Alex Bilski
Alli Berk
P.4
AP Ch. 4 Student Study Guide
Key Terms and Concepts:
-Prokaryotic= single-celled bacteria
-Eukaryotic= single-celled bacteria
-natural selection= survival traits become more prevalent in future populations of species
-evolution=change in population’s genetic make-up over time (population’s evolve by becoming
genetically different)
3 conditions necessary for biological evolution of population by natural selection:
a) must be enough genetic variability for trait to exist in population
b) trait must be heritable
c) trait must lead to differential reproduction (enable individuals w/the trait to leave
more offspring than other members of the population)
-The process of evolution explained in simple terms: Genes mutate, individuals are selected,
populations evolve that are better adapted for survival and reproduce.
-fossils=mineralized/petrified replicas of teeth, bones, leaves, etc. or impressions of such things
found on rocks
-mutations=random changes in the structure or number of DNA molecules in a cell that can be
inherited by offspring
Mutations can occur in 2 ways:
a) gene DNA exposed to external agents like X rays, chemicals, radioactivity
b) random mistakes occur in coded genetic instructions
-adaptation= heritable trait that enables an organism to survive thru natural selection and
reproduce better under prevailing environmental conditions
-when faced with a challenge, an organism must either:
a) adapt
b) migrate
c) become extinct
-coevolution= interactions between species can result in microevolution in each of their
populations
-2 limits to adaptations in nature thru conventional
natural selection:
a) change in environmental conditions can lead
to adaptation only for genetic traits already
in gene pool
b) population’s ability to adapt may be limited
by reproductive capacity
-fitness=measure of reproductive success
-things like earthquakes, climate change, and
catastrophes can affect evolution
-niche=species’ way of life or role in community
and includes everything that affects its survival and
reproduction
-fundamental niche= full potential range of
conditions and resources a species can potentially
use
-realized niche= part of potential niche that allows
species to survive and avoid competition
-generalist species=have broader niches
-specialist species= occupy narrow niches
-speciation= 2 species arise from one
Two phases
a) geographic isolation= different groups of same population of species become
physically isolated from one another for long periods of time
b) reproductive isolation= can no longer produce fertile offspring because gene pools
changed so much due to geographic isolation
-extinction=an entire species ceases to exist
Different types:
a) background extinction= when local environmental conditions change, some
species will disappear at a low rate
b) mass extinction= significant rise in extinction rates above background level
-mass depletion= extinction rates higher than normal but not high enough to classify as mass
extinction
-speciation-extinction=biodiversity
-endemic species=species found in only 1 area
-artificial selection= change genetic characteristics of populations with similar genes
-genetic engineering= alteration of organism’s genetic material thru adding, deleting or changing
segments of DNA
-recombinant DNA= DNA that has been altered to contain genes/portions of genes from
organisms of different species
-genetically modified organism= organisms that have been genetically engineered by use of
recombinant DNA technology
-biopharming=new field where GMAs act as biofactories to produce drugs, etc.
-clone= genetically identical version of an individual in a population
Significant Statistics:
-chemical evolution took 1 billion years
-biologists assume that 99.9% of all the species that ever existed are now extinct
-annual background extinction rate is 1:5 species for each million species on Earth
-the earth’s species have experienced 5 mass extinctions during the past 500 million years
-average success rate of genetic engineering experiments is 1%
-in mass extinctions, 25-70% of species are lost
Practice Questions:
1) What conditions are necessary for life on earth?
2) In this type of extinction, 25-70% of species are lost:
a) mass depletion
b) mass extinction
c) background extinction
d) background
depletion
3) What are the 2 ways in which mutations occur?
4) Do populations or do individuals in the population evolve by becoming genetically different?
5) Summarize the process of biological evolution by natural selection.
6) What is coevolution?
7) What are 2 limits to adaptations thru conventional natural selection?
8) What are some things that can affect natural selection?
9) The full potential range of physical, chemical and biological conditions and resources a
species could theoretically use if avoided competition is:
a) realized niche
b) niche
c) fundamental niche
d) carrying capacity
10) What are the two types of speciation?
11) What equal biodiversity?
12) What to we use to find which organisms lived in the past?
13) What is the difference between background extinction and mass extinction?
14) What is the average success rate of genetic engineering experiments?
15) What are some concerns in terms of genetic engineering?
16) What is the difference between generalist and specialist species?
17) When faced with a challenge, an organism must do one of what three things?
18) For natural selection to evolve in a population, what 3 conditions are necessary?
19) What is biopharming?
20) What two things have allowed humans to become a powerful species so quickly?
Answer Key:
1) The earth must be a certain distance from the sun in order to have a certain temperature range,
it must orbit the right distance from the sun, its size must be fairly large for life to exist, it must
contain oxygen, it must enact photosynthesis, etc.
2) B- Mass Extinction is defined as a SIGNIFICANT rise in extinction rates, specifically from
25-70%
3) a) gene DNA exposed to external agents, b) random mistakes occur
4) Populations; biological evolution is defined as the change in population’s genetic makeup thru
successive generations
5) Genes mutate, individuals are selected, populations evolve that are better adapted for survival
and reproduce.
6) The process in which interactions between species can result in microevolution in each of
their populations.
7) 1) change in environmental conditions 2) population’s ability to adapt may be limited by
reproductive capacity
8) Climate change, catastrophes and tectonic plates to name a few.
9) C-This is the fundamental niches’ definition
10) Geographic isolation and reproductive isolation
11) Speciation-extinction
12) Fossils, which are mineralized replicas of skeletons, bones, shells, teeth, leaves, etc.
impressions that are found on rocks, help us to identify various past organisms.
13) In background extinction, species disappear at a lower rate than during mass extinction in
which 25-70% of species disappear.
14) 1%; genetic engineering is still a fairly risky thing.
15) Some concerns include people losing their uniqueness due to a potential rise in ‘designer
babies’, the moral concern, etc.
16) Generalist species have broad niches whereas specialist species have specific niches.
17) They must either adapt, migrate or become extinct.
18) 1) population must have genetic variability 2) trait must be heritable 3) differential
reproduction
19) Biopharming is a field where genetically engineered animals act as biofactories to produce
antibiotics, hormones, etc.
20) Complex brains and opposable thumbs have allowed humans to become independent and
that allow them to meet their needs and wants.