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.
Answer:
C) binding to mRNAs and degrading them or blocking their translation
Explanation:
<u>miRNAs:</u>
miRNAs is the abbreviation of MicroRNAs. These are the small noncoding RNAs of ∼22 nucleotides which can not code for peptides. miRNAs are responsible for gene expression regulation at the level of post transcription. They can do so by forming complementary base pairing with target mRNA and inhibiting their translation.
They silenced mRNA by the following processes:
(1) Cleavage of the mRNA strand into pieces,
(2) stopping mRNA from translation into proteins by ribosomes.
(3) Shortening of mRNA poly(A) tail and destabilizing it.
There may be some strains of bacteria that are naturally resistant to these antibiotics, or there may be some that mutate to become resistant. This means that as antibiotics are used more and more, those that can be killed using the antibiotics die out, but those that are resistant will remain, and will reproduce. Over time, it will be the resistant species that predominate.
