Across
- 5. In chordates, the region of the throat that connects the mouth and nasal cavities to the digestive system and, in vertebrates, to the lungs.
- 6. nerve cord A nerve cord that develops in a location dorsal to the notochord; this embryonic feature is unique to chordates.
- 9. A group of mammals that includes kangaroos, koalas, and opossums; their young are born at an early stage of development and must crawl to abdominal mammary glands that provide them with milk.
- 10. feet In echinoderms, small projections of the water vascular system that extend outward from the body surface and facilitate locomotion, sensory perception, food capture, and gas exchange.
- 11. Action Pattern A sequence of behaviors that, once triggered, is followed through to completion.
- 12. A class of vertebrates distinguished by body hair and mammary glands from which they feed their young.
- 16. The group of vertebrate animals that produces amniotic eggs; this group includes lizards, snakes, turtles, crocodilians, birds, and mammals.
- 18. egg An egg that can exchange gases while retaining water, permitting reproduction in dry terrestrial habitats.
- 26. A random, undirected movement in response to a stimulus.
- 28. A monophyletic group of animals whose last common ancestor had four limbs; this group includes amphibians, lizards, turtles, crocodilians, birds, and mammals; some tetrapods, like snakes, have lost their legs in the course of evolution.
- 29. learning Learning that occurs in the absence of any particular outcome, such as a reward or punishment.
- 31. Several species of lobe-finned fish that use a simple lung to survive periods when their watery habitat dries by burying themselves in moist mud and breathing air; along with coelacanths, the closest relatives of tetrapods.
- 34. In chordates, a stiff rod of cartilage-like tissue that runs along the back and provides support for the axis of the body.
- 35. column A skeletal structure in vertebrates that functionally replaces the embryonic notochord that supports the body.
- 38. Conditioning Associative learning in which a behavior that was initially undirected has become paired with a particular stimulus through reward/punishment reinforcement.
- 39. Conditioning Associative learning in which two stimuli are paired.
- 40. Altruism The exchange of favors between individuals.
- 41. A vertebrate animal with a cranium built of cartilage but no jaws; hagfish feed on marine worms and dead and dying sea animals.
- 43. information The knowledge of where an individual is with respect to its goal.
- 44. fish, Chondrichthyes; a monophyletic group of fish that includes about 800 species of sharks, rays, and chimaeras.
- 45. fish Osteichthyes; fish that have a cranium, jaws, and mineralized bones. This group includes about 20,000–25,000 species.
- 46. fish Species of fish with paired pectoral and pelvic fins that have a bone structure similar to that of tetrapod limbs.
- 47. Selection A form of natural selection that favors the spread of alleles promoting behaviors that help close relatives.
- 51. Stable Selection A type of behavior that cannot readily be driven to extinction by an alternative strategy.
- 54. Observing and copying the behavior of another.
Down
- 1. The enhancement of a response to a stimulus that is achieved by first presenting a strong or novel stimulus.
- 2. The process in which experience leads to changes in behavior.
- 3. A pattern of behavior used in communication that is species specific and tends to be highly repeatable and similar from one individual to the next.
- 4. Detectors A specialized sensory receptor or group of sensory receptors that respond to important signals in the environment.
- 7. learning Learning that two events are correlated.
- 8. A subphylum of Chordata that includes about 3000 species of filter-feeding marine animals, such as sea squirts and salps.
- 13. Displays Behavior by which individuals draw attention to themselves or their status.
- 14. Two species of lobe-finned fish found long thought to have been extinct for 80 million years but which still live today; along with lungfish, the nearest relatives of tetrapods.
- 15. In placental mammals, an organ formed by the fusion of the chorion and allantois that allows the embryo to obtain nutrients directly from the mother.
- 17. In chordates, any one of a series of segments that organizes the body musculature.
- 18. Describes self-sacrificial behavior in which an individual’s actions decrease its own fitness while increasing that of another individual.
- 19. A subphylum of Chordata, distinguished by a bony cranium that protects the brain and (unless lost through evolution), a vertebral column; also known as craniates.
- 20. stimulus An exaggerated stimulus that elicits a response more strongly than the normal stimulus.
- 21. slits A vertical opening separated from other slits by stiff rods of protein in the pharynx of chordates.
- 22. A subphylum of Chordata that shares key features of body organization with vertebrates but lacks a well-developed brain and eyes, has no lateral appendages, and does not have a mineralized skeleton. Amphioxus, or the lancelet, is the best known example.
- 23. Tube In chordates, a cylinder of embryological tissue that develops into a dorsal nerve cord.
- 24. The series of hard bony segments making up the jointed skeleton that runs along the main axis of the body in vertebrates.
- 25. A subphylum of Chordata, distinguished by a bony cranium that protects the brain; also known as vertebrates.
- 27. Imprinting Imprinting in which newborn offspring rapidly learn to treat any animal they see shortly after birth as their mother.
- 30. Describes behavior most commonly observed in species of Hymenopteran insects, in which they have overlapping generations in a nest, cooperative care of the young, and clear and consistent division of labor between reproducers (the queen of a honeybee colony) and nonreproducers (the workers).
- 32. A vertebrate animal with a cranium and vertebral column built of cartilage but no jaws; many lampreys live parasitically, sucking body fluids from fish prey.
- 33. mammals A mammal that provides nutrition to the embryo through the placenta, a temporary organ that develops in the uterus.
- 36. vascular system A series of fluid-filled canals that permit bulk transport of oxygen and nutrients in echinoderms.
- 37. The process of co-opting and modifying behaviors used in another context by increasing the conspicuousness of the behavior, reducing the amount of variation in the behavior so that it can be immediately recognized, and increasing its separation from the original function.
- 42. The reduction or elimination of a behavioral response to a repeatedly presented stimulus.
- 48. Movement in a specific direction in response to a stimulus.
- 49. Selection Selection caused by the differential success of groups rather than individuals.
- 50. stimulus A stimulus that initiates a fixed action pattern.
- 52. A monophyletic group of vertebrates, including frogs and salamanders, with an aquatic larval form with gills and an adult terrestrial form that usually has lungs.
- 53. Four-legged vertebrate animals.