USU Biology 1610 final

If a long-day plant has a critical night length of 9 hours, which 24-hour cycle would prevent flowering?

14 hours light/10 hours dark

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. How many chromosomes should be in an embryo nucleus after fertilization?

16

In onions (Allium), cells of the sporophyte have 16 chromosomes within each nucleus. How many chromosomes should be in a tube cell nucleus?

8

Which of the following statements is consistent with the second law of thermodynamics?

A constant input of energy is required to maintain the high level of organization associated with living cells.

Disruption of the active site of an enzyme would most likely result in which of the following?

A decreased ability of the enzyme to bind substrates.

Select the correct statement about plant growth.

A plant may produce juvenile and adult leaves at the same time.

In which of the following pairs do the structures play comparable roles in the plant and animal life cycles?

A plant sporophyte and an adult animal

Which of the following statements about equilibrium of chemical reactions is correct?

A reaction that is at equilibrium is not capable of doing any work.

To understand how ATP powers cellular work, you need to understand basic concepts of free energy change in different types of chemical reactions. Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Terms may be used more than once.

A reaction that occurs spontaneously - without an input of energy - is exergonic. 2. A reaction that occurs nonspontaneously - it requires an input of energy - is endergonic. 3. Exergonic reactions result in products that have less free energy than the reactants, thus free energy is released and ΔΔG is negative Exergonic reactions result in products that have less free energy than the reactants, thus free energy is released and ΔG is negative. . 4. Endergonic reactions result in products that have more free energy than the reactants, thus free energy is absorbed and ΔΔG is positive Endergonic reactions result in products that have more free energy than the reactants, thus free energy is absorbed and ΔG is positive. . 5. A cell can only carry out an endergonic reaction by pairing it with an exergonic reaction, such as ATP hydrolysis.

Which of the following statements best describes some aspect of the function of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal?

A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose.

An enzyme-catalyzed reaction has a ΔG of -20 kcal/mol under standard conditions. What will be the ΔG for the reaction if the amount of enzyme is doubled?

-20 kcal/mol

The ΔG of ATP hydrolysis in a test tube under standard conditions is -7.3 kcal/mol. The ΔG for the reaction A + B = C under the same conditions is +4.0 kcal/mol. What is the overall free-energy change for the coupled reactions under these conditions?

-3.3 kcal/mol.

If photosynthesizing green algae are provided with CO2 containing heavy oxygen (18O), which of the following molecules produced by the algae (refer to the accompanying figure) would be least likely to contain 18O in subsequent analyses?

ADP

What does Figure 2 suggest about the relative thermal tolerances of D. lanuginosum roots and AM fungal hyphae?

AM fungal hyphae show greater tolerance for high temperature than D. lanuginosum roots do.

D. lanuginosum plants grow equally well at high temperatures when the soil is inoculated with thermal or nonthermal AM fungi. What does this suggest about the thermal tolerances of AM fungi from geothermal and grassland soils?

AM fungi from geothermal and grassland soils have similar tolerances to high temperatures.

Which of the following molecules will accumulate if light reactions occur normally, but the Calvin Cycle is inhibited?

ATP and NADPH

The enzyme phosphofructokinase (PFK) catalyzes a key step in glycolysis and is inhibited by high levels of which of the following molecules?

ATP and citrate

Which of the following statements best summarizes the metabolic results of photorespiration?

ATP is hydrolyzed, carbon dioxide is produced, and oxygen is consumed.

Which of the following statements best describes the central role that ATP plays in cellular metabolism?

ATP provides energy coupling between exergonic and endergonic reactions.

In the absence of oxygen, yeast cells can obtain energy by fermentation, which results in the net production of which of the following sets of molecules?

ATP, CO2, and ethanol

You have an enzymatic reaction proceeding at the optimum pH and optimum temperature. You add a competitive inhibitor to the reaction and notice that the reaction slows down. What can you do to speed the reaction up again?

Add more substrate; it will outcompete the inhibitor and increase the reaction rate.

Which of the following is a potential advantage of introducing apomixis into hybrid crop species?

All of the desirable traits of the cultivar would be passed on to offspring.

Complete this vocabulary exercise relating to the three types of enzyme inhibitors. Drag the words on the left to the appropriate blanks in the sentences on the right. Each word is used only once.

1. A (n)competitive inhibitor has a structure that is so similar to the substrate that it can bond to the enzyme just like the substrate. 2. A (n)noncompetitive inhibitor binds to a site on the enzyme that is not the active site. 3. Usually, a(n) irreversible inhibitor forms a covalent bond with an amino acid side group within the active site, which prevents the substrate from entering the active site or prevents catalytic activity. 4. The competitive inhibitor competes with the substrate for the active site on the enzyme. 5. When the noncompetitive inhibitor is bonded to the enzyme, the shape of the enzyme is distorted. 6. Enzyme inhibitors disrupt normal interactions between an enzyme and its substrate.

Complete this vocabulary exercise relating to enzymes. Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column.

1. An enzyme is denaturedwhen it loses its native conformation and its biological activity. 2. An enzyme is considered a catalystbecause it speeds up chemical reactions without being used up. 3. An enzyme is considered specificbecause of its ability to recognize the shape of a particular molecule. 4. A cofactor, such as a vitamin, binds to an enzyme and plays a role in catalysis. 5. When properly aligned, the enzyme and substrate form an enzyme-substrate (ES)complex. 6. A substrate binds to an enzyme at the active site, where the reaction occurs. 7. In a catalyzed reaction a reactant is often called a substrate.

What property of dishwashing liquid (detergent) makes it useful to wash grease from pans?

Amphipathic nature

Select the correct statement(s) about angiosperm seeds.

An angiosperm seed contains structures contributed by three generations of plants.

Which of the following events is most immediately associated with the absorption of energy by chlorophyll molecules of the reaction-center complex?

An electron is excited.

How does an enzyme increase the rate of the chemical reaction it catalyzes?

An enzyme reduces the free energy of activation (EA) of the reaction it catalyzes.

Which of the following statements is accurate with regard to the life cycle of mosses?

