heredity
Passing traits from parent to offspring
Genetics
The study of heredity and variation in organisms
The genetic material which determines the traits of
the organism, found in the nucleus of the cells
DNA
Chromosomes
Threadlike strands of DNA and proteins that code for
the traits of the organism
Gene
A distinct unit of hereditary material on the
chromosome
Allele
Different forms of a gene controlling a particular trait
Dominant allele The form of a gene that can mask the recessive allele.
The form that is expressed or “shown.”
T
Recessive allele The form of a the gene that can be masked or hidden
by the dominant allele.
t
Heterozygous
An organism that has two different allele for a trait.
Tt
Homozygous
TT tt
Genotype
Phenotype
Purebred
TT tt
An organism that has two of the same alleles for a
trait.
The genetic makeup of an organism.
The physical traits of an organism. What is seen.
Homozygous, has two of the same alleles for a trait.
Hybrid
Heterozygous, has two different alleles.
Tt
Punnett Square A diagram to show the possibilities of traits for the
offspring of “parents”.
Cross
Punnett square, showing the possibilities of traits
combining for offspring from the parents.
Probability
The chance or percentage of offspring having certain
traits.