Answer:
They are used as an indicator organism for pathogenic bacteria.
Explanation:
Coliforms are bacteria found in digestive tract of animals and humans. They are non-pathogenic, easy to culture and are used as an alternative indirect testing for presence of other microorganisms. Coliforms thrive in exact environmental conditions like other pathogenic bacteria, thus often used to indicate whether they are bacteria found in drinking water and swimming pools that might end up causing infections.
Therefore the existence of coliforms in water easily indicates feacal contamination.
Smog is an abiotic factor affecting a biotic factor(s).
This is because smog isn't a living organism so it is abiotic while humans are multicellular organisms so therefore, they are biotic factors.
Smog has a negative effect on many biotic factors.
Answer:
In this experiment, you changed the number of worms in the soil and measured the effect of this change on the plant growth in the population.
The independent variable was the number of worms, and the dependent variable was the plant growth.
Explanation:
right on edge!
Answer:
D. Lots of people die. Lots of people are born to make up for it. We can see this from the high orange and purple lines.