1. Introduction to Genetics
Chapter 11
Introduction to Genetics

2. Who was Gregor Mendel? He was known as the “FATHER OF GENETICS”
He discovered how traits were inherited
GENETICS – study of heredity
HEREDITY – the passing of traits from parents to offspring

3. Mendel’s Peas Mendel did his study on pea plants
Pea plants have many traits (tall/short, purple flowers/white flowers)
Pea plants can be self-fertilized or cross-fertilized

4. Types of Plants
True-Breeding - these plants always create plants that look like themselves
Hybrids – offspring of true-breeding plants
Tall x Short = Hybrid

5. Dominance Some traits are dominant over others.
Why you ask? That’s a great question. Lets do some reading.
Tall x Short = all tall offspring (hybrids)
*Tall is the dominant trait
* Short is recessive

6. Genes and Alleles
Mendel discovered that each trait is controlled by two factors (alleles)
Genes – factors that determine your traits (chunks of DNA that code for proteins)

7. Mendel’s Experiments
Draw the crosses

8. Explaining the Cross
When a parent makes sperm or eggs, their genes separate         (PRINCIPLE OF SEGREGATION)
The GAMETES (egg or sperm) contain either a T allele (tall) or a t allele (short)

11. GENOTYPE  -  what genes, letters, the organism has (TT, Tt, tt)
PHENOTYPE   - what it looks like (tall or short)

12. Let's review what you know about genetics......

13. 3. Are these offspring the F1 or F2 generation?
Check for understanding
1.  A one-eyed purple people eater is crossed with a two eyed purple people eater.  All of their offspring have two eyes.   Which trait is dominant?
2.  Use the letter E for this gene.   What is the genotype of the offspring? 
    3. Are these offspring the F1 or F2 generation?
4.  If you crossed the offspring with each other, how many ofthe new offspring would you expect to have two eyes?

14. 6. Who was the father of genetics? __________
More checking
5.   The passing of traits from parents to offspring is known as  ___________________________
6.  Who was the father of genetics?  __________
7.  A single gene will code for a _______________, such as flower color.
8.  Every gene is made of two ______________