BIOLOGY MAJOR FIELD 2026/2027 QUESTIONS AND
ANSWERS RATED A+
✔✔Approx. how old is Earth? - ✔✔4.6 Billion years old
✔✔Which of the following the closest the first life probably appeared on earth?
a) btw 4.6 and 4.2 bya
b) btw 3.8 and 3.5 bya
c) btw 2.5 and 2.1 bya - ✔✔b) between 3.8 and 3.5 billion years ago
✔✔Which of the following is not a condition of the Hardy-Weinberg Equilibrium?
a) asexual reproduction
b) random mating
c) no gene flow
d) no net mutation - ✔✔a) asexual reproduction
✔✔The _____ Explosion marked a dramatic and widespread diversification of animal
life in the oceans and plant life on land - ✔✔Cambrian
✔✔Which of the following is the best measure of the evolutionary fitness of an
individual?
a) how often it mates compared to others in the population
b) how good it is at getting food compared to others in the population
c) how many fertile grand-offspring it leaves behind compared to others in the
population - ✔✔c) how many fertile grand-offspring
✔✔Heterochrony is an: - ✔✔evolutionary change in the rate or timing of developmental
events
✔✔What is the correct sequence from the most to the east comprehensive of the major
taxonomic levels:
phylum, domain, kingdom, class, species, genus, family, order - ✔✔Domain - kingdom -
phylum - class- order - family - genus - species
DKPCOFGS - Dear King Philip Came Over for Good Spaghetti
✔✔Derived character states that related taxa share/ shared ancestral traits -
✔✔Homologous
✔✔Wing of a fruit fly and wing of a bird are an example of - ✔✔Homoplasious
✔✔The kind of grouping that best describes a clade is: - ✔✔Monophyletic
,✔✔Remnants of pelvic bones that partially develop in the bodies of boa constrictor
snakes, which have no back legs, is an example of a __________ structure -
✔✔Vestigial
✔✔Prezygotic reproductive isolating mechanisms and examples - ✔✔Prevent two
individuals from reproducing together because zygotes cannot be formed
Due to behavioral isolate due to differences in courtship rituals or mechanical isolation
in which the reproductive parts do not fit
✔✔Postzygotic reproductive isolating mechanisms and examples - ✔✔Mating can occur
but the zygote is in viable (ex. infertile)
✔✔General Systems Theory - ✔✔Pattern that explains the collection of parts that
operate interdependently to achieve a common purpose that are linked by energy and
matter flows
✔✔Population - ✔✔group of individuals of the same species in a particular geographic
area
✔✔Community - ✔✔Assemblage of populations of different species
✔✔Ecosystem - ✔✔All abiotic factors and the entire community of species in a given
area
✔✔Landscape - ✔✔Arrays of ecosystems arranged across a geographic region
✔✔Biome - ✔✔Large scale areas with morphologically similar dominant vegetation
✔✔Weather vs Climate - ✔✔Weather - current conditions; temperature, precipitation,
etc.
Climate- long term description of weather; based on averages and variation measured
over decades
✔✔Most of the world's major deserts occur in two latitudinal bands that are centered at
30 degrees N and 30 degrees S latitude. This pattern is best explained by: - ✔✔Major
patterns of atmospheric circulation above and below the equator due to equatorial
heating and circulation cells
✔✔Costal upwelling is when ______ from dead organisms accumulate in deep water
and then resurface to produce highly productive areas - ✔✔Nutrients
, ✔✔Air pressure, air temperature, and density _______ as elevation increases which
results in _____ water holding capacity - ✔✔Decreases; lower
✔✔Acidity is a measure of ____ - ✔✔pH
✔✔Directional Selection - ✔✔Individuals are one end of the trait distribution are favored
Distribution of traits shifts over time to the left or right more
✔✔Stabilizing Selection - ✔✔Individuals with intermediate traits are favored
The trait distribution remains constant
✔✔Disruptive Selection - ✔✔Individuals with traits at the extreme of the distribution
have the greatest fitness
Over time, distinct morphs emerge
✔✔Genetic Drift: Bottleneck Effect - ✔✔Drift due to drastic reduction in population #s
Results in reduced genetic availability
✔✔Genetic Drift: Founder Effect - ✔✔A few individuals from a larger populations
colonize a new location
Cause of some inherited disorders in some human populations
✔✔Genetic Drift: Effects of Small Populations - ✔✔Chance events determine which
alleles are passed on
Some genes are lost and others are fixed
Reduced genetic variation
Potential for fixation of deleterious alleles
Increases differences between populations
✔✔Fisher's Fundamental Theorem - ✔✔Loss of genetic variation reduces the ability of
the population to respond to changing environmental conditions
✔✔Gene flow: movement of alleles ______ populations which _______ differences
between populations - ✔✔Movement of alleles among populations which reduces
differences between populations
ANSWERS RATED A+
✔✔Approx. how old is Earth? - ✔✔4.6 Billion years old
✔✔Which of the following the closest the first life probably appeared on earth?
