Module 3.1 Flashcards
the patterns in which single-gene traits and disorders occur in families.
Modes of inheritance
Affects both sexes and appears in every generation
autosomal dominant
Affects both sexes and can skip generations
through carriers
autosomal recessive
a piece of DNA that encodes a
particular trait
Gene
an alternate form of a gene
Allele
expressed whether alone or in pairs.
Symbolized by a capital letter; ONE THAT
MASKS the expression of recessive trait
Dominant allele
expressed only in the absence of a dominant allele. Symbolized by lowercase; ONE THAT IS BEING MASKED
Recessive allele
the genetic composition of an individual (Ex. TT, tt,
Tt)
Genotype
grade of similarity between alleles that determine one specific trait in an organism
Zygosity
contains a pair of the same allele
Homozygous
two recessive alleles
Homozygous recessive
two dominant alleles
Homozygous dominant
contains two different alleles
Heterozygous
- the physical expression of a gene or allele
Phenotype
Most common phenotype
Wild Type
Variant of a gene’s expression that arises when the gene undergoes mutation
Mutant phenotype
A plant, that when self fertilized, only produces offspring with the same traits
True-breeding
a specific characteristic, such as seed color or plant height, that varies from one individual to
another
trait
One allele of the same gene masks the other
allele at the same locus
Law of Dominance and Recessiveness
Principle that the maternal and paternal alleles for a trait
separate from one another during gamete formation
Law of Segregation
*A graph or chart that illustrates predictions of all
possible gene combinations in a cross of parents
Punnett Square
*Simplest
* Involve only 1 characteristic
Monohybrid Cross
The inheritance of one does not influence the
chance of inheriting the other
Law of Independent Assortment
Study of inheritance patterns for organisms differing in two characteristics
Dihybrid Cross
application of probability theory that can predict the chance that parents with known genotype can produce offspring of a particular genotype
Product Rule
