1. Genetics
Chapter 2 Section 2

2. The passing of traits from parents to offspring
What is genetics?
The passing of traits from parents to offspring
Also referred to as heredity

3. Why is studying genetics important?
Allows us to understand how traits are passed from generation to generation
Allows us to understand how traits change over time
Treatments and cures for diseases can be developed

4. First scientist to determine the basic principles of genetics
Who is Gregor Mendel?
Father of Genetics
Austrian monk
First scientist to determine the basic principles of genetics
Without the knowledge of DNA and chromosomes

5. What is an allele?
Alternate forms of the same gene
Each trait of an individual is determined by two alleles
Results in dominant and recessive traits

6. What makes a trait dominant?
Alleles will show their effect on phenotype whenever they are present
Represented by a capital letter
Homozygous—TT
Heterozygous—Tt

7. What makes a trait recessive?
Alleles will only show their effect on phenotype when both alleles are present
Represented by lower case letter
Always homozygous—tt

8. What is the principle of segregation?
States that each parent passes only one of the alleles for a trait to its offspring
Explains variation among offspring
Why you don’t look exactly like your sibling

9. How are traits passed from parents to offspring?
Suppose that a parent has three pairs of chromosomes with a different trait on each pair.
The traits can be called A, B, and C.

10. Each trait has two different alleles—A and a, B and b, and C and c.
Parent can pass down any combination of these three alleles to their offspring
This example has 8 different possible combinations

11. What is a Punnett square?
A Punnett square is a model that is used to predict the possible offspring of crosses between different organisms of known genotypes

12. Punnett square practice with SpongeBob !!