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Natural Selection
a process in which organisms with certain inhertied characteristics are more likely to survive and reproduce than are organisms with other characteristics differential reproductive success
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Population
A group of intracting individualsbelonging to one species and living in the same geographic area at the same time.
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evolution
descent with modifications; genetic change in a population or species over generations; the heritable changes that heritable changes that have produced earths diversity of organisms.
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mammal
any vertebrate of the class Mammalia, having the body more orless covered with hair, nourishing the young with milk from themammary glands, and, with the exception of the egg-layingmonotremes, giving birth to live young.
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Directional Selection
natural selection that acts in favor of the individual at one end of the phenotypic range
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Disruptive selection
natural selection that favors extreme ove intermediate phenotpyes
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Stabilizing selection
A type of natural selection in which genetic diversity decreases as the population stabilizes on a particular trait value.
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genetic drift
random changes in the frequency of alleles in a gene pool, usuallyof small populations.
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gene flow
the alteration of the frequencies of alleles of particular genes in apopulation, resulting from interbreeding with organisms fromanother population having different frequencies.
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fitness
the ability of a population to maintain or increase itsnumbers in succeeding generations.
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species
a class of individuals having some common characteristics orqualities; distinct sort or kind.
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pangaea
the hypothetical landmass that existed when all continents werejoined, from about 300 to 200 million years ago.
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convergent evolution
adaptive change resulting in nonhomologous similarites among organisms species from different evolutionary lineages come to resemble each other as a result of living in very similar enviroments
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abiotic
air water light minerals and temperature
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ribozyme
an enzymatic rna molecule that catalyzes chemical reactions
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cocci
a spherical prokaryotic cell
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bacilli
a rod shaped prokaryotic cell
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nuclear fission
thesplitting of an atomic nucleus into approximately equal parts,either spontaneously or as a result of the impact of a particleusually with an associated release of energy
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exotoxin
a poisionious protein secreted by certain bacteria
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endotoxin
aposionious componant of the outer membrane of certain bacteria
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bioremediation
the use of living thing orangisms to detoxify and restore polluted and degraded ecosystems
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symbiosis
the interaction between organisms of different species the symbiont lives in or on another species the host.
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endosymbiosis
a type of symbiosis in which one organism lives inside the other,the two typically behaving as a single organism.
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mycorrhizae
a muturally beneficial symbiotic association of a plant root and fungus
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gametophyte
Compare sporophyte the plant body, in species showingalternation of generations, that produces the gametes
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cuticle
in animals a tough no living outer layer of the skin in plants a waxy coatting on the surface of stems and leaves that help retain water
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sporophyte
Compare gametophyte the diploid form of plants that havealternation of generations. It develops from a zygote andproduces asexual spores
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pollen
the fertilizing element of flowering plants, consisting of fine,powdery, yellowish grains or spores, sometimes in masses
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endosperm
the tissue within the seed of a flowering plant that surrounds andnourishes the developing embryo
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hyphae
one of many filaments making up the body of a fungus
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mycelium
the densely branched network of hyphae in a fungus
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blastula
an embryonic stage that marks the end of cleavage during animal development a hollow ball of cells in many species
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gastrula
the embryonic stage resulting from gastrulation in animal development most animals have gastrula made up of 3 layers, ectoderm endoderm mesoderm
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larva
a free living sexually immature form in some animal life cycles that may differ from the adult in morphology nutrition and habitat
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metamorphosis
the transformation of a larva into an adult
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amoebocyte
any cell having properties similar to an amoeba, such as shape,mobility, and ability to engulf particles
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exoskeleton
external skeleton that protects an aminal and provides points of attachment for muscles
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endoskeleton
interior skeleton located within soft tissues of an animal found in all veterbrates and a few inveterbrates
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notochord
A flexible rodlike structure that forms the main support of the bodyin all chordates during some stage of their development. Invertebrates, the notochord develops into a true backbone in theembryonic phase. Primitive chordates, such as lancelets andtunicates, retain a notochord throughout their lives.
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operculum
a protective flap on each side of a bony fish 's head that covers a chamber housing the gills
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amniotic egg
a shelled egg in which a embryo develops within a fluid filled amniotic sac and is nourished by yolk
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culture
the accumulated knowledge customs beliefs arts and other human products that are socially transmitted over the generations
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