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225 Cards in this Set

  • Front
  • Back
Definition:

- must eat food, organic molecules from their environment, to sustain life
Heterotroph
Definition:

- make organic molecules from inorganic sources
Autotroph
Definition:

- use light as a source of energy
- green plants, algae, cyanobacteria
Photoautotroph
Definition:

- energy within light is captured and used to synthesize carbohydrates
Photosynthesis
In photosynthesis, CO2 is _______ and H2O is _______.
CO2 is reduced;
H2O is oxidized
Photosynthesis is an ________ reaction.

endergonic or exergonic?
endergonic
Definition:

- double-membrane bound organelle
- organelles in plants and algae that carry out photosynthesis
Chloroplast
The majority of photosynthesis occurs in leaves in the ______ ________.
central mesophyll
In photosynthesis, the light reactions occur in the ______.
thylakoids
In photosynthesis, the dark reactions occur in the _______.
stroma
Matching:

- green discs stacked into a grana
- location of light reactions
thylakoid
Matching:

- surrounding thylakoid
stroma
Definition:

- type of electromagnetic radiation
- travels as waves
- also behaves as particles - photons
Light energy
_______ boosts electrons to higher energy levels.
Absorption
Definition:

- carbon dioxide enters and oxygen exits leaf through these cores
stomata
Oxygen that leaves the plant through the stomata comes from ______.
H2O
Matching - Pigments:

- primary e acceptor
- converts sun energy into chemical energy
- reflects blue-green light
Chlorophyll a
Matching - Pigments:

- secondary e acceptor
- reflects a yellow green
Chlorophyll b
Matching - Pigments:

- appear yellow orange
- responsible for fall colors
- not involved in reactions but offer some photoprotection
Carotenoids
The light harvesting complex and the reaction center are the two main components of __________.
Photosystem II
Definition:

- pops electrons up to primary e acceptor
- directly absorbs photons
- energy transferred via resonance energy transfer
light harvesting complex
Definition:

- relatively unstable
- transferred primary electron acceptor
- removes electrons from water to replace oxidized P680
Reaction Center in PSII
Photosystem I or II?

- requires light, H2O
Photosystem I
Definition:

- key role to make NADPH
PSI
PSI or PSII?

- high energy electron removed from P700 and transferred to a primary electron acceptor
PSI
Fill in the blank:

In 8 rxns, sunlight hits the _________, excite e- in photosystem ___ molecules.

e- transferred to chlorphyll _; passes e- down e- transport; molecules transferred to photosystem ___.

H2O is split in 2, in _____ ______, e's from this replace e- that left.
thylakoid
photosystem II
chlorophyll a
photosystem I
thylakoid membranes
Cyclic and noncyclic electron flow are both examples of ______ ______.
light reactions
In the Calvin Cycle, ATP and NADPH are used to make _________.
Carbohydrates
Definiton:

- requires massive input of energy
- component of Calvin Cycle
CO2 Incorporation
In CO2 incorporation, for every 6 CO2 incorporated, how many ATP and NADPH are used/.
18 ATP and 12 NADPH
What are the 3 phases of the Calvin Cycle?
1. Carbon fixation
2. Reduction and Carbohydrate Production
3. Regeneration of RuBP
Carbon fixation is a light or dark reaction?
dark reaction
In carbon fixation:
CO2 is incorporated in RuBP using what enzyme?
the rubisco enzyme
What are the substrates in carbon fixation?
6 CO2
What are the end products of carbon fixation?
12 (3C) sugars
6 RuBP act as _______ _______ in carbon fixation.
carbon acceptors
What are the substrates in Reduction and Carbohydrate Production?
12 3PG, 12 ATP, and 12 NADH
Name the end products in Reduction and Carbohydrate Production.
12 G3P's

- 2 of 12 G3P's will pull out of cycle and join to form one 6C sugar
What are the substrates in Regeneration of RuBP?
10 G3P, 6 ATP
Name the end products in Regeneration of RuBP.
6 (5C) RuBP (which are put back into the system to start again)
For every 6 CO2 put into Calvin cycle, how many ATP and NADH are used?
18 ATP, 12 NADH
Name 3 environmental conditions that can influence both the efficiency and way the Calvin Cycle works.
light intensity, temperature, water availability
Definition:

- decreases efficiency of photosynthesis because it uses the same RuBP molecule to release CO2 from the plant
- minimally used
Photorespiration
What process does this reaction describe?

