BIOL 1103, Test 5

Which yields the most energy during combustion?

1 glucose molecule

Consider the flux, movement of carbon between the pools in this diagram. Rank these in order of contribution to increasing atmospheric C each year (with highest contribution first):

1. burning of fossil fuels 2. ocean 3. plants 4. cellular respiration of microbes and decomposers

What are the steps of carbon through the slow carbon cycle?

1. carbon is fixed by phytoplankton through photosynthesis 2. phytoplankton die and become fossilized 3. fossil fuels are harvested 4. carbon is released into the atmosphere through combustion

What are the steps on how light energy gets converted to chemical energy during photosynthesis?

1. light energy is absorbed by chlorophyll 2. chlorophyll is "excited", freeing up an electron 3. electrons move in a way that allows ATP to be generated 4. ATP is formed and can be used to power metabolic processes

What is the path of nitrogen into a protein in the turkey for Thanksgiving?

1. lightning strikes, forming ammonia and nitrates 2. usable forms of nitrogen are absorbed from soil by plants 3. worms feed on decaying plant matter 4. the turkey acquires nitrogen by eating a decomposer

Sequence of events from fertilizer run off entering a large estuary like the Chesapeake Bay

1. phytoplankton population increase and O2 levels rise at the top water layers of estuary 2. decreased sunlight to submerged vegetation and O2 levels fall in lower levels of the estuary 3. dead phytoplankton and plants drift to the bottom of the estuary and O2 levels fall as respiration increases 4. insufficient O2 suffocates fish and shellfish 5. dead zone forms at the bottom of the estuary

Ethanol is inferior compared to many energy sources because it has only:

7 bonds that can be changed by cellular respiration or combustion to release energy

Where does most of the mass that makes up plants come from?

Air

What would you predict the final weight of the seeds would be in just sunlight?

about 2 g

Carbon can be found in ______

air, organic molecules, ocean water, plants, animals, bacteria

Plants acquire nitrogen from:

ammonium from bacteria and ammonium from fertilizers

Fertilizer run-off into water supplies leads to ______

an increase in photosynthetic organisms because they are nitrogen limited

Glucose is one product of photosynthesis? Which of the following organisms make use of glucose as a major source of carbon to build other molecules?

animals, plants, and bacteria

Gasoline is mostly a mixture of molecules such as C8H18. What happens when the atoms in the molecule of gasoline when it is burned in a car? Some of the atoms ______.

are released as CO2 into the air

If plants get raw materials from the soil and a willow is planted in a known amount of soil and allowed to grow, then...

as the plant mass increases, the soil mass should decrease

The majority of nitrogen on earth is found in the ____?

atmosphere

Which pool of carbon is most likely to be affected by changes on the order of 7 Gtons?

atmosphere

RuBisCO is the key enzyme for carbon fixation because it ____

attaches carbon dioxide to a molecule containing 5 carbons

In the light and water condition, which processes are active?

both photosynthesis and cellular respiration

Because zooxanthellae are photosynthetic, they provide the following nutrients to coral:

carbon and oxygen

What would happen to the fast carbon cycle if all decomposers suddenly died and were not replenished?

carbon would accumulate in organic matter

CO2 is produced by _____

cellular respiration

Glucose is required for _____

cellular respiration

H2O is produced by _____

cellular respiration

In the water, no light condition, which processes are active?

cellular respiration

O2 is required for _____

cellular respiration

Which processes cause flux of carbon INTO the atmosphere?

cellular respiration, burning fossil fuels, decomposition, and deforestation

Which fuel produces the lowest net amount of greenhouse gases?

cellulosic ethanol

In areas of fertilizer run off, fish and shellfish populations will ______

decrease because of limited availability of oxygen following an algal bloom

An increase in the population size of decomposers will _____

decrease oxygen levels through cellular respiration

What do plants get from fertilizer?

elements like N and P needed to make proteins and DNA

Once carbon enters a plant, it can ______

exit the plant as CO2, become a part of the plant cell walls protein and fat, exit the plant as water during photosynthesis, and be consumed by an insect feeding on the plant and become part of the insect's body

What ways could you have acquired nitrogen that is now in your proteins, DNA, and RNA?

from plants that acquired nitrogen from a mutualistic relationship with bacteria or from animals that ate plants that took up ammonia from the soil

