MindTap Biology: Evolution, Nutrition, and Immunology Practice Flashcards

Vocabulary flashcards based on the provided glossary covering biological evolution, digestive systems, nutrition, and the immune system.

natural theology

A belief that knowledge of God may be acquired through the study of natural phenomena.

taxonomy

The science of the classification of organisms into an ordered system that indicates natural relationships.

Biological evolution

The process by which some individuals in a population experience changes in their DNA and pass those modified instructions to their offspring.

natural history

The branch of biology that examines the form and variety of organisms in their natural environments.

biogeography

The study of the geographical distributions of plants and animals.

morphology

The form or shape of an organism, or of a part of an organism.

catastrophism

The theory that Earth has been affected by sudden, violent events that were sometimes worldwide in scope.

vestigial structures

An anatomical feature of living organisms that no longer retains its ancestral function.

fossils

The remains or traces of an organism of a past geologic age embedded and preserved in Earth’s crust.

paleobiology

The study of ancient organisms.

gradualism

The view that Earth and its living systems changed slowly over its history.

adaptive traits

A genetically based characteristic, preserved by natural selection, that increases an organism’s likelihood of survival or its reproductive output.

natural selection

The evolutionary process by which alleles that increase the likelihood of survival and the reproductive output of the individuals that carry them become more common in subsequent generations.

evolutionary divergence

A process whereby natural selection or genetic drift causes populations to become more different over time.

artificial selection

Selective breeding of organisms to ensure that certain desirable traits appear at higher frequency in successive generations.

uniformitarianism

The concept that the geological processes that sculpted Earth’s surface over long periods of time—such as volcanic eruptions, earthquakes, erosion, and the formation and movement of glaciers—are exactly the same as the processes observed today.

descent with modification

Biological evolution.

biological lineages

An evolutionary sequence of ancestral organisms and their descendants.

Microevolution

Small-scale genetic changes within populations, often in response to shifting environmental circumstances or chance events.

Macroevolution

Large-scale evolutionary patterns in the history of life, producing major changes in species and higher taxonomic groups.

modern synthesis

A unified theory of evolution developed in the middle of the twentieth century.

population genetics

The branch of science that studies the prevalence and variation in genes among populations of individuals.

historical biogeography

The study of the geographical distributions of plants and animals in relation to their evolutionary history.

homologous traits

Characteristics that are similar in two species because they inherited the genetic basis of the trait from their common ancestor.

comparative morphology

Analysis of the structure of living and extinct organisms.

orthogenesis

An obsolete theory that evolution is goal oriented, striving to perfect organisms.

phenotypic variation

Differences in appearance or function between individual organisms.

population

A group of organisms of the same kind that live together in the same place.

quantitative variation

Variation that is measured on a continuum (such as height in human beings) rather than in discrete units or categories.

qualitative variation

Variation that exists in two or more discrete states, with intermediate forms often being absent.

allele frequencies

The abundance of one allele relative to others at the same gene locus in individuals of a population.

genotype frequencies

The percentage of individuals in a population possessing a particular genotype.

gene pool

The sum of all alleles at all gene loci in all individuals in a population.

polymorphism

The existence of discrete variants of a character among individuals in a population.

null models

A conceptual model that predicts what one would see if a particular factor had no effect.

Hardy–Weinberg principle

An evolutionary rule of thumb that specifies the conditions under which a population of diploid organisms achieves genetic equilibrium.

genetic drift

Random fluctuations in allele frequencies as a result of chance events; usually reduces genetic variation in a population.

genetic equilibrium

The point at which neither the allele frequencies nor the genotype frequencies in a population change in succeeding generations.

founder effect

An evolutionary phenomenon in which a population that was established by just a few colonizing individuals has only a fraction of the genetic diversity seen in the population from which it was derived.

mutation

A spontaneous and heritable change in DNA.

directional selection

A type of natural selection in which individuals near one end of the phenotypic spectrum have the highest relative fitness.

relative fitness

The number of surviving offspring that an individual produces compared with the number left by others in the population.

stabilizing selection

A type of natural selection in which individuals expressing intermediate phenotypes have the highest relative fitness.

disruptive selection

A type of natural selection in which extreme phenotypes have higher relative fitness than intermediate phenotypes.

sexual selection

A form of natural selection established by male competition for access to females and by the females’ choice of mates.

Inbreeding

A special form of nonrandom mating in which genetically related individuals mate with each other.

sexual dimorphism

Differences in the size or appearance of males and females.

balanced polymorphism

The maintenance of two or more phenotypes in fairly stable proportions over many generations.

heterozygote advantage

An evolutionary circumstance in which individuals that are heterozygous at a particular locus have higher relative fitness than either homozygote.

neutral variation hypothesis

An evolutionary hypothesis that some variation at gene loci coding for enzymes and other soluble proteins is neither favored nor eliminated by natural selection.