RuBP + CO2 -> 2 3PG

- rubisco functions as a carboxylase
Photorespiration
Photorespiration is more likely to take place in what kind of environments?
Hot and dry
Photorespiration is favored when CO2 ____ and O2 ____.
CO2 low, O2 high
C4 plants make up what percentage of all plants?
10%
Name the main disadvantage of the C4 pathway.
requires more ATP
C3 or C4?

- make a 4 carbon compound in the first step of carbon fixation, no RuBP
- more efficient mechanism for producing sugar (no photorespiration)
C4 plants
In warm dry climates __ plants have the advantage in conserving water and preventing photorespiration.
C4
In cooler climates __ plants use less energy to fix CO2
C3
In C4 plants, ______ cells serve as a protective barrier for conserving water.
Mesophyll
____ plants open their stomata at night, close their stomata during the day to conserve water.
CAM
CAM plants open their stomata at night to bring ___ in, to send ___ out.
CO2 in; O2 out
Name 2 reasons why cells need to respond to signals.
1. Need to respond to a changing environment
2. Cells need to communicate with each other
Definition:

- plant's growth in response to the presence of light
phototropism
Name the effects of Auxin.
- promotes growth above and below the soil
- fruit maturation
- affects primary meristem and secondary meristem (makes plant grow taller and wider)
Name the effects of Gibberellins.
- promotes growth and elongation, but does NOT promote fruit maturation
- affect primary meristem (makes plants grow taller)
Name the growth substance.

- discovered in rice plants that had been infected by a fungus
- caused rice plants to grow very TALL, but never produced any rice
Gibberellins
Name the effects of cytokinins.
- increase rate of cytokinesis or cell division
- works with auxin to activate secondary meristems (makes plant grow wider)
Name the growth substance.

- important in coordinating developmental and stress responses (excessive cold or heat dehydration, etc.)
- slows down growth until environment becomes more favorable
- for herbivores, plant can sequester water in plant (into roots) and then herbivore will hopefully leave it alone
Ethylene
Name the growth substance.

- slows or stops plant metabolism when growing conditions are poor
- help respond to environmental stress
Abscisic Acid (ABA)
Name the 5 signals relayed between cells.
1. Direct intercellular signaling
2. Contact-dependent signaling
3. Autocrine signaling
4. Paracrine signaling
5. Endocrine signaling
Name the type of cell signaling.

in direct contact, but can be in contact through a receptor
Contact-dependent signaling
Name the type of cell signaling.

- cells secrete signaling molecules that bind to their OWN cell surface
Autocrine signaling
Name the type of cell signaling.

- CANNOT affect itself, but can affect neighboring cells of the same type
Paracrine signaling
Name the type of cell signaling.

- signals (hormones) travel long distances and are usually longer lasting
- target cell can be a different type of cell
Endocrine signaling
Name the 3 stages of cell signaling.
1. Receptor activation
2. Signal transduction
3. Cellular response
What requires GTP (energy) to be activated?
G-protein coupled receptors (GPCR)
Ligand-gated ion channels are present in what kind of cells?
plant and animal cells
Definition:

- do NOT require ATP - so ions can only go down concentration gradient
- open and close in response to a stimulus, allow specific ions to enter or leave cell
Ligand-gated ion channels
Definition:

- cell membrane less polarized, less negative relative to surrounding solution (having started at resting membrane potential)
Depolarization
Matching:

- gated channels open allowing Na+ to flow in and membrane becomes more positive (drive membrane potential towards 0V)
depolarization
Definition:

- cell membrane more polarized, more negative
Hyperpolarization
Matching:

- K+ moves out of the cell making the cell membrane less positive
- below -70V
Hyperpolarization
Definition:

- an electrical activity change in nerve cells
- change ion concentration
Action Potential
Matching:

- time when more negative inside compared to outside typically at -70 mV
Resting Membrane Potential
Name the gated ion channel.

