Question

I really need help with genetic class. This assignment is about pedigree

1 ) Pick any 2 traits from phenotypes of tongue rolling, detached earlobes, hitchhiker’s thumb and then examine the phenotypes of your siblings, parents, and you a) construct a pedigree for each trait (including parents and children) showing inheritance pattern of these traits

b) infer which phenotype is dominant (rolling vs non-rolling, detached earlobes vs attached earlobes, hitcher’s thumb vs regular). Include a brief explanation next to each pedigree.

c) infer the genotype of each member of the pedigree

Answer 1

Phenotype:

Traits

Symbols (for alleles)

Dominant Phenotype

Recessive phenotype

genotype representation

1. Free or detached ear lobe

F,f

Free ear lobe

Attached or no Free ear lobe

EE = homozygous dominant Ee= heterozygous dominant (carrier) ee= recessive

2. Hitchhiker’s thumb

H,h

Straight 180 degrees

Recessive- No Straight 180 degrees

HH = homozygous dominant Hh= heterozygous dominant (carrier) hh= recessive

Considering:

Trait1: detached earlobe:

Mother = Free or detached ear lobe, genotype= Ee or EE (preferably Ee or heterozygous, as one child has attached earlobe)

Father= Free or detached ear lobe, genotype = Ee or EE (preferably Ee or heterozygous, as one child has attached earlobe)

Father x mother cross: Ee x Ee

	E	e
E	EE	Ee
e	Ee	ee

Brother = attached ear lobe genotype = ee

Myself = Free or detached ear lobe, genotype = Ee or EE

Trait2: Hitchhiker’s thumb

Mother = no Hitchhiker’s thumb, genotype = HH (may be Hh)

Father= Hitchhiker’s thumb, genotype = hh

Father x mother cross: Hh x hh

	H	H
h	Hh	Hh
h	Hh	Hh

Brother = no Hitchhiker’s thumb, genotype = Hh

Myself = no Hitchhiker’s thumb, genotype = Hh