Mendelian Patterns of Inheritance Chapter 9 Gregor Mendel

Gregor Mendel v Monk who lived in early 1860’s. v Wanted to know heredity

Mendel’s Experiment v Worked with PEA plants v Why: 1. Easy to cultivate 2.

Mendel’s Final Theory v Particulate Theory of Inheritance: Inheritance is based on the existence

One-Trait Inheritance v v Chose plants that differed only in ONE trait Parent Generation

v Alleles: different forms of genes v Letters are assigned for different alleles (traits)

Punnett Square v Represents a cross between 2 parents, showing all possible offspring.

Practice Problem v In rabbits, if B = black hair, and b= white hair.

Practice Problem v What is the phenotypic ratio? ? 3: 1 B b B

Practice Problem v In pea plants, if Y = yellow, and y = green

Practice Problem v What is the phenotypic ratio? ? 9: 3: 3: 1 9

History v v Mendel knew that inheritance was passed on, but he didn’t know

DNA Structure v Watson and Crick – 1962 v Nucleotides bonded together in a

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Mendelian Patterns of Inheritance Chapter 9

Gregor Mendel v Monk who lived in early 1860’s. v Wanted to know heredity was passed on from generation to generation. v 1800’s theory: Blending Concept v Both parents contribute equally to offspring. v EX: red flower + white flower = pink

Mendel’s Experiment v Worked with PEA plants v Why: 1. Easy to cultivate 2. Has a short generation time 3. Easily cross pollinated 4. Many varieties

Pea Plant Traits

Mendel’s Final Theory v Particulate Theory of Inheritance: Inheritance is based on the existence of minute particles called genes; these genes are reshuffled from generation to generation.

One-Trait Inheritance v v Chose plants that differed only in ONE trait Parent Generation : P 1 st Generation : F 1 2 nd Generation : F 2

v Alleles: different forms of genes v Letters are assigned for different alleles (traits) v Y = yellow y = green v Dominant (Y) – visible trait v Recessive (y) – hidden trait v Homozygous – a trait where 2 alleles are the same (yy or YY) v Heterozygous – a trait where 2 alleles are different (Yy) v Genotype – the alleles the individual receives v Phenotype – the physical appearance

Punnett Square v Represents a cross between 2 parents, showing all possible offspring.

Practice Problem v In rabbits, if B = black hair, and b= white hair. When two heterozygous parents are crossed, B b what are the offsprings? -one trait cross- B BB Bb bb

Practice Problem v What is the phenotypic ratio? ? 3: 1 B b B BB Bb bb 3 = black 1 = white

Practice Problem v In pea plants, if Y = yellow, and y = green peas, and T = tall plant, and t = short plant. When two heterozygous parents are crossed, what are the offsprings? YT -two trait cross- YT YYTT Yt y. T yt YYTt Yy. TT Yy. Tt Yt YYTt YYtt Yy. Tt Yytt y. T Yy. Tt yy. TT yy. Tt yt Yy. Tt Yytt yy. Tt yytt

Practice Problem v What is the phenotypic ratio? ? 9: 3: 3: 1 9 = yellow & tall 3 = yellow & short 3 = green & tall 1 = green & short YT YT YYTT Yt y. T yt YYTt Yy. TT Yy. Tt Yt YYTt YYtt Yy. Tt Yytt y. T Yy. Tt yy. TT yy. Tt yt Yy. Tt Yytt yy. Tt yytt

DNA Structure Chapter 10

History v v Mendel knew that inheritance was passed on, but he didn’t know what! Two molecules that were thought to pass on inheritance – DIDN’T KNOW WHICH ONE 1. 2. Proteins DNA

DNA Structure v Watson and Crick – 1962 v Nucleotides bonded together in a double helix v 1. 2. 3. 4. 4 different ones A = adenine T = thymine G = guanine C = cytosine A=T G=C

Replication of DNA Eukaryote Prokaryote