BIO 1500 - COMPILATION OF ALL
EXAM STUDY SETS QUESTIONS WITH
CORRECT ANSWERS
Natural Selection - ANSWER--most fundamental process in all of biology
-all organisms: subject to natural selection, outcome of natural selection
-NASA definition of life: "chemical system that can evolve by natural selection"
-simple and elegant mechanism - but very powerful!
-many misconceptions held by students and teachers
characteristics of life - ANSWER-growth, respond, cellular, metabolism,
homeostasis, heredity, reproduce
Natural selection: the basics - ANSWER--phenotypes are variable in population
-offspring have same/similar phenotype as parents (phenotype is heritable)
-survival and reproduction depend on phenotype
-future generations: genetic composition of population changes
population - ANSWER-group of individuals that interbreed and reproduce
phenotype - ANSWER-observable traits
fitness - ANSWER-ability to survive & reproduce in an environment
adaptation - ANSWER-trait that increases fitness of individual with this trait relative
to others without it
-adaptation is a trait produced by the process of natural selection
evolution - ANSWER-a change in allele frequencies in a population
-natural selection is one of several mechanisms of evolution
-processes that cause allele frequencies to change
Sexual selection - ANSWER--competition among males favors *large* size
-if one sex is more competitive fighting for a mate, males are more competitive.
Larger mates win competition and end up mating with female, passing on larger
genes
Selection for female fecundity (egg/offspring number) - ANSWER-*large* size
-larger females = more eggs = more copies of her genes in future generations
selection for early reproduction - ANSWER-*small* size
-get reproduction in even if they aren't full grown
limited food avilability - ANSWER-*small* size
-don't need as much food to be healthy and reproduce
,selection for predation - ANSWER-*large* size in predator, *small* size in prey
-smaller prey are harder to catch
selection for locomotion - ANSWER-flight favors *small* size
-amount of energy needed to fly is reduced if you are smaller
selection for temperature - ANSWER-cold favors *large* size in mammals, *small*
size in ectotherms
-ectotherm: body temp varies with environment
Given the variety of selection pressures acting on body size, what determines
average body size in the end? - ANSWER-*the relative strengths of different
selection pressures*
-how big is the advantage/disadvantage of being small/large?
*constraints that limit the response to selection*
-even if selection would favor large body sizes, there may be things that limit these
favorable traits
-ex: physiological and/or genetic (too large of an exoskeleton = not able to move as
well; must be genetic variation for natural selection to act on)
respiration in insects - ANSWER--insects have no blood that transports O2
-instead: tracheas bring O2 directly to cell
-*spiracle:* opening to outside
-O2 and CO2 travel largely though diffusion; problem at long distances
-large and active insects: pump air in/out of air sacks and large trachea
-diffusion in small trachea
respiratory system limits insects' size - ANSWER--higher O2 concentration allows
insects to evolve bigger size
-concentration of oxygen decreases as it travels through trachea. minimum O2
requirement is farther up on the trachea
What does chlorophyll do with the E? - ANSWER-*light-dependent reactions*
-ATP is synthesized (meaning that a 3rd phosphate group is added to ADP;
absorbed energy ends up in bonds between 2nd and 3rd phosphate group)
-NADPH is generated (another E-carrier molecule)
-Water (H2O) is split apart in the process, releasing oxygen (O2) as a by-product
*light-independent reactions*
-the E from ATP and NADPH are used to build glucose from CO2 and water (=Calvin
Cycle)
Requirements for photosynthesis - ANSWER-sunlight
water
CO2
products of photosynthesis - ANSWER-glucose
O2 = byproduct
,What happens with glucose? - ANSWER--make other organic molecules in the plant
-make ATP out of it where needed
Gene - ANSWER-a segment of DNA with instructions for building a protein molecule
-specifies the sequence of a.a. that make up the protein
Alleles - ANSWER-different possible forms of the same gene
-differ in DNA sequence, and therefore in proteins structure they code
-there may be many different alleles of the same gene
-any 1 person can have max of 2 different alleles (b/c two copies of each
chromosome)
Great Oxygenation Event - ANSWER--sometime between 3 and 2.3 billion years ago
-before that: all organisms heterotrophic prokaryotes
-cyanobacteria evolved photosynthesis (more efficient: 10-20x higher metabolism
rates; autotrophs spread fast)
-O2 produced as a by-product (lead to some O2 levels, about 3%, in atmosphere)
Consequences of O2 accumulation in atmosphere/oceans - ANSWER--minerals
forced (banded iron ore)
-ozone layer formed (protection from UV light)
-free O2 is toxic to cells (global mass extinction)
-O2 reacted with methane (Greenhouse gas), removing it from atmosphere -->
snowball ice age (2.4-2.1 billion years ago)
-some prokaryotes evolved ways to use O2 (leading to evolution of cellular
respiration)
-(later) eukaryotes with chloroplasts (more effective photosynthesis, even higher O2
levels)
-(much later) evolution of multicellular life
Positives/Negatives of O2 accumulation - ANSWER--catastrophic for existing life
forms
-catastrophic for cyanobacteria - who caused it!
