定義： the air-filled cavity within the skull of vertebrates that lies between the outer ear and the inner ear. It is linked to the pharynx (and therefore to outside air) via the Eustachian tube and in mammals contains the three ear ossicles, which transmit auditory vibrations from the outer ear (via the tympanum) to the inner ear
定義： A taxon is Least Concern when it has been evaluated against the criteria and does not qualify for Critically Endangered, Endangered, Vulnerable or Near Threatened. Widespread and abundant taxa are included in this category.
定義： determinate reproductive shoot systems having as part at least one carpel or at least one stamen and containing no other determinate shoot system as a part.
定義： A grassland biome is a terrestrial biome which includes, across its entire spatial extent, an unbroken layer of grasses (Gramineae), sedges (Cyperaceae) or rushes (Juncaceae).
定義： A forest biome is a terrestrial biome which includes, across its entire spatial extent, densely packed vegetation which strongly limits light penetration to the forest floor.
定義： Solitary animals are those that spend a majority of their lives without others of their species, with possible exceptions for mating and raising their young. Antonyms for a solitary animal include a social animal or a colonial animal.
定義： Solitary animals are those that spend a majority of their lives without others of their species, with possible exceptions for mating and raising their young. Antonyms for a solitary animal include a social animal or a colonial animal.
定義： Because of the difference in refractive index between air and water (or corneal tissue), a curved cornea is an image-forming lens in its own right. Its focal length is determined by the radius of curvature of the cornea. Many corneal eyes (eg: in land vertebrates) also have lenses, but the lens is flattened and weakened compared with an aquatic lens; most of the refractive power is provided by the cornea. Corneal eyes cannot focus in aquatic habitat.