- open and close in response to voltage change
- used by neurons
Voltage-gated
Name the gated ion channel.

- open and close in response to ligands or chemicals
- chemical signal = neurotransmitter
Ligand-gated
Voltage-gated channels are ______ at resting membrane potential.
closed
Voltage-gated Na+ channels open and Na+ goes down concentration gradient into the cell in what phase of action potentials?
Depolarization (drive tracing up toward 0V)
Not all stimuli will result in full depolarization. Stimuli must be strong enough to reach what for depolarization to occur?
Threshold potential
Voltage-gated Na+ channels are inactivated. K+ gates open and K+ exits cell in what phase of action potentials?
Repolarization
Why do membranes often hyperpolarize?
K+ gate is slower to close
Voltage-gated Na+ channels respond to stimulus BUT if the ______ ____ is closed, I cannot generate another action potential no matter how strong the stimulus is.
inactivation gate
While the inactivation gate of Na+ is closed, the cell is _________ to another stimulus, no matter how strong.
unresponsive
Name the steps in order of action potentials.
1. Resting Membrane Potential (-70 mV)
2. Depolarization (Na+ channels open and Na+ goes into cell)
3. Reach threshold potential
4. Repolarization (K+ channels open and K+ exits cell)
(5. chance for hyperpolarization)
Name 4 examples of second messengers.
- CAMP
- Ca2+
- DAG
- IP3
Signals binding to cell surface are _____ messengers. (often protein hormones)
first
Name the 2 advantages of CAMP.
1. signal amplification (many CAMP activate PKA, each PKA can phosphorylate many proteins)
2. speed
What kind of hormones take much longer?
Steroid hormones
Signal transduction via CAMP does or does not require ATP?
it does require ATP
Ca2+ is an example of what kind of messenger?
second messenger
Cells maintain a ____ ____ Ca2+ gradient between inside and outside of cell.
very large (more Ca2+ outside)
When calcium channels open, Ca2+ will fly ____ cell, down concentration gradient.
fly INTO the cell
- influx of Ca2+ acts as second messenger
The second messenger Ca2+ benefits plants in what ways?
helps with opening and closing of stomata, phototropism, gravitropism
The second messenger Ca2+ benefits animals in what ways?
helps with nerve transmission, muscle contraction, secretion of digestive enzymes
Signal transduction via DAG and IP3 works with __ _______.
G protein (like CAMP!)
Epinephrine is an example of what kind of hormone?
protein hormone (epinephrine = adrenaline)
What second messenger is responsible for changing heart rate?
epinephrine (aka adrenaline)
If epinephrine, heart rate will ______.
increase
Epidermal Growth Factor (EGF) is an example of what kind of hormone?
protein hormone
Epidermal Growth Factor (EGF) is secreted by endocrine cells and stimulates what mechanism?
skin cells to divide
Definition:

- programmed cell death
- cell shrinks and forms rounder shape (due to destruction of nucleus and cytoskeleton)
Apoptosis
Matching:

- plasma membrane forms blebs
- necessary because we're constantly having to replaced aged or dead cells
Apoptosis
Some cancers have avoided _____.
apoptosis
What 3 phases are involved in interphase?
G1 - first gap
S - synthesis of DNA
G2 - second gap
90% of cell life is in ______.
interphase
Definition:

- substitute for G1 for cells postponing division or never dividing again
G0
Chromosomes replicate during what phase forming sister chromatids?
S phase
Definition:

- DNA that is hidden beneath kinetochore proteins in a chromosome
centromere
During ___, cell synthesizes proteins needed during mitosis and cytokinesis
G2
Environmental conditions primarily influence ______ organisms.
They will not divide unless the environment is favorable.
unicellular
What enzymes are responsible for advancing a cell through the phases of the cell cycle?
Cyclins of cyclin-dependent kinases
Name the 3 checkpoints.
1. G1 checkpoint
2. G2 checkpoint
3. Metaphase checkpoint
Name the checkpoint.

