Internal regulators allow the cell cycle to proceed only when certain processes have happened inside the cell. ... Cancer cells do not respond to the signals that regulate the growth of most cells. As a result, they divide uncontrollably and form masses of cells called tumors that can damage the surrounding tissues.
Answer:it was very effective.
Explanation:
According to report in America 1954, Salk conducted a national study, with over a million paediatric subjects wish yielded a positive outcome and on 12 April 1955, the vaccine was considered safe and efficacious. in 1955, the vaccines was used for over 29,000 cases of poliomyelitis in the US and the infection rate reduced to less than 6,000. This made Salk vaccine more recognized and it was speedily adopted worldwide reaching almost 90 countries in less than 2 years after it mass production.
Answer:It is known as a concentration gradient which in diffusion will always flow from ares of high concentration to areas of low concentrations
So i believe the answer to this is A.
Explanation:
Answer:
I'm not sure what is unclear but I can try to help...
Explanation:
So the group is the number at the top and is verticle. So H,Li,Na, and K share the same Group, 1.
The period is the number at the side and is horizontal. Soo H and He are Period 1.
Now using this information we can find the specifics of each element.
Chlorine, for example, is Group 17A and Period 3 because it matches those.
Let me know if you need further explanation :)
The correct answer is emphysema.
Emphysema is the enlargement of air sacs in the lungs.
It is a long-term, progressive disease of the lungs that primarily causes shortness of breath. People who have emphysema, their air sacs in the lungs (alveoli) is damaged. Over a period of time, the inner walls of the air sacs weaken and rupture creating larger spaces instead of many small ones. Normally, the lung tissue holds these small airways called bronchioles, open, allowing air to leave the lungs on exhalation. However, when the lung tissue is damaged like in the case of emphysema, these airway collapse, making it difficult for the lungs to empty and the air (gases) becomes trapped in the alveoli thus causing impaired gas exchange.