Grade 9 - Biological Diversity

species

a group of organisms that have the same structure and can reproduce with one another

biological diversity

all the different types of organisms on the earth

ecosystem

a particular environment where living things interact with other living things and non-living things

population

a group of individuals of the same species living in an area

community

a group of populations of different species living in the same area

species

living things of the same kind that are able to reproduce successfully

symbiosis

sym (together) bio (life); an association between members of different species

commensalism

one of the participating organisms benefits while the other one does not

mutualism

both of the participating organisms benefit

parasitism

one of the participating organisms benefits while the other is harmed

interspecies competition

happens when two or more species need the same resources. i.e. two differnet species competing for the same food...resulting in less of it for each species

niche

describes the role of an organism within an ecosystem

resource partitioning

when species are not targeting the same resources

variability

variation within a species

natural selection

occurs when an environment "selects" which individuals will survive long enough to reproduce

DNA

genetic information of organisms; double helix; made up of nucleotides; we have 2 copies of each stran

Chromosomes

DNA coiled around proteins; condensed DNA

Gene

Section of DNA that codes for a protein

Gene pool

all genes (alleles) present in a species (or population)

Allele

alternate forms of some gene; different DNA code in same region may produce a different protein

Genotype

combination of alleles an organism inherits

Homozygous dominant

combination of two dominant alleles

Homozygous recessive

combination of two recessive alleles

Heterozygous

combination of dominant and recessive allele

Phenotype

physical appearance

Species

organisms that resemble each other and can reproduce successfully

Intraspecies

members of the same species

Interspecies

members of different species

Population

all members of one species in the ecosystem at the same time; able to reproduce

Evolution

change in a species' genes over generations

Mutations

change in DNA sequence

Natural selection

organisms with traits (genetic or behavioral) that allows the individual to successfully reproduce and produce successful offspring

Bottleneck

small number of individuals survive or colonize a new ecosystem; know as founder population

Habitat

where a species lives

Niche

role of a species/organism within an ecosystem

Generalist

species that has a very broad niche; can withstand a wide range of environment condition

Specialist

species that has a very narrow niche, very sensitive to environmental changes

Meiosis

a type of cell division that produces four sex cells from one parent cell; each sex cell contains half the genetic material of the original cell

Mitosis

a type of cell division that produces two identical daughter cells from one parent cell

Hybrid

an organism produced by crossing two individuals purebred for different forms of a trait

Allele

a possible form of a gene

DNA

deoxyribonucleic acid, genetic material found mainly in the nuclei of cells of living things

Gene

a segment of DNA, located at one particular place on a chromosome, which determines a specific characteristic of an organism

Genetic Code

arrangement of four chemical "letters" on a DNA molecule that can be arranged into "words" that form the instructions for making an organism

Genetics

the study of how heritable characteristics are transmitted through generations of organisms

Purebred

referring to a plant or animal that has ancestors all with the same form of a trait

Recessive Trait

the outward form observed only when two same-acting, non-dominant alleles are inherited. Short leg length in fruit flies is an example. An offspring with two short-leg alleles will grow short legs. The short-leg allele is recessive; it has no influence if the dominant long-leg allele is present.

Trait

a characteristic of an organism

Dominant Trait

the outward form observed when two opposite-acting alleles are inherited, e.g., long leg length in fruit flies; an offspring with one short-leg allele and one long-leg allele will grow long legs; the short-leg allele is recessive because it has no influence if a dominant, long-leg allele is present

Embryo

an undeveloped organism in its beginning stages

Zygote

a fertilized female egg