Answer:
Semi-permeable membrane
Explanation:
In semi-permeable membranes, only some substances can pass through. Sometimes, some can also pass through the channel protein molecules or transport proteins on the cell membrane.
Using energy is the answer to this question :)
Every cell of the organism has the same DNA sequence and same genes. However, not all genes are expressed in every single cell at the same time. Only those genes necessary for a specialised function of a specialised cell are expressed in the specialised cell. For example, skin cells have some different proteins than nerve cells. Genes responsible for those "skin proteins" are activated in skin cells and are turned off in nerve cells.
Yes, as scientists could figure out what might have changed in the variables she used. Brainliest me and I can give you the whole system.
