QUESTION 21 Which of the following characteristic are observed in basophils during inflammation? a. Phagocytosis O b. Diapedesis Oc. Chemotaxis Od. Synthesis and release of histamine O e. All the above

QUESTION 4 Which of the following G protein subunits activate K+ channels in response to the GPCR for acetylcholine on heart muscle?   a. Galpha inhibitory.   b. G alpha stimulatory   c. G beta gamma dimer.   d. G alpha transducin.

QUESTION 7 All of the following statements agree with the germ theory of disease, except: A. Microorganisms can invade other organisms and cause disease B. Maggots only grow on meat that is left in an open flask because microbes are transmitted by flies and do not spontaneously generate OC. Disease-causing organisms will spontaneously arise from decaying meat OD. Disease is not caused by bad air or spirits

Question 3: The principal determinant of HIV tropism resides in the surface envelope (Env; gp160) glycoprotein spike. The CD4 molecule, found on a subset of T cells, was identified as the major cell-surface receptor for HIV. However, later work showed that mouse cells expressing human CD4 were not able to be infected with HIV [mouse cells are not permissive for HIV infection normally]. To experimentally address this puzzling issue, researchers tested the ability of heterokaryons, which are essentially just fused cells with more than one nucleus, made from two sources: (1) mouse cells engineered to express human CD4 and (2) human cells that did not express CD4. The researchers then induced fusion between these two cell types to create the heterokaryons. Using this system, researchers observed that CD4+ mouse/human heterokaryons - but not CD4+ mouse/monkey heterokaryons – were able to be infected with HIV. Provide an explanation for these findings and what they revealed about the…

Question 32 At a partial pressure of oxygen of 40 mmHg, hemoglobin will be 75% saturated at normal conditions. On average, how many oxygen molecules will be bound to the hemoglobin? A. 1 B. 2 C3 D.4 OE. 5