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There are 5 stages of the sleep cycle, and each stage lasts about 5-15 minutes long (usually around 10-15, though).
And that's youd answer! ^
The early shape of the fetal brain most resemble a tube. The fetal development starts after conception. After about four weeks the neural tube together with the back is closing. The fetal brain and the spinal cord will develop from the neural tube. Then the other organs and the heart are also starting to form.
A, turning on gene expression
Answer: B. The release of calcium ions causes myosin and actin to attach to each other. This statement best describes a cause and it's effects that occur during the process of muscle contraction.
Muscle contraction can be explained by sliding filament theory.
1. Activation of muscles: the motor nerve generates an impulse to transfer signals from neurons to neuromuscular junction. This stimulates sarcoplasmic reticulum to release calcium into the muscle cells.
2.Contraction of muscles: calcium in the muscle cells binds with troponin causes actin and myosin to bind. Actin and myosin in the muscle binds and contract by utilizing ATP as a source of energy.
Frame shift, possibly new amino acids instead of the original
