SA Node<span> which is also known as the sinus node, is the natural pacemaker of
the heart. It controls the heart rate by generating electrical impulses
and then sending electrical signals through the heart muscle, causing
the heart to contract and pump blood throughout the body. </span>
The SA Node is located in the outer layer of the right atrium of the heart, near the superior vena cava. It is made up of a group of cells (myocytes) positioned on the
wall of the right atrium, at the center of the heart and near the
entrance of the superior vena cava. These cells contract at a rate of
about 70-80 times per minute, which make up the natural heart beat.
Answer:
C) Because apoptosis genes kill cells, natural selection is seldom involved in apoptosis pathways.
Explanation:
Apoptosis is a natural process taking in the cell which causes the physiological and biochemical changes in the cell which could cause the death of the cell.
The apoptosis is controlled at the genetic level therefore apoptosis is also known as the programmed cell death.
The studies have shown that the process is involved in the development of the finger and the toes in humans and the sequences controlling the process has been conserved during the evolution in a different organism.
This shows that humans and nematode have the same conserved sequence of apoptosis but the natural selection does not control the apoptosis.
Thus, the selected option is the correct answer.
Answer: "To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells."
Answer:
If wolfs were absent from their environment the food they eat like rabbits for example would be overabundant and eat all the plants and not leave any food left for other animals that need it and those animals would die.
Explanation:
Answer: prokaryotic cells
Explanation:
