Which statement accurately describes bioaccumulation: 1) a substance, such as a pesticide, collects in the body of an organism over time.
2) the concentration of a substance increases as it moves up the food chain
3) a method to get rid of an invasive species in an ecosystem
4) pesticides in the soil, air and water become sources of pollution.

1

Explanation:

I think its the first one because I learned this before and the first one seems reasonable

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.