TRUE
Speciation is the creation of a new species through natural selection operating differently on 2 populations, NORMALLY due to a NEW NATURAL BARRIER (e.g. a new moutnain range or river) emerging that separates the 2 populations. The environmental conditions are different within these 2 new habitats and so natural selection operates differently for the 2 populations, favouring different characteristics to aid surivial. The new natural barrier prevents the 2 populations interbreeding. As a result, new characteristics are not genetically passed on between the 2 populations. Eventually, the 2 populations will thus become so different in their characteristics (i.e. their phenotype) that they will no longer be able to successfully interbreed/ reproduce to produce fertile offspring.
The definition of a species is: Organisms with similar characteristics that can successfully interbreed/ reproduce with each other to produce fertile offspring.
After speciation, a new species is created. Thus, by the very definition of a species, <span>members of a population must become reproductively isolated in order for speciation to occur.</span>
The Gecko. While human-made devices inspired by gecko feet have emerged in recent years, enabling their wearers to slowly scale a glass wall, the possible applications of gecko-adhesion technology go far beyond Spiderman-esque antics. A researcher is looking into how the technology could be applied in a high-precision industrial setting, such as in robot arms used in manufacturing computer chips.
That'll be guanine. If you look up "pyrimidine" in google, it will tell you the two nucleotides that are pyrmidines are cytosine and thymine. So that leaves guanine.
The location that should have lowest oxygen concentration would be the tissue because it is the furthermost location.
Other location with lowest oxygen concentration should be in the right part of the heart. It is when all unoxygenated blood pooled before going to the lungs. But the left part of the heart will have highest oxygenated blood, so it's ambiguous.
High oxygen concentration should be found in the environment, lungs, and the blood.
