Question

For items 8 to 10, refer to the situation below: Sam wished to investigate how fertilizer run-off affects the growth of algae in freshwater lakes and streams. He set his experiment this way. He placed 900 ml of water into each of five 1000 ml glass bookers. To each beaker he added 5 ml of water from an aquarium which contains a large concentration of algae. The beakers were placed under a grow light which was timed to provide 12 hours of light each day. Liquid fertilizer was odded to the beakers in the following amounts:

Beaker A - 8 ml fertilizer
Beaker B - 6 ml fertilizer
Beaker C - 4 ml fertilizer
Beaker D - 2 ml fertilizer
Beaker E - no fertilizer
Each week a random sample from each of the beakers was examined under a microscope to get a count of the number of algal cells present.

8. Which of the following is the control group for this experiment?
A. Beakers A & B
C. Beaker D
B. Beakers B & C
D. Beaker E

9. What is the dependent variable?
A. Amount of water
C. The size of the beaker/container
B. Amount of liquid fertilizer used
D. The number of algal cells present

10. Which variable is manipulated by the researcher in the experiment?

A. Amount of liquid fertilizer C. Amount of water B. The size of the beaker D. Amount of light​

Answer 1

Correct answer:-

Sam wished to investigate how fertilizer run-off affects the growth of algae in freshwater lakes and streams. He set his experiment this way. He placed 900 ml of water into each of five 1000 ml glass bookers. To each beaker he added 5 ml of water from an aquarium which contains a large concentration of algae. The beakers were placed under a grow light which was timed to provide 12 hours of light each day.

hope it helps ✅✅✅

#MichAditi✨✌️