Chapter 14 Second half Flashcards
Chromosome theory of inheritance
States that genes are found at specific locations on chromosomes and the behavior of chromosomes during meiosis can explain Mendel’s law of inheritance.
Who studied fruit flies and provided the first strong confirmation of chromosome theory
Thomas Hunt Morgan
Wild type
Common phenotypes
Mutation
heritable trait in a gene
Mutant
An individual that carries a mutation, particularly a new or rare mutation
Who figured out that the genes are on chromosomes
Walter Sutton and Theodor Boveri
X linked gene
Gene located on the X chromosome
Y linked gene
Gene located on the Y chromosome
X-linked inheritance (X linkage)
Inheritance patterns for genes located on X chromosome
Sex linked genes
gene located on either sex chromosome
Y linkage
Inheritance patterns for genes located on the Y chromosome.
Sex-linked inheritance
Inheritance patterns observed in genes carried on sex chromosomes.
Autosomal inheritance
The inheritance patterns that occur when genes are located on autosomes rather than on sex chromosomes.
Linkage
Tendency of alleles of particular genes to be inherited together
Difference between linkage and sex linkage
Linkage refers to two or more genes on the same chromosome
Sex linkage can refer to a single gene located on a sex chromosome
Recombinant
Possessing a new combination of alleles
Multiple allelism
Existence of more than two common alleles of the same gene
Complete dominance
when one allele is fully dominant over the other
Codominance
neither gene is dominant over the other
Incomplete dominance
both alleles of a gene at a locus are partially expressed, often resulting in an intermediate or different phenotype
Pleiotropic
Gene that influences many raits
Gene interaction
Interactions of two or more genes that effect a trait
Epistasis
one gene influences the expression or function of another gene, often masking its effects
Environmental effects
Anything that influences phenotypes other than the genotype, examples are temperature, sunlight and nutrient availability.
Discrete traits
Traits that are clearly different from each other
Quantitative traits
Quantitative traits are greatly influened by the environement
Polygenic traits
Any trait that is influenced by more than one gene
Polygenic traits are usually quantiative traits
Five basic modes of inheritance for single-gene diseases:
autosomal dominant, autosomal recessive, X-linked dominant, X-linked recessive, and mitochondria
Carriers
Heterozygous individuals who do not have an inherited disease but carries a recessive allele for it.
Autosomal recessive alle
Individuals with the trait must be homozygous
If the parents of an affected individual do not have the trait, then both parents are heterozygous for the trait
Autosomal Dominant trait
only one parent needs to have an altered gene to pass it on.
