Lactase refers to an enzyme that can dissociate lactose sugar into glucose and galactose. This enzyme plays an important role in the digestion of milk that comprises high lactose sugar. In case, if a mutation occurs in the gene codon of lactase, then two possibilities can take place. These are as follows:
1. Loss of mutation: In this case, the person becomes lactose intolerant because of mutation in lactase gene codon. Due to this, there is low mRNA expression and thus low production of the enzyme lactase. This is also known as lactase non-persistent phenotype.
2. Gain in mutation: In this case, the person gain an increase in mRNA expression of the lactase gene, thus more production of lactase takes place than usual. This kind of individual exhibits lactase persistent phenotype.
Cell-wall inhibiting antimicrobial drugs be less effective on gram-negative bacteria compared to gram-positive bacteria because the outer membrane of the gram-negative bacteria inhibits penetration of the drug and the peptidoglycan found in gram-positive bacteria is structurally different from that in gram-negative bacteria.
Answer: Option B & C
<u>Explanation:</u>
Antimicrobial drugs are induced into a body to act on that particular selective bacterium which causes disease. When antimicrobial drugs are injected they act efficiently on the gram positive bacteria inhibiting the proliferation of the cells by acting on the cell wall so that cell multiplication doesn’t happen.
On the other hand it is hard to act on the gram-negative bacteria as it has a cell membrane that inhibits drug penetration into it. Both cell walls contain peptidoglycan but in the gram-positive is more assembled and layered while in the gram-negative it is just a thin layer. As gram-positive is thick layered it provides place for another molecule to attach to it but the thin layer in gram-negative inhibits it.
Answer:
D: A density-independent factor.
Explanation:
An earthquake is a density-independent limiting factor
B) Suspect 2 is a match to the DNA evidence found on the victim.
The unit of measurement in an ecological footprint is the global hectare.
