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

Biotic components, or biotic factors, can be described as any living component that affects another organism or shapes the ecosystem. This includes both animals that consume other organisms within their ecosystem, and the organism that is being consumed.

Question 3

Abiotic factor

Answer 3

In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them underpin biology as a whole.

Question 4

Organism

Answer 4

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

Question 5

Species

Answer 5

A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche.

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

Community, also called biological community, in biology, an interacting group of various species in a common location. For example, a forest of trees and undergrowth plants, inhabited by animals and rooted in soil containing bacteria and fungi, constitutes a biological community.

Question 8

Habitat

Answer 8

A habitat is a place where an organism makes its home.

Question 9

natural selection

Answer 9

Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the heritable traits characteristic of a population over generations.

Question 10

evolution

Answer 10

Evolution is change in the heritable characteristics of biological populations over successive generations. These characteristics are the expressions of genes that are passed on from parent to offspring during reproduction.

Question 11

adaptation

Answer 11

A change or the process of change by which an organism or species becomes better suited to its environment.

Question 12

artificial selection

Answer 12

Artificial selection is the identification by humans of desirable traits in plants and animals, and the steps taken to enhance and perpetuate those traits in future generations

Question 13

resistance

Answer 13

The natural or genetic ability of an organism to avoid or repel attack by biotic agents (pathogens, pests, parasites, etc.) or to withstand the effects of abiotic agents (chemicals, pesticides, salt, wind, heavy metals, etc).

Question 14

archaea

Answer 14

Archaea constitute a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria, but this classification is obsolete.

Question 15

bacteria

Answer 15

Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. Bacteria were among the first life forms to appear on Earth, and are present in most of its habitats.

Question 16

fungus

Answer 16

A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, which is separate from the other eukaryotic life kingdoms of plants and animals.

Question 17

protist

Answer 17

A protist is any eukaryotic organism that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor, the exclusion of other eukaryotes means that protists do not form a natural group, or clade.

Question 18

gymnosperm

Answer 18

The gymnosperms, also known as Acrogymnospermae, are a group of seed-producing plants that includes conifers, cycads, Ginkgo, and gnetophytes. The term “gymnosperm” comes from the composite word in Greek: γυμνόσπερμος, literally meaning “naked seeds”. The name is based on the unenclosed condition of their seeds.

Question 19

invertebrate

Answer 19

Invertebrates are animals that neither possess nor develop a vertebral column, derived from the notochord. This includes all animals apart from the subphylum Vertebrata. Familiar examples of invertebrates include arthropods, mollusks, annelid, and cnidarians.

Question 20

vertebrate

Answer 20

Vertebrates comprise all species of animals within the subphylum Vertebrata. Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 69,963 species described.