Antheridia and archegonia are produced by gametophytes.

A defect in which of the following molecules would dramatically reduce the rate of diffusion of water across cell membranes?

Aquaporins

Which of the following pairs of organism groups consist solely of prokaryotic cells?

Bacteria and Archaea

_____ is/are identical in structure to centrioles.

Basal Bodies

Biologists use the fluid mosaic model to describe membrane structure. Which statements about the fluid mosaic structure of a membrane are correct? Select the three correct statements.

Because membranes are fluid, membrane proteins and phospholipids can drift about in the membrane.The framework of a membrane is a bilayer of phospholipids with their hydrophilic heads facing the aqueous environment inside and outside of the cell and their hydrophobic tails clustered in the center.The diverse proteins found in and attached to membranes perform many important functions.

What will happen to the rates of the forward and reverse reactions when a catalyst is added?

Both forward and reverse rates increase.

Which tissue(s) make(s) up the bark of the woody stem shown here?

Both secondary phloem and periderm

Which of the following statements is TRUE with regard to this animation?

Both sodium and potassium ions are transported against their concentration gradients.

Which of the summary statements below best describes the results of the following reaction?C6H12O6 + 6O2 →→ 6CO2 + 6H2O + Energy

C6H12O6 is oxidized and O2 is reduced.

Which of the following metabolic processes can occur without a net influx of energy from some other process?

C6H12O6+6O2→6CO2+6H2OC6H12O6+6O2→6CO2+6H2O

Select the correct statement about cellular respiration.

Cellular respiration and breathing differ in that cellular respiration is at the cellular level, whereas breathing is at the organismal level.

In what way do the membranes of a eukaryotic cell vary?

Certain proteins are unique to each membrane.

In which of the following ways do the membranes of a eukaryotic cell vary?

Certain proteins are unique to each membrane.

Select the correct statement about charophytes, a taxon of green algae.

Charophytes and land plants share three distinctive traits.

This figure shows the life cycle of the ciliate Paramecium caudatum. In this figure, what does the green arrow represent?

Conjugation

Which of these provides the cell with structural support?

D

Consider the results shown in Figure 1 and the table. How do AM fungi affect D. lanuginosum plants grown at high temperatures?

D. lanuginosum plants show increased shoot and root growth in pots inoculated with AM fungi.

Which molecules do not normally cross the nuclear membrane?

DNA

Which of the following options best depicts the flow of information when a gene directs the synthesis of a cellular component?

DNA →→ RNA →→ protein

Which one of the following statements about the transport of nutrients in phloem is correct?

Differences in osmotic concentration at the source and sink cause a hydrostatic pressure gradient to be formed.

Select the correct statement describing the life cycle of angiosperms.

Double fertilization in the life cycle of seed plants results in the production of a diploid zygote and a triploid endosperm nucleus

Which of the following statements best summarizes an important consequence of the first law of thermodynamics for living organisms?

Each organism ultimately must obtain all of the necessary energy for life from its environment.

Which of the following statements best describes the first law of thermodynamics?

Energy cannot be created or destroyed.

How are the flow and transformation of energy different in a photosynthesizing cell? Match the terms in the left column to the appropriate blanks in the sentences on the right. Not all terms will be used.

Energy enters a(n) plant cell Energy enters a(n) plant cell in the form of plant cell, which is converted to the plant cell like glucose. in the form of light Energy enters a(n) plant cell in the form of plant cell, which is converted to the plant cell like glucose. , which is converted to the chemical energy of sugars Energy enters a(n) light in the form of light, which is converted to the light like glucose. like glucose. Energy enters a(n) animal cell Energy enters a(n) animal cell in the form of the animal cell such as glucose. in the form of the chemical potential energy of fuel molecules Energy enters a(n) animal cell in the form of the animal cell such as glucose. such as glucose.

Which of the following statements best describes enzyme function?

Enzymes increase the rate of chemical reactions by lowering activation energy barriers. Submit

Which of the following statements best describes one major difference between prokaryotic cells and eukaryotic cells?

Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

Which of the following statements correctly describes some aspect of exocytosis or endocytosis?

Exocytosis and endocytosis change the surface area of the plasma membrane.

Which of the following molecules is the lowest-energy donor of electrons to the electron transport chain?

FADH2

True or false? Large proteins containing a nuclear localization signal (NLS) bind to the nuclear pore and enter the nucleus without any expenditure of energy.

False

How does nitrogen fixation lead to enhanced plant growth?

Fixed nitrogen can be used by plants to produce protein.

Many aspects of the angiosperm life cycle make flowering plants particularly well-suited to life on land. In fact, angiosperms are the most diverse and widespread of all plants.

Floral parts of the sporophyte protect the reduced female gametophyte from drying out and from UV radiation. Seeds enable plant embryos to be dispersed long distances from the parent plant via wind or animals.Seeds protect and nourish plant embryos, and fruits protect the seeds. Fruits aid in the dispersal of seeds by wind or by animals that carry or eat the fruits.Flowers attract animal pollinators carrying pollen from other plants of the same species.In many angiosperms, the male gametophyte contained in a pollen grain can be transported many miles away by wind or animal pollinators. Submit

Select the correct molecule that is the main product of the Calvin cycle.

G3P

Which of the following is the best argument for pursuing plant biotechnology?

Genetically modified (GM) plants can provide greater plant productivity on the same amount of land.

Which of the following organelles is primarily responsible for the production and modification of polysaccharides that will be secreted?

Golgi apparatus

Which structure is part of the endomembrane system?

Golgi apparatus

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

H2OH2O →→ NADPHNADPH →→ Calvin cycle

Which of the following statements best describes why hydrolysis reactions occur more readily in solution than dehydration reactions do?

Hydrolysis reactions are exergonic and increase entropy of the system.

Which of the following events occurs first in the development of a spore into a mature mushroom?

Hyphae are produced by mitosis.

Four physiological events that occur during de-etiolation (greening) of plants are listed below.I)detection of light signalII)activation of phytochromeIII)activation of specific protein kinase1IV)formation of de-etiolation response proteinWhich of the following lists these events in the correct order?

