Genetics
&
Heredity
Who was Gregor Mendel?
Who was Gregor Mendel?
• Austrian monk who studied
mathematics and science
• As a boy he could predict the
possible types of flowers and
fruits that would result from
crossbreeding two plants in his
father’s garden
Who was Gregor Mendel?
• Curiosity about the connection
between the color of a pea flower and
the type of seed that same plant
produced inspired him to begin
experimenting with garden peas in
1856.
• Made careful use of scientific
methods, which resulted in the first
recorded study of how traits pass
from one generation to the next.
What is GENETICS?
What is GENETICS?
The study of how traits are
inherited through the
interactions of genes.
What is a GENE?
What is a GENE?
• The material that controls
which traits are expressed
in an organism
• Genes come in pairs and
offspring inherit one copy
of each gene from each
parent
Define the following terms:
• Heredity
• Allele
• Trait
Define HEREDITY
The passing of traits from
parent to offspring
Define ALLELE
• The different forms of a
trait that a gene may have
• One form of a gene
Define TRAIT
• Characteristics – can be
physical or behavioral
• Traits that are genetic
are passed down through
the genes from parents to
offspring
Describe RECESSIVE
Describe RECESSIVE
• A trait that is covered over,
or dominated, by another
form of that trait and seems
to disappear
• Hidden when the other copy
of the gene contains the
dominant allele.
• A recessive allele shows up
only when there is no
dominant allele present
• Shown with a lower-case
letter
Describe DOMINANT
Describe DOMINANT
• A trait that covers over,
or dominates, another
form of that trait
• Trait that always shows
up, even when only one of
the two alleles is in the
dominant form
• Shown by a capital letter
Define GENOTYPE
Define GENOTYPE
An organism's genetic makeup
Define PHENOTYPE
Define PHENOTYPE
Outward physical appearance
and behavior of an organism
Heredity
• Traits are controlled by alleles on
chromosomes
• An allele’s effect is dominant or
recessive