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Describes young that are mobile and fairly self-sufficient at birth. Precocial young are generally well-developed (and large) at birth, born with their eyes open, and able to walk. Chickens and grebes are examples of precocial birds; sheep and guinea pigs are examples of precocial mammals.
Industry:Biology
In trilobites and other arthropods, pleurae are elongated flat outgrowths from each body segment, that overlie and protect the appendages.
Industry:Biology
In mammals, a tissue formed within the uterus through which nutrients are passed from the mother to the embryo (and later the fetus) and its wastes are removed. It is analogous to the protective membranes in the egg of other amniotes. placental n. A mammal that gives live birth to well-developed young that have prolonged embryonic development within the mother’s uterus. Marsupial mammals also have a placenta, but the embryo spends less time developing in the uterus before birth. Placentals include animals as diverse as humans, elephants, dogs, and mice.
Industry:Biology
A category in the hierarchy of animal classification between class and kingdom; phyla- pl.
Industry:Biology
Cavity in the digestive tract just past the mouth itself. May be muscularized for sucking or swallowing in various animals.
Industry:Biology
Characteristic of chordates, pharyngeal slits are openings through which water is taken into the pharynx, or throat. In primitive chordates the pharyngeal slits are used to strain water and filter out food particles; in fishes they are modified for respiration. Most terrestrial vertebrates have pharyngeal slits only in the embryonic stage.
Industry:Biology
The second pair of appendages of cheliceromorphs. In many arachnids, such as spiders, the pedipalps are enlarged in the male and used for copulation.
Industry:Biology
1. The study of disease and abnormalities. 2. The manifestation of a disease, injury, or abnormality, as in bone or eggshell for example.
Industry:Biology
A sort of "false foot" formed by extension of the body cavity. Polychaetes and some insect larvae have parapodia in addition to their legs, and these provide extra help in locomotion.
Industry:Biology
