15. 7 Key Terms

Key Terms

allele

alternative forms of a gene that occupy a specific locus on a specific gene

autosomal chromosome/autosome

in humans, the 22 pairs of chromosomes that are not the sex chromosomes (XX or XY)

autosomal dominant

pattern of dominant inheritance that corresponds to a gene on one of the 22 autosomal chromosomes

autosomal recessive

pattern of recessive inheritance that corresponds to a gene on one of the 22 autosomal chromosomes

biomarker

an individual protein that is uniquely produced in a diseased state

carrier

heterozygous individual who does not display symptoms of a recessive genetic disorder but can transmit the disorder to their offspring

codominance

pattern of inheritance that corresponds to the equal, distinct, and simultaneous expression of two different alleles

dominant

describes a trait that is expressed both in homozygous and heterozygous form

dominant lethal

inheritance pattern in which individuals with one or two copies of a lethal allele do not survive in utero or have a shortened life span

genetic map

an outline of genes and their location on a chromosome that is based on recombination frequencies between markers

genomics

the study of entire genomes, including the complete set of genes, their nucleotide sequence and organization, and their interactions within a species and with other species

genotype

complete genetic makeup of an individual

heterozygous

having two different alleles for a given gene

homozygous

having two identical alleles for a given gene

incomplete dominance

pattern of inheritance in which a heterozygous genotype expresses a phenotype intermediate between dominant and recessive phenotypes

karyotype

systematic arrangement of images of chromosomes into homologous pairs

model organism

a species that is studied and used as a model to understand the biological processes in other species represented by the model organism

mutation

change in the nucleotide sequence of DNA

pharmacogenomics

the study of drug interactions with the genome or proteome; also called toxicogenomics

phenotype

physical or biochemical manifestation of the genotype; expression of the alleles

physical map

a representation of the physical distance between genes or genetic markers

protein signature

a set of over- or under-expressed proteins characteristic of cells in a particular diseased tissue

proteomics

study of the function of proteomes

Punnett square

grid used to display all possible combinations of alleles transmitted by parents to offspring and predict the mathematical probability of offspring inheriting a given genotype

recessive

describes a trait that is only expressed in homozygous form and is masked in heterozygous form

recessive lethal

inheritance pattern in which individuals with two copies of a lethal allele do not survive in utero or have a shortened life span

sex chromosomes

pair of chromosomes involved in sex determination; in males, the XY chromosomes; in females, the XX chromosomes

trait

variation of an expressed characteristic

X-linked

pattern of inheritance in which an allele is carried on the X chromosome of the 23rd pair

X-linked dominant

pattern of dominant inheritance that corresponds to a gene on the X chromosome of the 23rd pair

X-linked recessive

pattern of recessive inheritance that corresponds to a gene on the X chromosome of the 23rd pair

whole genome sequencing

a process that determines the nucleotide sequence of an entire genome