1. Which statement is correct? A — all birds can fly B — birds have two limbs C — the body of all birds is covered in

2. Choose the correct answer. Feathers that are located on the wings and enable flight: A — contour flight feathers B — tail feathers C — contour feathers D — down feathers

3. Mark the feature that is not typical for birds: A — presence of a beak B — presence of teeth C — uropygial gland D — feather covering

4. Choose the correct answer. Among terrestrial vertebrates, the class of birds is: A — the least progressive B — the most highly organized C — the least numerous D — the most numerous

5. Match the type of feathers, their location, and functions: 1 — contour feathers 2 — tail feathers 3 — contour flight feathers 4 — down feathers 5 — filoplume feathers A — wings B — entire body C — tail (uropygial) D — insulation, streamlined body shape E — flight F — touch G — insulation

6. Match the animal class with the characteristic features of its representatives: 1 — birds 2 — reptiles 3 — amphibians 4 — bony fish A — uropygial gland B — bony scales C — horny scales D — absence of teeth E — skin covered in mucus

7. Mark the true statements: A — some representatives of the class of birds have small teeth on their beaks B — birds are cold-blooded animals C — birds are warm-blooded animals D — the central shaft of bird feathers is made of chitin E — teeth disappeared in birds during evolution F — rachis is a part of the shaft of a feather that is located in the skin G — bird beak is a modified form of teeth H — bird beak is formed by bony jaws I — down feathers are only present in chicks, they are not characteristic of adult birds

8. From the listed characteristics, select those that apply to mammals: 1 — development of hair covering 2 — development of feather covering 3 — skin covered in scales 4 — no glands in the skin 5 — feed offspring with milk 6 — many glands in the skin 7 — gill respiration 8 — no diaphragm between thoracic and abdominal cavities 9 — eyes without eyelids 10 — lung respiration 11 — three-chambered heart 12 — four-chambered heart 13 — warm-blooded animals 14 — presence of a diaphragm separating the thoracic and abdominal cavities 15 — developed central nervous system 16 — reproduction by laying eggs 17 — eyes with eyelids 18 — ribs only in the thoracic region