Selectively permeable (or semi permeable) means where for example a membrane can choose what material can pass through while others cannot. They control the in and out of materials.
This is because the membrane has tiny spaces, where only smaller molecules can pass through, other larger ones cannot.
(1) they keep toxic substances out of the cell;
(2) they contain receptors and channels that allow specific molecules, such as ions, nutrients, wastes, and metabolic products, that mediate cellular and extracellular activities to pass between organelles and between the cell and the outside environment;
(3) they separate vital but incompatible metabolic processes conducted within organelles.
Diverging plate boundaries, earthquakes occur as the plates pull away from each other. Volcanoes also form as magma rises upward from the underlying mantle along the gap between the two plates. We almost never see these volcanoes, because most of them are located on the sea floor.
Answer:
The main difference is that EUKARYOTIC cells <em><u>have</u></em> a nucleus while a PROKARYOTIC cell <em><u>does not</u></em>. Instead, prokaryotes have free floating genetic material.
Explanation:
To help you remember this distinction:
EU = YES eukaryotes <em><u>HAVE</u></em> a nucleus.
PRO = NO prokaryotes <em><u>DO NOT</u></em> have a nucleus.
I hope this helps and good luck with your assignment.