Biology Questions and Answers
that present more adapted phenotypes
for the environmental pface). ressure they
- In hospitals where many
tuberculosis patients are
treated the population of the
tuberculosis mycobacteria
may be constituted of
multiresistant (to antibiotics)
strains. How does the
synthetic theory of evolution
explain this fact?
The appearancof pathogenic parasitese of multiresistant in hospitals, for strains
example, of multiresistant tuberculosis
bacteria,synthetic theory of evolution. can be explained by the
As in any environment, TB bacteria inhospitals undergo changes in their
genetic material. In the hospital
environment however they sucontinuous exposition to antibiotics.ffer (^)
Many of them die by the antibiotic
action bprovide resistanceut carriers o to those af mutationsntibiotics that (^)
proliferate freely. These resistant
microorother antibioticsganisms when submitted to again undergo natural (^)
selection anresistant to these other drugs ared those which became
preserved and proliferate. Thus strains
of multiresistantbacteria emerge in hospitals. (nontreatable) mutant
The use of antibioticspromotes natural selection and the is a factor that
emergence of multiresistant bacteria.
This is the reason have committees that cowhy hospitalsntrol the oftenuse of (^)
antibiotics.
- What is reproductive
isolation?
Living beings are considered under
reproductive isolation wcross among themselves ohen they cannr if they canot
cross but cannot generate fertile
offspring. - What is the relationship
between the concept of
reproductive isolation and the
concept of species?
Reproductive isolation is an important
concept bof species: only ecause living bit defines the concepteings that can
cross among themselves and generate
fertile oreproductive isolation, bffspring, i.e., that arelong to thee not under
same species. For example, humans
and chimisolation aps are under reproductivend are not of the same
species. - What is speciation?
Speciation isdifferent species e the process by whichmerge from a
common ancestor species. Speciation
generally bthe same species begins when populations oecome f
geographically isolated, i.e., when they
are separated that disallows crossing bby some physicaletween barrier
individuals from one population and
individuals of another population.
Groups that for a long time are kept
under geographical isolationaccumulate different phenotypical tend to
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