Tamara is doing a scientific investigation to answer the question, "do corn seeds germinate faster at warmer temperatures than they do at cooler temperatures? " in tamara's experiment, which variables need to be held constant?

The tools/instruments, the type of seed, the soil or planting products, the amount of germination time/days, and where the seedling is placed.

Explanation:

If anything but the temperature is changed, it can result in false results. For instance, if Tamera uses red corn for one but yellow corn for the other, it can change the germination rate. So can the type of soil, water or the amount of time each plant has to grow. If she changes thermometers or any other tool she uses, it may give her a different result than the ones she used before. And finally, if she moves the warm plant from the windowsill to her bedroom, it can mess with the results she gets from the heated sample.

The tools/instruments, the type of seed, the soil or planting products, the amount of germination time/days, and where the seedling is placed.

Explanation: