Phenotype:  Your phenotype can be determined by examining your own body!  A phenotype is a visible appearance, written as a descriptive word or phrase, “tongue –roller”. 

Genotype: You can deduce what possible genotype that could cause this phenotype.  An autosomal genotype is a pair of genes, written as a pair of letters, such as AA or Aa.  If you show a recessivetrait then your genotype must be a homozygous recessive (aa).  If you show the dominant trait, it will usually be impossible to determine if you are homozygous or heterozygous for that particular trait.  In such cases you should note both your genotypes (AA or Aa, for example) in Table 1. 

Table:  1:  Genetic data for your autosomal dominant or recessive traits. 

Genetic trait Phenotype: (Descriptive words)Genotype (s):  Pairs (s) of letters

Hair line

Earlobes

Tongue Rolling

Freckles

Bent thumb

Interlacing fingers

Based on what you have learned about autosomal inheritance answer the following questions:

  1. Mona does not have freckles but her parents do. What is the expected phenotypic ratio among the parents’ children? 
  2. Joseph is adopted.  He has hair on the back of his hand.  Could both his parents have had hair on the back of their hands?    Could both his parents have had no hair on the back of their hands?  ________.  Explain.  ____________________________________________________________________

In table 2 deduce the genotype of the person by considering the gender and the phenotype,

Phenotype & gender

Genotype(s)

Hemophiliac male

Normal clotting in male

Hemophiliac female

Normal clotting in female