What is the underlying mechanism that allows striated muscles to contract more rapidly when very little force is required?
A) The muscle is shortening so rapidly that some myosin heads are moved to their new position without actually generating any force.
B) Fewer myosin heads actually attach to the actin, increasing the rate of shortening.
C) Lighter loads stimulate only a very high speed, low tension isoform of myosin.
D) Lighter loads stimulate a myosin isoform with a very long unitary displacement.
Answer: A
You might also like to view...
In typical women of reproductive age, the epithelial cells lining the uterus (the endometrium) die and are shed from the body roughly once every month, in the process of menstruation. The triggers in this process include chemical (hormonal) changes and contraction of the blood vessels in the lining. Cell death may be a result of either apoptosis or necrosis. Give the characteristics of each
process. Devise an argument for classifying the process of menstruation as an example of apoptosis, and then argue for classifying it as necrosis. Which is correct? What will be an ideal response?
Birds, fish, and some reptiles are __________ layers
Fill in the blank(s) with correct word
One difference between anaerobic and aerobic respiration is that
A. aerobic respiration takes place after anaerobic respiration. B. aerobic respiration does not require oxygen. C. aerobic respiration produces more ATP than anaerobic respiration. D. anaerobic respiration utilizes the citric acid cycle, but aerobic respiration does not. E. anaerobic respiration takes place inside cells, while aerobic respiration takes place in the extracellular fluid.
Following the nomenclature for cells, what type of cells take in solid particles like bacteria?
A. Phagase B. Phagozyme C. Phagocyte D. Phagosome