No, cells are very complex. They are composed of highly specialized organelles that each have different functions.
Answer:
of diffusion
Explanation:
Molecules move down a concentration gradient without the need to use energy. This means they move from a high concentration to a low concentration. This occurs across a semi-permeable membrane, like the cell membrane, by simple diffusion.
Answer:
1, 4, 5 are true. 2, 6, 7, 9 are not true. 3 and 8 are not known.
Explanation:
According to the information we have gathered from the vehicles sent to Mars and the data they collected and analyzed, "Minerals of types known to form in liquid water" on Mars. There is "abundant water ice" and also "dried-up river beds".These statements actually exist.
"Surface pools of liquid water" does not exist on Mars. "A network of straight-line canals", "cities built by an ancient civilization" and "frequent rainfall and snowfall" also do not exist on Mars according to the data.
We do not have any information to prove the existense of "underground pockets of liquid" and "microscopic life" but they are possibilities.
I hope this answer helps.
<span>Cells control cell division in order to maintain normal cell function. If something happens to the control of the cell division, the healthy cells will divide uncontrollably. These new cells are cancer cells. </span>
The mutations in three genes are responsible for development of cancers:
1. Mutation in proto-oncogenes. Proto-oncogenes normally signal cells to grow and differentiate. Proto-oncogenes can become oncogenes due to mutations which result in the uncontrollable division of the cells.
2. Mutation in tumor suppressor genes. In normal cells, tumor suppressor genes suppress genes essential for cell cycle and that way they prevent uncontrollable cell division. However, after a mutation in these genes, suppression is lost and the cell may progress to cancer.
3. Mutation in stability genes. In normal cells, they have no role either in cell death or growth, but they control mutation rate. Mutation in stability genes results in situation where all genes, including proto-oncogenes and tumor suppression genes, are more frequently mutated.
Answer:
Proximal tubule
Explanation:
Calcium is an important element in the body with majority of its percentage located in the bones. Its ions perform different functions in the body which includes muscle contraction, hormones secretion and including all other functions.
Calcium ion is absorbed in the intestines and then reabsorbed in the kidney. Much percentage of calcium ions is reabsorbed by passive mechanisms in the proximal convoluted tubule of the kidney tubule as compared to all other parts of the kidney tubule.
