Classify organisms using the features identified for the plant kingdom.

1.3 Features of Organisms – Classifying the Plant Kingdom

Key Features of Plants

Plants are a special group of organisms that share several important traits. Think of them as the “green builders” of the natural world. 🌱

• Multicellularity – Made of many cells working together.
• Cell walls made of cellulose – Gives structure like a sturdy frame.
• Chlorophyll a & b – The green pigment that captures sunlight.
• Photosynthesis – Turns light into energy: 6 CO₂ + 6 H₂O + light → C₆H₁₂O₆ + 6 O₂
• Growth from meristems – New cells are produced at growth points.
• Reproduction – Sexual (seeds, spores) or asexual (cuttings, runners).
• Response to stimuli – Grow towards light (phototropism) and open/close stomata for gas exchange.

Analogy: Plants as a Library

Imagine a library where each book is a species. The genre is the family, the author is the genus, and the title is the species. Just as books share a genre, plants share a family.

Taxonomic Hierarchy for Plants

Classifying a Plant – Step‑by‑Step

1. Identify basic features – e.g., presence of roots, stems, leaves.
2. Check for cell walls and chlorophyll (green colour).
3. Determine if it is vascular (has xylem & phloem) or non‑vascular.
4. Look at the reproductive structures – seeds, spores, flowers.
5. Use a key (like a flowchart) to narrow down to family and genus.
6. Finally, give the scientific name (binomial nomenclature).

Examples of Plant Groups

• Mosses (Bryophyta) – Non‑vascular, reproduce via spores.
• Ferns (Pteridophyta) – Vascular, reproduce via spores.
• Gymnosperms (e.g., conifers) – Vascular, seeds exposed on cones.
• Angiosperms (flowering plants) – Vascular, seeds inside fruits.

Practice Question

Given the following plant characteristics, classify it:

• Has a woody stem and needle‑like leaves.
• Reproduces via seeds found on exposed cones.
• Is a vascular plant.

Answer: Gymnosperm – conifer (e.g., Picea abies).