1. Discovered Modern Genetics
Gregor Mendel:
Discovered Modern Genetics

2. I never know the words genetics, chromosomes or genes
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.

3. I went to work in my little garden and 20 years later, I knew how inheritance worked.

4. 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.

5. 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.

6. Traits of Pea Plants Height Seed Color Seed Coat Color Pod Color
Round/wrinkled seed
Pod appearance
Flower position on stem

7. 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

8. Parents F1 F2
Actual
ratio
Probability
In your journal, make a five column table and write in headings as listed above.

11. What results when you cross 2 of the offspring tall plants?

12. 3 tall plants for every
1 short plant

15. What results when you cross 2 of the offspring round seed plants?

16. 3 round seed plants for every
1 wrinkled seed plant

25. Let’s look at a few numbers.
Write them in your table.

26. Tall x short Tall 787 Tall 277 Short 2.84:1 3:1 Green Pod X Yellow Pod
Parents F1 F2
Actual
ratio
Probability
Tall x short
Tall
787 Tall
277 Short
2.84:1
3:1
Green Pod
X Yellow Pod
Green
428 Green
152 yellow
2.82:1

27. Yellow seed x Green seed Yellow 6,022 Y 2,001 G 3.01:1 3:1 Round Seed
Parents F1 F2
Actual
ratio
Probability
Yellow seed x
Green
seed
Yellow
6,022 Y
2,001 G
3.01:1
3:1
Round Seed x
Wrinkled
Seed
Round
5,474 rd
1,850 wr
2.96:1

28. 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)

29. Words to know
Pure (refers to dominant) The letters are the same (TT, RR)
Hybrid The letters are different (Tt, Rr)

30. 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

31. Thank you ,
Mr. Mendel!