BIOL Unit 3
T or F: CO2 is released during photorespiration
True
Which two countries have the highest total carbon emissions?
United States and China
Which of the following is ideal habitat for a CAM plant?
a crotch of a tree
The process by which inorganic nutrients are converted to organic forms is ________.
immobilization
The process of photosynthesis probably originated ________.
in prokaryotes
"Liming" (adding carbonates to the soil) is a management technique used to _________soil pH.
increase
Plants more readily uptake ____________ nutrients.
inorganic
C4 leaf anatomy is also called ______.
kranz
Detritivores tend to be __________ than decomposers.
larger
C3 plants discriminate_________against C13 when the plant is water stressed.
less
Up until now temperature increases have been ________ in the Midwest than the rest of the world.
less extreme
The molecule stored until night in CAM plants is called?
malic acid
Organic materials transform into inorganic forms through which process?
mineralization
The process by which organic nutrients are converted to inorganic forms is ________.
mineralization
Many factors contribute to net primary productivity, but generally it is higher _______.
near the equator
Considering the global carbon cycle, which of the following is the largest reservoir of carbon?
oceans
Plants photosynthesize ________.
only in the light but respire in light and dark
What structure transports photosynthates to storage tissues?
phloem
Which of the following processes uses ATP and CO2 without a subsequent gain in ATP?
photorespiration
What is the most cultivated CAM plant?
pineapple
Name one strategy for agriculture to adapt to climate change.
plant cover crops leave land fallow contour planting Plant prairie strips crop rotations
Photorespiration is more likely to occur when_________.
plants close their stomata
The photosynthetic pigment chlorophyll a absorbs
red and blue light
Which of the following is NOT a human activity that results in carbon release to the atmosphere?
reforestation
What process is most directly driven by light energy?
removal of electrons from chlorophyll molecules
Beneficial plant-soil feedbacks would include______.
rhizobia n-fixing bacteria mycorrhizal fungi
The largest soil particle size is__________.
sand
Annual plants have __________ root systems
shallow
When oxygen is released as a result of photosynthesis, it is a direct by-product of ________.
splitting water molecules
This structure allows CO2 to enter the leaf?
stomata
Carbon is sequestered in the Earth's mantle through which process?
subduction
Which of the following would be considered a short-term reservoir in the carbon cycle?
surface ocean
Assume a thylakoid is somehow punctured so that the interior of the thylakoid is no longer separated from the stroma. This damage will most directly affect the ________.
synthesis of ATP
What is the primary function of the Calvin cycle?
synthesizing simple sugars from carbon dioxide
What are the two primary climate factors that affect soil development?
temperature and precipitation
When a photon is absorbed by chlorophyll,
the chlorophyll becomes "excited," or energized
Global climate change refers to ________.
the sum of the changes in local precipitation and temperature patterns that result from global warming
How do red and blue light differ from each other?
their wavelengths are different
Which of the following areas are more likely to be dominated by C4 plants?
grassland near the equator
The total solar energy captured by photosynthetic processes is called_________.
gross primary productivity
The concept where the soil microbial community develops a specificity to a plant's litter composition is called________.
home field advantage
What condition is most likely to cause photorespiration in C3 plants?
hot and dry
What percent of solar energy is captured by photosynthetic processes?
0.8%
Carbon released in a single day of fossil fuel use is equal to _______ year(s) of photosynthesis in the past.
1
The 4th National Climate Assessment models 3 different scenarios of change: Higher, Lower, Even Lower. By 2100, what degree of temperature change is expected under the Even Lower scenario?
1 C
How many Gt of carbon is returned to the atmosphere through BOTH plant and soil respiration?
120 GT/yr
What is the approximate size of carbon flux due to photosynthesis?
120 GT/yr
Approximately how many plants have CAM photosynthesis?
16,000
The approximate concentration of O2 in the atmosphere is _______; and the approximate concentration of CO2 is __________.
21%; <1%
Which of the following CN ratios is within the "ideal" range for good crop management?
25:1
Enteric fermentation (in ruminant guts) accounts for approximately _______% of US methane emissions?
26%
One molecule of N20 is approximately equal to _______CO2 molecules?
298
What is the optimal temperature (in C) for C4 plants?
30-40
Our best estimate is that CAM and C4 photosynthesis systems evolved approximately __________ years ago.
35 million
Fossil fuel combustion is adding approximately _______ GT/Yr carbon into the atmosphere
5.5
A rough estimate of the CN ratio of bacteria is _______.
5:1
In temperature, 4 Celsius is roughly equivalent to _______ Fahrenheit?
7
What is the current size of the atmospheric carbon pool?
750 GT
What are products of the light reactions of photosynthesis that are utilized in the Calvin cycle?
ATP and NADPH
What does photosynthesis and respiration have in common?
ATP synthesis in both processes relies on the chemiosmotic mechanism.
What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex)?
An electron is excited.
Oxygen is not produced in this type of photosynthesis
Anoxygenic
What is the difference between NAD+ and NADP?
Both function as electron carriers, but NADP has a phosphate group and NAD+ does not.
The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why?
Both minimize photorespiration but expend more ATP during carbon fixation.
Smooth brome is an invasive grass that is increasing in tall grass prairies. It has what photosynthesis system?
