The exchange of matter or substances between the cell and its environment is dynamic as it varies in direction and rate as per the requirements of the cell. Thus,a cell attains a stead -state wherein the internal conditions of the cell remain constant. Hence, cell is considered to be a open dynamic system
An example of something that does not have mass would most likely be air. Because in order for something to have mass, it must take up space and have shape. Anything that you can think of that does <u>not</u> have <u>space or shape</u> does not have mass.
I believe it has something to deal with helping the zebras adapt to their surroundings.
Darwins observations explain that zebras have stripes to adapt to their surroundings.
1. I think it is C
2. Possibly A, as shale is a sedimentary mineral
3. C possibly
4. C, obsibian, very glossy and fine, i have some at home, so i know the charactisitics
5. C
Night. they are closed during the day. hope this helps
