Answer:
It means that the cell membrane allows certain substances to pass through and not others. As the cell membrane consists of a phospholipid bilayer with a hydrophobic core, only small uncharged hydrophobic molecules can pass through the cell membrane e.g. glucocorticoid and other larger charged particles require transporters or channel proteins to pass through the cell membrane, e.g. glucose.
Answer:B, D
Explanation:
When the roller coaster starts flying down the hill, it gains kinetic energy and loses potential energy.
Answer:
Prokaryotes are organisms that consist of a single prokaryotic cell. Eukaryotic cells are found in plants, animals, fungi, and protists. They range from 10–100 μm in diameter, and their DNA is contained within a membrane-bound nucleus. Eukaryotes are organisms containing eukaryotic cells.
Explanation:
Answer:
Bacteria
Explanation:
Bacteria have no true nucleus because it's a prokaryote. It couldn't have been a virus because all naturally occurring viruses are pathogenic unless treated by radiation.
We have two types of bacteria,
- Pathogenic
- Commensals
Pathogenic bacteria will definitely cause disease. Commensals, however, have don't harm us and have the ability to help us.
Eg: Flora (bacteria) in our intestines produce vitamin K and most of the vitamin B complex. They also compete with the pathogenic bacteria that you might've ingested and don't allow them to increase to the number that can cause disease.