Biodiversity of Animals is one of 10 topics in the Grade 11 Life Sciences CAPS syllabus, covered across 3 lessons on Study Vault. Below are real practice questions from this topic with full worked answers.
Sample practice questions
Easy
1. Sponges (phylum Porifera) are considered the simplest multicellular animals mainly because they:
Have no true tissues, organs, or nervous system
Have highly developed organs and a complex nervous system
Are single-celled organisms
Have a jointed vertebral column
Answer: Have no true tissues, organs, or nervous system — Sponges lack true tissues, organs, and a nervous system, consisting instead of a loose aggregation of specialised cells, making them the simplest multicellular animals studied at this level.
Easy
2. Cnidarians (such as jellyfish) use which specialised cells to capture prey and for defence?
Cnidocytes, containing nematocysts
Nephrons
Hyphae
Chondrocytes
Answer: Cnidocytes, containing nematocysts — Cnidarians possess specialised stinging cells called cnidocytes, containing structures called nematocysts, used to capture prey and for defence.
Medium
3. What type of body symmetry do cnidarians typically display, and why is it well suited to their lifestyle?
Radial symmetry, suited to organisms encountering their environment from all directions equally
Bilateral symmetry, suited to organisms that always move in one direction
No symmetry at all, since they have no defined body plan
Segmented symmetry, suited to burrowing animals
Answer: Radial symmetry, suited to organisms encountering their environment from all directions equally — Cnidarians display radial symmetry, where the body can be divided into similar halves along any plane through a central axis, an arrangement well suited to organisms such as sea anemones and jellyfish that encounter food, threats, and their environment from all directions.
