The answer is A!
Ron is showing an invalid experimental placebo in this experiment due to the positive response.
goodluck, :)
Ecosystems disturbed by a nature will be eventually restored unless it's a really big cataclysm, but most of the ecosystems are now a human caused disturbance. For example there are plenty of species which are already extinct or nearly extinct because of hunting industry.
Answer:
Answer is Sinoatrial node, SA.
Explanation:
The sinoatrial node, SA, is known to be a group of cells which are found at the top of the heart.
The electrical signal that is initiated by the sinoatrial node bring about or stimulates the atria and then the ventricle of the heart.
It should be noted that, the sinoatrial node are regarded as the pacemaker cells.
Answer: C
The substance that must come through the cell membrane for the cell to live is nutrients. Cells would die if they did not get nutrients. Nutrients are what keeps the cell running.
The materials and equipment needed and procedures to follow in an experiment is termed as experiment protocol. It <span> is a predefined written procedural method in the design and implementation of </span>experiments<span>. Hope this answers the question. Have a nice day.</span>
