The answer to your question is a
Answer:
Viruses are not living things.
Answer: No.
Explanation:
Viruses are complicated assemblies of molecules, including proteins, nucleic acids, lipids, and carbohydrates, but on their own they can do nothing until they enter a living cell. Without cells, viruses would not be able to multiply.
Answer:
All the given statements are correct except b.
Antimicrobial resistance (AMR) refers to the ability of a microorganism to grow in the presence of drug or a chemical that would normally limit its growth or kill it.
It makes it difficult for the existing drugs to eliminate the infection as they become less effective against the microbe.
There are five major mechanisms by which a microbe attains resistance against antimicrobial chemical or drug:
- Drug modification or inactivation: A microbial enzyme inactivates the antimicrobial agent. For example, few bacteria produce β-lactamases which provide multi-resistance against β-lactam antibiotics such as penicillin, cephalosporin etc.
- Alteration or modification of target site: An altered target site prevents the antimicrobial agent from binding to its target. For example, alteration of penicillin binding protein (PBP) in Methicillin-resistant <em>Staphylococcus aureus </em>(MRSA).
- Alteration of metabolic pathway: The microbe uses an alternative pathway to circumvent the blocked pathway. For example, sulfonamides-resistant bacteria started using preformed folic acid in place of para-aminobenzoic acid (PABA).
- Decreased drug accumulation: Microbial efflux pumps remove the antimicrobial agent (before it could do any damage) by pumping it out of the cell.
- Decrease in cell permeability: The permeability of the microbial envelope to the antimicrobial agent is decreased
Answer:
Stabilizing selection
Explanation:
Stabilizing selection may be defined as the type of a natural selection where the genetic diversity decreases and the population mean stabilizes on the particular value. It occurs to the individual trait when an extreme of the trait are selected against.
In birds, the bright color males attract more mates for survival but they also attract more predators. Over generation, the highest frequency color is for the intermediate coloring males.
