Astudent wants to test the effect of nitrogen rich fertilizers on the growth of rose bushes. which of the following is a variable that must be kept constant?

growth of the rose bush
amount of water the rose bush receives
the use of nitrogen rich fertilizer

What mistake did john needham make that caused him to conclude that spontaneous generation for microorganisms occurred? a. he re-contaminated his boiled broth solutions. b. he destroyed the vital force in the solutions. c. he did not boil his broth solutions, only warmed them. d. he failed to seal his flasks of boiled broth. e. he allowed his assistant to conduct the experiment which he did not monitor closely.

In meiosis ii during anaphase ii which structures separated homologous chromosomes or sister chromatids

The wind is to parities grasses because it them