Download Sickle cell lab

Name: _____________________________________________
What do Normal and Sickled Cells Look Like
Sickle Cell Anemia is a disorder in which red blood cells are sickle shaped rather than round.
Sickle cell anemia is a genetic disorder. Hemoglobin is the protein molecule in red blood cells
that carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the
tissues back to the heart. The sickled-cells do not carry as much oxygen as normal red blood
cells. A person with this disorder does not get enough oxygen to the body cells.
Objectives:
a. Learn that there are two different conditions to this disease
b. Solve genetic problems involving sickle cell anemia
Procedure:
Part A: Comparison of Sickle-Cell Trait with Sickle-Cell Anemia
1. Examine table 1. Note that not all people that possess the sickle-cell gene have sickle-cell
anemia. There are two different sickle-cell conditions that are determined by the genes that are
received from the parents. Sickle-cell trait is less of a problem than sickle-cell anemia.
Table 1. Gene Combinations
Gene Combination
Blood Cell Shape
Name of disease
RR
All round
Normal
RR’
Half Round
Half sickled
All Sickled
Sickle-cell trait
R’R’
Sickle-cell anemia
2. Examine Figure 1. These drawing represent blood samples from three different people. Count
the number of normal and sickled cells in all three samples. Record your answers in Table 2.
Figure 1: Blood Samples
Table 2. Number of Normal and Sickled Cells Seen
Blood Sample
Number of normal cells
Number of sickled cell
A
B
C
3.
Examine your data and Table 1. Determine the blood condition for each of the samples and
write the correct condition on the first line below the picture: normal, sickle-cell trait,
sickle cell anemia.
4. Examine your data and table 1. Determine the correct gene combination that produced each
sample and write them on the second line below the picture: RR,
RR’ or R’R’
Part B Genetics Problems
Construct and use a Punnett square for each of the following problems.
1. Two parents have the following genes for blood cell shape. RR’ and RR. What kind of blood
might their children have:
Number of children
Have Normal blood
________________
Have sickle-cell trait
________________
Have sickle-cell anemia
________________
2. Two parents have the following genes for blood cell shape: RR’ and RR’. What kind of blood
might their children have?
Number of children
Have Normal blood
________________
Have sickle-cell trait
________________
Have sickle-cell anemia
________________
3. Two parents have the following genes for blood cell shape: RR’ and R’R’. What kind of blood
might their children have?
Number of children
Have Normal blood
________________
Have sickle-cell trait
________________
Have sickle-cell anemia
________________
Questions
1. Describe the shape of normal blood cells
2. Describe the shape of sickled cells
3. Explain how the number of normal and sickled red blood cells differ in a person with sickle-cell
trait and sickle cell anemia.
4. What type of cell probably contains more hemoglobin? (Normal or sickled)
5. The less hemoglobin a person has, the more difficult it is for the cells of the body to get enough
oxygen. With too little oxygen, a person will tire easily and cannot do a lot of exercising. Would
a person with sickle-cell trait be able to do more or less exercising than a person with sickle-cell
anemia?
Explain why
6. Which condition is more of a problem for a person, sickle-cell trait or sickle-cell anemia
Explain why
A scientist gathered the following information while studying people with sickle cell anemia.
Number of children born in the United States with sickle cell-anemia:
To white parents – less than 1/100,000 births
To African-American parents – about 200/100,000 births
7. Which racial group seems to suffer most from this genetic disorder?
8. Why do we call sickle cell-anemia a genetic disorder?
9. How does this disorder serve as an example of
lack of dominance
?