-generated new niches - opportunities to diversify
-set stage for geology and biology as we know it
Today's signs of the GOE - ANSWER--anti-oxidants: protect proteins from oxidation
(ex: ascorbic acid = vitamin C)
-photo-oxidation: if photosynthesis is too fast, too much O2 damages chlorophyll)
Why would higher O2 result in the evolution of larger size on insects? - ANSWER-
higher O2 allows insects to get bigger, removes constraint, compete better for mates
for food, produce more/better eggs, produce more/better sperm
, -high O2 selects to get bigger; resist oxygen damage better
respiratory system reduces O2 damage - ANSWER-higher O2 concentration select
for larger insect size
remembering - ANSWER-recalling facts and basic concepts
-How many years ago was the start fo the Cretaceous period?
understand - ANSWER-explaining ideas or concepts
-Explain how scientists know that dragonflies were much larger during the
Cretaceous than they are today.
Apply - ANSWER-using knowledge gained in new ways
-Use your understanding of the factors influencing dragonfly size to predict how the
size of terrestrial invertebrates has changed over deep time.
analyze - ANSWER-breaking the concept into parts and understanding how each
part is related to one another; drawing connections among ideas
-examine the role of natural selection in the observed changes in dragonfly size over
time. What traits were under selection pressure in a) dragonflies, and b) aerial
predators?
evaluate - ANSWER-making judgments; justifying a stand or decision
-how strong is the evidence supporting the conclusion that predation limited the size
of dragonflies following the evolution of birds? Do you agree with this conclusion?
create - ANSWER-putting information together in an innovative way; producing new
or original work
-design an experiment to test the hypothesis that higher levels of O2 in the
atmosphere allow insects to grow.
How are COVID-19 and SARS-CoV-2 related? - ANSWER-COVID-19 illness is
caused by SARS-CoV-2 virus
2 entry routes for virus into host cell - ANSWER-*endocytotic pathway:*
- virus taken into endosome (membrane bound vesicle)
- virus fuses with endosome membrane and empties genome into host
- *cathepsin (enzyme)* modifies spike protein to allow fusion with membrane
*receptor-mediated diffusion:*
- bind to receptor on surface of cell
- fuses with cell membrane
- empty genes into host cell
- spike protein binds to ACE2 receptors (found on cells in lungs and capillaries)
EXAM STUDY SETS QUESTIONS WITH
CORRECT ANSWERS
Natural Selection - ANSWER--most fundamental process in all of biology
-all organisms: subject to natural selection, outcome of natural selection
-NASA definition of life: "chemical system that can evolve by natural selection"
-simple and elegant mechanism - but very powerful!
-many misconceptions held by students and teachers
characteristics of life - ANSWER-growth, respond, cellular, metabolism,
homeostasis, heredity, reproduce
Natural selection: the basics - ANSWER--phenotypes are variable in population
-offspring have same/similar phenotype as parents (phenotype is heritable)
-survival and reproduction depend on phenotype
-future generations: genetic composition of population changes
population - ANSWER-group of individuals that interbreed and reproduce
phenotype - ANSWER-observable traits
fitness - ANSWER-ability to survive & reproduce in an environment
adaptation - ANSWER-trait that increases fitness of individual with this trait relative
to others without it
-adaptation is a trait produced by the process of natural selection
evolution - ANSWER-a change in allele frequencies in a population
-natural selection is one of several mechanisms of evolution
-processes that cause allele frequencies to change
Sexual selection - ANSWER--competition among males favors *large* size
-if one sex is more competitive fighting for a mate, males are more competitive.
Larger mates win competition and end up mating with female, passing on larger
genes
Selection for female fecundity (egg/offspring number) - ANSWER-*large* size
-larger females = more eggs = more copies of her genes in future generations
selection for early reproduction - ANSWER-*small* size
-get reproduction in even if they aren't full grown
limited food avilability - ANSWER-*small* size
-don't need as much food to be healthy and reproduce
,selection for predation - ANSWER-*large* size in predator, *small* size in prey
-smaller prey are harder to catch
selection for locomotion - ANSWER-flight favors *small* size
-amount of energy needed to fly is reduced if you are smaller
selection for temperature - ANSWER-cold favors *large* size in mammals, *small*
size in ectotherms
-ectotherm: body temp varies with environment
Given the variety of selection pressures acting on body size, what determines
average body size in the end? - ANSWER-*the relative strengths of different
selection pressures*
-how big is the advantage/disadvantage of being small/large?
