IB 150 Unit 1 Questions With Complete Solutions
Be able to identify the most common sources of chemical
potential energy. Correct Answers Glucose (in the C-H bonds)
ATP (in the O-P bonds)
Be able to use these terms in context: catalyst, enzyme, active
site Correct Answers Catalyst - Any substance that increases the
rate of a chemical reaction without itself undergoing any
permanent chemical change
Enzyme - a protein catalyst used by living organisms to speed
up and control biological reactions
Active site - The location in an enzyme molecule where
substrates (reactant molecules) bind and react
Compare and contrast density-dependent and density-
independent limits on population growth and provide examples
of each. Correct Answers DD- change in intensity as a function
of population size; usually are biotic
Ex: lack of resources, disease
DI- factors alter b & d rates without regard to population;
usually involve changes in abiotic environment
Ex: storms, wildfires
Contrast r- and K-selected life history strategies, and identify
what life-history factors each life-history strategy maximizes.
Correct Answers R-strategist: many butterflies lay hundreds of
eggs, increasing the birthrate, however the death rate of the
offspring is high (maximize r)
Mother cannot care for all of them
,Smaller, shorter life spans, younger age of reproduction, more
offspring, little or none parental care, wild fluctuations of
population stability
K-strategist: elephants have only one offspring at a time and
often only give birth once every 4 years. By caring for the
offspring, however, they reduce the death rate of juvenile
elephant (maximize K)
Larger, longer life span (more chances to give birth), older age
of reproduction, fewer offspring, long and involved parental
care, mostly stable population
Define and contrast Gross primary Production (GPP) and net
primary production (NPP): Correct Answers GPP= total amount
of chemical energy produced in a given area and time period
(Ex: 100% from captured sunlight)
NPP=energy that is invested by primary producers in building
new tissue or offspring (Ex: 10% plant growth)
Define exergonic and endergonic chemical reactions. Correct
Answers Exergonic Reactions
Release energy (can be used to do work)
Tend to be spontaneous
Reactants have a higher Gibbs Free Energy than the products
ΔH (Enthalpy) is negative (heat given off)
ΔS (Entropy) is positive
Endergonic Reactions
Requires energy to be done on the system for the reaction to
proceed
ΔH (Enthalpy) is positive (heat absorbed)
, Define Tansley's ecosystem concept Correct Answers
Ecosystem is a unit that covers all organisms of a given area as
well as their relationship to the inorganic environment.
Define the First and Second Law of Thermodynamics. Correct
Answers First Law of Thermodynamics - Energy is conserved,
it cannot be created or destroyed, but only transferred and
transformed
Second Law of Thermodynamics - entropy always increases in
an isolated system
Define the terms b, d, r and K and relate them to change in
population size (N) Correct Answers b = birth rate/individual d
= death rate/individual
r = per capita rate of increase K = carrying capacity
r=b-d
Nt=rmaxN rmax = growth rate's maximum value
Nt=rmaxN⌊K-NK⌋ N = # of additional individuals that can be
accommodated
Describe the four steps of the Light-Dependent Reactions, and
able to list the inputs and outputs of the Light-Dependent
Reactions. Correct Answers Light excitation of electron (from
H2O)
A photon (with correct wavelength (blue or red)) will hit a
chlorophyll molecule in the plant, causing an electron to become
excited
Most chlorophyll molecules in the Photosystems will be 'normal'
(electron is excited and energy will be given off)
Energy is given off from one chlorophyll to another, until it
reaches the Reaction Center
Be able to identify the most common sources of chemical
potential energy. Correct Answers Glucose (in the C-H bonds)
ATP (in the O-P bonds)
Be able to use these terms in context: catalyst, enzyme, active
site Correct Answers Catalyst - Any substance that increases the
rate of a chemical reaction without itself undergoing any
permanent chemical change
Enzyme - a protein catalyst used by living organisms to speed
up and control biological reactions
Active site - The location in an enzyme molecule where
substrates (reactant molecules) bind and react
Compare and contrast density-dependent and density-
independent limits on population growth and provide examples
of each. Correct Answers DD- change in intensity as a function
of population size; usually are biotic
Ex: lack of resources, disease
DI- factors alter b & d rates without regard to population;
usually involve changes in abiotic environment
Ex: storms, wildfires
Contrast r- and K-selected life history strategies, and identify
what life-history factors each life-history strategy maximizes.
Correct Answers R-strategist: many butterflies lay hundreds of
eggs, increasing the birthrate, however the death rate of the
offspring is high (maximize r)
Mother cannot care for all of them
,Smaller, shorter life spans, younger age of reproduction, more
offspring, little or none parental care, wild fluctuations of
population stability
K-strategist: elephants have only one offspring at a time and
often only give birth once every 4 years. By caring for the
offspring, however, they reduce the death rate of juvenile
elephant (maximize K)
Larger, longer life span (more chances to give birth), older age
of reproduction, fewer offspring, long and involved parental
care, mostly stable population
Define and contrast Gross primary Production (GPP) and net
primary production (NPP): Correct Answers GPP= total amount
of chemical energy produced in a given area and time period
(Ex: 100% from captured sunlight)
NPP=energy that is invested by primary producers in building
new tissue or offspring (Ex: 10% plant growth)
Define exergonic and endergonic chemical reactions. Correct
Answers Exergonic Reactions
Release energy (can be used to do work)
Tend to be spontaneous
Reactants have a higher Gibbs Free Energy than the products
ΔH (Enthalpy) is negative (heat given off)
ΔS (Entropy) is positive
Endergonic Reactions
Requires energy to be done on the system for the reaction to
proceed
ΔH (Enthalpy) is positive (heat absorbed)
, Define Tansley's ecosystem concept Correct Answers
Ecosystem is a unit that covers all organisms of a given area as
well as their relationship to the inorganic environment.
Define the First and Second Law of Thermodynamics. Correct
Answers First Law of Thermodynamics - Energy is conserved,
it cannot be created or destroyed, but only transferred and
transformed
Second Law of Thermodynamics - entropy always increases in
an isolated system
Define the terms b, d, r and K and relate them to change in
population size (N) Correct Answers b = birth rate/individual d
= death rate/individual
r = per capita rate of increase K = carrying capacity
r=b-d
Nt=rmaxN rmax = growth rate's maximum value
Nt=rmaxN⌊K-NK⌋ N = # of additional individuals that can be
accommodated
Describe the four steps of the Light-Dependent Reactions, and
able to list the inputs and outputs of the Light-Dependent
Reactions. Correct Answers Light excitation of electron (from
H2O)
A photon (with correct wavelength (blue or red)) will hit a
chlorophyll molecule in the plant, causing an electron to become
excited
Most chlorophyll molecules in the Photosystems will be 'normal'
(electron is excited and energy will be given off)
Energy is given off from one chlorophyll to another, until it
reaches the Reaction Center
