Question

Question 1)

Which of the following is a correct statement? Group of answer choices

A) The A band of a sarcomere appears light in color when viewed under a microscope

B) The tropomyosin protein contains 3 subunits: one that binds to myosin, one that binds to actin and one that binds to ATP

C) During the power stroke of skeletal muscle contraction, ADP and Pi are released as the hinge region of the myosin head undergoes a conformational change, resulting in the sliding of the actin filament in the opposite direction.

D) The Z line is a filamentuous protein complex that that delimits a myofibril

E) When skeletal muscle contraction is initiated at the neuromuscular junction, ACh binds to and opens ligand gated chloride channels, resulting in the efflux of Cl- out of the skeletal muscle cell that initiates a depolarization

QUESTION 2 Chickens occasionally use their breasts for flying extremely short distances, usually to escape perceived danger. Chickens generally use their legs for support while standing, and for walking. Chicken breasts are composed of “white meat” while chicken legs are composed of “dark meat”. Which of the following is true?

Group of answer choices

A) Chicken breasts are composed mostly of slow oxidative fibers; chicken legs are composed mostly of fast anaerobic fibers

B) Chicken breasts are composed mostly of slow oxidative fibers and fast aerobic fibers; chicken legs are composed mostly of fast anaerobic fibers.

C) Both chicken breasts and legs are composed of slow oxidative fibers; and the color is determined by the total myoglobin content in each muscle

D) Both chicken breast and legs are composed primarily of fast aerobic fibers and the color is determined by how many blood vessels there are in the particular muscle

E) Chicken breast are composed mostly of fast anaerobic fibers; chicken legs are composed mostly of slow oxidative and fast aerobic fibers.

QUESTION 3) While the semilunar valves are open during a normal cardiac cycle, the pressure in the left ventricle is ___

Group of answer choices

A) None of the choices are correct

B) greater than the pressure in the aorta

C) less than the pressure in the aorta

D) less than the pressure in the left atrium

E) the same as the pressure in the left atrium

QUESTION 4) The parasympathetic effect on the heart ___

Group of answer choices

A) All of the choices are correct

B) slows the rate of depolarization in the cells of the SA node

C) utilizes the vagus nerve

D) causes an increase in permeability to K+ and a decrease in permeability to Na+ and Ca2+

E) involves acetylcholine

Answer 1

Answer 1:

Statement A, The A band of a sarcomere appears light in color when viewed under a microscope, is false. This is because A band appears dark under a microscope.

Statement B, The tropomyosin protein contains 3 subunits: one that binds to myosin, one that binds to actin, and one that binds to ATP is false because tropomyosin does not bind to ATP.

Statement C is false because myosin head and actin moves in the same direction during power stroke.

Statement E is false because depolarization is initiated by an influx of sodium ions.

The correct statement should be:

D) The Z line is a filamentuous protein complex that that delimits a myofibril .