Answer:
DNA replication needs to occur because existing cells divide to produce new cells. Each cell needs a full instruction manual to operate properly. So the DNA needs to be copied before cell division so that each new cell receives a full set of instructions!
Answer: True
Explanation: The plasma membrane is a membrane the protects the cell and its environment. It regulates what goes inside and what comes out of the cell. .
Plasma membrane as a structure composed of multiple components, including phospholipid bilayer, carbohydrates, and other lipids. The phospholipids possess one head and two tails. The head is basically polar and hydrophilic (water-loving) while the tails are non-polar and hydrophobic (water-fearing).
The plasma membrane is decorated with proteins. Some protiens are extrinsic proteins that run halfway through the membrane, while others are called integral proteins that go entirely through the membrane. The function of these proteins is to serve as channels to allow the molecules to enter and leave the cell.
Answer:
A. By burning coal in a boiler to produce steam. The steam produced, under pressure, flows in a turbine, which spins a generator to create electricity
B. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity
Answer:
D. A brown gas produced
Explanation:
When a chemical reaction occur, there are several changes that takes place such as change in color, odor change, formation of a gas, and formation of a precipitate etcetera.
In the given chemical reaction, two colorless gas (NO and O2) react together and form brown gas (NO2). So, the change of gas from colorless to brown gas is the evidence that shows chemical reaction occurred.
Hence, the correct option is "D. A brown gas produced".
