Answer:
An extreme version of scoria occurs when volatile-rich lava is very quickly quenched and becomes a meringue-like froth of glass called pumice. Some pumice is so full of vesicles that the density of the rock drops low enough that it will float
Explanation:
Answer:
The heat they lose is proportional to the surface area of their bodies, while the heat they produce is proportional to their mass. This means that larger warm-blooded animals can generate more heat than they lose and they can keep their body temperatures stable more easily.
Answer:
Flu vaccinations are fundamental as they reduce the risk of flu illness by over 50%.
Explanation:
Flu vaccinations reduce the risk of flu illness by over 50%. This makes this process extremely important and fundamental for all human beings as they not only protect the person who gets the vaccine, but it also contributes to the prevention of spreading to other people, especially children and older adults who possess a greater risk of developing flu complications.
The antibodies that are produced by the vaccine prevent the flu virus from attaching to a healthy cell. However, if a person has not been vaccinated, the virus will attack the healthy cells because there is an absence of antibodies that prevent this process.
Answer:
Option B, 2 percent
Explanation:
Complete question is
In a community, autotrophs generate 1,000 calories per hour of GPP and 500 calories per hour of NPP. Primary consumers convert 10 calories per hour into their own biomass. What is the ecological efficiency in the link between autotrophs and primary consumers in this community?
1 percent
2 percent
20 percent
10 percent
Solution
Given
Autotrophs generating calories per hour of GPP 
Autotrophs generating calories per hour of NPP 
The rate at which the primary consumers convert calories per hour into biomass is equal to
calories per hour
The ecological efficiency is equal to" the rate of calorie conversion to biomass" divided by the net produced calories multiplied by 
Rearranging the above relation in a mathematical equation, we get -

Hence, option B is correct