Answer:
The return of blood to the heart is assisted by the action of the skeletal- muscle pump. As muscles move, they squeeze the veins running through them. Veins contain a series of one-way valves, and they are squeezed, blood is pushed through the valves, which then close to prevent backflow.
The structure that serves as the cell's boundaries from its environment is known as the CELL MEMBRANE. It keeps the bad things from coming in, and releases waste out into the environment.
<span>Answer: cell membrane</span>
The pyramid of biomass represents a range of food webs found in one trophic level
A pyramid of biomass refers to graphical representation of biomass that is present per unit area of all the various trophic levels of the ecosystem.
<h2>Further Explanation</h2>
The graphical representation shows the relationship between biomass and trophic level that quantify the biomass that is present in each trophic level of energy community at a given period of time.
There are two types of pyramid of biomass, they include
- Inverted pyramid of biomass
- The upright pyramid of biomass
Inverted pyramid of biomass: a very good example of inverted pyramid can be seen in a case of pond ecosystem, where major producers in the ecosystem (mass of phytoplankton) will be lower than the mass of heterotrophs, such as insects.
The upright pyramid: The first thing on the upright pyramid is the producers, such as plants. The plants are present at the bottom level of the pyramid and followed by consumers.
Within the pyramid, the highest level is occupied by the carnivores; they are the lowest quantified amount of biomass. In upright pyramid the total weight of the producers is far more than when the weights of all the consumers are combined.
However, the main issues with the pyramid of biomass are that every trophic level of the pyramid seems to have more energy than it does.
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KEYWORDS:
- pyramid of biomass
- trophic level
- consumers
- graphical representation
- ecosystem
Answer:
brainliest answer if correct
Explanation:
plants
proteins