- checks for: favorable environment? is current DNA in the cell damaged?
G1 checkpoint
Name the checkpoint.

- is DNA damaged now? copied correctly? monitors level of proteins that are needed for M phase
- if all are okay, mitotic cyclin activated and cell proceeds to mitosis; then mitotic cyclin degrades
G2 checkpoint
Name the checkpoint.

- are all chromosomes attached to the spindle apparatus? chromosomes lined up at midpoint?
Metaphase checkpoint
Loss of checkpoint function can lead to what?
mutation or cancer
Chromosomes are composed of:
DNA and proteins
Definition:

- DNA-protein complex making up chromosomes
chromatin
Definition:

- contains single, linear, double-stranded DNA molecule
Eukaryotic chromosome
When a species is diploid, members of a pair of chromosomes are called _______.
homologues
Definition:

- 2 identical copies with associated proteins
- tightly associated at centromere
sister chromatids
Definition:

- microtubule organizing center, located at each side of cell (define a pole)
centrosome
Definition:

- originate from centrosomes, attach to centromeres and eventually separate sister chromatids
Kinetochore microtubules
Definition:

- stretching out from centrosomes but don't attach to centromeres, expand size of cell
Non-kinetochore microtubules
Definition:

- phase of cell cycle during which the chromosomes are (replicated and) decondensed and found in nucleus
Interphase
Name the phase of mitosis.

1. nuclear membrane starts to dissolve, dissociate
2. spindle fibers start to come out of centrosomes and form
3. sister chromatids condense, becoming very discrete units
Prophase
Name the phase of mitosis.

1. nuclear membrane has completely dissociated
2. spindle fibers fully formed
3. sister chromatids attach to spindle via kinetochore microtubules
4. sister chromatids align along metaphase plate (center)
Metaphase
Name the phase.

1. sister chromatids separate
2. nonkinetochore fibers try to push through center, pulling sister chromatids apart, lengthen cell
3. centromeres are pulled apart because each sister chromatid goes to opposite side of cell (each arm of sister chromatids is now referred to as a chromosome)
Anaphase (of mitosis)
Name the phase of mitosis.

1. nuclear membrane starts to reform around both units of chromosomes
2. spindle fibers have started dissipating
3. chromosomes start to decondense
4. see cleavage furrow (plasma membrane begins pinching off)
Telophase and Cytokinesis
Discuss the difference in cytokinesis between animals and plants.
-animals: cleavage furrow constricts life a drawstring to separate the cell
-plants: cell plate forms a cell wall between the 2 daughter cells
Definition:

- process by which 4 haploid cells are produced from a cell that was originally diploid
Meiosis
Egg and sperm cells are an example of _____ is animals.
Meiosis
Name the 3 key differences between mitosis and meiosis.
1. homologous pairs form a bivalent or tetrad
2. crossing over occurs
3. end up with 1/2 genetic information instead of identical cell
Definition:

- homologous pairs of sister chromatids associate with each other, lying side by side to form a tetrad
tetrad
In meiosis, the centromeres separate in _______.
anaphase II
Definition:

- physical exchange between chromosome pieces of the crossing tetrad (EQUAL pieces exchanged)
Crossing over
Crossing over may cause what?

- arms of the chromosomes tend to separate but remain adhered at a crossover site -- unequal pieces may be exchanged (leads to mutations)
chiasma
Name the phase of meiosis.

- nuclear membrane starts to dissociate
- chromosomes condense (becoming individual units)
- spindle fibers forming
- bivalents form - crossing over occurs
Prophase I
Name the phase of meiosis.

- nuclear membrane completely dissipating
- kinetochore microtubules attaching to centrosomes
- tetrads align along metaphase plate (double file line)
Metaphase I
Name the phase of meiosis.

- pull chromosomes to opposite sides of cell
- not splitting centromeres!
Anaphase I
Name the phase of meiosis.

- nuclear membranes re-form and chromosomes decondense
- 2 cells separated by cleavage furrow
- nuclear envelope does not always reform
Telophase I and Cytokinesis
Name the phase of meiosis.

