Answer:
For a muscle cell to contract, the sarcomere must shorten. However, thick and thin filaments—the components of sarcomeres—do not shorten. Instead, they slide by one another, causing the sarcomere to shorten while the filaments remain the same length. The sliding filament theory of muscle contraction was developed to fit the differences observed in the named bands on the sarcomere at different degrees of muscle contraction and relaxation. The mechanism of contraction is the binding of myosin to actin, forming cross-bridges that generate filament movement.
Explanation:
<span>The term "warm-up" describes?
- light-aerobic and cardiovascular activities done to prepare for more rigorous activities
</span>
Answer:
sea star
Explanation:
Pharyngeal arches are organs that only invertebrate chordates have. The only invertebrate chordate among these options is C. sea star, also known as starfish, so I would say that is the organism that develops breathing organs from pharyngeal arches.