Speciation, the formation of new species, can be defined as the evolution of reproduc-tive barriers between two different populations
How could sexual selection lead to the reproductive isolation of two allopatric (= geo-graphically separated) populations?
What will be an ideal response?
ANS:
Sexual selection could lead to the evolution of different sexually attractive traits in the two populations (e.g., red vs. yellow color in males). Upon secondary contact, mates from the other population will have become unattractive and a prezygotic barrier has evolved.
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Answer the following statements true (T) or false (F)
1. Valley fever is another name for cryptococcosis. 2. The yeast form of Histoplasma capsulatum is quite distinctive because of its large capsule. 3. Both histoplasmosis and cryptococcosis may be acquired by inhalation of dried bat droppings (guano). 4. Molds in the genus Mucor are commonly referred to as bread molds. 5. If a patient is infected with a dimorphic fungus, it is likely that fungal hyphae would be seen in the infected tissues.
Consider the transplantation of tissue from a donor to a recipient who has a different HLA type but the same ABO blood type. Why will the recipient be likely to reject a kidney from the donor, but will not reject the blood from the donor?
A. There are no Class II MHC molecules on the red blood cells in the donor blood. B. There are no Class I MHC molecules on the kidney tissue from the donor. C. There are no Class I MHC molecules on the red blood cells in the donor blood. D. There are no ABO antigens on the kidney tissue.
Plasma is responsible for transporting
a. nutrients. b. wastes. c. signaling molecules. d. various proteins. e. all of these.
Joan and her doctor notice a suspicious lump in her breast. Joan also has a family history of breast cancer. Which of the following is not a likely next step as they work to determine the cause of the lump?
A. performing a diagnostic mammogram B. genetic testing for mutations in the BRCA1 gene C. taking a biopsy of the lump to look for the presence of cancer cells D. performing a mastectomy to remove all breast tissue in that breast