I, II, III, and IV

Which of the following are potential benefits of producing genetically modified crops?I) create crops that can grow on land previously unsuitable for agricultureII) create crops with better potential for biofuel productionIII) create crops with better nutritional attributesIV) increase crop yield

I, II, III, and IV

Long-distance transport in phloem requires which of the following processes? I)a positive water potential II)active transport through parenchyma cells III)cohesion between water molecules IV)evaporation of water molecules

I, II, and III only

Which of the following plant parts elongate in response to etiolation during seedling germination? I)Roots II)Hypocotyl III)Internodes IV)Leaves

II and III

In the diagram above, the dark "dots" represent axillary buds. Which diagram illustrates a compound leaf?

II only

Which of the following statements best summarizes a consequence of the second law of thermodynamics?

If entropy of a system decreases, there must be a corresponding increase in the entropy of the universe.

How is photosynthesis similar in C4C4 plants and CAM plants?

In both cases, rubisco is not used to fix carbon initially.

How may a forest of lycophyte trees have differed from a forest of large ferns or seed plants?

In these two types of forests, the amount of light below the forest canopy would be different.

Consider a situation in which the enzyme is operating at optimum temperature and pHpH, and has been saturated with substrate. What is your best option for increasing the rate of the reaction?

Increase the enzyme concentration.

What is the first step in a pulse-chase experiment?

Incubating cells with a labeled molecule

Suppose an efficient conducting system evolved in a moss that could transport water and other materials as high as a tall tree. Which of the following statements about "trees" of such a species would be accurate?

Individuals would probably compete more effectively for access to light.

Which of the following statements best describes the electron transport chain?

It consists of a series of redox reactions.

Which of the following statements best describes a characteristic feature of a carrier protein in a plasma membrane?

It exhibits specificity for a particular type of molecule

Which of the following statements best explains why the sodium-potassium pump is an electrogenic pump?

It generates voltage across the membrane.

Which of the following statements best describes a characteristic feature of diffusion?

It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

When chemical, transport, or mechanical work is performed by an organism, what happens to the heat that is generated?

It is lost to the environment.

Which of the following characteristics would best support your assertion that a particular plant is an angiosperm?

It lacks gametangia.

When ATP is hydrolyzed to activate a target protein, what is often the fate of the inorganic phosphate that is released?

It may be used to form a phosphorylated intermediate.

How might this organ be an adaptation for dry conditions? Select all that apply.

It might preserve large amounts of water.It might be protected from dry conditions by a thick cuticle.It might prevent water loss by reduction of the stomatal number.

Which of the following statements best describes the function of the nuclear pore complex found in eukaryotic cells?

It regulates the movement of proteins and RNAs into and out of the nucleus.

Which of the following statements best describes the accompanying figure?

It represents a C4 photosynthetic system.

Which of the following statements best describes the primary role played by oxygen in cellular respiration?

It serves as the final acceptor for electrons from the electron transport chain.

The ΔG of ATP hydrolysis in a test tube under standard conditions is -7.3 kcal/mol. The ΔG for the reaction A+B C under the same conditions is +4.0 kcal/mol. How would the addition of an enzyme that catalyzes A+B C most likely alter the coupled reactions?

It would result in no change in the overall ΔG for the coupled reactions.

The flux of which one of the following ions plays a dominant role in adjusting the turgor of guard cells during the opening and closing of stomata?

K+

Select the correct statement about chemical energy, a term used by biologists to refer to potential energy available for release in a chemical reaction.

Light energy is converted to chemical energy during photosynthesis

Which of the following is a true statement about asexual reproduction in plants?

Making cuttings of ornamental plants is a form of fragmentation.

In the citric acid cycle, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. This reaction is inhibited by malonate, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Increasing the ratio of succinate molecules to those of malonate in the reaction reduces the inhibitory effect of malonate. What role does malonate play with respect to succinate dehydrogenase?

Malonate is a competitive inhibitor.

Which of the following accurately describes meristematic plant cells?

Meristematic cells are undifferentiated cells that produce new cells.

Which of the following statements best describes metabolism in its entirety in all organisms?

Metabolism consists of all the energy transformation reactions in an organism.

Which of the following is a major difference between prokaryotic and eukaryotic cells?

Most prokaryotic cells have no internal membranes; eukaryotic cells do. Submit

Which of the following is a correct statement about sugar movement in phloem?

Movement can occur both upward and downward in the plant.

Which of the following functions is NOT associated with the cytoskeleton in eukaryotic cells? See Concept 6.6 (Page)

Movement of RNA molecules from the nucleus to the cytoplasm

What scientific hypotheses can be tested by a pulse-chase experiment?

Movement of molecules through a cell over time

Depletion of which of the following molecules from the mitochondria will most directly inhibit the citric acid cycle?

NAD+

Which of the following statements best describes what happens to a molecule of NAD+ (nicotinamide adenine dinucleotide) when it gains a hydrogen atom?

NAD+ becomes reduced.

Which of the following products result from the oxidation of pyruvate to acetyl-CoA?

NADH and CO2

Which of the following molecules is the final electron acceptor for electrons from photosystem I?

NADP+

Which of the following statements correctly describe nitrogen and its role as a plant nutrient?

Nitrogen deficiency usually causes plant leaves to turn yellow. Nitrogen-fixing bacteria in the soil convert N2N2 to NH3NH3. Nitrogen is a component of nucleic acids, proteins, hormones, and coenzymes.Nitrogen is a macronutrient in plants.Plant root hairs can only absorb nitrogen in the form of ammonium ions (NH4+)(NH4+) or nitrate ions (NO3−)(NO3−).

If an enzyme is added to a solution where its substrate and product are in equilibrium, what will occur?

Nothing; the reaction will stay at equilibrium.

Which of the following molecules would likely diffuse through the lipid bilayer of a plasma membrane most rapidly?

O2

During fertilization, the pollen tube discharges two sperm nuclei into the female gametophyte, where double fertilization occurs. Which two cells are fertilized and what do they develop into? Select the two correct answers.

