Marsh frog internal structure and amphibian reproduction
Answers are for parents and teachers.
1
Write 3 features of frog development that resemble fishes.
External fertilisation in water; the tadpole’s gills; two-chambered heart and lateral line.
2
What is metamorphosis? Give a frog example.
The process of a larva turning into an adult; tadpole → frog (legs grow, gills are replaced by lungs, tail disappears).
3
Compare frog and toad (3 features).
Frog: near water, day, smooth skin. Toad: on land, night, rough skin and toxic glands.
4
Explain frog circulation in 4 sentences.
Heart with 2 atria and 1 ventricle; systemic circuit – to organs and back to the right atrium; pulmonary circuit – to the lungs and back to the left atrium; blood partly mixes in the ventricle.
5
Why must amphibians be protected?
They eat pests, are important in food chains and are indicators of environmental health.