unit 4 vocab Flashcards
A horizon
Topsoil composed of mineral-containing weathered parent material and organic matter.
Age-structure diagram
Useful in determining the future growth or decline of a population.
Anemia
A condition resulting from a diet that is deficient in iron. Increases the risk of death in women due to excessive bleeding during childbirth.
B horizon
Subsoil, which contains a lower concentration of organic material than the first two layers and a higher concentration of mineral particles.
Baby boom
A temporary marked increase in the birth rate, especially the one following World War II.
Biological control
The control of a pest by the introduction of a natural enemy or predator.
Bycatch
Species that are inadvertently caught and killed. (sea turtles, dolphins, and sea birds)
C horizon
Composed of weathered parent material sitting on top of bedrock.
Chlorinated hydrocarbon
Broad spectrum pesticide. (kills many different species)
Contour plowing
The practice of plowing across the slope of a hill rather than up and down the slope.
Crop rotation
The system of growing a sequence of different crops on the same ground so as to maintain or increase its fertility.
Crude death rate
The number of deaths per 1,000 people in a population.
DDT
Type of Chlorinated hydrocarbon, (broad spectrum pesticide)
Desertification
Occurs when marginal lands on the outskirts of deserts are overgrazed by livestock or farmed. The removal of native vegetation causes the soil to dry out.
Demographic transition
A feature of the population growth pattern for countries as they change from primarily agricultural economies to industrialized nations.
Doubling time
The time in years required for the population to double.
Emigration
The migration of people out of a population.
Factory farm
A farm on which large numbers of livestock are raised indoors in conditions intended to maximize production at minimal cost.
Genetically modified organism (GMO)
Organism altered by the techniques of genetic engineering so that its DNA contains one or more genes not normally found there.
Goiter
A condition resulting from a diet that is deficient in iodine. A swollen neck results from an enlarged thyroid gland.
Immigration
The migration of people into a population.
Industrialized culture
Production of large quantities of crops and livestock for domestic and foreign sale.