The answer is C ; Refinement
When a muscle cell contracts some myosin heads bind to actin molecules as other myosin heads release from actin molecules.
Muscle contraction occurs when the thick filament and the thin filaments slide over one another in a series of repetitive events.
Answer:
The correct answer is option C. "Uncovered meat that had contact with air".
Explanation:
In 1668, the Italian scientist Francesco Redi performed a celebrated experiment to prove that maggots are not spontaneously created by placing fresh meat in each of two different jars: one opened and one covered with a cloth. Redi used an uncovered meat that had contact with air as a control, expecting that flies will come in and the maggots will be developed as they do in nature.
Answer: The tubule is long and highly coiled to provide a large surface area for selective reabsorption. The coiling of the tubule reduces the speed of the flow of the filtrate to give more time for efficient reabsorption. The tubule is well supplied with blood capillaries to increase a steep diffusion gradient for selective re-absorption.
Explanation: Selective reabsorption occurs because during ultrafiltration, important components of the blood are filtered out and they need to be reabsorbed into the body.
