Daddys Dimples Jodi Sheffield St Rita Catholic School

Daddy’s Dimples Jodi Sheffield St. Rita Catholic School KERA Teacher Core

Unraveling the Chromosome DNA Adenine with Thymine Cytosine with Guanine

Nuclear divisions 1 2 Number of cells produced 2 4 Genetic content ID Identical O L P to parent I D I O L One Phalf A of. Hparent D Which process produces the cells used in sexual reproduction? ?

http: //www. accessexcellence. org/AB/GG/mitosis 2.

Inherited Traits Survey Trait Roll tongue Widow’s Peak Attached Ear lobe Hand Clasp Me Mom Dad Sib 1 Sib 2 Sib 3

http: //www. genomenewsnetwork. org/resources/whats_a_genome/Chp 1_2_1. shtml

http: //www. spaceship. com/~monte/Biology/Jonas 3. html

Chromosome pair #3 Alleles – buddy genes on matched chromosomes Locus – location of gene on the chromosome

Watch for these terms Dominant - the trait (allele) is expressed Recessive - a trait that is only expressed when both alleles are the same Phenotype - the physical expression of traits Genotype - the actual genetic composition Homozygous -when the two alleles are the same ( purebred) Heterozygous -when the two alleles are different (hybrid)

What did Mendel show? Each pair of parent factors (alleles) separate Each parent passes only one factor (allele) to an offspring Which factor (allele) the parent passes is strictly chance

What else did Mendel show? Inheritance of separate traits stays separate

And this means… Dominant - the trait (allele) is expressed Recessive - a trait that is only expressed when both alleles are the same Phenotype - the physical expression of traits Genotype - the actual genetic composition Homozygous - when the two alleles are the same Heterozygous - when the two alleles are different

Using Mendel’s Know How Dominant gene is usually represented by UPPERCASE Recessive gene is usually represented by lowercase T tall t short

Putting alleles together. . T tall; dominant Genotype t short; recessive Phenotype TT homozygous tall Tt heterozygous tall tt homozygous short

Let’s see some Random Segregation Probablity - the science that determines chance Punnett squares - probability diagram illustrating the possible offspring Mama - Tt Dad - Tt heterozygous; Tall Mom T t T TT Tt t T t tt Dad

Interpreting the Punnett Square mom T t T TT Tt t T t tt Dad Genotypes Phenotypes TT 1 : Tt 2 : tall 3 tt 1 short : 1

Family Traits Earlobes Detached – D Attached - d Mom D Dad D d Dd Dd Genotype Dd Phenotype Detached

Can two parents with detached earlobes have an attached kid? Mom D d D DD Dd dd Dad Which genotype? What is the probability?

A Few Things Beyond Brother Mendel Incomplete Dominance two different phenotypes produce offspring with a third phenotype that is a mixing of the parental traits For example: Red Flower + White flower = Pink flower http: //www. borg. com/~lubehawk/inccodom. htm

Multiple Alleles More than two alleles can be selected for the allelic pair (more than two choices) For example: Blood type alleles – A, B, O Genotype Phenotype (Blood Type) AA, AO A BB, BO B OO O AB AB Codominance The trait (allele) is expressed with another dominant allele

Polygenic inheritance traits result from the interaction of several genes For example: Skin color Height Eye color