Phylum Coelenterates
Answers are for parents and teachers.
1
Draw a cross-section of a hydra and mark the two layers.
Outer layer – ectoderm, inner layer – endoderm, body cavity in the centre.
2
Name the hydra’s two ways of reproducing.
Asexual – budding (summer); sexual – egg and sperm (autumn).
3
Why should you not touch jellyfish? Write 2 sentences.
Their stinging threads burn and some species are dangerous to people. If stung, see a doctor.
4
Write the stages of coral reef formation in order.
Polyps bud → the colony grows toward the surface → its dead lower part piles up → a reef and island form.
5
Write 2 features showing coelenterates are ancient.
Weakly specialised cells; strong regeneration; digestion inside cells.