12
Biology Unit 5 Notes: Mendelian Genetics

Biology unit 5 genetics mendelian genetics notes

Embed Size (px)

DESCRIPTION

 

Citation preview

Page 1: Biology unit 5 genetics mendelian genetics notes

Biology

Unit 5 Notes:Mendelian Genetics

Page 2: Biology unit 5 genetics mendelian genetics notes

(1) Gregor Mendel

• Monk• Studied genetics of pea plants.

• He noticed that:– There were some traits which showed up all of

the time (dominant).– There were some traits which showed up some

times (recessive).– These traits are passed down from parents.– You can’t tell just by looking at an organism,

which genes it has.

Page 3: Biology unit 5 genetics mendelian genetics notes
Page 4: Biology unit 5 genetics mendelian genetics notes
Page 5: Biology unit 5 genetics mendelian genetics notes

(2) Dominant + Recessive Traits

• Dominant Trait:– These will ALWAYS SHOW UP if they are

present.– Representation Capital Letters

• Recessive Trait:– These will ONLY SHOW UP if the organism

inherited 2 together.– Representation Lower Case Letters

Page 6: Biology unit 5 genetics mendelian genetics notes
Page 7: Biology unit 5 genetics mendelian genetics notes

(3) Inheriting Traits

• You inherit 2 alleles for every gene.– Gene = Chunk of DNA.– Allele = Variation that chunk can come in.

• “Heterozygous” = You inherited 1-Dominant and 1-Recessive allele.

• “Homozygous” = You inherited 2 of the same alleles.– “Homozygous Dominant” = You inherited 2-Dominant

alleles.– “Homozygous Recessive” = You inherited 2-Recessive

alleles

Page 8: Biology unit 5 genetics mendelian genetics notes
Page 9: Biology unit 5 genetics mendelian genetics notes

(4) Ways to Describe Inheritance

• Phenotype:– Physical Description.– Examples:

• “White”• “Brown”• “White and Brown Spotted”

• Genotype:– Genetic Description.– Examples:

• AA or Homozygous Dominant• Aa or Heterozygous• aa or Homozygous Recessive

Page 10: Biology unit 5 genetics mendelian genetics notes
Page 11: Biology unit 5 genetics mendelian genetics notes

(5) What’s With These Letters?

• The letters represent the alleles an organism can inherit.

• You should choose letters with a different Capital + Lower Case appearance:– A and a– B and b– Bad Life Choices: S and s, X and x, C and c

• Actual Letters DO NOT MATTER:– Heterozygous needs to be: Capital + Lower– Homozygous Dominant needs to be: 2 Capital– Homozygous Recessive needs to be: 2 Lower

Page 12: Biology unit 5 genetics mendelian genetics notes