Human Phenotype Lab Are you dominant or recessive

Human Phenotype Lab • Are you dominant or recessive for each trait? • What is your genotype and phenotype for each trait?

Important Concepts • Remember it takes two copies of the gene. • Different copies of genes, the letters, are called alleles. ex. H or h • Capital letter = dominant (H) • Lower case letter = recessive (h) • For today’s lab, COMPLETE DOMINANCE; Big letter always wins • HH or Hh = show dominant trait • hh = show recessive trait. • If Dominant, we don’t know your 2 nd allele, so show a H? • Genotype is the “letters” of the genes • Phenotype is the physical trait (what you see)

Unattached or Attached Ears? E? or ee

Widow’s Peak – yes or no? W? or ww

Rolling tongue – yes or no? R? or rr

Bent or Straight Little Fingers? B? or bb

Colored or Blue eyes? P? or pp

Mid-digital hair –yes or no? M? or mm

Straight or bent thumb? T? or tt

Dimples – yes or no? D? or dd

Curly or straight hair? CC or SS or CS

Right or Left Handed? H? or hh

Freckles – yes or no? F? or ff

Red hair – yes or no? dd or D?

Long eyelashes – yes or no? L? or ll

Do you have a blaze – yes or no? B? or bb

Which leg crossed on top? Right or left? R? or rr

Question 1 • Does being a dominant trait mean that most people have that trait?

Question 2 • Is it possible for parents who both have dimples to have a biological child who doesn’t have dimples? • Prove your answer using the alleles. • Hint: Dimples is a dominant trait.

Question 3 • We used a question mark when you had the dominant trait because we didn’t know your second letter. • It could have been TT or Tt. • What could you do in order to determine if your second allele is Big or little letter?

Question 4 • Come up with a way to remember the difference between genotype and phenotype.