Answer:
The most common elements, like carbon and nitrogen, are created in the cores of most stars, fused from lighter elements like hydrogen and helium. The heaviest elements, like iron, however, are only formed in the massive stars which end their lives in supernova explosions.
Explanation:
Answer:
Details about DNA are given in the explanation section. Hope it will be helpful for you.
Explanation:
DNA, or deoxyribonucleic acid, is the hereditary element in humans and almost all other organisms. Nearly every cell in a person’s body has the same type of DNA. Most DNA is found in the cell nucleus (nuclear DNA), but a small quantity of DNA can also be found in the mitochondria (mitochondrial DNA or mtDNA).
The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same type in all people.
DNA bases pair up with each other, A with T and C with G, to form units that are called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. A base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix.
A valuable feature of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases.
Answer:
(D) Strenuous exercise has caused her body to be in oxygen debt, and she is breathing hard while lactate is transported to the liver. This is a result of anaerobic respiration.
Explanation:
As Frida was exercising, her muscle cells were undergoing a frantic pace of metabolism (contraction and relaxation), where oxygen supply did not supply the required effort, thus causing muscle fatigue and heavy breathing.
Physical activity is synonymous with moving muscles. The more muscle fibers strive to accomplish a task, the more they consume the oxygen brought into the bloodstream. When this occurs, the body begins to breathe hard as lactate is transported to the liver.
This forces the lungs to work at a fast pace, as they are responsible for oxygenation. The heart also speeds up because it needs to pump blood more vigorously. This is why during exercise the heart rate and breathing rate increase and we breathe heavily.
Respiration is a chemical reaction that takes place in cells and allows them to release energy. Reactants are the substances that react together in a chemical reaction. In respiration the reactants are glucose and oxygen.
Ductus Arteriosus is a blood vessel normally present in fetuses during development. The blood vessel is designed to bypass the pulmonary artery and brings blood to the Descending Aorta, as the fetus cannot breath through the lung (being as they are fluid filled). This is normally not a problem because oxygenated blood comes from the mother's blood supply.
Patent Ductus Arteriosus, is what happens when that vessel does not close. While not as dangerous as other congenital defects. However, because there is still a bypass, blood that normally need to be oxygenated by going through the pulmonary arteries to the lungs, can be diverted and placed into the blood stream without vital oxygen. This condition may eventually lead to CHF (congestive Heart Failure) and Pulmonary Hypertension if not treated.
