Midterm Review Flashcards
Define True Breeding.
If an organism has a certain characteristic
Define Allelle.
One of a pair of genes that occupies the same position on homologous chromosomes.
Define Genotype.
Two letter set that represents the alleles an organism possesses for a certain trait.
Define Phenotype.
The observable expression of an organism’s genes
Define Homozygous Genotype.
A genotype in which both alleles are identical.
Define Heterozygous genotype.
A genotype with two different alleles.
Define Dominant allele.
An allele that will determine phenotype if just one is present in the genotype.
Define recessive allele.
An allele that will not determine the phenotype unless the genotype is homozygous in that allele.
Define Monohybrid cross.
A cross between two individuals, concentrating on only one definable trait.
Define Dihybrid cross.
A cross between two individuals, concentrating on two definable traits.
Define Immutability of species.
The idea that each individual species on the planet was specially created by God and could never fundamentally change.
Define Macroevolution.
The theory that natural selection can, over time, take an organism and transform it into a more specialized species of that organism.
Define Microevolution.
The theory that natural selection can, over time, take an organism and transform it into a more specialized species of that organism.
Define Strata.
Distinct layers of rock.
Define fossils.
Preserved remains of once-living organisms.
Define Structural Homology.
The study of similar structures in different species.
Define Population.
A group of interbreeding organisms coexisting together.
Define ecosystem.
An association of living organisms and their physical environment.
Define biome.
A group of ecosystems classified by climate and plant life.
Define community.
A group of populations living and interacting in the same area.
Define biomass.
A measure of the total dry mass of organisms within a particular region.
Define ecological pyramid.
A diagram that shows the biomass of organisms at each trophic leve.
Define Greenhouse effect.
The process by which certain gases (principally water vapor, carbon dioxide, and methane) trap heat that would otherwise escape the earth and radiate into space.
Define Nitrogen fixation.
Converts nitrogen gas into chemically active molecules that many organisms can use.
Define invertebrates.
Animals that lack a backbone.
Define vertebrates.
Animals that possess a backbone.
Define collar cells.
flagellated cells that push water through an organism.