a) btw 4.6 and 4.2 bya
b) btw 3.8 and 3.5 bya
c) btw 2.5 and 2.1 bya - ✔✔b) between 3.8 and 3.5 billion years ago
✔✔Which of the following is not a condition of the Hardy-Weinberg Equilibrium?
a) asexual reproduction
b) random mating
c) no gene flow
d) no net mutation - ✔✔a) asexual reproduction
✔✔The _____ Explosion marked a dramatic and widespread diversification of animal
life in the oceans and plant life on land - ✔✔Cambrian
✔✔Which of the following is the best measure of the evolutionary fitness of an
individual?
a) how often it mates compared to others in the population
b) how good it is at getting food compared to others in the population
c) how many fertile grand-offspring it leaves behind compared to others in the
population - ✔✔c) how many fertile grand-offspring
✔✔Heterochrony is an: - ✔✔evolutionary change in the rate or timing of developmental
events
✔✔What is the correct sequence from the most to the east comprehensive of the major
taxonomic levels:
phylum, domain, kingdom, class, species, genus, family, order - ✔✔Domain - kingdom -
phylum - class- order - family - genus - species
DKPCOFGS - Dear King Philip Came Over for Good Spaghetti
✔✔Derived character states that related taxa share/ shared ancestral traits -
✔✔Homologous
✔✔Wing of a fruit fly and wing of a bird are an example of - ✔✔Homoplasious
✔✔The kind of grouping that best describes a clade is: - ✔✔Monophyletic
,✔✔Remnants of pelvic bones that partially develop in the bodies of boa constrictor
snakes, which have no back legs, is an example of a __________ structure -
✔✔Vestigial
✔✔Prezygotic reproductive isolating mechanisms and examples - ✔✔Prevent two
individuals from reproducing together because zygotes cannot be formed
Due to behavioral isolate due to differences in courtship rituals or mechanical isolation
in which the reproductive parts do not fit
✔✔Postzygotic reproductive isolating mechanisms and examples - ✔✔Mating can occur
but the zygote is in viable (ex. infertile)
✔✔General Systems Theory - ✔✔Pattern that explains the collection of parts that
operate interdependently to achieve a common purpose that are linked by energy and
matter flows
✔✔Population - ✔✔group of individuals of the same species in a particular geographic
area
✔✔Community - ✔✔Assemblage of populations of different species
✔✔Ecosystem - ✔✔All abiotic factors and the entire community of species in a given
area
✔✔Landscape - ✔✔Arrays of ecosystems arranged across a geographic region
✔✔Biome - ✔✔Large scale areas with morphologically similar dominant vegetation
✔✔Weather vs Climate - ✔✔Weather - current conditions; temperature, precipitation,
etc.
Climate- long term description of weather; based on averages and variation measured
over decades
✔✔Most of the world's major deserts occur in two latitudinal bands that are centered at
30 degrees N and 30 degrees S latitude. This pattern is best explained by: - ✔✔Major
patterns of atmospheric circulation above and below the equator due to equatorial
heating and circulation cells
✔✔Costal upwelling is when ______ from dead organisms accumulate in deep water
and then resurface to produce highly productive areas - ✔✔Nutrients
, ✔✔Air pressure, air temperature, and density _______ as elevation increases which
results in _____ water holding capacity - ✔✔Decreases; lower
✔✔Acidity is a measure of ____ - ✔✔pH
✔✔Directional Selection - ✔✔Individuals are one end of the trait distribution are favored
Distribution of traits shifts over time to the left or right more
✔✔Stabilizing Selection - ✔✔Individuals with intermediate traits are favored
The trait distribution remains constant
✔✔Disruptive Selection - ✔✔Individuals with traits at the extreme of the distribution
have the greatest fitness
Over time, distinct morphs emerge
✔✔Genetic Drift: Bottleneck Effect - ✔✔Drift due to drastic reduction in population #s
Results in reduced genetic availability
✔✔Genetic Drift: Founder Effect - ✔✔A few individuals from a larger populations
colonize a new location
Cause of some inherited disorders in some human populations
✔✔Genetic Drift: Effects of Small Populations - ✔✔Chance events determine which
alleles are passed on
Some genes are lost and others are fixed
Reduced genetic variation
Potential for fixation of deleterious alleles
Increases differences between populations
✔✔Fisher's Fundamental Theorem - ✔✔Loss of genetic variation reduces the ability of
the population to respond to changing environmental conditions
✔✔Gene flow: movement of alleles ______ populations which _______ differences
between populations - ✔✔Movement of alleles among populations which reduces
differences between populations
