Answer:A. The release of calcium ions causes myosin and actin to attach to each other.
The contraction of skeletal muscles takes place by induction of a nerve impulse, which produces a movement and the interaction of the filaments containing proteins named as actin and myosin. This interaction of filaments is regulated by proteins called tropomyosin and troponin present on the actin filaments. The motor nerve causes the depolarization of the muscle membrane sarcolemma. This triggers the sarcoplasmic reticulum to release calcium ions. This calcium binds to troponin and thus allows the tropomyosine strand on the actin filament to displace so that the part of the actin where myosine head needs to be attached remain uncovered. Binding of the actin myosine filament results in contraction.
Hence, the release of calcium ions causes myosin and actin to attach to each other causes muscle contraction.
Adaptation is a phenomenon that is about adjusting certain features to environmental conditions. Ie. birds are adapted to flight as they possess wings, very efficient lungs etc. or tropical plants are adapted to high temperature and humidity as they modified their photosynthesis process. but if some creature is adapted to the specific habitat or conditions, it is hard for it to manage in another habitat/different conditions. ie. birds are fast in the air but on the ground they are quite weak and prone to predators' attacks.
The answer is c it's the best one
Answer:
Human interaction with the ecosystem has rapidly spread disease to Yellowstone's wildlife, which has proven to have adverse effects on populations. Also, humans tend to leave trash in poor areas. Littering is a problem in Yellowstone because it can be ingested by the wildlife and also pollute the park.
Explanation: