I think you spelled the question wrong
Answer: flexor, hamstring muscle
Explanation:
Electromagnets can easily be turned on and off.
Explanation:
An electromagnet produces magnetic field which is done by the electric current. These electromagnets contain a wire would like a coil. The current passes through the wire and the magnetic field is concentrated in the center which is the "center of the coil".
When the current is "turned off" the magnetic field "disappears". This shows that we have can have a control over the passage of current or the magnetic field. Thus, the "main advantage" of the electromagnet is that it can be easily turned on and off whenever necessary.
Answer: It can decrease or increase a population of species.
Explanation: Limiting factors include the availability of food, water, shelter, and etc. When a population of species are limited in any of these, they either move or adapt to their environment. So, population tends to decrease. The population that may finds an abundance of resources will find that their numbers tend to increase. This cycle is repeated over and over again.
Hope this helps!!!
Answer:
When a muscle cell contracts, the myosin heads each produce a single power stroke.
Explanation:
In rest, attraction strengths between myosin and actin filaments are inhibited by the tropomyosin. When the muscle fiber membrane depolarizes, the action potential caused by this depolarization enters the t-tubules depolarizing the inner portion of the muscle fiber. This activates calcium channels in the T tubules membrane and releases calcium into the sarcolemma. At this point, <em>tropomyosin is obstructing binding sites for myosin on the thin filament</em>. When calcium binds to the troponin C, the troponin T alters the tropomyosin by moving it and then unblocks the binding sites. Myosin heads bind to the uncovered actin-binding sites forming cross-bridges, and while doing it ATP is transformed into ADP and inorganic phosphate which is liberated. Myofilaments slide impulsed by chemical energy collected in myosin heads, <u>producing a power stroke</u>. The power stroke initiates when the myosin cross-bridge binds to actin. As they slide, ADP molecules are released. A new ATP links to myosin heads and breaks the bindings to the actin filament. Then ATP splits into ADP and phosphate, and the energy produced is accumulated in the myosin heads, which starts a new binding cycle to actin. Z-bands are then pulled toward each other, thus shortening the sarcomere and the I-band, and producing muscle fiber contraction.
