CENTRIOLES. Centrioles help align the chromosomes so they can be split.
1. Contraction
2. Actin
3. Tendons
4. Epidermis
5. Dermis
6. Acne
7. A nerve signal from the brain arrives at the intersection of the nerve and muscle cells and releases acetylcholine from the neuron. This triggers chemical changes in the muscle cell involving ions, including Ca2+. Calcium triggers the thick filaments, made of myosin, to attach to the thin filaments, made of actin, in the muscle cell, and the myosin pulls the actin toward the center of the muscle cell. ATP causes the release of the actin fibers, allowing the muscle to relax and the process to begin again.
For Penn Foster.
<span>An ecosystem consists of a population of organisms and its
physical environment, and a population is made up of many different
communities of organisms. Every one of the creatures of similar species
living together that live in a particular biological system are known
as a populace The people in the populace contend with one another for
sustenance, settling space, and mates.</span>
B ecosystem. They include abiotic factors and biotic factors.
