You want to study the potential interaction between nucleosome-bound DNA and a specific histone deacetylase. You decide to perform an electrophoretic mobility shift assay (EMSA). You use a 32P end-labelled, linear template DNA that contains two nucleosome positioning sites. You assemble two nucleosomes on the DNA template before incubation with and without the histone deacetylase. For some reactions, you use unmodified nucleosomes. For other reactions, you use nucleosomes that are methylated at lysine 36 of the histone protein H3.

A. The histone deacetylase binds nucleosome bound-DNA in lanes 1, 2, 3, and 4.

B. The histone deacetylase binds nucleosome bound-DNA in lanes 3& 4.

C. The histone deacetylase seems to recognize methylated nucleosomes at lysine 36 of histone H3 in lane 1, 2 & 3 better than unmethylated nucleosomes in lane 4 &5

D. The histone deacetylase seems to recognize methylated nucleosomes at lysine 36 of histone H3 in lane 1 & 2 better than unmethylated nucleosomes in lane 3 &4

#Question id: 11032

#Unit 7. System Physiology – Animal

An electrocardiogram (ECG) provides information about ________.

#Question id: 11033

#Unit 7. System Physiology – Animal

The velocity of blood flow is the lowest in capillaries because ________.

#Question id: 11034

#Unit 7. System Physiology – Animal

An increase in shear stress in a blood vessel results in which of the following changes?

#Question id: 11035

#Unit 7. System Physiology – Animal

A 72-year-old man had surgery to remove an abdominal tumor. Pathohistologic studies reveal that the tumor mass contains a large number of blood vessels. An increase in which of the following is the most likely stimulus for the growth of vessels in a solid tumor?

#Question id: 11036

#Unit 7. System Physiology – Animal

Under control conditions, flow through a blood vessel is 100 ml/min under a pressure gradient of 50 mm Hg. What would be the approximate flow through the vessel after increasing the vessel diameter to four times normal, assuming that the pressure gradient was maintained at 50 mm Hg?

#Question id: 11037

#Unit 7. System Physiology – Animal

A 22-year-old man has a muscle blood flow of 250 ml/min and a hematocrit of 50. He has a mean arterial pressure of 130 mm Hg, a muscle venous pressure of 5 mm Hg, and a heart rate of 80 beats/min. Which of the following is the approximate vascular resistance in the muscle of this man?