Answer:
When patient takes in antibiotics the resistance bacteria gets a competitive survival advantage over the normal sensitive bacteria and hence grows faster.
Explanation:
- Bacteria can acquire resistance by taking in plasmids containing MDR (Multi-Drug Resistance) gene cassettes. The MDR genes produces proteins that can:
- Render the antibiotic ineffective to act on its target by inducing chemical modifications on the drug.
- Promote efflux of the drug from the bacterial cell so that the drug cannot act upon its target.
- When a healthy person ( having no prior exposure to the antibiotic) is infected by bacteria ( both sensitive and resistant varieties):
- A competition develops for the host cells and nutrients between the sensitive and the resistant variety.
- This mutual competition restricts either of the sensitive or resistant bacterial strain to grow profusely.
- When a person (having prior antibiotic exposure), gets infected by bacteria ( both sensitive and resistant varieties) and is exposed to the same antibiotic:
- The sensitive variety, due to its sensitivity towards the drug, gets killed.
- The resistant variety, due to its MDR genes, bypasses the lethal effect of the drug and survives.
- These surviving resistant bacteria can now infect all the available host cells and utilise all the available nutrients without facing any competition and multiply rapidly.
Answer:
The correct answer is:
population of the predator species is larger and the populations of the prey species are smaller. (C)
Explanation:
apparent competition occurs occurs between two species or group of organisms that do not directly compete for resources affect each other indirectly by being prey to the same predator. For example consider three species of organisms; sparrows, earthworms and beetles, where earthworms and beetles are preys of the sparrows, an increase in the population of earthworms will in the long term lead to an increase in the population of sparrows, which means that more predators will be available, leading to a decrease in the population of beetles, because more predators are available to prey on them. Also a decrease in the population of earthworms will also lead to a decrease in the population of beetles because their probability of being seen by the predators will increase leading to an increase in their killing.
Therefore in apparent competition, although it occurs between two prey species, their in an increase in the number of predators and a decrease in the population of the prey.
Anatomical there are similarities among many organisms. Homologous structures <span>found in different species that are anatomically similar because they have been inherited from a common ancestor.</span>
Answer:
precipitation is when it rains. it occurs last
Explanation:
They protect bacterial cells from white blood cells.
