Transcript Intro to Genetics Notesx

Genetics
Part
1
You have your genes to thank
– or blame for how you look
• Genes are
your body's
instruction
manual.
• They affect the
way you look,
your health,
and the way
your body
works.
Heredity is the passing on of
characteristics from one generation
to the next.
• Genetics is the study
of heredity. The
scientists that study
heredity are called
geneticists.
Genes and Inheritance
• Your genes are unique –
unless you have an
identical twin.
Genes and Inheritance
• Half of your genes you get from your
mother and the other half from your
father,
• You will give half of yours
to your children.
DOMINANT & RECESSIVE
• Certain genes are
dominant, and you only
need one of the pair to
give you its trait.
• Dominant genes mask
recessive genes.
• Dominant genes are
represented as capital
letters and recessive
genes as lower-case
letters.
Some
Human
Traits
Some
Human
Traits
6 Fingers
and
Toes
Are Dominant
Genotype
vs
Phenotype
• Genotype
is the actual
genetic
combination
an individual
has for a trait
• Phenotype
the physical
expression of
the genes
Homozygous vs. Heterozygous
• If the alleles in the genotype are both the
same, they are called homozygous.
Examples would be BB (brown eyes) OR
bb (blue eyes).
Homozygous vs. Heterozygous
• If the alleles in the genotype are different,
they are called heterozygous. Examples
would be Bb (Brown eyes). Organisms
with a heterozygous genotype (Tt) will
never exhibit or show the recessive trait
because it is hidden (masked) by the
dominant.
Alleles
• Are all the
possible
genes for a
trait
The Gene Locus
• Is the location
of a gene on
the on the
chromosome
Let’s check your understanding
with……….
A Game of X’s and O’s
1
2
4
7
3
5
8
6
9
Scoreboard
1
2
3
X
4
5
6
O
7
Click Here if
X Wins
Click Here if
O Wins
8
9
1
What structure on chromosomes
carry the instructions for a trait?
1
Home
Genes
2
What is the passing of characteristics
from one generation to the next?
2
Home
Heredity
3
What is the study of heredity?
3
Home
Genetics
4
True or False: You get all of your
genes from your mother.
4
Home
False
5
You must have two of these genes
in order for it to be expressed.
5
Home
Recessive
6
All the possible genes for a trait
6
Home
Allele
7
The location of a gene on a
chromosome
7
Home
Locus
8
True or False: The color purple is an
example of genotype
8
Home
False
9
True or False: Dominant genes are
represented by capital letters
9
Home
True
Adapted From
Presentation
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