One sperm nuclei fertilizes the egg cell, forming the zygote.One sperm nuclei combines with two polar nuclei in the central cell, forming the 3n endosperm.

How is fertilization in flowering plants different from fertilization in other plant groups?

One sperm nucleus fuses with the egg to form a diploid zygote, whereas the other sperm nucleus fuses with two polar nuclei to form a cell that develops into endosperm.

Which of the following statements correctly describes a distinction between autotrophs and heterotrophs?

Only autotrophs can produce organic molecules from CO2 and other inorganic materials.

Nucleoplasmin is a nuclear protein. This protein was divided into two segments and linked to the same large cytoplasmic protein, generating two fusion proteins. After injecting these fusion proteins into a cell, one of the proteins was found in the nucleus and the other in the cytoplasm. Which of the following conclusions can be drawn from these results?

Only one of the two fusion proteins possesses a nuclear localization signal

Select the correct statement about osmosis.

Osmosis is the diffusion of water molecules across a selectively permeable membrane.

If pyruvate oxidation is blocked, what is the most likely effect on the levels of oxaloacetate and citrate in the citric acid cycle shown in the accompanying figure?

Oxaloacetate will accumulate and citrate will decrease.

Which of the following statements is most likely to be true in the case of the feedback-regulated enzymatic pathway shown?

P4 binds E1 and deactivates it.

A small protein (molecular weight = 25,000 daltons) is injected into a cell and observed in the nucleus a short time later. What type of transport has taken place?

Passive transport

Which cell would be best for studying lysosomes?

Phagocytic white blood cell

Which of the following statements best describes a characteristic of biological membranes?

Phospholipids move laterally within the plane of the membrane.

Select the correct statement describing cellular structure or function.

Plant and animal cells both carry out cellular respiration, producing ATP.

Extensive irrigation in arid regions causes salts to accumulate in the soil. (When water evaporates, salts that were dissolved in the water are left behind in the soil.) Based on what you learned about water balance in plant cells, explain why increased soil salinity (saltiness) might be harmful to crops. Match the terms in the left column to the appropriate blanks in the sentences on the right. Not all terms will be used.

Plant cells are turgid in a hypotonic environment, where the uptake of water is eventually balanced by the wall pushing back on the cell. A high salt concentration in soil solution is a hypertonic environment for the epidermal cells of the plant roots. In this case, the plant cells undergo plasmolysis. Thus, salt causes a(n) reduction in the rate and amount of water that the plant roots can take up from the soil.

Select the correct statement about the life cycle of a fern.

Plant gametophytes are haploid multicellular bodies.

Which major benefits do plants and mycorrhizal fungi receive from their symbiotic relationship?

Plants receive water and phosphorus, and fungi receive photosynthetic products.

Which of the following results is most likely when a plant cell is submerged in a hypertonic solution?

Plasmolysis will shrink the interior of the cell.

Among plants known as legumes (beans, peas, alfalfa, clover, for example) the seeds are contained in a fruit that is itself called a legume, better known as a pod. Upon opening such pods, it is commonly observed that some ovules have become mature seeds, whereas other ovules have not. Which of the following statements best explains this observation?

Pollen tubes did not enter all of the ovules in such pods, and fruit can develop even if all ovules within have not been fertilized.

Which of the following statements is true regarding potential energy?

Potential energy is the energy possessed by matter due to its location or structure.

Which statement correctly describes an endomembrane function?

Products of the ER are usually modified during their transit from the cis to the trans region of the Golgi apparatus.

Select the valid comparison between eukaryotes and prokaryotes.

Prokaryote cells have simpler internal structure and genomic organization than eukaryotic cells.

Which of the following statements about the zygotes of plants is most likely to be accurate?

Protection of the zygote from the drying effects of air was important.

Which one of the following statements about the endomembrane system is correct?

Proteins that will be secreted from the cell are likely to be found in closed spaces bounded by membranes of the endomembrane system.

Examination of a cell by transmission electron microscopy reveals a high density of ribosomes in the cytoplasm. This observation suggests that the cell is actively producing large amounts of which of the following molecules?

Protiens

What water regulation adaptations might have evolved in protists in habitats with changing salt concentration? Match the terms in the left column to the appropriate blanks in the sentences on the right. Terms can be used once, more than once, or not at all.

Protists in a changing salt concentration will have a semi-permeable membrane in order to keep up with fluctuations in concentration and take in water as they need, along with a contractile vacuole in order to pump out any unnecessary water they take in.

What water regulation adaptations might have evolved in protists in hypertonic habitats such as the Great Salt Lake?

Protists would have more permeable membranes than those in hypotonic or isotonic environments, allowing more water to enter the cell. Also, they could possibly develop higher salt concentration within the cell to retain water.

Which of the following statements best explains the observation that proton pumps are used by organisms in every domain of life?

Proton gradients across a membrane were used by cells that were the common ancestor of all three domains of life.

How do thermal and nonthermal AM fungi affect D. lanuginosum plants grown at high temperatures?

Root and shoot growth were similar whether the soil was inoculated with thermal or nonthermal AM fungi.

What path does a protein in the secretory pathway take, starting from its site of synthesis?

Rough ER, Golgi apparatus, secretory vesicles, plasma membrane

If you are provided with a cube of modeling clay, which of the following changes to the shape of this cube will decrease its surface area relative to its volume?

Round the clay up into a sphere. Submit

In a species showing sporophytic incompatibility, which type(s) of pollen could successfully fertilize an S2S3S2S3 flower?

S1 pollen from an S1 S1flower

Many plants flower in response to day-length cues. Which of the following statements correctly describes the relationship between day length and flowering?

Short-day plants flower in direct response to long nights.

Which of the following statements most accurately compares primary factors responsible for simple diffusion versus active transport?

Simple diffusion is driven by a concentration gradient, while active transport is driven by ATP hydrolysis.

How does the greater thermal tolerance of AM fungal hyphae explain the differences in growth of D. lanuginosum plants grown in soils with and without AM fungi?