C3
What would be the expected effect on plants if the atmospheric CO2 concentration was doubled?
C3 plants would have faster growth; C4 plants would be minimally affected.
The phylogenetic distribution of the enzyme rubisco is limited to ________.
C3, C4, and CAM plants
At current CO2 concentrations (~400 ppm) which photosynthesis system is more efficient, assuming environmental conditions are ideal.
C4
Which isotope of carbon is most common?
C12
The Calvin cycle uses _______ to produce glucose.
CO2, ATP, NADPH, rubisco
What is a difference between chlorophyll a and chlorophyll b?
Chlorophyll a and b absorb light energy at slightly different wavelengths.
___________ forest stands are less vulnerable to disease.
Diverse
CAM plants keep stomata closed in the daytime, thus reducing loss of water. They can do this because they ________.
fix CO2 into organic acids during the night
T or F: "Organic matter" is regulated by the United States Department of Agriculture.
False
T or F: Plants do not respire at night
False
T or F: Stomata open when plants are water stressed
False
What sequence correctly represents the flow of electrons during photosynthesis?
H2O → NADPH → Calvin cycle
As electrons are passed through the system of electron carriers associated with photosystem II, they lose energy. What happens to this energy?
It is used to establish and maintain a proton gradient.
In C4 plants carbon is fixed twice, once by the enzyme _________ and next by the enzyme___________.
PEPCase; RuBisCO
T or F: CAM plants have bundle sheath cells
false
T or F: Photorespiration produces sugar
false
Which of the events listed below occurs in the light reactions of photosynthesis?
Light is absorbed and funneled to reaction-center chlorophyll a.
What is the largest carbon reservoir?
Lithosphere
The energy source for the synthesis of carbohydrates in the Calvin cycle is?
NADPH and ATP.
The figure below shows the absorption spectrum for chlorophyll a and the action spectrum for photosynthesis. Why are they different?
Other pigments absorb light in addition to chlorophyll a.
What statement best describes the relationship between photosynthesis and respiration?
Photosynthesis stores energy in complex organic molecules; respiration releases energy from complex organic molecules
CAM plants have which of the following enzymes?
RuBisCO and PEPCase
C3 plants have which of the following?
RuBisCO only
Plants acquire the energy for exciting electrons in the photosynthesis process from which source?
Sun or other light source
T or F: The Polar Vortex is a human-caused phenomenon.
false
The soil clumps held together with organic matter are called__________-.
aggregates
List one non-living part of the soil.
air inorganic materials water
High humidity _______.
allows plants to maintain leaf moisture
T or F: Water is the electron donor in anoxygenic photosynthesis
false
Rhizobia are in what group?
bacteria
A flask containing photosynthetic green algae and a control flask containing water with no algae are both placed under a bank of lights, which are set to cycle between 12 hours of light and 12 hours of dark. The dissolved oxygen concentrations in both flasks are monitored. Predict what the relative dissolved oxygen concentrations will be in the flask with algae compared to the control flask. The dissolved oxygen in the flask with algae will ________.
be higher in the light but lower in the dark
Which phenomenon is likely to increase agricultural pest populations?
fewer frost free days
Organic matter must contain which element.
carbon
In autumn, the leaves of deciduous trees change colors. This is because chlorophyll is degraded and ________.
carotenoids and other pigments are still present in the leaves
Fungi cell walls are made of a complex material called_________.
chitin
Plants are green because...
chlorophylls absorb blue and orange-red wavelengths of light and reflect green light.
The enzyme RuBisCO is found in
chloroplasts
The smallest soil particle is ___________.
clay
List the 5 soil formation factors
climate parent material biological factors (vegetation) topography time
What is the most common reason bacteria are inactive in soil?
cold temperatures
Decomposers________.
convert organic materials from all trophic levels to inorganic compounds usable by primary producers
What condition would C3 plants be the best competitor against C4 or CAM plants?
cool and wet
Cultivation _____________ soil organic matter.
decreases
In both photosynthesis and cellular respiration, protons are pumped across a membrane during...
electron transport.
Plant roots release _________ to feed nearby soil microbes.
exudates
T or F: Allergies are expected to DECREASE in a warmer climate
false
T or F: Organic matter is a way to sequester soil carbon
true
T or F: Total soil carbon includes both organic carbon and inorganic carbon (carbonates).
true
In CAM plants the carbon storage molecules are stored in what structure until night when they enter the Calvin cycle?
vacuole
The C4 photosynthetic pathway provides a physical separation between oxygen and RuBisCO. This reduces photorespiration, a costly process that consumes energy that the plant could use to grow. This plant is particularly vulnerable to this process when water is limiting and the plant needs to close its somata. There is a small energy for this process, but it is not as costly as photorespiration. Based on this information, what habitat would C4 photosynthesis be most adventurous.
warm and dry environments
In oxygenic photosynthesis, oxygen is released because ________is split to provide an electron to replace one that absorbs a photon of light.
water
Photosynthesis is the process that, in part, uses light energy to extract hydrogen atoms from_______.
water
The electrons of photosystem II are excited and transferred to electron carriers. From which molecule or structure do the photosystem II replacement electrons come?
water
Adding ________, a high CN material, is often used as a way to "remove" nitrogen from the soil in restorations.
wood chips sugar sawdust
