CORRECT ANSWERS GRADED A+
(2026)
Common Descent - answer-principle that all living things were derived from common
ancestors
Natural Selection - answer-Differential reproductive success of individuals of a
population, due to inherited differences between them. IE Some individuals have lots of
strong traits or adaptations, that allow them to live longer and mate more.
What is the result of Natural Selection? - answer-Evolution
Evolution - answer-a change in the allele frequencies in a population over an extended
period of time.
Homology - answer-Similarity in characteristics resulting from a shared ancestry.
Biogeography - answer-dealing with the geographical distribution of animals and plants
Comparative Anatomy - answer-The comparison of body structures and how they vary
among species
Karyotype - answer-A picture of all the chromosomes in a cell arranged in pairs
Fossils - answer-works because of the formation of sedimentary rocks. Best fossils
come from ocean sediments.
Scientific Theory - answer-A broad explanation that has been subjected to a lot of
testing, that reliably gives up accurate predictions.
, A Theory tells you why something is true
Scientific Theory - answer-1. Helps explain the why of things that we already know to be
true.
2. Reveals connections between known facts that are not already known to be true.
3. Allows to accurately predict new facts (most important)
Biological species concept - answer-A group of similar organisms, that will mate with
one another under natural conditions. And produce fertile offspring.
Morphological Species concept - answer-(Most species identified using this method)
Organisms are classified in the same species if they appear identified by morphological
(anatomical) criteria. This is used when species do not reproduce sexually.
Reproductive isolation - answer-collection of mechanisms, behaviors and physiological
processes that prevent the members of two different species that cross or mate from
producing offspring, or which ensure that any offspring that may be produced is not
fertile. These barriers maintain the integrity of a species over time, reducing or directly
impeding gene flow between individuals of different species, allowing the conservation
of each species' characteristics
Reproductive Barriers - answer-a biological feature of a species that prevents it from
interbreeding with other species even when populations of the two species live together
Allopatric speciation - answer-Step 1. Geographic Isolation- A barrier is put in place to
stop migration of a specific population of species. (gene flow)
Step 2. A separate population of the species must be subjected to a very different set of
environmental conditions.
Either one alone would not cause a major change in the population. They have to
happen together.
Sympatric Speciation - answer-(more common in plants)