Since AM fungi are more tolerant of high temperature than plant roots, fungal hyphae can grow into soils at temperatures that prevent root growth, increasing plants' access to water and nutrients in those soils.

Several tomato plants are growing in a small garden plot. If soil water potential were to drop significantly on a hot, summer afternoon, which of the following would most likely occur?

Size of stomatal openings would decrease.

Why do fleshy fruits often have seeds with very tough seed coats?

So the seeds can survive the mechanical forces and conditions in an animal's gut

If bryophytes do not have vascular tissue, how can some mosses reach 60 centimeters tall?

Some mosses independently evolved conducting tissues. Submit

Which statement concerning grafting is correct

Stocks provide root systems for grafting.

How did stomata facilitate life on land?

Stomata can close to reduce water loss in dry conditions.

Select the correct statement about variation in stomatal density.

Stomatal density is developmentally plastic.

In the citric acid cycle, succinate dehydrogenase catalyzes the conversion of succinate to fumarate. This reaction is inhibited by malonate, which resembles succinate but cannot be acted upon by succinate dehydrogenase. Which of the following statements best describes the role played by molecules described in the reaction?

Succinate is the substrate, and fumarate is the product in the reaction.

use the following information to answer the question.For the past several decades, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis. Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment.When adult amphibian skin harbors populations of the bacterium Janthinobacterium lividum, chytrid infection seems to be inhibited. Which of the following is the best experimental design to test whether this inhibition is actually due to the presence of J. lividum?

Take infected amphibians and assign them to two populations. Leave one population alone; inoculate the other with J. lividum. Measure the rate at which infection proceeds in both populations. Submit

Which of the following statements best describes the conditions under which the Calvin cycle and cellular respiration occur in plants?

The Calvin cycle and cellular respiration both occur in the dark and the light.

Select the correct statement about the Calvin cycle.

The Calvin cycle has three phases: carbon fixation, reduction, and regeneration of RuBP.

The free energy released by ATP hydrolysis can be used to drive endergonic reactions, such as the conversion of glutamic acid to glutamine. As you saw in the video, the synthesis of glutamine from glutamic acid is a two-step process:ATP phosphorylates glutamic acid.Ammonia displaces the phosphate group, forming glutamine. How does the phosphorylation of glutamic acid (Glu) provide energy for the rest of the reaction to occur?

The addition of a phosphate to Glu forms a phosphorylated intermediate with more free energy than Glu. The ammonia can thus displace the phosphate in an exergonic reaction.

In cellular respiration, a series of molecules forming an electron transport chain alternately accepts and then donates electrons. What is the advantage of such an electron transport chain?

The advantage of an electron transport chain is that a small amount of energy is released with the transfer of an electron between each pair of intermediates.

Which of the following assumptions led to the hypothesis that the first plants exhibited low, sprawling growth?

The ancestors of plants, green algae, lacked the structural support to stand erect in air.

Which of the following results is most likely result if a portion of an animal's blood is replaced with distilled water?

The animal's red blood cells will swell and possibly burst because the blood has become hypotonic compared to the cells.

Will the artificial cell become more flaccid, more turgid, or stay the same?

The artificial cell will become more turgid.

Identify all correct statements about the basic function of fermentation. Select all that apply.

The basic function of fermentation is the regeneration of NAD+, which allows continued ATP production by glycolysis.

Which of the following statements best describes how addition of a catalyst will affect a chemical reaction?

The catalyzed reaction will have the same ΔG as the uncatalyzed reaction.

Which of the following statements is true?

The cell walls of archaea lack peptidoglycan

What will happen to a red blood cell (RBC), which has an internal ion content of about 0.9%, if it is placed into a beaker of pure water?

The cell will swell because the water in the beaker is hypotonic relative to the cytoplasm of the RBC.

Which of the following best explains the specific relationship between a particular legume species and its mutualistic Rhizobium strain?

The chemical signals of a legume species match the signal receptors of a specific Rhizobium strain.

Which of these facts provides the best support for the hypothesis that plants evolved from green algae?

The chloroplasts of plants and green algae all have both chlorophyll aand b.

Which statement is correct?

The contents of a red blood cell are hyperosmotic to distilled water.

Which of the following statements best summarizes how the ATP cycle illustrated in the accompanying figure functions in cells?

The cycle is used to regenerate ATP.

Which of the following statements about ATP (adenosine triphosphate) is correct?

The cycling between ATP and ADP + Pi provides an energy coupling between catabolic and anabolic pathways.

Which of the following statements best describes how unsaturated fatty acids increase membrane fluidity at lower temperatures?

The double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packing tightly.

Which of the following statements about the role of ATP in cell metabolism is true?

The energy from the hydrolysis of ATP may be directly coupled to endergonic processes by the transfer of the phosphate group to another molecule.

Which of the following statements about the combustion of glucose with oxygen to form water and carbon dioxide (C6H12O6 + 6 O2 → 6 CO2 + 6 H2O) is correct?

The entropy of the products is greater than the entropy of the reactants

Which of the following characteristics is most likely to be associated with an enzyme that catalyzes two different chemical reactions?

The enzyme has two distinct active sites.

You have added an irreversible inhibitor to a sample of enzyme and substrate. At this point, the reaction has stopped completely. What can you do to regain the activity of the enzyme?

The enzyme is inactive at this point. New enzyme must be added to regain enzyme activity.

During a pulse-chase experiment, photographic emulsions were prepared at different times during the chase, and radioactive spots were detected at the following times and locations: 5 minutes: rough ER; 10 minutes: Golgi apparatus; 40 minutes: endosomes; 70 minutes: lysosomes; 140 minutes: lysosomes. Which of the following conclusions can be drawn from these results?

The final destination of the proteins was the lysosome.

Life requires energy. Describe the basic principles of bioenergetics in an animal cell. Match the terms in the left column to the appropriate blanks in the sentences on the right. Not all terms will be used.

