A. they arose out of Africa less than 200,00 years ago
Answer:
The correct answer would be D.Alveolar sacs are surrounded by thin capillaries where gases can be exchanged.
Alveoli are tiny sacs which form the site of gas exchange in the lungs.
The features of alveoli which help in gas exchange are:
- They increase the surface area in the lungs thus, more space is available for gas exchange.
- They have very thin walls, as thin as the thickness of a single cell only.
- They are surrounded by a bunch of thin capillaries which exchange gases with alveoli.
Answer:
The answer is D) Generate the energy required for lipids to diffuse through the membrane.
Explanation:
Membrane proteins don't produce energy in any required process inside the cell. Therefore, is not a function to generate the energy that lipids require to diffuse to the membrane. Although membrane proteins develop many functions, producing energy isn't one of them.
Wrap your specimen in the original wrapping and give it your instruct to dispose of
Answer:
B and D
Explanation:
Since it says all carbon atoms have six electrons, we know that they only have six protons too. The carbon 13 and 14 means they have extra neutrons that increases their atomic mass.
