Bio 212 vocab 2

darwinian fitness

A measure of contribution to the gene pool, such as lifetime reproductive success

diploid

Having two copies of each chromosome

incomplete dominance

The heterozygote expresses a phenotype in between the two homozygotes

introns

Non-coding sections of DNA that separate the exons in a gene

transcription

Making a messenger RNA from the information in the DNA

gene

A functional unit of DNA

phenotypic plasticity

The ability of the same genotype to produce different phenotypes

genetic recombination

Crossing over of chromosomes and exchange of genetic material during meiosis

phenotype

The appearance or function of an organism

assortative mating

Mating based on genotype. Preference for genetically similar individuals is positive assortative mating, and preference for genetically different individuals is negative assortative mating

inbreeding depression

The negative consequences of inbreeding, caused by high levels of homozygosity and expression of recessive genetic diseases

exon

Sections of a gene that are used to make mRNA, separated by introns

muation-selection balance

The point at which a deleterious recessive allele is being replaced in the population as quickly as selection is removing it

hetrozygote advantage

A form of incomplete dominance in which the heterozygote has higher fitness than either homozygote.

inbreeding coefficient

A measure of the degree of inbreeding, represented as the probability that alleles inherited from both parents will be identical by descent

somatic cells

Body cells – any cells other than the germ line cells

gamete

A s cell, either sperm or egg

polymorphism

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A gene that has more than one allele

founders effect

The changes in a gene pool that occur when a small number of individuals begin a new population

genetic link

Alleles that are close together on a chromosome such that they are inherited together, rather than independently

genotype

The alleles carried by an individual for a gene

homozygous

The genotype in which both alleles are the same

mutation

Change in DNA sequence

dominant

The phenotype for an allele is expressed fully in the heterozygote

recessive

The phenotype for an allele is only expressed when it is homozygous

translation

Using the information in a messenger RNA to assemble amino acids into a polypeptide

haploid

Having one copy of each chromosome

emzyme

Proteins that catalyze biochemical reactions

population bottleneck

A period of small population size during which genetic diversity is lost rapidly

allele

A variant of a gene

structural protien

Proteins that are used to make tissues, such as hair or insect exoskeleton

heterozygous

The genotype in which the alleles are different

frequency-dependent selection

Selection on a trait whose fitness depends on whether it is common or rare. Higher fitness when common is positive frequency dependence, and higher fitness when rare is negative frequency dependence.