Answer:
D: Short and Straightforward
Explanation:
Answer:
To move substances against a concentration or electrochemical gradient, a cell must use energy. Active transport mechanisms do just this, expending energy (often in the form of ATP) to maintain the right concentrations of ions and molecules in living cells.
Explanation:
Answer:
The acceleration of the box across the floor is 7.0588 
Explanation:
Given:
Mass of the box = 2550 gram
net force acting on the box = 18 .0 N.
To Find:
The acceleration of the box across the floor = ?
Solution:
Newton's 2nd Law of Motion states that the acceleration of an object as produced by a net force is "directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
"
Newton's Second Law formula is
F = m a
Where:
F = the magnitude of the net force, in N
m = the mass of the object, in Kilogram
a = the acceleration of the object, in 
Now substituting the values, we get
18.0 = a (2.55) [since 2550 gram = 2.55 kg]

a = 7.0588 
Answer:
D
. Energy flows from the Sun or from rocks through the primary producers and the successive levels of consumers.
Explanation:
Energy flows only through the sun not the rock because sun is the ultimate source of energy which can be used by the plants for making their own food in the form of glucose during the process of photosynthesis. This plant is then eaten by primary consumer known as herbivore. These primary consumer is eaten by secondary consumer is called carnivores. The tertiary consumer feeds on the secondary consumer and so on. In the end, decomposers feed on the dead bodies of animals and releases nutrients which can be used again by the plants for making food.