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.
Answer:
The correct answer is - 1/2
Explanation:
the ability to roll the tongue is dominant over those who can not roll the tongue. The man is Rr (man), heterozygous. The woman is recessive and can not roll
Rr (man) x rr (woman)---Parents
r
R Rr (roll)
r rr (cann't roll)
The probability of their children to able to roll = 1/2 = 50%
Theory of adaptation is valid because scientist can see facts that supported the theory. Adaptation makes organism survive especially in this rapid changing world. For instance, parts of human anatomy like appendix and tail bone were still present in humans but are no longer functional.
