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.
Oncogenes result from turning on, or activating proto oncogenes. Proto oncogenes are genes that code for positive cell cycle regulators, so proto oncogenes code for proteins that turn on cell division. Proto oncogenes are normal genes, but when they are mutated, they become oncogenes. Oncogenes are expressed too much, which makes them turn on cell division too much, which is cancer.
Answer:
Cell respiration begins with Glycolysis
.
Explanation:
Glycolysis is the first and initial step in the cellular respiration. Cellular respiration is the anaerobic process, which takes place in cytosol of the cells. Two molecule of pyruvate(CH3COCOO-) are formed from 1 molecule of glucose(C6H12O6)through glycolysis. The NADH and ATP are high energy molecules formed when the free energy are released. It is the process which takes place through a series of ten enzyme catalysed reactions. 10 enzymes are required to break down the sugar molecule. It occurs in cytoplasm.
<span>Which one of the following statements does not accurately describe vibrations?
</span>A: Forced vibrations, such as those between a tuning fork and a large cabinet surface, result in a much lower sound than was produced by the original vibrating body.
The fir tree can be found in the coniferous forest biome, and the cactus can be found in the desert biome.
Option C.
<h3><u>Explanation:</u></h3>
Both the cactus and fir trees are having modified tree leaves due to the same purpose - saving water.
The fir trees are found in the coniferous forests which are mainly seen in mountains or in the temperate region. Both the regions face very cold climates and frequent snowfalls in every years. This is why there's a lack of water in the surroundings. This is why they need to save water and minimize transpiration.
Whereas the cacti are found in desert or semi arid regions where water is itself very scarce and temperature is either very high or very low. So they have their leaves converted into spines which help to reduce transpiration.
