In humans, sickle-cell anemia is caused by an allele that results in abnormal hemoglobin that sickles red blood cells in certain situations. Individuals who are heterozygous for normal and sickle-cell alleles are protected from malaria; homozygous normal has no protection and homozygous sickle-cell has symptoms such as low tolerance for exertion and a shortened life span. This is an example of
A. stabilizing selection.
B. directional selection.
C. disruptive selection.
D. balancing selection.
E. cryptic selection.
D. balancing selection.
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A proteome is an organism's full array of expressed proteins, and proteomics is the study of those proteins and the functions they mediate.
Answer the following statement true (T) or false (F)
Amphibians are most dependent on an aquatic environment for ____
a. respiration b. feeding c. reproduction d. urination e. defecation
The accompanying figure illustrates ____
a. the production of recombinant DNA b. probing for transferred genes c. DNA fingerprinting d. DNA sequencing e. producing radioactive probes
For an XX female to express a recessive sex-linked trait, she must have
A.) a Y chromosome B.) an inactivated allele C.) two dominant alleles D.) two recessive alleles