Answer:
D. Molecules called pumps function to control active transport.
Explanation:
Active transport is one of the two types of transport (the other being passive transport). It is the type of transport in which substances move against their concentration gradient i.e. from a lower concentration to a higher concentration. Hence, due to this, energy input in form of ATP is required by the cell.
However, the process of active transport makes use of certain molecules called PUMPS to control it. The pumps moves ions/molecules against their concentration gradient. An example is the sodium-pottasium pump which moves sodium ions from a region of low conc. to a region of high conc.
<span>It binds itself to the receptors present on the surface of the cell membrane, which activates the enzymes present inside cell. Then It passes through the cell membrane and attaches itself to a receptor protein present in the cytoplasm.
It passes on the signal to the secondary messengers inside the cell, which activate the receptors on the cell membrane.</span>
Answer:
Velocity
Explanation:
Given the change in positive (direction) over time we are given the velocity formula.
V = Change in direction/Change in time
Since we are given a direction we can rule out speed as well as direction in itself. We can also rule out acceleration because that is the change in Velocity divided by change in time.
The Grand Canyon is made of sedimentary rock that contains fossils up to 1 billion years old. and the several upper layers of rock contain terrestrial, or land-based, fossils, such as dragonfly wing impressions and the footprints of scorpions, centipedes, and reptiles
