What do the polar bears, reindeer, and shrubs that live in a single area make up? organism
population
community
ecosystem

The arrangements of lipids in the membrane makes the cell semi permeable .

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass

Closing a ring restricts the rotation around individual car bon carbon bonds hope it will you !

Yes, take risk in life