Download 10 - gwbiology

10. Species help to distinguish between different types of plants and animals by their
difference appearances. Species can be determined by their physical form or structure
called morphology, other factors that can determine a species is differentiation in body
functions, biochemistry, behavior and genetic makeup. The biological species concept is
a species as a population or group of populations whose members have the opportunity to
interbreed with each other in nature to produce offspring. However, a member of one
species can not mate with a member from a different species because members of a
species are reproductively compatible with each other.
11. Gene flow is the additions and/or subtractions in a population due to the movement of
fertile gametes. Gene flow is important because it modifies the original population’s
allele frequencies for the next generation. However, if gene pool doesn’t take place it can
limit modification, and there are three examples of the barriers to cause this. One
example of the barriers that prevent gene flow is geographical isolation. For example
oceans, vast deserts and impassable mountain ranges can be viewed as a barrier because
there are obstacles to transfer alleles of genes from one population to another. The second
barrier between gene pools is hybrid infertility. Hybrid infertility is a major barrier
because the result is adverse interaction because each of the genes in one genome won’t
be compatible with all the genes of the other. The third example of a barrier in a gene
pool is behavior or ethological isolation, where two compatible species do not mate
because of differences in their mating behavior. Temporal or reproductive isolation ties in
with the behavioral isolation because it prevents the reproductive process.