Review: Meiosis
SpermFather’s
Characteristics
EggMother’s
Characteristics
+
Zygote
Sexual Reproduction and GeneticsChapter 10
Gregor Mendel’s Peas• Genetics – the scientific study of heredity
• Gregor Mendel – a monk from Austria, and is known as the father of genetics
• He did his most notable work with pea plants in his garden.
10.2 Mendelian Genetics
Sexual Reproduction and GeneticsChapter 10
The passing of traits to the next generation is called inheritance, or heredity.
10.2 Mendelian Genetics
Sexual Reproduction and Genetics
Mendel performed cross-pollination in pea plants.
Mendel followed various traits in the pea plants he bred.
A trait is a characteristic such as hair or eye color, and height.
Chapter 10
The parent generation is also known as the P generation.
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Chapter 10
Sexual Reproduction and Genetics
The second filial (F2) generation is the offspring from the F1 cross.
10.2 Mendelian Genetics
Chapter 10
The offspring of this P cross are called the first filial (F1) generation.
Mendel studied seven different traits.
Sexual Reproduction and Genetics
Seed or pea color – Yellow or Green Flower color – Purple or White Seed pod color – Yellow or Green
10.2 Mendelian Genetics
Chapter 10
Mendel studied seven different traits.
Sexual Reproduction and Genetics
Seed shape or texture – Round or Wrinkled Seed pod shape – Inflated or Constricted Stem length – Tall or Dwarf Flower position – Axial or Terminal
10.2 Mendelian Genetics
Chapter 10
Genes in Pairs
Sexual Reproduction and Genetics
Allele An alternative form of a
single gene passed from generation to generation
Expressed as a letter (A or a, B or b, etc.) Found on the same
location of homologous chromosomes.
10.2 Mendelian Genetics
Chapter 10
Dominance
Sexual Reproduction and Genetics
An organism with two of the same alleles for a particular trait is homozygous.Example: AA or aa
An organism with two different alleles for a particular trait is heterozygous.Example: Aa
10.2 Mendelian Genetics
Chapter 10
Dominance
Sexual Reproduction and Genetics
A dominant trait needs only one copy of an allele to express its phenotype.
A recessive trait requires two copies of an allele to express its phenotype.
10.2 Mendelian Genetics
Chapter 10
Genotype and Phenotype
Sexual Reproduction and Genetics
An organism’s allele pairs are called its genotype.
The observable characteristic or outward expression of an allele pair is called the phenotype.
10.2 Mendelian Genetics
Chapter 10
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Chapter 10
Seed or pea color – Yellow or Green
Seed color Phenotype
Yellow or Green
Seed color Genotype
Yellow (YY or Yy)Green (yy)
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Chapter 10
Seed or pea color – Yellow or Green
Yellow is dominant to green!!A dominant allele will mask the expression of a recessive allele.You only need one dominantallele to represent yellow.
GenotypeYellow (YY or Yy)Green (yy)
YY or Yy
Must have two yy.
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Chapter 10
Genotype and Phenotype?
Yellow is dominant to green.
Sexual Reproduction and Genetics
10.2 Mendelian Genetics
Chapter 10
Genotype and Phenotype?
Yellow is dominant to green.