- sister chromatids condense and spindle starts to form
- nuclear membrane begins to vesiculate
Prophase II
Name the phase of meiosis.

- centrosomes on opposite sides, microtubules expanding
- sister chromatids align on metaphase plate (single file line)
Metaphase II
Name the phase of meiosis.

- centromeres split and sister chromatids pulled to opposite sides of cell
Anaphase II
Name the end products of meiosis.
4 haploid cells with 1/2 genetic information
Definition:

- organism spends majority of life as diploid organism
- animals
Diploid-dominant species
Definition:

- organism spends majority of life haploid
- yeast, fungus, and lower level plants (moss, algae)
Haploid-dominant species
Definition:

- intermediate, some time as diploid, some as haploid
- higher level plants (angiosperms, conifers, flower-producing, ferns)
Alternation of generations
Chromosomal Mutations:

- missing a piece of a chromosome
Deficiencies
Chromosomal Mutations:

- doubles a particular region (piece of DNA copied twice)
Duplications
Chromosomal Mutations:

- flips a region to the opposite orientation
Inversions
Chromosomal Mutations:

- piece of chromosome got transferred to a completely different chromosome
Translocations
Definition:

- chromosomes do not sort properly during cell division
- during meiosis, can produce gametes with too many or too few chromosomes
Nondisjunction
Definition:

- change in chromosome #
- often leads to non-viable organism
Aneuploidy
30-35% of fern and flowering plant species are _______.
Polyploidy
Synapsis (pairing of 2 homologous chromosomes) during prophase?
Mitosis:
Meiosis I:
Meiosis II:
Mitosis: no
Meiosis I: yes, bivalents/tetrads are formed
Meiosis II: no
Crossing over during prophase?
Mitosis:
Meiosis I:
Meiosis II:
Mitosis: rarely
Meiosis I: commonly
Meiosis II: rarely
Alignment along metaphase plate?
Mitosis:
Meiosis I:
Meiosis II:
Mitosis: sister chromatids
Meiosis I: bivalents
Meiosis II: sister chromatids
When does meiosis, fertilization happen in diploid-dominant organisms?
meiosis: first step of life cycle
fertilization: second step
When does meiosis, fertilization happen in haploid-dominant organisms?
fertilization: second step of life cycle
meiosis: third step
When does meiosis, fertilization happen in alternation of generations organisms?
meiosis: first step of life cycle
fertilization: 4th step
This is the main reaction of what process?

CO2 + H2O + light energy -> C6H12O6 + O2 + H2O
photosynthesis
When does crossing over start to take place?

