The population of the mice would most likely increase. This is because the number of predators of mice will decrease. Predators are those that feed on others, in this case mice. When predators decrease, the prey (which would be the mice) will be able to populate thus leading to an increase in population.
Answer:
student 4 bcoz thymine is replaced by uracil in RNA
Answer:
1. Stabilizing Selection
2. Directional Selection
3. Disruptive Selection
Explanation:
Stabilizing Selection
This type of natural selection occurs when there are selective pressures working against two extremes of a trait and therefore the intermediate or “middle” trait is selected for. If we look at a distribution of traits in the population, it is noticeable that a standard distribution is followed:
Example: For a plant, the plants that are very tall are exposed to more wind and are at risk of being blown over. The plants that are very short fail to get enough sunlight to prosper. Therefore, the plants that are a middle height between the two get both enough sunlight and protection from the wind.
Directional Selection
This type of natural selection occurs when selective pressures are working in favour of one extreme of a trait. Therefore when looking at a distribution of traits in a population, a graph tends to lean more to one side:
Example: Giraffes with the longest necks are able to reach more leaves to each. Selective pressures will work in the advantage of the longer neck giraffes and therefore the distribution of the trait within the population will shift towards the longer neck trait.
Disruptive Selection
This type of natural selection occurs when selective pressures are working in favour of the two extremes and against the intermediate trait. This type of selection is not as common. When looking at a trait distribution, there are two higher peaks on both ends with a minimum in the middle as such:
Example: An area that has black, white and grey bunnies contains both black and white rocks. Both the traits for white and black will be favored by natural selection since they both prove useful for camouflage. The intermediate trait of grey does not prove as useful and therefore selective pressures act against the trait.
Answer:
It depends on the size of the amplified DNA fragments (for example for SPAR markers consisting of 200 bp in length >> 1600 / 200 = 8)
Explanation:
The PCR based single primer amplification reaction (SPAR) methods are tools for detecting genetic diversity by using DNA markers such as Simple Sequence Repeats (ISSRs), Minisatellite DNA regions (DAMDs) and Random Amplified Polymorphic DNAs (RAPDs), which can be used alone or combined with each other. In the last years, the SPAR methods have gained attention in the scientific community because they are cost-effective and highly effective for the detection of both intraspecific and interspecific genetic variation. In the SPAR methods, the size of the bands will depend on the length of the amplified DNA fragments.
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
