BI $211$ Graded problem set $10$

$1.$ You have been learning all term about sickle cell disease and so you know that sickle cell anemia is a rare disease that causes red blood cells to have a shape like a sickle rather than the normal round disc. Sickled cells plug blood capillaries and block blood flow, leading to pain, tissue degeneration, and in some cases early death. In the pedigree here, people with sickle cell disease are filled in$.$ No carriers are marked.

In the questions below, indicate whether the mode of inheritance is possible and then justify the answer by referring to specific individuals in the pedigree $($as an example, part a is done for you$).$

a$.$ The mode is $\backslash ($ Y $\backslash )$ linked.

$($circle one$)$

possible

not possible Justify your answer.

Females I$3\backslash$& II$3$ have sickle cell anemia but they do not have a Y chromosome.

b$.$ The mode is $\backslash (\backslash$underline$\{$X$\}\backslash )-$linked recessive.

$($circle one$)$

possible

not possible Justify your answer.

c$.$ The mode is $\backslash ($ X $\backslash )-$linked dominant.

$($circle one$)$

possible

not possible

Justify your answer.

d$.$ The mode is autosomal recessive.

$($circle one$)$

possible

not possible Justify your answer.

e$.$ The mode is autosomal dominant.

$($circle one$)$

possible

not possible

f$.$ On the pedigree, fill in the individuals you know must be sickle cell carriers. Use the symbols you learned in class that indicate "carrier."

D $\backslash (\backslash$square $\backslash )$