Answer:
c) Combustion of fossil fuels
Explanation:
Burning of fossil fuels is the main cause of increasing carbondioxide concentration in the environment which results in air pollution. This increase in carbondioxide concentration absorbed more heat energy from reflected solar radiation which increases the temperature of earth surface causes global warming. Due to this global warming, snow melting occurs on the poles of the earth which increases sea level.
Answer: It’s definitely not D. I’m thinking A or C
Explanation:
Because survival of the fittest mean that the ones that aren’t the best will die basically. So that why it’s not D
Answer:
I wasn't quite sure what virus you were referring to in your question, but here's a general answer: Viruses use their host cells' machinery to replicate themselves.
If they are a specific type of virus known as a retrovirus, they have the ability to use the host cells' enzymes to change the RNA contained within the virus into DNA (via some type of replication I suppose).
In other cases, if they contain DNA instead of RNA (that is, the virus), they can use the host cell's machinery to create RNA via enzymes involved in transcription and/or they can incorporate that DNA into the host cell's DNA. This is part of a type of viral replication cycle known as the lysogenic cycle.
In another type of viral replication cycle known as the lytic cycle, the virus simply has itself and its genome duplicated until the host cell bursts, releasing the viral material. Here, again, the virus uses the host cell's machinery to replicate itself.
This questions seems like its missing other parts
Answer: Water can hold an unlimited amount of oxygen.
Explanation:
Water cannot hold an unlimited amount of oxygen because it would get to a point where it is saturated as it needs to hold Hydrogen as well. Air on the other hand, has significantly more space for oxygen as it contains only 21% and can keep taking more.
Underwater organisms need oxygen for respiration and a small decrease in the oxygen available in water affects aquatic life because they rely on it to survive.
