The EKG will show up very unnormal and will change the pattern.
Answer:
performing a controled experiment
Explanation:
this is because they can experience it themselcves, without having risk of external disturbance that would change tha outcome
The answer is most likely: 'with an abundance of plant life without oxygen in the atmosphere '. The atmosphere contained almost no free oxygen during the Archean. It does not appear as if this epoch had an abundance of plant life, but rather mats of single-celled photosynthesising cyanobacteria. So I am not completely sure that either of the given choices are correct.
The answer is step 3. Nerve impulse on a muscle cell induces release of calcium ions
Steps of a muscle contraction are:
1. Nerve impulse travels down the axon and causes a release of acetylcholine.
2. Acetylcholine binds to the receptor of a muscle cell.
3. Nerve impulse on a muscle cell induces a release of calcium ions.
4. Calcium ions induce exposing of myosin to actin.
5. Sliding of actin filaments past myosin filaments.
6. The muscle contract.
