
**Molecular evidence** — comparing the **amino-acid sequence** of a shared protein (e.g. myoglobin) or the **DNA base sequence**. Fewer differences ⇒ more recent common ancestor.
Question
If two organisms are in the same genus (or family/order), what does that tell you?
Answer
They share **characteristics inherited from a common ancestor** — the shared rank reflects a recent common ancestry.
Read the notes
Full study notes for Recognising the major groups
Topic 1.6 hub
Diversity of organisms
More from Topic 1.6
All flashcards in this topic
Biology exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free