Answer:
Keratin has two main functions: to adhere cells to each other and to form a protective layer on the outside of the skin. In epithelial cells, keratin proteins inside the cell attach to proteins called desmosomes on the surface. The desmosomes act as anchors, holding the cells together.
Potential gravitational energy is computed with the formula:

Where:
PEgrav = Potential gravitation energy (J)
m = mass (kg)
h = height (m)
g = acceleration due to gravity (9.8m/s^2)
Take note that acceleration due to gravity is a constant.
All you need to do is put in what you know and solve for what you don't know. So your given is the following:
PEgrav = 3,528J
m = 24 kg
g = 9.8 m/s^2
Put that into your formula:




The height of the cliff is 15m.
the answer to your question is the amount of time and the effect it has on each material as well as the fact that the nitrogen cannot change it is an unchangeable variable whereas everything else the time, the substance of the subject, the possible formation of nodules can change without changing the identity of the experiment itself otherwise, you have a dependent variable. I hope this helps :-)
The reproductive isolating mechanism most likely responsible for the divergence of bonobos and chimpanzees is ECOLOGICAL ISOLATION.
The ecological mechanism of reproductive isolation is also known as TEMPORAL ISOLATION or HABITAT ISOLATION. This includes the barrier for reproduction that leads to isolation such as different habitats or any physical barriers.