I think the correct answer would be the second option. The group of archaebacteria would be found on the lowest branch of a phylogenetic tree of all life. Phylogenic trees are illustrations of a hypothetical evolution of the organisms and its relationship with the other organisms. From the listed options, the archaebacteria is most likely to be the most basic and simplest life form. It should be placed before the other options so at the lowest branch. This illustration is being used by scientists to describe how evolution and the connection of the organisms came about. It sometimes called as the tree of life.
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
Desertification of non desert land can occur due to several reason like,overgrazing, deforestation, tilling of land, drastic climate change and drought that ultimately leads to excessive soil erosion or soil death .
Explanation:
- Desertification is the phenomena in which a productive land becomes completely unproductive, resulting in the loss of any vegetation cover over it.
- Desertification results in degradation of the soil to such an extent that the entire biotic community thriving on it is destroyed.
- Overgrazing, deforestation, tilling of land are major activities that ultimately leads to the washing away of the top soil and leaves the land deserted.
- Some natural causes include climate shifts and drought.
haploid means there is 23 pair of chromosome but have n ploidy
