Natural selection means that the organisms better adapted to their environment, that is, they have developed the right characteristics/skills/response to the external ambient, have higher chance to survive, making the next generations genetically inherit such acquired surviving characteristics.
These generations will thus have a higher chance of survival, making these species being "naturally selected" as survivors, while those who haven't or are slower in this process, have a higher risk of elimination.
<u>Answer</u>: Cystic fibrosis is a genetic disorder that causes thick mucus secretions.
<u>Explanation</u>:
- <em>Cystic fibrosis</em> is a genetic disorder caused by mutations in a gene that makes a protein called CFTR (cystic fibrosis transmembrane regulator).
- The CFTR protein normally functions as a channel for transport of chloride ions in cells responsible for mucus production.
- A person suffering from cystic fibrosis produces abnormal CFTR protein or no CFTR protein at all.
- This is the reason that thick, sticky mucus is produced instead of the thin, watery kind.
Answer: C
The substance that must come through the cell membrane for the cell to live is nutrients. Cells would die if they did not get nutrients. Nutrients are what keeps the cell running.
