Ch.4 Key Terms

Question 1

ecosystem

Answer 1

a biological community of interacting organisms and their physical environment.

Question 2

biotic factor

Answer 2

any living component that affects another organism or shapes the ecosystem.

Question 3

abiotic factor

Answer 3

non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems.

Question 4

organism

Answer 4

an individual animal, plant, or single-celled life form.

Question 5

species

Answer 5

A species consists of organisms that can mate and produce fertile offspring. Species can change over time and even divide into subspecies, like breeds of dogs.

Question 6

population

Answer 6

a population is all the organisms of the same group or species who live in a particular geographical area and are capable of interbreeding.

Question 7

community

Answer 7

a community is a group or association of populations of two or more different species occupying the same geographical area at the same time.

Question 8

habitat

Answer 8

the natural home or environment of an animal, plant, or other organism.

Question 9

natural selection

Answer 9

the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin and is now believed to be the main process that brings about evolution.

Question 10

evolution

Answer 10

evolution is the change in the characteristics of a species over several generations and relies on the process of natural selection.

Question 11

adaptation

Answer 11

the action or process of adapting or being adapted.

Question 12

artificial selection

Answer 12

he process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits by choosing which typically animal or plant males and females will sexually reproduce and have offspring together.

Question 13

resistance

Answer 13

the property of communities or populations to remain “essentially unchanged” when subject to disturbance.

Question 14

archaea

Answer 14

microorganisms that are similar to bacteria in size and simplicity of structure but radically different in molecular organization. They are now believed to constitute an ancient intermediate group between the bacteria and eukaryotes.

Question 15

bacteria

Answer 15

a member of a large group of unicellular microorganisms which have cell walls but lack organelles and an organized nucleus, including some which can cause disease.

Question 16

fungus

Answer 16

any of a group of spore-producing organisms feeding on organic matter, including molds, yeast, mushrooms, and toadstools.

Question 17

protist

Answer 17

a single-celled organism of the kingdom Protista, such as a protozoan or simple alga.

Question 18

gymnosperm

Answer 18

a plant that has seeds unprotected by an ovary or fruit. Gymnosperms include the conifers, cycads, and ginkgo.

Question 19

angiosperm

Answer 19

a plant that has flowers and produces seeds enclosed within a carpel. The angiosperms are a large group and include herbaceous plants, shrubs, grasses, and most trees.

Question 20

invertebrate

Answer 20

an animal lacking a backbone, such as an arthropod, mollusk, annelid, coelenterate, etc. The invertebrates constitute an artificial division of the animal kingdom, comprising 95 percent of animal species and about 30 different phyla.

Question 21

vertebrate

Answer 21

an animal of a large group distinguished by the possession of a backbone or spinal column, including mammals, birds, reptiles, amphibians, and fishes.