Answer: D) The amount of air in a room never changes.
Explanation: Equilibrium is defined as the state in which the concentration of reactants and products is constant or the rate of forward direction is equal to the rate of backward direction.
a) The percentage of nitrogen gas in a room decreases steadily: the amount decreases that means the reaction is taking place in one direction and hence the reaction is not in equilibrium.
b) A blade of grass grows taller : the plant gets taller that means the reaction is taking place in one direction and hence the reaction is not in equilibrium.
c) The amount of water in a cup decreases as it evaporates: The amount of water is decreasing that means the reaction is taking place in one direction and hence the reaction is not in equilibrium.
d) The amount of air in a room never changes: the amount of air does not change as the amount of air leaving the room is same as that of the air entering the room and hence the reaction is in equilibrium.
Answer:
All cells share four common components: (1) a plasma membrane, an outer covering that separates the cell's interior from its surrounding environment; (2) cytoplasm, consisting of a jelly-like region within the cell in which other cellular components are found; (3) DNA, the genetic material of the cell; and (4)
Explanation:
Answer:
External means on the outside, so it can be something like their fur color. Some other features can be number of legs, if they have wings or not, etc.
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