A. Prophase I
B. Anaphase I
C. Metaphase II
D. Prophase II
E. Anaphase II
A. Prophase I
Homologous chromosomes move to opposite poles of a dividing cell during
A. mitosis
B. meiosis I
C. meiosis II
D. fertilization
E. none of the above
B. meiosis I
What phase of meiosis is being described by the following sentence?
Centromeres of sister chromatids separate and each sister (now individual chromosome) move toward opposite poles of the cell.
A. Metaphase I
B. Metaphase II
C. Anaphase I
D. Anaphase II
E. none of the above
D. Anaphase II
DNA is organized into chromosomes by being wrapped around
A. microtubules
B. spindle fibers
C. second messengers
D. histone proteins
E. centromeres
E. centromeres
Checkpoints during the cell cycle are important because they
A. allow the organelle activity to catch up to cellular demands
B. ensure the integrity of the cell's DNA
C. allow the cell to generate sufficient ATP for cellular division
D. are the only time DNA replication can occur
E. all of the above
B. ensure the integrity
The main difference between mitosis in plants versus animals is
A. plants do not have cell division checkpoints
B. plants do not use cleavage furrows for cytokinesis
C. plants do not have spindle fibers
D. plants don't form sister chromatids
E. there are no differences between mitosis in plants and animals
B. plants do not use cleavage furrows for cytokinesis
Which of the following is a reason for mitotic cell division?
A. reproduction in single celled organisms
B. gamete formation in animals
C. multicellularity
D. all of the above
E. both A and C
e. both a and c
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
A. CO2 and glucose
B. H2O and O2
C. ADP, Phosphate, and NADP+
D. electrons and H+
E. ATP and NADPH
E. ATP and NADPH
All of the following are directly associated with photosystem II except
A. photolysis (splitting of water)
B. release of oxygen
C. harvesting of light energy by chlorophyll
D. production of ATP
E. production of CO2
D. production of ATP
The Calvin cycle requires all of the following molecules except
A. CO2
B. ATP
C. RuBP
D. glucose
E. NADPH
D. glucose
The dark reactions of photosynthesis occur in the
A. thylakoid membranes
B. cytoplasm
C. stroma
D. mitochondria
E. lysosomes
C. stroma
A chromosome mutation where a portion of the chromosome is flipped to a region in the opposite orientation is known as
A. duplication
B. translocation
C. deficiency
D. inversion
E. none of the above
D. inversion
Plants that are commonly found in hot and dry environments that carry out carbon fixation at night are
A. oak trees
B. C3 plants
C. CAM plants
D. all of the above
E. A and B only
C. CAM plants
The NADPH produced during the light reactions is necessary for
A. the carbon fixation phase
B. the reduction phase
C. the regeneration of RuBP of the Calvin Cycle
D. all of the above
E. A and B only
B. the reduction phase
Which life cycle is characterized by a 2n zygote undergoing meiosis to form 4 1n cells that undergo mitosis to form a 1n adult organism?
A. diploid-dominant species
B. haploid-dominant species
C. alternation of organisms
D. all of the above
E. A and B only
B. haploid-dominant species
What type of signaling is due to a molecule traveling long distance from its synthesis site to different target tissues?
A. direct intercellular
B. contact-dependent
C. autocrine
D. paracrine
E. endocrine
E. endocrine
When sodium channels are open during an action potential, which way does the potassium go?
A. into the cells
B. out of the cells
B. out of the cells
The majority of the G3P produced during the reduction and carbohydrate production phase is used to produce
A. glucose
B. ATP
C. RuB to continue the cycle
D. rubisco
E. all of the above
D. rubisco
Sodium channels are closed and potassium channels are open during
A. resting period
B. depolarization
C. repolarization
D. hyperpolarization
E. C and D
E. C and D
Put the following events in order.
1. Ca++ channels open and calcium enters the axon terminal
2. Neurotransmitter is released into the synaptic cleft
3. Action potential travels down the axon of the first neuron
4. Action potential is triggered in the second neuron
5. Synaptic vesicles fuse with the axon terminal ending

A. 51324
B. 52134
C. 31524
D. 35142
E. 35124
E. 35124
What is the number?

Number of carbons in a RuBP molecule.
5
What is the number?

Number of CO2 molecules needed to produce one molecule of glucose in the Calvin cycle.
6
What is the number?

Number of ATPs needed in the carbon fixation phase of the Calvin cycle for every 6 CO2 incorporated.
0
What is the number?

Number of NADPHs needed in the Calvin cycle for every 6 CO2 incorporated.
12
What is the number?

Number of ATPs needed in the Calvin cycle for every 6 CO2 incorporated.
18
Matching:

- structure at the cell poles where the spindles are formed
centrosome
Matching:

- chromosomes that carry similar information in a diploid species
Sister chromatids
Matching:

- replicated forms of chromosomes joined together
Homologous chromosomes
Matching:

- phase in cell cycle where the cell synthesizes proteins necessary for cell division
G2
Matching:

- centralized region joining replicated chromosomes
centromeres
Matching:

- phase in the cell cycle where DNA is replicated
S
Matching:

- spindle fibers that attached the centromere and pull the chromosome to cell poles
Kinetochore microtubules
Matching:

- division of cytoplasm to produce 2 distinct daughter cells
cytokinesis
Matching:

- phase in the cell cycle where the cell accumulates molecular changes in preparation for DNA synthesis
G1
Matching:

- gene-carrying structure consisting of packaged DNA molecules
chromosome
Fill-in-the-Blank:

- The _____ is the time that another action potential can not occur, regardless of the strength of the stimulus.
refractory period
Fill-in-the-Blank:

