The correct answer is C. The temperature of the water
Explanation:
In an experiment such as the one described about the speed of snails in water, the manipulated variable is the factor or element that is manipulated on purpose. This means the researcher or researchers slightly change this element to compare how this affects another variable. In this context, the manipulated variable is the temperature of the water because researchers used three different temperatures (cool, room-temperature, and warm), and therefore they manipulated or changed this factor. Moreover, it is expected temperature affects the distance nails move, which is the main variable.
12/20 is the answer I think. I hope this helps you!!
The correct answer is absence of jaws.
Lampreys and hagfish are in the class Agnatha, they are jaw-less fish. The members of the agantha class are probably the earliest vertebrates. Scientists have found fossils of agnathan species from the late Cambrian period that occurred 500 million years ago.
Answer: False
Explanation:
Some organisms have an advantage with some traits, but they could be a disadvantage in other situations.