Genetic Terminology

What makes these two individuals so similar?

What makes these two individuals so different?

What makes these two dogs so different?

What makes this mom so similar to her cub?

Heredity vs. Genetics Heredity: Characteristics an organism receives from his parents Genetics: The study of heredity

Deoxyribonucleic Acid (DNA) Definition: Genetic “blueprint”

Chromosomes Definition: Storage unit of DNA

In EVERY CELL Humans have 46 pairs of chromosomes Where they come from: 23 chromosomes from their mother 23 chromosomes from their father

Gene Definition: Made up of DNA Chemical factors that determine traits Where genes are located: On chromosomes Gene for eye color

Phenotype Expressed traits of an organism (traits you can see with your own eyes) Ex: hair color, eye color, skin color Phenotype = Physical Appearance

List Will Smith’s Phenotypes

Allele Definition: Alternate forms of genes Allele coding for blue eyes Identical allelesDifferent alleles Allele coding for blue eyes Allele coding for brown eyes Gene codes for eye color

Genotype Genetic make up an organism (Cc) Codes for phenotype (Cc = Curly Hair) Ex: Cc is the genotype for the phenotype curly hair

Label each of the following as either phenotype or genotype 1)Brown eyes 2)Aa 3)Round face 4)TT 5)kk 6)Detached ears 7)Straight hair

Dominant Allele -Represented by a capital letter -Determines phenotype Ex: A

Recessive Allele -Represented by a lower case letter -Can be Hidden by a dominant allele (Rr) -Only expressed if TWO recessive alleles are present (rr) Ex: r

Homozygous -Homo = Same -Both Alleles are either Lower case or both are Capital Ex: Homozygous: RR Homozygous: rr

Heterozygous -Hetero = Different -One Allele is Capital the other is Lower Case Ex: -Heterozygous: Rr

Correctly identify which gene pair is homozygous or heterozygous 1)Aa 2)dD 3)Kk 4)Tt 5)Rr 6)ff

Gene Pairs Two alleles Ex: AA Cc dd

Correctly identify which gene pair is dominant or recessive 1)Aa 2)dD 3)kk 4)Tt 5)rr 6)ff

Correctly identify if the gene pair is heterozygous, homozygous dominant or homozygous recessive 1)Kk 2)UU 3)bb 4)ii 5)VV 6)Aa

An Inventory of My Traits

Detached earlobe Attached earlobe Hitchhiker’s thumb No Hitchhiker’s thumb Widow’s Peak Tongue rolling Cleft Chin

Trait# of Students with TraitFrequency Detached earlobe Hitchhiker’s thumb Tongue rolling Dimples Right-handed Freckles Naturally Curly Hair Cleft Chin Widow’s Peak Left thumb over right See red and green Male Number of students with trait x 100 = Frequency Number of students in the class