Adaptation

Characteristic that helps an organism survive longer or reproduce more under a particular set of environmental conditions.

selectively neutral

An evolutionary hypothesis that some variation at gene loci coding for enzymes and other soluble proteins is neither favored nor eliminated by natural selection.

frequency-dependent selection

A form of natural selection in which rare phenotypes have a selective advantage simply because they are rare.

nutrition

The processes by which an organism takes in, digests, absorbs, and converts food into organic compounds.

ingestion

The feeding methods used to take food into the digestive cavity.

digestion

The splitting of carbohydrates, proteins, lipids, and nucleic acids in foods into chemical subunits small enough to be absorbed into the body fluids and cells of an animal.

undernutrition

A form of malnutrition. A condition in animals in which intake of organic fuels is inadequate, or whose assimilation of such fuels is abnormal.

feeding

The uptake of food from the surroundings.

Omnivores

An animal that feeds at several trophic levels, consuming plants, animals, and other sources of organic matter.

Herbivores

An animal that obtains energy and nutrients primarily by eating plants.

Carnivores

An animal that primarily eats other animals.

overnutrition

A form of malnutrition. The condition caused by excessive intake of specific nutrients.

essential amino acids

Any amino acid that is not made by the human body but must be taken in as part of the diet.

malnutrition

A condition resulting from a diet in which intake of organic fuels is inadequate or whose assimilation of such fuels is abnormal (= undernutrition), or in which there is excessive intake of specific nutrients (= overnutrition).

essential fatty acids

Any fatty acid that the body cannot synthesize but needs for normal metabolism.

essential minerals

Any inorganic element such as calcium, iron, or magnesium that is required in the diet of an animal or, in the case of plants, that generally must be present in soil.

vitamins

An organic molecule required in small quantities that the animal cannot synthesize for itself.

essential nutrients

Any of the essential amino acids, fatty acids, vitamins, and minerals required in the diet of an animal.

Fluid feeders

An animal that obtains nourishment by ingesting liquids that contain organic molecules in solution.

Suspension feeders

An animal that ingests small food items suspended in water.

enzymatic hydrolysis

A process in which chemical bonds are broken by the addition of $\text{H}^+$ and $\text{OH}^-$, the components of a molecule of water.

Deposit feeders

An animal that consumes particles of organic matter from the solid substrate on which it lives.

Bulk feeders

An animal that consumes sizeable food items whole or in large chunks.

amylases

An enzyme that catalyzes the hydrolysis of starches.

lipases

A pancreatic enzyme that hydrolyzes fats.

intracellular digestion

The process in which cells take in food particles by endocytosis.

Extracellular digestion

Digestion that takes place outside body cells, in a pouch or tube enclosed within the body; in fungi, extracellular digestion occurs by way of enzymes released to the environment where they break down nearby organic matter into particles the fungus can absorb.

proteases

An enzyme that hydrolyses proteins.

nucleases

An enzyme that digests a nucleic acid molecule.

gastrovascular cavity

A saclike body cavity with a single opening, a mouth, which serves both digestive and circulatory functions.

digestive tract

Part of an extracellular digestive system; it is tubelike with two openings that form a separate mouth and anus. Digestive contents move in one direction through specialized regions of the tube, from the mouth to the anus.

pharynx

The throat. In some invertebrates, a protrusible tube used to bring food into the mouth for passage to the gastrovascular cavity; in mammals, the common pathway for air entering the larynx and food entering the esophagus.

esophagus

A connecting passage of the digestive tube.

lumen

The inside of the digestive tube.

crop

Of birds, an enlargement of the digestive tube where the digestive contents are stored and mixed with lubricating mucus.

gizzard

The part of the digestive tube that grinds ingested material into fine particles by muscular contractions of the wall.

fat-soluble vitamins

A vitamin that dissolves in liquid fat or fatty oils, in addition to water.

intestine

The portion of digestive system where organic matter is hydrolyzed by enzymes secreted into the digestive tube. As muscular contractions of the intestinal wall move the mixture along, cells lining the intestine absorb the molecular subunits produced by digestion.

water-soluble vitamins

A vitamin with a high proportion of oxygen and nitrogen able to form hydrogen bonds with water.

mucosa

The lining of the digestive tract, which contains epithelial and glandular cells, connective tissue, and some smooth muscle.

submucosa

A thick layer of elastic connective tissue in the digestive tract that contains neuron networks, blood and lymph vessels, and glands.

muscularis

The muscular coat of a hollow organ or tubular structure.

mastication

In mammals with teeth, the first step in the digestive process in which ingested food is sliced, torn, and ground into small pieces.

chewing

In mammals with teeth, the first step in the digestive process in which ingested food is sliced, torn, and ground into small pieces. Also called mastication.

sphincters

A powerful ring of smooth muscle that forms a valve between major regions of the digestive tract.

serosa

The outermost layer of the digestive tract consisting of a layer of epithelium on the outside of the tube with a layer of connective tissue beneath it. Cells of the serosa protect the underlying tissues and secrete an aqueous, slippery fluid that lubricates the areas between the digestive organs and other organs.

bolus

The food mass after chewing.

saliva

In humans, a secretion of three pairs of salivary glands in the mouth.

salivary amylase

A substance that hydrolyzes starches to the disaccharide maltose.

swallowing reflex

The involuntary action produced by contractions of muscles in the walls of the pharynx that direct food into the esophagus.