Chapter 20 Pt. 1 Flashcards
What is a gene?
directs the synthesis of a specific protein that can play either a structural or a functional role in the cell
What are alleles?
different versions of a gene
________ produce different versions of the trait they determine
alleles
What is the difference between homozygous and heterozygous alleles?
homozygous-individuals with two copies of the same allele of a gene
heterozygous- individuals with different alleles of a given gene
homozygous:
homo=______
zygo= _______ ________
same
joined together
heterozygous:
hetero=_________
zygo= ________ _________
different
joined together
What is the difference between dominant and recessive alleles?
dominant allele- when the effects of a certain allele can be detected regardless of whether an alternative allele is also present
recessive allele- an allele whose effects are masked in the heterozygous condition
What are the designated signs for dominant and recessive alleles?
dominant allele-capital letter
recessive allele-lowercase letter
What is a genotype?
the precise set of alleles a person possesses for a given trait or traits
The ________ tells us whether the individual is homozygous or heterozygous for a given gene
genotype
The genotype tells us whether the individual is ___________ or ____________ for a given gene
homozygous
heterozygous
What is a phenotype?
the observable physical trait or traits of an individual
What is the law of segregation?
during the production of gametes the two copies of each hereditary factor segregate so that offspring acquire one factor from each parent
The ____ ___ ___________, explains how, for every gene in our chromosomes, one of the alleles comes from our mother, and one comes from our father
law of segregation
What is the law of independent assortment?
when two or more characteristics are inherited individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together
The ____ __ ____________ __________, explains why the mixture of alleles that came from the mother, and alleles that came from the father, is different in every gamete
law of independent assortment
_______ _______ is a monk, whose ideas are used today to predict the outcome of hereditary crosses
Gregor Mendel
What is a one-trait crosses?
consider the inheritance of a single trait
What is a Pungent Square?
a diagram used to predict the genetic makeup of the offspring of individuals of particular genotypes
What does a Pungent Square diagram look like?
columns are set up and labeled to represent each of the possible gametes of one parents
What are two-trait crosses?
predict the probable outcome for inheritance of two traits of interest
What is a dihybrid cross?
a mating of individuals who are both heterozygous for two traits of interest
