1. Fundamental Genetics

2. Intro to genetics
Genetics - A branch of biology that deals with heredity and variation of organisms.
Heredity, also known as inheritance, is the passing of traits to the next generation.
Chromosomes carry the heredity information
DNA RNA Protein

3. Gregor Mendel Austrian Monk Began his research in 1860 Used pea plants
father of genetics
Austrian Monk
Began his research in 1860
Used pea plants
He concluded that characteristics (traits) are determined by discrete factors
Discrete Factors = Genes

4. Self-fertilization produces true breeding generations
Why Peas?
Self-fertilization produces true breeding generations
Female parts
Male parts

5. Why pea plants? Pea plants self-pollinate
Fertilization occurs with female gametes uniting with male gametes of the same flower.
Mendel could easily manipulate the plants by cross-pollinating.

6. Why Peas?

7. Chromosomes & Genes Characteristics (traits) are determined by genes.
These genes are found on homologous chromosomes.
As crossing over occurs, new combinations of genes are formed

8. Genes & Alleles
Genes – A unit of heredity; a specific section of DNA that codes for a single protein.
Alleles – Two genes that occupy the same position on a homologous chromosome, and cover the same trait.

9. Mendel’s Work Traits are passed on by factors (genes)
Factors (genes) have more than 1 form called alleles
There are at least 2 alleles for each trait

10. Law of Segregation
Mendel found that two alleles for each trait separate during meiosis.
The two alleles unite during fertilization.

11. Law of Independent Assortment
Random distribution of alleles occurs during gamete formation
Genes on separate chromosomes sort independently during meiosis
Each combination is equally likely to occur.

12. Generations The parent generation is also known as the P generation
The offspring of this P cross are called the first filial (F1) generation.
The second filial (F2)
generation is the offspring from the F1 cross.

13. Dominant & Recessive
A characteristic that is expressed (seen) is labeled as dominant.
A characteristic that is masked (unseen) is labeled as recessive.
Yellow = Dominant
Green = Recessive

14. Mendel’s Work
Alleles are represented by the first letter of the dominant trait
Pea plant flower color (trait)
Purple or white
Purple is dominant over white
Alleles are represented as
P=purple p=white

15. Which is Dominant/Recessive?

16. Which is Dominant/Recessive?
Black = Dominant White = Recessive

17. Dominant & Recessive We use capital letters to show dominance
For example – T, R, B, D, A
Y = dominant yellow pea
We use lower case letters to show recessive traits
For example – t, r, b, d, a
y = recessive green pea

18. Homozygous & Heterozygous
An organism with two of the same alleles for a particular trait is homozygous.
Homo = Same
TT, rr, BB, DD, aa
An organism with two different alleles for a particular trait is heterozygous.
Hetero = Different
Tt, Rr, Bb, Dd, Aa
Heterozygous organisms are known as hybrids.
Ex. Liger
Homozygous
Heterozygous
Heterozygous
Homozygous

19. If bb is the allele pair for being tall, then:
Phenotype & Genotype
An organism’s allele pairs are called its genotype.
TT, Rr, bb
The observable characteristic or outward expression of an allele pair is called the phenotype.
Tall, Short, Round
If bb is the allele pair for being tall, then:
bb = genotype
being tall = phenotype

20. Monohybrid Cross- tool used to predict the traits of a cross between 2 parents
A cross that involves hybrids for a single trait is called a monohybrid cross.
Crossing two heterozygous organisms:
Yy x Yy
Tt x Tt
Rr x Rr
Dihybrid- cross 2 traits