DNA<span> is a double helix, while RNA is a single helix. Both have sets of nucleotides that contain genetic information. </span>DNA<span> is a molecule that contains the instructions an organism needs to develop, live and reproduce.</span>
The correct answers are:
• Liver cells are abundant in SER.
This is because liver cells contain enzymes that metabolize various lipid-soluble compounds.
• The testes and ovaries are tissue types whose cells are abundant in SER.
This is because testes and ovaries produce steroid hormones (cholesterol is the precursor for their synthesis).
• Cholesterol is made in the SER.
ER is the organelle at which all membrane lipids are synthesized.
• Phospholipids are synthesized from cytosolic water soluble precursor molecules.
Phospholipids are the main lipids that are the main structural components of the cell membrane. They are synthesized on the cytosolic side of the ER membrane, from water-soluble cytosolic precursors.
Answer:
B. Neurons are cells that conduct electrical impulses.
Explanation:
Red blood cells carry oxygen throughout the body. White blood cells protect against pathogens and aid in blood clotting after injury. Blood cells cannot contract.
Neurons generate and conduct electrical impulses. So this one is correct.
Epithelial cells line the cavities and surfaces of blood vessels and organs, protect underlying tissue, regulate the exchange of chemicals, and secrete various substances. They do not react to stimuli, however neurons do.
Smooth muscles helps the skeleton move, smooth muscle is found in blood vessels and some organs, and cardiac muscle helps the heart beat and pump blood. They are however, not components of blood.