Question

1. Use the chart below to determine your phenotype (appearance) and possible genotypes (a pair of alleles). Since you cannot do a genetic test right now, if you have the dominant phenotype, you should include both the homozygous and heterozygous genotypes—see the examples on little finger and dimpled cheeks on the first two rows.  Capital letters indicate dominant traits and lower case letters indicate recessive traits.

Trait	Possible Alleles	Your Genotype	Your Phenotype
Little finger (Instructor example)	Bent little finger (C) Straight little finger (c)	CC (homozygous dominant) or Cc (heterozygous)	Bent little finger
Dimpled cheeks (Instructor example)	Dimpled cheeks (D) No dimpled cheeks (d)	cc (homozygous recessive)	No dimpled cheeks
Little finger	Bent little finger (C) Straight little finger (c)		Bent little finger
Tongue Rolling	Able to roll (R) Unable to roll (r)		Unable to roll tongue
Widow’ Peak	Widow’s peak (W) Straight (w)
Dimpled Chin	Dimpled chin (D) Non-dimpled chin (d)		Dimpled Chin
Free earlobe	Free hanging (E) Attached (e)		Free Hanging
Thumb crossing – Interlocking fingers (when hands are clasped)	Left Thumb on top (L) Right thumb on top (l)
Finger hair	Hair on middle segment of your fingers (H) No hair on middle segment of finger (h)		No hair
Freckles	Have freckles (Z) No freckles (z)		No freckles
Dimpled cheeks	Dimples on one or both cheeks (D) Dimple-absence (d)		Dimple-Absence

Answer 1

Ans 1- Little finger- CC - homozygous dominant

CC- heterozygous.

Ans 2- tongue rolling - rr - homozygous recessive.

Ans 3-widow's peak - WW and Ww for window's peak.

ww for straight.

Ans 4-Dimpled chin - DD- homozygous dominant

Dd-heterozygous

Ans 5-free earlobe - EE - heterozygous dominant.

Ee - heterozygous.

Ans 6-thumb crossing - LL and Ll for left thumb on top

ll for right thumb on top.

Ans 7-finger hair - hh - homozygous recessive.

Ans 8- freckles- zz - homozygous recessive.

Ans 9-dimpled cheeks - dd - homozygous recessive.