______ is the period of the cell cycle where G1, G2, and S occur.
Interphase
Fill-in-the-Blank:

______ is the plant growth hormone that aids in fruit ripening.
ethylene
Fill-in-the-Blank:

Depolarization occurs when ______ channels are closed and _______ channels are open.
K+, Na+
Fill-in-the-Blank:

Estrogen does or does not (choose one) require a membrane receptor.
does not
Fill-in-the-Blank:

Second messengers have 2 specific advantages. Name one. ______________
signal amplification, speed
CO2 and O2 travel in and out of the plant through pores called ______.
stomata
_______ is the plant growth hormone that aids in phototropism.
auxin
The nuclear membrane begins to disintegrate what phase of mitosis? ______
prophase
Light reactions occur in the ________ membranes.
Thylakoid
The water necessary for photosynthesis
a. is split into H2 and O2
b. is directly involved in the synthesis of carbohydrates
c. provides the electrons to replace lost electrons in PSII
d. provides H+ needed to synthesize G3P
e. does none of the above
c.
The cyclic electron flow that occurs via PSI produces
a. NADPH
b. oxygen
c. ATP
d. all of the above
e. a and c only
c. ATP
During the light reactions, the high-energy electron from P680*
a. eventually moves to NADPH+
b. becomes incorporated in water molecules
a.
The majority of the G3P produced during the reduction and carbohydrate production phase is used to produce
A. glucose
B. ATP
C. RuBP to continue the cycle
D. rubisco
E. all of the above
c.
Photorespiration
a. is the process where plants use sunlight to make ATP
b. is an inefficient way plants can produce organic molecules and in the process use O2 and release CO2
c. is a process that plants use to convert light energy to NADPH
d. occurs in the thylakoid lumen
b.
Photorespiration is avoided in C4 plants because
a. these plants separate the formation of a 4-C molecule
b. these plants carry out only anaerobic respiration
c. the enzyme PEP functions to maintain high CO2 concentrations in the bundle-sheath cells
d. all of the above
e. a and c only
e.
The ability of a cell to respond to changes in its environment is termed
a. signaling
b. apoptosis
c. irritability
d. adaptation
d. adaptation
When a cell secretes a signaling molecule that binds to receptors on neighboring cells as well as the same cell, this is called _____ signaling.

a. direct intercellular
b. contact-dependent
c. autocrine
d. paracrine
e. endocrine
c. autocrine
Which of the following does not describe a typical cellular response to signaling molecules?
a. activation of enzymes within the cell
b. change in the function of structural proteins, which determine cell shape
c. alteration of levels of certain proteins in the cell by changing the level of gene expressions
d. change in a gene sequence that encodes a particular protein
e. all of the above
d.
_______binds to receptors inside cells.

a. estrogen
b. epinephrine
c. epidermal growth factor
d. all of the above
e. none of the above
a. estrogen
All cells of a multicellular organism may not respond in the same way to a particular ligand (signaling molecule) that binds to a cell surface receptor. The difference in response may be due to

a. the type of receptor for the ligand that the cell expresses
b. the affinity of the ligand for the receptor is a given cell type
c. the type of signal transduction pathways that the cell expresses
d. the type of target proteins that the cell expresses
e. all of the above
d. all of the above
In which phase of the cell cycle are chromosomes replicated?

a. G1 phase
b. S phase
c. M phase
d. G2 phase
e. none of the above
b.
Checkpoints during the cell cycle are important because they

a. allow the organelle activity to catch up to cellular demands
b. ensure the integrity of the cell's DNA
c. allow the cell to generate sufficient ATP for cellular division
d. are the only time DNA replication can occur
e. do all of the above
b.
Which of the following is a reason for mitotic cell division?

a. asexual reproduction
b. gamete formation in animals
c. multicellularity
d. all of the above
e. both a and c
E. both a and c
a. duplication of a region of a chromosome
b. inversion of a region of a chromosome
c. nondisjunction during meiosis
d. interspecies breeding
e. all of the above
C. nondisjunction during meiosis