Question

julia wants to determine if temperature affects the growth of bacillus subtilis (b. subtilis). after preparing five petri dishes with equal amounts of nutrient agar, julia transfers one drop of b. subtilis broth culture into each petri dish. as shown in the table, she places each petri dish at a certain temperature. julia measures and records the growth of the bacteria in each plate every day for two weeks. temperature and total growth dish 1 dish 2 dish 3 dish 4 dish 5 10°c 20°c 30°c 40°c 50°c 3 colonies 5 colonies 9 colonies 11 colonies 8 colonies what is the independent variable in this example? the length of time the bacteria are observed the number of b. subtilis colonies the species of bacteria the amount of nutrient agar the temperature

Explanation:

An independent variable is what is changed or controlled in a scientific experiment. Here, Julia changes the temperature for each Petri - dish to see its effect on B. subtilis growth. Other factors like the length of observation, species of bacteria, and amount of nutrient agar are kept constant. The number of colonies is the dependent variable (changes based on temperature).

Answer:

the temperature