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.
Selective breeding is the traditional method for improving crops and livestock, such as increasing disease resistance or milk yield.
Genetic engineering is a faster way, which transplants genes for a desired characteristic into an organism. However, genetic engineering offers many potential benefits but carries the risk of unexpected harmful effects.
Answer:
what do you mean don't understand
Explanation:
you're not telling good information
True
A diploid is a cell that contains two haploid sets of chromosomes
The pulmonary vein carries oxygenated blood from the lungs to the left atrium
