A family in which club foot was inherited as an autosomal dominant trait. They discovered a mutation in the PITXI gene that caused club foot in this family. Through DNA testing, they determined that 11 people in the family carried the PITXI mutation, but only 8 of these people had club foot. Which of the following is the correct interpretation of the observation?

#Question id: 1998

#Unit 4. Cell Communication and Cell Signaling

Jenner successfully used cowpox virus as a vaccine against the virus that causes smallpox. Why was he successful even though he used viruses of different kinds?

#Question id: 1999

#Unit 4. Cell Communication and Cell Signaling

Which of the following would be most beneficial in treating an individual who has been bitten by a poisonous snake that has a fast-acting toxin?

#Question id: 2000

#Unit 4. Cell Communication and Cell Signaling

Which of the following is true of the successful development of a vaccine to be used against a pathogen?

#Question id: 2001

#Unit 4. Cell Communication and Cell Signaling

A researcher is analyzing the immune response of a patient following the patientʹs exposure to an unknown agent while out of the country. The patientʹs blood is found to have a high proportion of lymphocytes with CD8 surface proteins. What is the likely cause?

#Question id: 2002

#Unit 4. Cell Communication and Cell Signaling

What accounts for antibody switching (i.e., the switch of one B cell from producing one class of antibody to another antibody class that is responsive to the same antigen)?

#Question id: 2003

#Unit 4. Cell Communication and Cell Signaling

The number of MHC protein combinations possible in a given population is enormous. However, an individual in that population has only a couple of MHC possibilities. Why?