Which of the following is the effect to contractile vacuole when Amoeba sp is placed in salt water? A. Burst and die
B. Stop contracting
C. Contract at fast rate
D. Contract at slow rate

Which of the following is an oxidation-reduction reaction? (pictured below)

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

What drives an advertising campaign?