Transcript Medelian Genetics

Who is the Father of
Genetics?
Mendel
a type of gene that is hidden
by a dominant gene
Recessive
used to show the possible
gene combinations in a cross
between two organisms
Punnett Square
Punnet Squares
• What tools can we use to predict each generation?
• Simplest tool is a Punnet Square
A
A
a
a
Parents
A
a
A
AA
Aa
a
Aa
aa
a gene responsible for
determining traits in an
organism
Allele
chromosomes that do not
determine the sex of a
person
Autosome
HH
Homozygous
Dominant
pattern where the phenotypes of
both homozygous parents are
present in heterozygous
offspring; both alleles are
equally expressed
Codominant
Alleles
the stronger trait in a gene
pair
Dominant
union of a sperm and egg
Fertilization
the branch of biology that
studies heredity and variation in
organisms
Genetics
an organism's genetic makeup, or
allele combinations
Genotype
an organism that has two
different alleles for a single trait,
for example (Hh)
Heterozygous
two of the same alleles for a
trait, for example (HH)
Homozygous
an organism that is heterozygous
for a particular trait
Hybrid
a genetic pattern in which
neither of the two forms of a
trait completely masks the other
Incomplete
Dominance
any chromosome other than
a sex chromosome
Autosome
a picture of all the
chromosomes in a cell
arranged in pairs
Karyotype
having more than two alleles
that control a trait
Multiple
Alleles
a chart or "family tree" that
tracks which members of a
family have a particular trait
Pedigree
what an organism looks like
as a consequence of its
genotype
Phenotype
transfer of pollen from the
anther to the stigma of a
plant
Pollination
hh
Homozygous
Recessive
occurs when groups of gene
pairs act together to produce
a specific trait
Polygenic
Inheritance
a trait that will be masked by
more dominant trait
•Recessive
a trait that will be masked by
more dominant trait
What part of the
flower does the
pollen land on?
Anther
Stigma
Fig. 10.01
What is the function of
the
Anther?
To make pollen
Black (BB)
Crossed with
Brown (bb)
If homozygous
Black (BB)
Homozygous
Brown (bb)
If heterozygous
Black (Bb)
Homozygous
Brown (bb)
Gametes
All Bb
All offspring are black and heterozygous
(a)
(b)
Fig. 10. 06
X and Y chromosomes that
determine the sex of an
individual
Sex
Chromosome
What are the female
Sex Chromosomes
XX
What are the male
Sex Chromosomes
XY
characteristics that are
inherited, such as your
eye color
Traits
heterozygous offspring show a
phenotype that is in between the
phenotypes of the two
homozygous parents
Incomplete
Dominance
Hh
Heterozygous
(Also called)
Hybrid
Punnett Square
b
B
B
b
b
b
B
Bb
Bb
B
Bb
Bb
How many traits are
in a di-hybrid cross
two
Dihybrid Crosses With Guinea Pigs
• The first cross,
considering
two genes in
true-breeding
parents, has
predictable
outcome
• All dominant in
the F1
cross a red (RR)
and a
white (WW)
flower
W
R
R
W
W
W
R
RW
RW
R
RW
RW
What type of cross
Created pink
flowers?
Incomplete
Dominance
Cross two pink
flowers
R
W
R
RR
RW
W
RW
WW
What is the
Phenotype ratio?
1 red:2pink:1white
Cross to
checked
chickens (BW)
B
W
B
BB
BW
W
BW
WW
What is the
Genotype ratio?
1BB:2BW:1WW
What type of cross
produces
checkered chickens
Co-Dominance
Blood type is
What type of
inheritance ?
Multiple
Alleles
How many
Alleles are there
for blood type?
There are 3
A, B, and O
What blood types
are possible
A, B, AB and O
What blood type
is recessive
Type O
Cross type O
With type AB
AO
B
BO
BO
Probability is
The chance that an
event will occur