• Matthias Schleiden observed that all plants were made of cells; Theodor Schwann observed that all animals were also made of cells; and Rudolf Virchow observed that cells only come from other cells.
• Prokaryotic cells- don’t contain a nucleus or any other membrane-bound organelle. Eukaryotic cells- contain membrane-bound organelles, including a nucleus.
• Phospholipids make up the basic structure of a cell membrane and are arranged in a double layer called the lipid bilayer.
• Active Transport- moves ions from low concentration to high, using metabolic energy in the form of ATP. Passive Transport - moves ions from high concentration to low, using no metabolic energy.
The best way to determine if these populations form part of the same species is to study the existence of reproductive isolation between populations. Moreover, the result of an experiment based on the study of reproductive barriers may be complemented with molecular biology approaches that determine the level of sequence homology between populations