The free energy released by the exergonic The free energy released by the exergonic reactions of exergonic is stored in exergonic. The energy released by its hydrolysis to exergonic and P i drives the exergonic reactions of exergonic, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, exergonic is transformed into exergonic. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and exergonic activation energy, thus speeding up metabolic reactions. reactions of catabolic pathways The free energy released by the exergonic reactions of exergonic is stored in exergonic. The energy released by its hydrolysis to exergonic and P i drives the exergonic reactions of exergonic, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, exergonic is transformed into exergonic. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and exergonic activation energy, thus speeding up metabolic reactions. is stored in ATPATP The free energy released by the exergonic reactions of catabolic pathways is stored in catabolic pathways. The energy released by its hydrolysis to catabolic pathways and P i drives the catabolic pathways reactions of catabolic pathways, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, catabolic pathways is transformed into catabolic pathways. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and catabolic pathways activation energy, thus speeding up metabolic reactions. . The energy released by its hydrolysis to ADPADP The free energy released by the catabolic pathways reactions of catabolic pathways is stored in catabolic pathways. The energy released by its hydrolysis to catabolic pathways and P i drives the catabolic pathways reactions of catabolic pathways, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, catabolic pathways is transformed into catabolic pathways. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and catabolic pathways activation energy, thus speeding up metabolic reactions. and PiPi drives the endergonic The free energy released by the catabolic pathways reactions of catabolic pathways is stored in A T P. The energy released by its hydrolysis to A T P and P i drives the A T P reactions of A T P, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, A T P is transformed into A T P. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and A T P activation energy, thus speeding up metabolic reactions. reactions of anabolic pathways The free energy released by the A T P reactions of A T P is stored in A T P. The energy released by its hydrolysis to A T P and P i drives the A T P reactions of A T P, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, A T P is transformed into A T P. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and A T P activation energy, thus speeding up metabolic reactions. , which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, potential energy The free energy released by the A T P reactions of A T P is stored in A T P. The energy released by its hydrolysis to A D P and P i drives the A D P reactions of A D P, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, A D P is transformed into A D P. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and A D P activation energy, thus speeding up metabolic reactions. is transformed into kinetic energy The free energy released by the A D P reactions of A D P is stored in A D P. The energy released by its hydrolysis to A D P and P i drives the A D P reactions of A D P, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, A D P is transformed into A D P. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and A D P activation energy, thus speeding up metabolic reactions. . In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and lowering The free energy released by the A D P reactions of A D P is stored in A D P. The energy released by its hydrolysis to A D P and P i drives the endergonic reactions of endergonic, which synthesize the complex molecules. Also, during hydrolysis in mechanical and transport work, endergonic is transformed into endergonic. In these transfers and transformations, some energy is lost as heat. All the reactions of a cell require enzymes, which ensure efficient cell function by binding substrates and endergonic activation energy, thus speeding up metabolic reactions. activation energy, thus speeding up metabolic reactions.

What is the free energy change (ΔGΔG) of the hydrolysis of ATP to ADP?

The free-energy change (ΔGΔG) of the hydrolysis of ATP to ADP and Pimay vary considerably with variations in pH, temperature, atmospheric pressure, and concentrations of reactants and products.

Celery stalks that are immersed in fresh water for several hours become stiff. Which of the following statements best explains the observation that similar stalks left in a 0.15 M salt solution become limp?

The fresh water is hypotonic and the salt solution is hypertonic to the cells of the celery stalks

Which of the following statements accurately describes the function of a metabolic pathway involved in cellular respiration?

The function of glycolysis is to begin catabolism by breaking glucose into two molecules of pyruvate, with a net yield of two ATP.

Which of the following statements about the citric acid cycle is correct?

The last reaction in the citric acid cycle produces a product that is a substrate for the first reaction of the citric acid cycle.

Which of the following statements best describes the structure of a membrane based on the fluid mosaic model?

The membrane is composed of a fluid bilayer of phospholipids with embedded amphipathic proteins.

Which of the following statements best explains how the membranes in winter wheat are able to remain fluid in extremely cold temperatures?

The membranes contain an increased proportion of unsaturated phospholipids.

When H. V. Wilson exposed two species of differently pigmented sponges to a chemical that disrupted intercellular junctions, the cells of the sponges dissociated. Wilson then removed the chemical that caused dissociation and mixed the cells of the two species. He found that the sponges reassembled and that the cells from one species did not interact or form associations with the cells of the other species.Which of the following statements provides the most plausible explanation for the results of this experiment?

The molecules responsible for cell-cell adhesion (cell junctions) differed between the two species of sponge.

Which of the following statements about the nuclear envelope is false?

The nuclear envelope is continuous with the Golgi apparatus.

Which statement correctly describes the nuclear envelope of a eukaryotic cell?

The nuclear envelope is continuous with the endoplasmic reticulum.

Identify the correct statement about differences between rough and smooth endoplasmic reticulum (ER).

The outer surface of smooth ER lacks ribosomes, whereas the outer surface of rough ER has ribosomes.

Step 3 is a major point of regulation of glycolysis. The enzyme phosphofructokinase is allosterically regulated by ATPATP and related molecules. Considering the overall result of glycolysis, would you expect ATPATP to inhibit or stimulate activity of this enzyme? (Hint: Make sure you consider the role of ATPATP as an allosteric regulator, not as a substrate of the enzyme.)

The overall process of glycolysis results in net production of ATPATP. Thus, we would expect ATPATP to allosterically inhibit phosphofructokinase.

Which of the following events are associated with chemiosmosis in chloroplasts?

The pH of the thylakoid space increases and ATP is synthesized.

When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?

The pHpH of the matrix increases.

You are weeding your garden when you accidentally expose some roots of your pea plants, which are legumes like soybeans. You notice swellings (root nodules) on the roots, and there is a reddish tinge to the ones you accidentally damaged. These observations are evidence for which of the following?

The peas are benefiting from a mutualistic bacterium.

How do membrane phospholipids interact with water?

The polar heads interact with water; the nonpolar tails do not.

Which of the following statements about osmosis is correct?

The presence of aquaporins (proteins that form water channels in the membrane) speeds up the process of osmosis.

