Answer: I think it‘s 1, it just makes more sense. Sorry if I am wrong but hope this helps anyone.
Answer:
In nature, populations are usually evolving. The grass in an open meadow, the wolves in a forest, and even the bacteria in a person's body are all natural populations. And all of these populations are likely to be evolving for at least some of their genes. Evolution is happening right here, right now!
To be clear, that doesn't mean these populations are marching towards some final state of perfection. All evolution means is that a population is changing in its genetic makeup over generations. And the changes may be subtle—for instance, in a wolf population, there might be a shift in the frequency of a gene variant for black rather than gray fur. Sometimes, this type of change is due to natural selection. Other times, it comes from migration of new organisms into the population, or from random events—the evolutionary "luck of the draw."
I hope this helps a little bit.
Answer: feed-back
When the product of a metabolic pathway accumulates, it may be able to slow down or turn off the pathway by inhibiting the activity of an enzyme that catalyzes an early step in the pathway. This is referred to as feed-back inhibition.
Explanation:
Feed-back inhibition is said to occur when the final product of a biochemical pathway signal the inactivation of the starting materials of the pathway.
For example: when pyruvate signal the inactivation of phosphofructokinase, the glycolytic pathway gets turned off.
Answer is b. Burning fossil fuels causes a decrease in the pH of ocean water making it more acidic.
Burning of fossil fuels release carbon dioxide and other harmful gases in the atmosphere. Carbon dioxide gets dissolves in the ocean to form carbonic acid. Due to formation carbonic acid, the pH of ocean water changes slightly. The average pH of ocean water was 8.2 slightly basic. Now it 8.1, it means there is 25 % increase in acidity of ocean water.
