Vertebrates and the frog’s life cycle
Answers are for parents and teachers.
1
Complete a table comparing the five vertebrate classes: body covering, breathing organ, heart, body temperature.
Fish: scales/slime, gills, 2, cold-blooded; amphibian: bare moist skin, skin+lungs, 3, cold-blooded; reptile: horny scales, lungs, 3 (crocodile 4), cold-blooded; bird: feathers, lungs, 4, warm-blooded; mammal: hair, lungs, 4, warm-blooded.
2
Write three sentences about the adaptations of a bird (structure, flight).
Free answer; features such as feathers, forelimbs turned into wings and air sacs should be mentioned.
3
Describe each stage of the frog’s life cycle in one sentence.
Eggs in water; the embryo feeds on yolk; the tadpole breathes with gills; hind and front legs form; young frog; adult frog.
4
Why do cold-blooded animals hibernate or become inactive in cold winter? Write 2–3 sentences.
Their body temperature follows the surroundings; in the cold metabolism slows down, so they become inactive.