Praxis Biology 5236 key terms

A testable, falsifiable prediction or explanation about a natural phenomenon that can be supported or rejected by observation and experiment rather than by opinion.

A study in which researchers manipulate one factor while keeping other conditions constant, allowing them to compare treated and untreated groups and attribute differences to the manipulated factor.

The factor that a researcher deliberately changes or manipulates in an experiment, whose effect on the measured outcome is being investigated.

The outcome that is measured or observed in an experiment; it is expected to respond to changes in the independent variable.

A broad, well-tested explanation supported by a large body of evidence from many experiments and observations, such as the theory of evolution by natural selection.

A selectively permeable phospholipid bilayer surrounding a cell that controls which substances enter and leave and helps maintain a stable internal environment.

The net movement of particles from an area of higher concentration to an area of lower concentration, driven by random molecular motion and requiring no added energy.

The diffusion of water across a selectively permeable membrane from a region of higher water concentration to one of lower water concentration.

Movement of substances across a cell membrane against their concentration gradient, using energy supplied by ATP and often involving carrier proteins.

A protein that speeds up a specific biochemical reaction by lowering its activation energy, without being consumed, and whose shape determines its substrate specificity.

Adenosine triphosphate, a small molecule that stores usable chemical energy in its phosphate bonds and releases it when those bonds are broken to power cellular work.

The set of reactions in cells that break down glucose and other fuels, using oxygen in aerobic forms, to produce ATP, carbon dioxide, and water.

The process by which plants, algae, and some bacteria use light energy to convert carbon dioxide and water into glucose and oxygen inside chloroplasts.

The process in which RNA polymerase builds a messenger RNA copy from a DNA template, carrying genetic instructions from the nucleus to the cytoplasm.

The process at ribosomes in which messenger RNA codons are matched to transfer RNAs, and amino acids are joined to form a polypeptide chain.

A type of nuclear division that produces two genetically identical daughter nuclei, used for growth, repair, and asexual reproduction in eukaryotes.

A two-part nuclear division that produces haploid gametes with new combinations of alleles, halving chromosome number and increasing genetic variation.

One of two or more alternative forms of a gene that occupy the same locus on homologous chromosomes and may produce different traits.

The particular combination of alleles an individual carries for a gene or set of genes, which together with environment influences observable traits.

The observable physical, biochemical, or behavioral characteristics of an organism, resulting from its genotype interacting with environmental factors and developmental history.

An allele whose effect is seen in the phenotype even when only one copy is present, masking the expression of a recessive allele at the same locus.

A change in the nucleotide sequence of DNA that can alter a gene product and is a primary source of new genetic variation.

The process by which heritable traits that improve survival and reproduction become more common in a population over generations, because bearers leave more offspring.

A random change in allele frequencies from one generation to the next, especially strong in small populations, that is not caused by natural selection.

The branch of biology that names, describes, and classifies organisms into hierarchical groups based on shared characteristics and evolutionary relationships.

The two-part naming system for species in which the genus name is capitalized, the species epithet is lowercase, and both are italicized or underlined.

A branching diagram showing hypothesized evolutionary relationships among organisms, with branch points representing common ancestors and branch lengths often indicating time or change.

A single-celled organism lacking a membrane-bound nucleus and other organelles, including bacteria and archaea, whose DNA is usually circular and free in the cytoplasm.

An organism whose cells contain a membrane-bound nucleus and other membrane-bound organelles, including protists, fungi, plants, and animals, and whose DNA is organized into chromosomes.

A nonliving infectious particle made of nucleic acid enclosed in a protein coat that can reproduce only by using a host cell's machinery.

A community of living organisms interacting with one another and with nonliving components such as water, soil, and sunlight in a defined area.

A nonliving physical or chemical feature of an environment, such as temperature, light, water, or soil minerals, that affects organisms.

A feeding position in a food chain or web, such as producer, primary consumer, or secondary consumer, defined by how the organism obtains energy.

The maximum population size of a species that an environment can sustain indefinitely given the available resources, such as food, water, and space.

A close, long-term interaction between individuals of two different species, which may benefit both, benefit one at the other's expense, or benefit one while harming neither.

The variety of life in a given area, measured as the number and kinds of species, the genetic variation within them, and the ecosystems they form.

The use of living organisms or their components, such as enzymes or DNA, to make products or perform useful processes for medicine, agriculture, or industry.

An organism whose genetic material has been altered using recombinant DNA techniques to introduce a new trait, such as pest resistance in a crop.

A medical approach that treats or prevents disease by introducing, removing, or altering genetic material within a patient's cells to correct a faulty gene.

The ability of bacteria to survive and grow in the presence of an antibiotic that would normally kill or inhibit them, often arising through mutation and selection.