Anatomy and Physiology
What lightweight feature of bird skeletons reduces weight for flight?
Hollow bones (lightweight skeleton).
What type of reproduction do most birds have (egg-laying or live birth)?
Oviparous (egg-laying)
Term for animals that maintain a constant internal body temperature.
Endotherm (endothermic)
What is the large breastbone called that provides attachment for powerful flight muscles in many birds?
Keel (on the sternum)
Define "endothermic."
Endothermic: capable of internal heat production to maintain constant body temperature.
Name the organ in birds that stores food before digestion.
Crop.
Which group of mammals lays eggs?
Monotremes.
What behavior do many bird species perform seasonally to find hospitable living conditions?
Migration.
Name the voice-producing organ in birds
Syrinx
Define "oviparous."
Oviparous: reproducing by laying eggs that develop outside the mother's body.
What gas-exchange adaptation provides a constant flow of oxygen to bird muscles?
Air sacs
How do marsupial young continue development after a short gestation?
They are born underdeveloped and crawl to the mother's pouch to continue development and feeding.
Give two reasons why many mammals have a layer of fat (blubber or subcutaneous fat).
Insulation (retain body heat) and energy storage/ buoyancy (blubber); also protection of organs.
Which organ in ruminant ungulates (like cows) helps break down cellulose?
Rumen
Define "placenta."
Placenta: an organ in eutherian mammals that provides nutrients and oxygen to, and removes wastes from, the developing embryo/fetus.
Describe the primary feature that distinguishes mammals from most other vertebrates.
Hair (presence of hair/fur) and mammary glands
What structure in eutherian mammals attaches an embryo to the uterine wall and nourishes it?
Placenta.
Describe two courtship displays birds might use to attract mates (one visual, one vocal)
Visual: plumage displays, dances, erection of crests; Vocal: complex songs or calls produced by the syrinx.
Identify the mammalian gland that produces milk for young.
Mammary gland
Define "incubation" in the context of birds.
Incubation: the process of keeping eggs at the proper temperature and conditions for embryo development until hatching.
Explain how a gizzard and crop work together in the digestion of many birds.
The crop stores and softens food; the gizzard grinds food mechanically to aid digestion.
Compare the typical gestation lengths and developmental strategies of monotremes, marsupials, and eutherians.
Monotremes: egg-laying, external incubation, no prolonged internal gestation; Marsupials: short gestation, young continue development in pouch; Eutherians: longer gestation with placenta, young more developed at birth.
Explain how being a generalist benefits many mammal species in changing environments; give one example.
Generalists can exploit a variety of food sources and habitats, increasing resilience to environmental change (example: raccoons eat many foods and thrive near human habitats).
Explain the functional differences between a bird's hollow bones and a mammal's denser bones in relation to their lifestyles.
Bird hollow bones reduce weight for flight and sometimes contain air sacs connecting to respiratory system; mammal bones are denser for support, muscle attachment, and different locomotive stresses.
Match each term to the correct group (Birds, Mammals, or Both): syrinx, fur/hair, albumen, keel, mammary gland.
syrinx — Birds; fur/hair — Mammals; albumen — Birds (egg white); keel — Birds; mammary gland — Mammals.