Transcript Genetics

Genetics
The study of genes and the
inheritance of traits
What is Genetics?
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Genetics is the science
of genes and how traits
are passed on from one
generation to the next.
Everything Has DNA!
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DNA is an amazing
chemical present in
every cell. It contains
all the information
cells need to make a
fish a fish, or you
YOU.
DNA influences many
individual traits, such as
whether you are a boy
or a girl and whether
you are tall or short.
DNA is made up of Genes
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Where do traits, such
as eye color and
shape, come from?
Why do you look more
like your relatives
than other people?
The parts of your
cells that determine
these traits are
called genes
DNA is made up of Genes
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Genes come in pairs.
You get half of
your genes from
your mother, and
the other half
from your father.
Human Genes
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Today, scientists are
studying human genes
to learn about traits
and diseases.
There are so many
genes in humans — at
least 30,000 of them
— that it will take a
long time to study
every one in detail and
find out what it does.
Gregor Mendel
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Gregor Mendel was the
“Father of Modern
Genetics”
Personal history
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Austrian monk
Teacher of high school natural
science- love of evolution,
nature, meteorology
“for the fun of it”: crossed
peas and mice- saw inheritance
patterns
Pea plants- a formal test
Characteristics
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These are features
you exhibit
physically
( your looks)
Example: Eye color green
Traits
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The different
versions of a
characteristic
Example: blue,
green, and brown
eyes
Inheritance
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Occurs when traits
are passed down
from parent to child.
Genes
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Bits of genetic
information passed
down from parent to
child.
Made of chemicals
called DNA.
Genetic Diseases
Can be passed on through
genes from a parent to
the child.
 Example : Marfan
Syndrome
(Individual is tall, has
long arms and legs, may
have arthritis and heart
problems)
Ex: Abraham Lincoln
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Reproduction
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Sexual – Sperm
fertilizes an egg to
produce offspring
Asexual – occurs
when 1 organism
copies itself to
produce offspring
Fertilization
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Occurs when a
sperm unites with an
egg
Offspring
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Another name for
the children of a
male and female
parent
Mutation
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Occurs when genes
make a mistake
mixing and produce
new or different
traits in the
offspring.
Genotype
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bb
BB
Example: BB, Bb, or bb
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Bb
A combination of
alleles inherited from
both parents
B is dominant for
black fur,
b is recessive for
brown fur
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BB = black fur
Bb = black fur
bb = brown fur
Phenotype
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They are the
traits expressed
by reading the
genotype.
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Black, brown or
Golden
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“T” – is considered a
dominant allele
Alleles
“t” – is considered a
recessive allele
TT – is dominant
The dominant allele
is stronger than the
recessive allele and
is the characteristic
that is expressed.
Tt or tT – is dominant
tt - is recessive
Allele types
Homozygous
 Both alleles are
identical
 tt, TT
Heterozygous
Both alleles are
different
 Tt, Dd