Bio Exam 3 Flashcards
Eukaryote
A member of the domain Eukarya; an organism whose cells contain a nucleus, numerous membrane-bound organelles, and an extensive cytoskeleton. May be unicellular or multicellular.
Multicellular
The state of being composed of many cells that adhere to each other and do not all express the same genes, resulting in some cells having specialized functions.
Endoderm
The innermost of the three basic cell layers (germ layers) in most animal embryos; gives rise to the digestive tract and organs that connect to it (liver, lungs, etc.). Compare with ectoderm and mesoderm.
Ectoderm
The outermost of the three basic cell layers (germ layers) in most animal embryos; gives rise to the outer covering and nervous system
Mesoderm
The middle of the three basic cell layers (germ layers) in most animal embryos; gives rise to muscles, bones, blood, and some internal organs (kidney, spleen, etc.)
Radial Symmetry
An animal body pattern that has at least two planes of symmetry. Typically, the body is in the form of a cylinder or disk, and the body parts radiate from a central hub.
Bilateral Symmetry
An animal body pattern in which one plane of symmetry divides the body into a left side and a right side. Typically, the body is long and narrow, with a distinct head end and tail end.
Cephalization
The formation in animals of a distinct anterior region (the head) where sense organs and a mouth are clustered.
Coelom (Body Cavity)
An internal, usually fluid-filled body cavity that is completely or partially lined with mesoderm
Segmentation
Division of the body or a part of it into a series of similar structures; exemplified by the body segments of insects, annelid worms, and vertebrates.
Diploblast
An animal whose body develops from two basic embryonic cell layers or tissues—ectoderm and endoderm
Triploblast
An animal whose body develops from three basic embryonic cell layers or tissues: ectoderm, mesoderm, and endoderm
Optimal Foraging Theory
The concept that animals forage in a way that maximizes the amount of usable energy they take in, given the costs of finding and ingesting their food and the risk of being eaten while they’re at it.
Fitness trade-offs
In evolutionary biology, an inescapable compromise
between two traits that cannot be optimized
simultaneously.
Ecology
The study of how organisms interact with each other and with their environment.
Sexual Selection
A type of natural selection that favors individuals with traits that increase their ability to obtain mates or choose good mates.
Monogamous
A type of mating system where one male mates with one female per breeding season, forming a pair bond
polygynous
A type of mating system where one male mates with two or more females (polygyny) or one female mates with more than one male (polyandry) during a breeding season
Intrasexual selection
A type of sexual selection driven by competition among members of one sex (usually male–male) for an opportunity to mate.
Intersexual selection
A type of sexual selection in which an individual of one sex choses a particular individual of the other sex for mating (often occurs through female choice).
Ethogram
a catalog or table of all the different kinds of behavior or activity observed in an animal.
Sexual Dimorphism
Any trait that differs between
males and females