Non Mendelian Punnett Square Problems

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					Non-Mendelian Punnett Square Problems                                       Name:


Directions: Use the punnett squares and information to answer the following questions. At times, you may have
to drag and drop the correct genotypes into the square and place the correct alleles in the square.

1. Butterflies come in many different colors but some butterflies exhibit incomplete dominance. The three colors
   that show this trait are dark blue (B), white (W) and light blue (BW).

     a. What is the genotype of a light blue butterfly? **

     b. What is the phenotype of a WW butterfly? **

                             c. What is the phenotype & percent of each
                                phenotype from a cross between a white and
                                light blue butterfly?
                                phenotype: ** percent: **
                                phenotype: ** percent: **



      W W WW WW W B BW                                               BW

2. Blood Type exhibits multiple alleles and codominance. There are 4 blood types: A, B, AB and O. Blood types
   A and B are codominant and Type O is recessive to both A and B. A chart is shown to the left of phenotypes
   and genotypes.
  Phenotype      Genotype
  Type A         IAIA or IAi       a. What is the phenotype of a person who has IAIA ? **
                                   b. What is the genotype of a person who is has type O blood? **
  Type B         IBIB or IBi
                                   c. A man has type AB blood. Is it possible for him to have an O child? **
  Type AB        IAIB
  Type O         ii                d. Why or why not? **



3. Use the chart from question 2 to answer the following questions.

A heterozygous type B man and a type AB woman want ot have a child.

a. What are the chances that they will have a type B child?

b. What are the chances that their child will be a type O carrier?

c. Other than a blood type B, what other blood types could their child have?

d. The child is type AB. Is the child from the man and woman?



          IB IA IB i                IBIB         IAIB IBi             IAi
4. Black cows (B), brown cows (R) and roan cows (BR) show incomplete dominance. A roan cow is a cow
                                          with a red hue (like the one shown in the picture).

                                             a. A black cow and a brown bull (male cow) are crossed.
                                             What are the chances they will
                                             have a roan cow?
                                                                                               B       B
                                             b. Is a roan cow a purebred?                    R BR BR
                                             c. Why?
                                                                                             R BR BR

5. Snapdragon flowers exhibit incomplete codominance. There are three colors of
snapdragons: white (W), red (R) and pink (RW).

a. What is the genotype of a red flower?

b. Is a red flower homozygous or heterozygous?
c. Why?

                              d. A pink flower and a pink flower are crossed.
                              Approximately 100 seeds are produced from the
                              cross. How many of the seeds are
                              for red flowers?

                              e. How many of the 100 seeds
   R                          are for pink flowers?

   R W W                                    RR
                       RW       RW                    WW
6. Blood type exhibits codominance and multiple alleles. The chart below shows the phenotype and genotype of
blood types.
 Phenotype     Genotype
 Type A        IAIA or IAi         a. A type AB man and type O woman decide to have a child. What are the
                                   chances that they will have a type O baby?
 Type B        IBIB or IBi
 Type AB       IAIB                b. The couple have a type B baby. What are the chances that their second
 Type O        ii                  child will have type B blood?
                                                                                              IA       IB
                                                                                         i    IAi      IBi
        IA         ?          c. A type A woman and a type B man have a type
                              O child. What was the genotype of the man?
                                                                                         i    IAi      IBi
 IB IAIB IBi
                              d. What was the genotype of the woman?
   ? IAi           i
                   i          e. What are the chances that this couple will have a type AB child?
7. Anhydrotic ectodermal dysplasia is a X-linked recessive condition. The symptoms
for anhydrotic ectodermal dysplasia include the lack of sweat glands, no teeth and
underdeveloped fingernails. Let XA represent the presence of sweat glands and
teeth and Xa represent anhydrotic ectodermal dysplasia.

    XA Y                      a. What is the phenotype of a woman is XAXa?
XA XAXA XAY                   b. Is the woman above a carrier of the gene?

Xa XAXa XaY                   c. What is the phenotype of a
                              man who has XAY?

d. What are the chances of the two people described in a & b having a
anhydrotic ectodermal dysplasia male child?



8. Rickets is a X-linked dominant condition due to the lack of vitamin D. The symptoms
of rickets are swelling in the joints and the bend of the long bones which causes bow legs.
Let XR represent rickets and Xr represent non-rickets.

a. A man with rickets has children with a woman who does not have rickets.
What are the chances that they will have rickets males?

     XR Y                     b. What are the chances that they
 X XRXr XrY                   will have rickets females?

 r                            c. Which sex is more prone to rickets in this situation?
 Xr XRXr XrY                  d. Why?
                                                                   X? Y
e. A woman is homozygous for rickets. What is the chance       XR XR? XRY
that all of her children will have rickets?
f. Why?
                                                               XR XR?             XRY
9. Lesch-Nyhan Syndrome is a X-linked recessive condition. Symptoms of the syndrome include poor motor skills
and self-mutiliation. In self mutilation, the individual will bite off the inside of their mouths, tongues and fingers
(see picture of shortened fingers due to self-mutilation). Let XL represent a normal functioning person and Xl
represent a person with Lesch-Nyhan Syndrome.

                              a. A Lesch-Nyhan Syndrome man and a woman who is a carrier of the Lesch-
                              Nyhan Syndrome gene want to have a child. What are the
                              chances that they will have a Lesch-Nyhan                 Xl         Y
                              Syndrome child?
                                                                                     X XLXl XLY
b. What are the chances that the child will                                          L
be a male with Lesch-Nyhan Syndrome?                                                 X l X lX l X lY

				
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