<span>Microevolution refers to changes in the genetic pool
of a species population. The changes in the genes (probably gene and allele frequencies)
are observed over short time periods hence are small changes. This is in comparison
to macroevolution that observes huge changes over longer time periods in the population that warrant that the new populations
is considered to be a new species</span>
The olfactory cortex (nucus) of the temporal lobe is where the nerve fibers of the olfactory bulb projects directly. This cortex is where you get the smell sensation before determining what the smell actually is. The olfactory cortex is located on the medial aspect of the temporal lobe, particularly in the uncus or the piriform lobe. It is also called the Rhinoencephalon or the nose brain.
Answer:
The above paragraphs describes that how salt- and fresh-water fish regulates their osmoregulation. Hence, the correct answer would be c. have adapted to deal with osmosis.
Osmosis is the process by which solvent's molecule move from region of low concentration (hypo-tonic) to the region of high concentration (hyper-tonic) through a semi-permeable membrane.
In sea-water fishes, the body fluids are hypo-tonic to the surrounding water and thus water is kept moving out of their gills. In order to prevent the excess water loss they need to drink water constantly and excrete concentrated urine.
In contrast, fresh-water fishes body fluids are hyper-tonic to surrounding water and hence, water keeps entering in their body through gills. So, in order to prevent excess dilution they absorb salt from surrounding with the help of gills and also their bodies reabsorb salt from urine.
Both have a pump that pushes materials throughout the organism.