Answer:
Option B, When the cell needs to move a compound against its concentration gradient.
Explanation:
A cell uses active transport when it has to transport substances against the concentration gradient across its membrane.
In active transport additional energy is used (generally provided by energy molecules like ATP) to push the substance across any membrane from low concentration side to high concentration side.
Option B is correct
Answer:
H2O
H2O
Explanation:
because the are only two hydrogen that can react to Oxygen
Atomic orbitals will fuse to new orbital that comes to be.
Option
A)
and
C)
just cross check with somet
Answer: Asteroids are a concern to earth due to the energy they posses and most catch on fire when they enter earths atmosphere, making them a fire hazard. Asteroids are considered natural disasters.
Explanation:
