Terms and Definitions A
Prokaryote
A unicellular organism that doesn’t have a nucleus or membrane-bound organelles
Omnivore
An organism that eats both plants and animals.
Eukaryote
An organism whose cells contain a nucleus and membrane-bound organelles
Organism
Any living thing, ranging from a single cell to multicellular life forms.
Carrying Capacity
The maximum number of individuals of a species that an environment can sustainably support.
Asexual
A kind of reproduction involving only one parent but producing genetically identical offspring.
Heterozygous
Having two different alleles for a particular gene.
Meiosis
A type of cell division that reduces the chromosome number by half, producing four genetically unique gametes.
DNA
Deoxyribonucleic acid; the molecule that carries genetic instructions for life.
Homozygous
Having two identical alleles for a particular gene.
speciation
The formation of new species through the process of evolution.
Codominance
A genetic scenario where both alleles in a heterozygous individual are fully expressed.
Evolution
The change in the genetic makeup of a population over time, often leading to the development of new species.
Food Chain
A sequence showing how energy and nutrients flow from one organism to another in an ecosystem.
Enzyme
A protein that speeds up chemical reactions in living organisms without being consumed in the process.
scientific theory
A well-substantiated explanation of some aspect of the natural world that is based on a good amount of evidence and repeated testing.
Dichotomous Key
A tool that helps identify organisms by giving a series of choices that lead to the correct name of the organism.
Binomial Nomenclature
A two-name system for classifying organisms, consisting of the genus and species names.
Abiotic factor
A nonliving part of an ecosystem (temperature, water, and sunlight).
Biotic Factor
A living component of an ecosystem (plants, animals, and microorganisms).
Punctuated Equilibrium
A model of evolution in which short periods of rapid change are followed by long periods of stability.
Endosymbiont Theory
The theory that eukaryotic cells originated from a symbiotic relationship between ancient prokaryotic cells.
Codon
A sequence of three DNA or RNA nucleotides that corresponds to a specific amino acid or stop signal in protein synthesis.
Eubacteria
A large group of true bacteria which are characterized by simple cell structure without a nucleus.
Phospholipid Bilayer
A double layer of phospholipids that makes up the core of all cell membranes, providing a barrier and matrix for membrane proteins.