Biology and Earth Science Vocabulary

Flashcards of vocabulary terms and definitions related to Biology and Earth Science.

adaptation

a physical characteristic or behavior that evolved through natural selection and allows the organism to survive in its environment

aeolian processes

a method by which wind shapes the surface of Earth

alimentary canal

the body structures that food passes through, from mouth to anus

allele

an alternate form of a specific gene

alveoli

air sacs in the lungs

antibody

a blood protein that aids in immunity by reacting to a specific antigen

antigen

a substance that can trigger an immune response by the body

appendicular skeleton

the part of the skeleton that consists of shoulders, arms, hips, and legs

artery

a blood vessel that carries blood away from the heart

asexual reproduction

a type of reproduction in which offspring receive all their genetic material from one parent

atmosphere

an envelope of gas surrounding planets or other celestial bodies held in place by the body's own gravity

atrium

one of two upper chambers of the heart that receives blood; plural atria

autonomic nervous system

the part of the nervous system responsible for involuntary functions

axial skeleton

the part of the skeleton that consists of the skull, vertebrae, and ribs

biodiversity

the variety of species in an ecosystem

bronchiole

tubes in the respiratory system that branch to the lungs

capillary

microscopic vessels that connect arterioles and venules

carbon sink

any object or organism that absorbs more carbon than it emits

cartilage

firm and flexible connective tissue that provides cushioning and support for body structures

cell cycle

a series of events that involves the growth and division of a cell

cerebellum

the part of the brain that controls balance, coordination, and muscle activity

cerebrum

the largest part of the brain; controls voluntary movements, language, memory, speech, and processing of sensory information

chemical digestion

the breakdown of food into nutrients that will be used by the body

chromosome

a strand of DNA that contains genes and is located in the nucleus of a cell

chyme

the pulpy food that passes from the stomach to the small intestine

climate

the long-term weather conditions of a region

climate change

a change in global or regional climate patterns, most commonly referring to the current rise in atmospheric carbon dioxide levels due to fossil fuel use and other human activities

compact bone

a type of bone tissue that is hard and rigid

corrugated

shaped into a series of small parallel folds

cyanobacteria

a very early type of bacteria that performs photosynthesis

data

facts, statistics, and calculations used in scientific analysis

dependent variable

a tested variable in a scientific investigation; a dependent variable is affected by changes made to the independent variable

deposition

a process by which matter changes from a gas into a solid

desertification

the process by which fertile land becomes a desert because of deforestation or drought

diffusion

passive transport of ions and small molecules in and out of the cell

DNA

deoxyribonucleic acid, a nucleic acid that has a double helix structure and carries genetic information

dominant gene

an allele that can supress the expression of another allele

egg

a female reproductive cell; a gamete

electrocardiogram

a test that measures the electrical activity of the heart; abbreviated EKG

endocrine

relating to glands that secrete hormones directly into the bloodstream

enzyme

a substance that acts as a catalyst for chemical reactions in living things

erosion

the slow wearing away and transport of rocks caused by environmental factors such as wind, water, and ice

estrogen

a group of chemically similar sex hormones that are particularly important for reproductive growth and development in females

eukaryote

a unicellular or multicellular organism that has cells with a defined nucleus

eutrophication

an increase in the level of nutrients in aquatic and marine systems

evolution

the process by which organisms on Earth have developed and diversified

exocrine

relating to glands that secrete their products into ducts

fluvial process

a method by which rivers and streams shape the surface of Earth

follicle (egg)

in human reproduction, a structure that contains an undeveloped egg

fossil fuel

a material such as coal, oil, or natural gas that is formed under Earth’s surface from dead plants and animals

fracking

the process of injecting liquid at high pressure into rocks deep underground to force open existing rock fissures and extract oil or gas

freshwater

inland water found in ponds, lakes, and streams with very low levels of salt

frost wedging

physical weathering of rock caused by water repeatedly freezing and thawing within the rock's fissures

gene

an area of DNA that codes for a protein or certain nucleic acids

genetic mutation

a change in the genetic sequence of an organism

genetic variation

the number of different alleles available in a population of organisms of the same species

genotype

an organism's entire genetic code, including genes that are not expressed in the phenotype

greenhouse gas

a gas that absorbs infrared radiation and emits heat

groundwater

water found underground in cracks and spaces in soil, sand, and rock

gut flora

bacteria that naturally live in the intestinal tract

heterozygous

carrying unmatched alleles for a given trait

homozygous

carrying identical alleles for a given trait

hormone

a substance in the body important for regulation and homeostasis

hydrosphere

the part of Earth that includes all the freshwater and salt water

hypothalamus

the part of the of the brain responsible for thirst, hunger, sleep, and other processes that maintain homeostasis

hypothesis

a proposed explanation for an occurrence based on available data, observations, or evidence

igneous rock

rock formed by the cooling of magma or lava

independent variable

a variable controlled by the scientist during a scientific investigation

inherited mutation

a genetic mutation that occurs in gamete cells; mutation exists in all cells in the organism

larynx

the organ forming an air passage to the lungs and housing the vocal cords; the voice box

ligament

tissue that attaches bone to bone

lymph

a clear fluid in the body that drains through the lymphatic system

mechanical digestion

physically breaking down food into smaller pieces

medulla oblongata

the part of the brain stem responsible for vital functions, including control of the heart and the lungs

meiosis

a type of cell division that yields four haploid daughter cells

meninges

the lining of the brain and spinal cord

menstrual cycle

the biological process in human females of preparing an egg for fertilization by the sperm

mitosis

a type of cell division that yields two diploid daughter cells

myofibril

an enlongated thread that plays a role in the contraction of muscle fibers

natural resource

a resource that is provided by Earth

nephron

the functional unit of the kidney that forms urine

neuron

a nerve cell

nonrenewable resource

a natural resource that exists in a fixed amount and can be replaced only by processes that take millions of years

oocyte

an immature egg cell in an ovary

ore

a naturally occurring material containing a valuable substance that can be mined for a profit

ossification

the formation of bone

osteoblast

a cell that synthesizes bone

osteoclast

a cell that breaks down bone

ozone

a form of oxygen that protects Earth from ultraviolet radiation but is also hazardous to breathe

paleoclimatology

the study of past climatic conditions based on evidence obtained from Earth's geologic record

parasympathetic nervous system

the part of the autonomic nervous system that is active when the body is relaxed

pathogen

a virus or microorganism that causes disease

peristalsis

the involuntary contraction and relaxation of muscles that moves food through the digestive tract

pharynx

the cavity that connects the nose and mouth to the esophagus

phenotype

the expressed traits of a given organism

photosynthesis

the process by which plants and select other organisms transform radiant energy from the Sun into usable chemical energy

platelet

a cell fragment in the blood that is important for blood clotting

pons

the part of the brain stem that sends messages between the cerebellum and cerebrum

population

a group of the same species that inhabits a geographical area

Precambrian

the first four billion years of Earth's history