*constraints that limit the response to selection*
-even if selection would favor large body sizes, there may be things that limit these
favorable traits
-ex: physiological and/or genetic (too large of an exoskeleton = not able to move as
well; must be genetic variation for natural selection to act on)
respiration in insects - ANSWER--insects have no blood that transports O2
-instead: tracheas bring O2 directly to cell
-*spiracle:* opening to outside
-O2 and CO2 travel largely though diffusion; problem at long distances
-large and active insects: pump air in/out of air sacks and large trachea
-diffusion in small trachea
respiratory system limits insects' size - ANSWER--higher O2 concentration allows
insects to evolve bigger size
-concentration of oxygen decreases as it travels through trachea. minimum O2
requirement is farther up on the trachea
What does chlorophyll do with the E? - ANSWER-*light-dependent reactions*
-ATP is synthesized (meaning that a 3rd phosphate group is added to ADP;
absorbed energy ends up in bonds between 2nd and 3rd phosphate group)
-NADPH is generated (another E-carrier molecule)
-Water (H2O) is split apart in the process, releasing oxygen (O2) as a by-product
*light-independent reactions*
-the E from ATP and NADPH are used to build glucose from CO2 and water (=Calvin
Cycle)
Requirements for photosynthesis - ANSWER-sunlight
water
CO2
products of photosynthesis - ANSWER-glucose
O2 = byproduct
,What happens with glucose? - ANSWER--make other organic molecules in the plant
-make ATP out of it where needed
Gene - ANSWER-a segment of DNA with instructions for building a protein molecule
-specifies the sequence of a.a. that make up the protein
Alleles - ANSWER-different possible forms of the same gene
-differ in DNA sequence, and therefore in proteins structure they code
-there may be many different alleles of the same gene
-any 1 person can have max of 2 different alleles (b/c two copies of each
chromosome)
Great Oxygenation Event - ANSWER--sometime between 3 and 2.3 billion years ago
-before that: all organisms heterotrophic prokaryotes
-cyanobacteria evolved photosynthesis (more efficient: 10-20x higher metabolism
rates; autotrophs spread fast)
-O2 produced as a by-product (lead to some O2 levels, about 3%, in atmosphere)
Consequences of O2 accumulation in atmosphere/oceans - ANSWER--minerals
forced (banded iron ore)
-ozone layer formed (protection from UV light)
-free O2 is toxic to cells (global mass extinction)
-O2 reacted with methane (Greenhouse gas), removing it from atmosphere -->
snowball ice age (2.4-2.1 billion years ago)
-some prokaryotes evolved ways to use O2 (leading to evolution of cellular
respiration)
-(later) eukaryotes with chloroplasts (more effective photosynthesis, even higher O2
levels)
-(much later) evolution of multicellular life
Positives/Negatives of O2 accumulation - ANSWER--catastrophic for existing life
forms
-catastrophic for cyanobacteria - who caused it!
-generated new niches - opportunities to diversify
-set stage for geology and biology as we know it
Today's signs of the GOE - ANSWER--anti-oxidants: protect proteins from oxidation
(ex: ascorbic acid = vitamin C)
-photo-oxidation: if photosynthesis is too fast, too much O2 damages chlorophyll)
Why would higher O2 result in the evolution of larger size on insects? - ANSWER-
higher O2 allows insects to get bigger, removes constraint, compete better for mates
for food, produce more/better eggs, produce more/better sperm
, -high O2 selects to get bigger; resist oxygen damage better
respiratory system reduces O2 damage - ANSWER-higher O2 concentration select
for larger insect size
remembering - ANSWER-recalling facts and basic concepts
-How many years ago was the start fo the Cretaceous period?
understand - ANSWER-explaining ideas or concepts
-Explain how scientists know that dragonflies were much larger during the
Cretaceous than they are today.
Apply - ANSWER-using knowledge gained in new ways
-Use your understanding of the factors influencing dragonfly size to predict how the
size of terrestrial invertebrates has changed over deep time.
analyze - ANSWER-breaking the concept into parts and understanding how each
part is related to one another; drawing connections among ideas
-examine the role of natural selection in the observed changes in dragonfly size over
time. What traits were under selection pressure in a) dragonflies, and b) aerial
predators?
evaluate - ANSWER-making judgments; justifying a stand or decision
-how strong is the evidence supporting the conclusion that predation limited the size
of dragonflies following the evolution of birds? Do you agree with this conclusion?
create - ANSWER-putting information together in an innovative way; producing new
or original work
-design an experiment to test the hypothesis that higher levels of O2 in the
atmosphere allow insects to grow.
How are COVID-19 and SARS-CoV-2 related? - ANSWER-COVID-19 illness is
caused by SARS-CoV-2 virus
2 entry routes for virus into host cell - ANSWER-*endocytotic pathway:*
- virus taken into endosome (membrane bound vesicle)
- virus fuses with endosome membrane and empties genome into host
- *cathepsin (enzyme)* modifies spike protein to allow fusion with membrane
*receptor-mediated diffusion:*
- bind to receptor on surface of cell
- fuses with cell membrane
- empty genes into host cell
- spike protein binds to ACE2 receptors (found on cells in lungs and capillaries)
