Unit 5 Chapter 11Fundamentals of Genetics

Section 11.1

Mendel’s Legacy

1. Genetics: study of how traits & characteristics are transferred from parent to _________

2. Gregor Mendel: “Father of Genetics”

3. Combined a) Plant breeding

b) Statistics

c) Careful recordkeeping

I) Gregor Mendel

1. Mendel experiment a. garden peas with 7 characteristics to see

which trait would be passed to offspring

2. Traits: specific inherited characteristicsa) Example: Characteristic:

Trait:

II) Mendel’s Experiment

II) Mendel’s Experiments

3. Mendel started growing peas that were pure for each trait

a. Pure:

b. Mendel self-pollinated the peas until:

c. P1 generation:

3. Mendel controlled the reproduction of the plants (___________)

4. Pollination: pollen from reproductive parts of one flower is mixed w/ another flower

II. Mendel’s Experiment

5. Self-pollination: mixing with the same plant/flower

6. Cross-pollination: mixing anther a different plant/flower

II. Mendel’s Experiment

II. Mendel’s Experiments

7. Cross Pollinated:a) Ex: Characteristic: Plant Height

b) Trait: Short x Tall

c) Mendel recorded the results & called the offspring the F1 generation

P1 generation:

Pure Green x Pure Yellow = __ generation

Example

II. Mendel’s Experiments

7) Mendel then crossed two F1 generation seeds

P1 generation:

Pure Green x Pure Yellow = __ generation

F1 generation x F1 generation =

____ generation

Example

1. there was a “factor” in pea controlling the traits

2. results varied btwn 2 traits he felt that the “factor” came in pairs

III) Mendel’s Results and Conclusions

P1 generation: Pure Green, Pure Yellow

Pure Green x Pure Yellow = F1 generation

F1 generation: 2 Green

F1 gen. x F1 gen. = F2 generation

Green x Green = 3 Green + 1 Yellow

F2 generation: 3 Green + 1 Yellow

Example

1. Mendel saw that one P1 trait would not show in the F1, and reappear in F2

a. Dominant: factor that would dominated and mask the other trait

b. Recessive: factor that could be masked by a dominant trait

III. Recessive and Dominant Traits

IV. Mendel’s Laws

1. Law of Segregation: a pair of factors is segregated, or separated, during the formation of gametes

IV. Mendel’s Laws

2. Law of Independent Assortment: factors for different characteristics are distributed to gametes independently

1. Molecular Genetics: study of structure and function of chromosomes and genes

2. Genes are in pairs or alleles

3. Alleles are represented by lettersa. Dominant: Uppercase

b. Recessive: Lowercase

V. Chromosomes and Genes