How would Earth’s mantle and crust be different if they did not contain radioactive isotopes? (at lest three sentences)

lysosomes contain a variety of enzymes, enabling the cell to break down various biomolecules it engulfs, including peptides, nucleic acids, carbohydrates, and lipids (lysosomal lipase). the enzymes responsible for this hydrolysis require an acidic environment for optimal activity. hope i !

a- multicellular

b-eukaryotic

c-no cell wall

d-heterotrophic

e-autotrophic

looks like the answer is     c     to me!

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.