Chapter 11 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 ID: 625994
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Slide1
Mendel’s Genetics
Chapter 11Slide2
Who was Gregor Mendel?
He was known as the “FATHER OF GENETICS” He discovered how traits were inheritedGENETICS – study of heredity
HEREDITY
– the passing of traits from parents to offspringSlide3
Mendel’s Peas
Mendel did his study on pea plantsPea plants have many traits (tall/short, purple flowers/white flowers)Pea plants can beself-fertilized
or
cross-fertilizedSlide4
True Breeding
Meaning that if they are allowed to self-pollinate, they will produce offspring identical to themselvesSelf-pollinate: some plants have both male and female flowersOne plant is producing both male and female gametes that are fertilizedSlide5
Dominance
Some traits are dominant over others. Tall x Short = all tall offspring (hybrids)*Tall is the dominant trait* Short is recessiveSlide6
Genes and Alleles
Mendel discovered that each trait is controlled by two factors (alleles)Genes – factors that determine your traitsSlide7
Mendel’s ExperimentsSlide8
The Cross
Monohybrid Cross, that isSlide9
Explaining the Cross
When a parent makes sperm or eggs, their genes separate (PRINCIPLE/LAW OF SEGREGATION)The GAMETES (egg or sperm) contain either a T allele (tall) or a t allele (short)This works for various traits like hair colorSlide10Slide11
More on the CrossSlide12
Genes
→TraitsGENOTYPE - what genes ( letters) the organism has (TT, Tt, tt)PHENOTYPE - what it looks like (tall or short)Slide13
Understanding Check
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. If you use the letter E for this gene. What is the genotype of the offspring? 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?Slide14
Incomplete Dominance
When both alleles are expressed, making colors somewhere in the middleMore like a mixing of the two allelesSlide15
Codominance
When both alleles are expressed equallyNot mixing, but blotched usuallySlide16
Another Cross
Dihybrid CrossWhen you do a cross for two traits at the same timeFor example: a cross for eye AND hair colorSlide17
Example Cross
What do you get when you cross a tall purple flower plant with a short white flower plant???