1. Mendelelian Genetics (pgs.262-273)
Mendelian Genetics
5/23/2019
Mendelelian Genetics (pgs )

2. Responsible for the Laws governing Inheritance of Traits
Gregor Mendel ( )
Responsible for the Laws governing Inheritance of Traits

3. Gregor Johann Mendel Austrian monk
Studied the inheritance of traits in pea plants
Developed the laws of inheritance
Mendel's work was not recognized until the turn of the 20th century

4. Mendelian Genetics
5/23/2019
Gregor Johann Mendel
Between 1856 and 1863, Mendel cultivated and tested some 28,000 pea plants
He found that the plants' offspring retained traits of the parents
Called the “Father of Genetics"

5. Eight Pea Plant Traits Seed shape --- Round (R) or Wrinkled (r)
Seed Color ---- Yellow (Y) or  Green (y)
Pod Shape --- Smooth (S) or wrinkled (s)
Pod Color ---  Green (G) or Yellow (g)
Seed Coat Color ---Gray (G) or White (g)
Flower position---Axial (A) or Terminal (a)
Plant Height --- Tall (T) or Short (t)
Flower color --- Purple (P) or white (p)

8. Mendel’s Pea Plant Experiments

9. Mendel’s Experiments
1. He crossed true breeding parents (P Generation):
Tall x short
AA x aa
2. He counted the offspring produced in the first generation (first Filial or F1). Findings: the offspring were always the same (They all expressed the same trait- TALL). They were all Aa.

10. 3. The F1 offspring were then crossed with each other.
Aa (tall) x Aa (tall)
The second generation of offspring are called the F2 Findings: 3:1 ratio, 3 offspring would express the same trait (TALL) as their parents and 1 offspring would look like one of the grandparents(SHORT)
(3 Tall : 1 short)

11. GENES DIDN’T DISAPPEAR
2 things learned
SOME GENES ARE DOMINANT OVER OTHER ONES.
GENES DIDN’T DISAPPEAR

12. Genetic Terminology
Alleles - two forms of a gene (dominant & recessive)
Represented by two letters,
AA, Aa, aa

13. Dominant - stronger of two genes expressed in the hybrid; represented by a capital letter (R)
Recessive - gene that shows up less often in a cross; represented by a lowercase letter (r)

14. Homozygous – two identical alleles (e. g
Homozygous – two identical alleles (e.g. AA, aa) also called purebred Heterozygous – two different alleles (e.g. Aa) also called hybrid Genotype- genetic makeup of an of an organism (letters) Phenotype- physical make up of an organism

15. Parental P1 Generation = the parental generation in a breeding experiment.
F1 generation = the first-generation offspring in a breeding experiment. (1st filial generation)
From breeding individuals from the P1 generation
F2 generation = the second-generation offspring in a breeding experiment. (2nd filial generation)
From breeding individuals from the F1 generation

16. Punnett Square
Used to help solve genetics problems

18. DIHYBRID CROSSES
A cross (or mating) between two organisms where two genes are studied is called a DIHYBRID cross.

19. BEYOND DOMINANT & RECESSIVE
Some alleles are neither dominant nor recessive and many traits are controlled by multiple alleles or multiple genes.

20. Incomplete Dominance
One allele is not completely dominant over another.
R = Red
W = White

21. Both alleles contribute to the phenotype.
Codominance
Both alleles contribute to the phenotype.

22. Multiple Alleles
Many genes have more than two alleles for a given trait. See page 273 in text.

23. AB - universal acceptor O – universal donor
Multiple Alleles
AB - universal acceptor O – universal donor

24. How is sex determined?
Male – XY Female -XX

26. Sex Linked
Genes that are carried by either sex chromosome are said to be sex linked

27. Independent Assortment
Genes for different traits can segregate independently during the formation of gametes.

28. Chapter 11 quizlet