Question 1
Random segregation of organelles during cell division in a multicellular species is likely to result in an increased rate of which of the following?
◦ incomplete penetrance
◦ dominant loss-of-function mutations
◦ dominant gain-of-function mutations
◦ chromosomal duplication mutations
◦ chromosomal deletion mutations
Question 2
Sigma virus infection in
Drosophila melanogaster causes flies to become paralyzed and then die in high concentrations of CO
2. The virus is passed on extrachromosomally. Two isogenic strains of
Drosophila cultures are maintained: R (resistant to CO
2 or wild type) and S (susceptible to CO
2, infected with sigma). After crosses between male R and female S flies, subsets of offspring of each sex are tested for CO
2 sensitivity. Which of the following results do you expect?
◦ All the offspring are sensitive.
◦ All the offspring are female.
◦ All the offspring are male.
◦ All the offspring are sensitive, but only males pass it on.
◦ Only male offspring backcrossed to the female parent are sensitive.
Summary of events in the killing of virus-infected cells by cytotoxic T cells.
Otitis media. This illustration shows an inflamed tympanic cavity, which is the most common source o
Reaction against infection
Four Brain Structures with High Myelination in Early Childhood
Human immunodeficiency virus (HIV) micrograph
Influenza Virus