Human Traits
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Transcript Human Traits
Intro to
Genetics
Human Traits
How
do we get our traits? Why are we tall, short,
blonde? What makes us…us?
Genetics
Every
living thing – plant or animal, microbe or human being –
has a set of characteristics inherited from its parent or
parents.
Since
the beginning of recorded history, people have wanted
to understand how inheritance is passed from generation to
generation
What is Genetics?
Genetics Heredity Traits-
branch of biology that studies heredity
passing of traits from parents to offspring
Characteristics that are inherited through DNA
Gregor Mendel
Gregor
Mendel - an Austrian monk, “Father of Modern
Genetics”
Mendel
He
was born in 1822 in what is now the Czech republic
studied to be a priest and spent several years studying
science and math
Gregor Mendel
Mendel
spent many years of his life
working in the local monastery and
teaching high school.
While
there, Mendel was in charge
of the garden and spent much of
his time tending to and studying
the plants around him.
Observations
Mendel
observed seven traits in pea plants that only
occurred in two forms. (Shape, color, size…)
Why these traits?
Were
How
these genetic or environmental factors?
did pea plants pass their traits?
Pea Plants
Pea
plants reproduce sexually. (Require both male and
female sex cells)
Gamete
half of the chromosomes
Somatic
= sex cell.
Cell = the “regular” cells in your body.
full set of chromosomes
Experiments
Mendel
forced pea plants with different traits to pollinate each
Wanted
to see how offspring compared to parents.
other.
The
experiments are called genetic crosses
Genetic Portraits
Genetic Portraits
Offspring
Mendel
noticed that many times the second
generation plants showed different traits from the
parents
Genetic Vocabulary
Phenotype=
the physical characteristics of an
organism. (Purple flowers or white flowers)
Genotype=
the gene combination of an organism
that determines its phenotype.
Alleles
Allele
= the specific form of a trait/gene. We have two alleles
for each trait in our DNA.
(Ex: Brown eye or blue eye gene / purple or white flower)
Dominant
Allele = observable trait requiring only one allele to
be expressed.
(Written as a capital letter)
Recessive
Allele = allele that is not observed when a
dominant allele is present in the genes. Can be hidden.
(Written as a lower case letter)
Allele Pairing
Homozygous
= two alleles for a trait are the same.
(Ex: BB or bb )
Heterozygous
= two alleles for a trait are not the same.
(Ex: Bb)
Dominant trait will be observed.
Science Show - Gregor Mendel
100 Greatest Discoveries Mendel (First section)
Chromosome – Gene – Allele – Protein – Trait