Download Mendel`s Experiments

Gregor Mendel:
Discovered Modern
Genetics
I never know the
words genetics,
chromosomes
or genes. DNA
wouldn’t be
discovered for
over 100 years.
No one knew
how traits were
passed down.
I went to work in
my little garden
and 20 years
later, I knew how
inheritance
worked.
• Born July 22, 1822
• Entered the Augustinian monastery at
Brünn, Czech Republic.
• Carefully analyzed seven pairs of seed
and plant characteristics of peas.
• Between 1856 and 1863 he cultivated
and tested at least 28,000 pea plants.
• Published his important work on
heredity in 1866.
• Experiments resulted the laws of
heredity
• His work not used for the next 34 years.
• In 1900, his work recognized by three
investigators.
• He died in January 6, 1884.
Traits of Pea Plants
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•
•
Height
Seed Color
Seed Coat Color
Pod Color
Round/wrinkled seed
Pod appearance
Flower position on stem
What he did…
•
•
•
•
•
•
•
Began with pure-breeding plants
Crossed plants with different traits
Planted resulting peas
Examined offspring plants
Wrote down ALL observations
Did the math
Wrote the laws of inheritance
Parents
F1
F2
Actual
ratio
Probability
In your journal, make a
five column table and
write in headings as
listed above.
What results when
you cross 2 of the
offspring tall
plants?
3 tall plants for
every
1 short plant
What results when
you cross 2 of the
offspring round
seed plants?
3 round seed plants
for every
1 wrinkled seed
plant
Let’s look at a few numbers.
Write them in your table.
Parents
Tall x
short
Green
Pod
X Yellow
Pod
F1
F2
Actual
ratio
Tall
787 Tall
277 Short
2.84:1
3:1
428 Green
2.82:1
152 yellow
3:1
Green
Probability
Parents
Yellow
seed x
Green
seed
Round
Seed
x
Wrinkled
Seed
F1
F2
Actual
ratio
Yellow
6,022 Y
2,001 G
3.01:1
3:1
Round
5,474 rd
1,850 wr
2.96:1
3:1
Probability
Words to know
Gene
The DNA on the chromosomes.
Allele or Alleles
The letter(s) we use to represent genes
Genotype
The letter combinations (like TT, Tt, tt)
Phenotype
What you actually see (like tall or short)
Words to know
Pure
(refers to dominant)
The letters are the same (TT, RR)
Hybrid
The letters are different (Tt, Rr)
Words to know
Homozygous
(refers to dominant)
The letters are the same (TT, RR)
Heterozygous
The letters are different (Tt, Rr)
The same as hybrid
Thank you ,
Mr. Mendel!