Based on your knowledge of how energy is released when carbon switches bonding partners, which molecule is a better energy source, fructose or butanol?

fructose

If the carbon entering a pool exceeds the carbon exiting the pool, the level of carbon in that pool will:

go up

A mature maple tree can have a mass of one ton or more, yet it starts from a seed that weighs less than one gram. Which of the following processes contribute most to this huge increase in biomass?

incorporation of CO2 gas from the atmosphere into molecules by the leaves

The washing of fertilizer into bodies of water can lead to?

increased growth of aquatic microorganisms, higher concentrations of nitrogen in the water, decreased oxygen levels in the water, and decreased numbers of aquatic animals

Because phytoplankton are nitrogen limited, fertilizer run-off into ocean water should result in...

increased phytoplankton growth because nitrogen in the fertilizer will be available for the phytoplankton to use

On a hot, dry day, plants close their stomata to conserve water. What impact will this have on photosynthesis?

it will reduce it because less carbon dioxide will be available

A potted geranium plant sits on a windowsill absorbing sunlight. After I put this plant in a dark closet for a few days (but keep it watered as needed), will it weigh more or less (discounting the weight of the water) that before I put it in the closet?

it will weigh less because it is still repairing for cellular respiration and because no photosynthesis is occurring

You have a piece of bread that you place on the counter. After a few days bread mold starts to grow on it. Does the piece of bread with mold on it weigh less or more than the same piece of bread did before it got moldy?

less

What would you predict the final weight of the seedling to be if they were placed in water but left in the dark?

less than 2 g

What would you predict the final weight of the seedling to be if they were placed in sunlight and water?

more than 2 g

In the light, no water condition, which processes are active?

neither photosynthesis nor cellular respiration

Application of fertilizer results in plant growth because fertilizer provides which nutrient?

nitrogen

Some farmers alternate the crops they are growing in a field between legumes, such as soybeans, and non-legumes, such as corn. This works because...

nitrogen fixed by bacteria in the soybeans can be used by the corn

CO2 is required for ______

photosynthesis

Glucose is produced by _____

photosynthesis

H2O is required for _____

photosynthesis

O2 is produced by _____

photosynthesis

Annual fluctuations in CO2 levels can be observed in the Keeling curve (depicted). These oscillations are primarily due to changes in the global rate of:

photosynthesis with changes in seasons

Which processes cause flux of carbon OUT OF the atmosphere?

photosynthesis, ocean absorption, and reforestation

For plants, the total amount of carbon gained by photosynthesis must be greater than that respired over their lifetime because...

plants need carbon to grow and therefore must take in more than they lose

What organisms can incorporate nitrogen directly from the atmosphere into their bodies?

plants, bacteria, animals, and cyanobacteria

Which would release the most energy when burned as a biofuel?

saturated fat with 6Cs in a chain

What is the largest carbon reservoir on the planet?

sediment, including limestone

A potato is left outside and decays gradually. One of the main substances in the potato is the starch amylose (C6H10O5). What happens to the carbon atoms in the amylose molecules as the potato decays?

some of the atoms are incorporated into carbon dioxide and some of the atoms are transformed by decomposers to form other organic molecules that make up their bodies

What 3 things does photosynthesis require?

sunlight, carbon dioxide, and water

You have a friend who lost 15 pounds of weight on a diet. Where did the atoms in the molecules of fat go?

the mass was released as CO2 and H2O

Imagine you leave a piece of bread out on the counter. After a week, you check back and it's moldy. How does the mass of the moldy bread compare to the mass of the original piece of bread?

the moldy bread has less mass

Lipids in soybean are typically found in the form of fatty acids linked to glycerol (depicted in this image). Which of the following statements accurately describes the amount of energy that can be harvested from this lipid?

the same amount of energy can be harvested from this lipid regardless of whether this occurs by combustion or cellular respiration

The plants lose mass in the water, no light condition because ______

they are not gaining carbon through photosynthesis and they are losing carbon through cellular respiration

Where do plants get the sugar to run and build their bodies?

they make their own sugars internally, mainly from gas absorbed from the air

What is the main reason that corn and cellulosic ethanol result in less CO2 emissions?

they result in more CO2 being taken up from the atmosphere

Carbon dioxide can be released into the atmosphere by what ways?

volcanic eruptions, cellular respiration, and burning of fossil fuels