Parietal cells produce gastric acid (hydrochloric acid) in response to histamine (via H2 receptors), acetylcholine (M3 receptors) and gastrin (gastrin receptors). Parietal cells contain an extensive secretory network (called canaliculi) from which the HCl is secreted by active transport into the stomach.
Answer:
B.Active transport, because energy is being used to move molecules against the concentration gradient
Explanation:
Substances move in and out of living cells through various transport means. Some substances move passively (without energy) while others move actively (with energy). Active transport of substances involves the movement of molecules against the concentration gradient.
Active transport moves against concentration gradient in the sense that the movement occurs from a region which is less concentrated to one which is more concentrated, hence, energy input in form of ATP is required for such transport to occur. This is the case of the cellular transport in the diagram. Therefore, it is an ACTIVE TRANSPORT because energy input (ATP) is required.
Note, Osmosis and facilitated diffusion are types of passive transport that requires no energy to occur.
Answer:
- Autotrophs are usually defined as those that can prepare their own food by carrying out the process of photosynthesis, but heterotrophs cannot prepare their own food and are directly dependent on the autotrophs for food. Examples of autotrophs are plants and trees, and examples of heterotrophs are animals and human beings.
- Autotrophs are the lowest organisms in the trophic level, where they produce the food for the consumers (heterotrophs). On the other hand, the heterotrophs lie above the autotrophs and when they consume their food, they obtain only 10% of the energy, and the remaining energy is released into the environment.
- Autotrophs can make organic substances by the use of inorganic molecules, but heterotrophs cannot make these substances. They are only dependent on the molecules prepared by these autotrophs.
Thus, these are three of the facts regarding autotrophs and heterotrophs existing on earth that are true.
Grana is the term that describes stacks of thylakoids.