If isolated plant cells with a water potential averaging -0.5 MPa are placed into a solution with a water potential of -0.3 MPa which of the following would be the most likely outcome?

The pressure potential of the cells would increase.

Which statement is true for all sexually reproducing plants and animals?

The process of meiosis produces haploid cells.

Which of the following statements best describes characteristic activities of a sodium-potassium pump?

The pump moves three sodium ions out of a cell and two potassium ions into a cell using energy from ATP hydrolysis.

Select the correct mechanism of stomatal opening and closing.

The radial orientation of cellulose microfibrils in the cell walls of guard cells causes them to bow outward and open the stomatal pore when turgid.

Which factors affect the rate of osmotic movement of water?

The rate of osmosis increases with increasing differences in solute concentrations between two solutions separated by a selectively permeable membrane. Submit

Which of the following statements best describes an exergonic reaction?

The reaction proceeds with a net release of free energy.

The Haber process is typically carried out at a temperature of approximately 500∘C∘C. What would happen to the rate of the forward reaction if the temperature were lowered to 100∘C∘C?

The reaction rate would decrease .

What would happen to the rate of the forward reaction if the concentration of nitrogen were decreased?

The reaction rate would decrease . Submit

Which one of the following statements about the redox reactions of the electron transport chain is correct?

The redox reactions of the electron transport chain are directly coupled to the movement of protons across a membrane.

Which of the following statements best describes a primary mechanism by which the energy released in ATP hydrolysis is used directly to drive endergonic chemical reactions in a cell?

The released phosphate is used to form phosphorylated intermediates that are more reactive than the original unphosphorylated substrate.

Which of the following statements correctly answers how the large amount of genetic variation observed in prokaryotes arises?

The second and third answers are correct.

Which of the following statements about seed formation in a flowering plant is true?

The swellings that develop into cotyledons are located at the end of the embryo on top of the row of single cells.

Which of the following statements best describes a system at chemical equilibrium?

The system can do no work.

Cell membranes have distinct inside and outside faces. Which of the following statements is the most plausible explanation for the asymmetrical nature of the two layers of the membrane?

The two layers of a cell membrane face different environments and carry out different functions.

Which of the following statements about a typical plasma membrane is correct?

The two sides of the plasma membrane have different lipid and protein composition.

Eventually, will the two solutions have the same or different solute concentrations?

The two solutions will have the same solute concentration.

A plant cell is placed in distilled water, as shown in the figure. There is a net uptake of water by osmosis, causing the cell to become turgid. Select the correct statement about this setup, after the cell is fully turgid

The water potentials (ΨΨ) of the cell and its surroundings are the same.

Photorespiration can decrease soybeans' photosynthetic output by about 50%%. Would this figure be higher or lower in wild relatives of soybeans? Why?

The wild relatives of modern soybeans would be expected to have levels of photorespiration higher than 50%%. Crop scientists would have selected strains with reduced levels of photorespiration to maximize the size of the harvested soybeans.

Which of the following statements best explains the reason that lipids and proteins are free to move laterally in membranes?

There are only weak hydrophobic interactions in the interior of the membrane.

When the interior of a cell is in equilibrium with its environment, which of the following statements best describes the relative movement of molecules that can diffuse through the plasma membrane?

There is random movement of molecules into and out of the cell.

A mutation that eliminates a plant's ability to perform photorespiration will most likely have which of the following effects on the plant?

There would be more cellular damage from harmful products of the light reactions of photosynthesis.

In fungi, haploid hyphae fuse to produce dikaryotic and then diploid nuclei, only to restore the haploid condition by meiosis before the growth of new hyphae. What is the significance of a transient diploid state in fungi?

These sexual processes generate genetic variation. Submit

Which of the following statements best describes a characteristic feature of integral membrane proteins?

They are amphipathic, with at least one hydrophobic region.

Which of the following statements best describes catabolic pathways?

They are exergonic and provide energy that can be used to produce ATP from ADP and Pi.

Which of the following statements correctly describes the haploid gametophytes of bryophytes?

They are usually multicellular, but lack vascular tissue.

Which of the following is a characteristic feature of anabolic pathways?

They consume energy to build up polymers from monomers

Which of the following statements best explains why carbohydrates and fats may be considered high-energy foods?

They contain many electrons associated with hydrogen atoms.

Which of the following statements best explains the ability of CAM plants to synthesize sugars in the daytime while keeping their stomata closed to reduce water loss?

They fix CO2 into organic acids during the night.

What characterizes the fruit of seeds that are dispersed by the wind?

They have structures to extend the distance they travel on the wind.

Carotenoids are often found in foods that are considered to have antioxidant properties in human nutrition. Which of the following statements best describes a related function they serve in plants?

They protect against oxidative damage from excessive light energy.

Consider the following data:· Most ancient eukaryotes are unicellular.· All eukaryotes alive today have a nucleus and cytoskeleton.· Most ancient eukaryotes lack a cell wall.Which of the following conclusions about the first eukaryotes is most consistent with the data presented?

They were capable of phagocytosis.

Which of the following processes contributes to genetic recombination in prokaryotes?

Transduction

Which of the following statements describes the role of the transport protein in facilitated diffusion?

Transport proteins allow solutes to move passively down their concentration gradients across the membrane.

Select the accurate statement about water potential.

Water in a turgid cell has positive pressure potential.

What happens when two solutions separated by a selectively permeable membrane reach osmotic equilibrium?

Water molecules move between the two solutions, but there is no net movement of water across the membrane.

Which statement about the binding of enzymes and substrates is correct?

When substrate molecules bind to the active site of the enzyme, the enzyme undergoes a slight change in shape

Which of the following factors would tend to increase membrane fluidity?

Which of the following factors would tend to increase membrane fluidity?

Which of the following statements best describes a characteristic feature of osmosis?

Which of the following statements best describes a characteristic feature of osmosis?

Which of the following statements best summarizes the figure above?

Which of the following statements best summarizes the figure above?

