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.
B and D. The xylem and the phloem make up the vascular tissue of plants and transport water, sugar, and other important substances around a plant.
The cells that die are emptied, leaving hollow cell walls with their ends open, thus forming pipe-like structures
Hope this helps
Answer: living things such as “human beings”, “animals”, “plants”, and “microorganisms”.. Nonliving things do no exhibit any characteristics
Explanation: Nonliving things do not grow,respire, need energy, move, reproduce, evolve, or maintain homeostasis. They are made up of non living materials
Amino acids is the correct answer (:
I would say that answer choice C is the best out of this selection. Carbon is the main element in organic compounds, and organic compounds just so happen to make up the cells that carry out life processes for all living things. Hope this helps.
