What is defined as the variable in a controlled experiment that is purposely changed or manipulated? PLEASE HELP!! constant
independent variable
controlled variable
dependent variable

Ecologist have observed a sharp increase of sulfur dioxide in the air . what might be a possible consequence of excessive sulfur dioxide in the air ? a. acid rain b. ozone layer depletion c.ozone layer hole d.increase in sea levels

In pea plants, the allele for inflated pod seed, i, is dominant over the allele for constricted pod seed, i. the punnett square shows a cross for this trait. which offspring will be homozygous dominant

Which are reasons cells undergo cell division?