Flu vaccines need to be revised and changed every year because the flu virus constantly mutates. Flu viruses can change in two ways: drift or shift. Antigenic drift occurs when genes of the virus slowly change during replication until the immune system no longer recognizes it. On the other hand, antigenic shift occurs when a major change in the virus happens. This usually leads to a totally different kind of virus. This is what happened during the H1N1 scare in 2009.
DNA viruses like mumps are less prone to mutation due to the presence of DNA polymerase. RNA viruses are more prone to mutation because they undergo reverse transcription to simulate the role of DNA.
The cardiovascular system is a system of organs that facilitates the circulation of blood to all parts of the body. Blood is required to reach all living cells as the blood carries essential elements for cell life and regulation, such as nutrients, amino acids, electrolytes,oxygen and hormones. The blood also has a role in maintaining body temperature, fighting diseases, maintaining a stable pH and maintaining homeostasis. The blood also carries carbon dioxide away from the cells. The cardiovascular system consists of a network of arteries, veins and capillaries, as well as the heart, which acts to pump blood around the body, Blood leaves the heart via arteries and return via veins. The lymphatic system transports lymph, typically at a much slower rate than blood. The lymphatic system is an important part of the immune system. Unlike the cardiovascular system, the lymphatic system is not a closed system. The cardiovascular system processes a lot of blood each day through capillary filtration, which separates the blood cells from the plasma. Not all plasma is re-absorbed into the blood vessels, and the lymphatic system is responsible for returning the remaining plasma to the cardiovascular system. <span> </span>
Di = 2
Tri = 3
C. Since there are only 2 Phosphates, the molecule shown is ADP.
Answer:
O The neuron has more potassium ions inside than outside.
Explanation:
The membrane resting potential is defined as the difference in electrical charge between the interior of neurons and their outer environment. In neurons, both sodium (Na+) and potassium (K+) pumps contribute to generating the resting potential. Neurons have a higher concentration of K+ inside than outside and a higher concentration of Na+ outside than inside. When a neuron is at its rest state, where the inside is negative with respect to the outside, its membrane is more permeable to K+ than Na+, and therefore the resting membrane potential is closer to the equilibrium potential of K+.
They all under the kingdom animalia. The others are plantae, fungi and Protoctista.
