Biology keystones 1

abiotic

nonliving factor in an ecosystem, such as moisture, temperature, wind, sunlight, soil, and minerals

active transport

energy-requiring movement of molecules across a membrane from a region of lower concentration to a region of higher concentration

adenosine triphosphate (atp)

high-energy molecule that contains, within its bonds, energy that cells can use

adhesion

attraction between molecules of different substances

agriculture

the science of raising plants and/or animals for food, clothing, or other useful product

allele

any of the alternative forms of a gene that occurs at a specific place on a chromosome

analogous structure

body part that is similar in function as a body part of another organism but is structurally different

aquatic

relating to water; living in or near water or taking place in water; implies an environment where plants and animals live

artificial selection

process by which humans modify a species by breeding it for certain traits

asexual reproduction

process by which offspring are produced from a single parent; does not involve the joining of gametes

atom

smallest basic unit of matter

biochemical conversion

breaks down biomass using enzymes generated by bacteria or other microorganisms

bioenergetics

the part of biochemistry concerned with the energy involved in making and breaking of chemical bonds in the molecules found in biological organisms

biogeochemical cycles

movement of a chemical through the biological and geological, or living and nonliving, parts of an ecosystem

biological macromolecules

large molecules, necessary for life, that are built from smaller organic molecules; carbohydrates, lipids, proteins, and nucleic acids

biology

scientific study of all forms of life

biomass

total dry mass of all organisms in a giver area

biome

regional or global community of organisms characterized by the climate conditions and plant communities that thrive there

biosphere

all organisms and the part of Earth where they exist

biotechnology

use and application of living things and biological processes

biotic

living things, such as plants, animals, fungi, and bacteria

carbohydrate

molecule composed of carbon, hydrogen, and oxygen; includes sugars and starches

carnivore

organism that obtains energy by eating only animals

carrier (transport) proteins

bind specific molecules to be transported on one side of the membrane

catalyst

substance that decreases activation energy and increases reaction rate in a chemical reaction

cell

basic unit of life

cell cycle

pattern of growth, DNA replication, and cell division that occurs in a eukaryotic cell

cellular respiration

process of producing ATP by breaking down carbon-based molecules when oxygen is present

chlorophyll

light-absorbing pigment molecule in photosynthetic organisms

chloroplast

organelle composed of numerous membranes that are used to convert solar energy into chemical energy; contains chlorophyll

chromosomal mutation

a change in one or more genes

chromosomes

long, continuous thread of DNA that consists of numerous genes and regulatory information

cloning

a deliberate production of genetically identical individuals

co-dominance

heterozygous genotype that equally expresses the trait from both alleles

cohesion

attraction between molecules of the same substance

commensalism

ecological relationship in which one species receives a benefit but the other species is not affected one way or another

community (ecological)

collection of all of the different populations that live in one area

competition

ecological relationship in which two organisms attempt to obtain the same resource

concentration

the amount of a substance, such as a salt, that is in a certain amount of tissue or liquid, such as blood

concentration gradient

difference in the concentration of a substance from one location to another

consumer (ecological)

organism that obtains its energy and nutrients by eating other organisms

crossing-over

exchange of chromosome segments between homologous chromosomes during meiosis I

cytokinesis

process by which the cell cytoplasm divides

decomposer

detritivore that breaks down organic matter into simpler compounds, returning nutrients back into an ecosystem

deoxyribonucleic acid (dna)

molecule that stores genetic information in all organisms

diffusion

movement of dissolved molecules in a fluid or gas from a region of higher concentration to a region or lower concentration

dna replication

the process by which the genome’s dna is copied in cells

dominant inheritance

allele that is expressed when two different alleles are present in an organism’s genotype

ecology

the study of the interactions among living things and their surroundings

ecosystem

collection of organisms and nonliving things, such as climate, soil, water, and rocks, in an area

embryology

the branch or biology and medicine concerned with the study or embryos and their development

endemic species

those that live in a limited area

endocytosis

uptake of liquids or large molecules into a cell by inward folding of the cell membrane.

endoplasmic reticulum (er)

interconnected network of thin, folded membranes that produce, process, and distribute proteins

endosymbiosis

ecological relationship in which one organism lives within the body of another

energy pyramid

diagram that compares energy used by producers, primary consumers, and other trophic levels

energy transformation

processes that convert energy from one type into another

environment

the complex of physical, chemical, and biotic factors that act upon an organism or an ecological community and ultimately determine its form and survival

enzyme

protein that catalyzes chemical reactions for organisms

eukaryote

any cell or organism that possesses a clearly defined nucleus within a membrane

evolution

change in a species over time; process of biological change by which descendants come to differ from their ancestors

exocytosis

release of substances out of a cell by the fusion of a vesicle with the membrane

extinction

elimination of a species from earth

extracellular

situated or occurring outside a cell or the cells of the body

facilitated diffusion

diffusion of molecules assisted by protein channels that pierce a cell membrane

fact

an observation that has been confirmed so many times that scientists can, for all intents and purposed, accept it as “true”

food chain

model that links organisms by their feeding relationships

food web

model that shows the complex network of feeding relationships within an ecosystem

forensics

the application of concepts and procedures used in the biological sciences

fossils

trace of an organism from the past