Inheritance
The process of physical traits being
passed on from one generation to the
next
The Blending Theory of Inheritance
Sperm and egg combine resulting in a
blend of parental characteristics
Traits
Distinguishing characteristics that make
up a unique individual
Gametes
A mature haploid male or female germ
cell that can unite with another of the
opposite sex in sexual reproduction to
form a zygote.
Charles Darwin
English natural scientist who
formulated a theory of evolution by
natural selection
Gregor Mendel
Augustinian monk and botanist whose
experiments in breeding garden peas
led to his eventual recognition as
founder of the science of genetics
Monohybrid cross
A mating between two organisms with
different variations at one genetic
chromosome of interest.
Purebred
Offspring resulting from a true breeding
True breeding
A cross that will only produce a certain
phenotype
Parent generation
The first set of parents crossed in
which their genotype is the basis for
predicting the genotype of their
offspring
Filial generation
A generation in a breeding experiment
Hybrid
Carries two different alleles of the
same gene
Dominant
An allele or a gene that is expressed in
an organism's phenotype, masking the
effect of the recessive allele or gene
when present.
Recessive
A gene that can be masked by a
dominant gene
Latent
Being in a condition of biological rest or
inactivity
Principle of dominance
When individuals with contrasting traits
are crossed, the offspring will express
only the dominant trait
Law of segregation
Inherited traits are determined by pairs
of factors, which segregate, or separate
in the gametes (sex cells), with one in
each gamete
Mendelian ratio
The F2 generation resembled one
parent from the P generation 75% of
the time, and the other parent only 25%
of the time
Genes
The part of the chromosome that
regulates the expression of a trait
Alleles
A gene that occurs in alternate forms
Homozygous
When both alleles in a gene are the
same.
Heterozygous
When alleles in a gene are different
Punnett square
A square diagram that is composed of
a grid of usually four boxes and is used
to calculate and depict all the
combinations and frequencies of the
different genotypes and phenotypes
among the offspring of a cross
Genotype
Genetic make-up of the organism
Phenotype
Physical characteristics of the organism