If a plant's stomata are closed and no transpiration is occurring, which of the following predictions is accurate?

Without transpiration, less water will be absorbed from the soil.

You know that this cell is in a(n) _____ solution because it _____.

You know that this cell is in a(n) _____ solution because it _____.

Which component in the figure above represents a protein fiber of the extracellular matrix?

a

Which of these structures stores, modifies, and packages products?

a

The nuclear lamina is an array of intermediate filaments that line the inner surface of the nuclear membrane. Disassembly of the lamina by chemical treatment would most likely result in which of the following consequences?

a change in the shape of the nucleus

Which of the following statements best describes an example of a reaction that may be at chemical equilibrium in a cell?

a chemical reaction in which there is no change in the net concentrations of reactants or products at that time in the cell

A biological cycle with a period of about 24 hours is called __________.

a circadian rhythm

The force driving simple diffusion is ________, while the energy source for active transport is ________.

a concentration gradient; ATP hydrolysis Submit

This stained light micrograph shows a cross section through a plant organ from Hakea purpurea, a shrub native to some arid regions of Australia. Identify whether this is a root, stem, or leaf.

a leaf

A newly discovered unicellular organism isolated from acidic mine drainage is found to contain a cell wall, a plasma membrane, two flagella, and peroxisomes. Based on this information only, the organism is most likely to be ________.

a motile eukaryote

In this diagram of the plasma membranes of two adjoining cells, identify the protein indicated by the white arrow, including its function.

a receptor protein that binds with a signaling molecule and relays the message into the cell by activating other molecules inside the cell

In which of the following circumstances would the cell or organism have the greatest need for osmoregulation?

a salmon moving from a river into an ocean

Which of the following examples describes a type of potential rather than kinetic energy?

a sucrose molecule

Which of the following symbiotic relationships would most likely allow bryophytes to live successfully in a bare, moist area?

a symbiosis with nitrogen-fixing cyanobacteria Submit

Which of these plant hormones is not typically considered a growth-promoting substance? See Concept 39.2 (Page)

abscisic acid Submit

The hormone that helps plants respond to drought is

abscisic acid.

Which of the following is the main function associated with structure Y?

absorption of carbon dioxide

What is the name of the barrier that must be overcome before products are formed in a spontaneous reaction?

activation energy

If the concentration of phosphate in the cytosol is 2.0 mM, and the concentration of phosphate in the surrounding fluid is 0.1 mM, how could the cell increase the concentration of phosphate in the cytosol?

active transport

Active and passive transport of solutes across a membrane typically differ in which of the following ways?

active transport always involves the utilization of cellular energy, whereas passive transport does not require cellular energy

If an enzyme in solution is saturated with substrate, the most effective way to obtain a faster yield of products is to

add more of the enzyme.

Exposing inner mitochondrial membranes to ultrasonic vibrations will fragment the membranes and pieces will reseal "inside out" to form small vesicles. The fact that these vesicles can transfer electrons from NADH to oxygen and synthesize ATP suggests that which of the following components must be present?

all of the electron transport system and ATP synthase

What types of cells carry out ATP synthesis by chemiosmosis?

all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors Submit

Which of the following types of metabolic poison would most directly interfere with glycolysis?

an agent that closely mimics the structure of glucose but is not metabolized

The opening of stomata involves which of the following processes?

an increase in the solute concentration of the guard cells

Which of the following types of reactions would decrease the entropy within a cell?

anabolic reactions

Which of the following plant responses requires integration of auxin, cytokinin, and strigolactone?

apical dominance

Zinc is an essential trace element for most organisms. Zinc is required in the active site of the enzyme carboxypeptidase where it most likely functions in which of the following ways?

as a cofactor necessary for enzyme activity

The figure illustrates the energy states associated with the reaction A + B ↔↔ C + D. Which of the lower-case letters represents the activation energy required for the enzyme-catalyzed reaction in the figure?

b

Which component in the accompanying figure plays a critical role in cell-cell recognition?

b

Which line or lines in the graph represent(s) bags that contain a solution that is hypertonic to the solution in the beaker at 50 minutes?

b

Which of the following types of pathogenic prokaryotes cause cholera?

bacteria that release an exotoxin

Where does meiosis occur in a mushroom?

basidia

A clasping handshake may be used as an analogy for an enzyme-catalyzed reaction because it represents the specific manner in which an enzyme ________.

binds substrate

Which of the following is a common trait of chloroplasts and mitochondria?

both contain their own DNA

According to the phylogeny, which protists are in the same eukaryotic supergroup as plants?

both green algae and red algae

A sample of mosses and ferns is comprised of which of the following?

both sporophyte and gametophyte generation

Which of the following structures cannot be formed by an axillary bud?

branch root

A seaweed that grows in shallow, cold water and undergoes heteromorphic alternation of generations is most probably what type of alga?

brown

Which of the following modified roots has a similar function as prop roots?

buttress roots

How does a noncompetitive inhibitor decrease the rate of an enzyme-catalyzed reaction?

by binding to an allosteric site, thus changing the shape of the active site of the enzyme

A change of a single amino acid at a position distant from the active site of an enzyme can alter the substrate specificity by changing the ________.

by changing the 3-D shape of the enzyme

Choose the letter that indicates the organelle that contains most of a cell's DNA.

c

The figure illustrates the energy states associated with the reaction A + B ↔↔ C + D. Which of the lower-case letters represents the activation energy required for the non-enzyme-catalyzed reaction in the figure?

c

Which component in the figure above represents a microfilament of the cytoskeleton?

c

Which of the flowers diagramed below is most likely to be self-compatible?

c

Which of the following occurs during the Calvin cycle?

carbon fixation

Which of the following terms most precisely identifies the cellular process of breaking down large molecules into smaller ones?

catabolism (catabolic pathways)

In which cell of the accompanying figure would elevated oxygen concentrations have the greatest inhibitory effect on carbon fixation reactions?

cell II only

Shoot elongation in a growing bud is due primarily to which of the following?

cell elongation localized in each internode

An animal cell that lacks carbohydrates on the external surface of its plasma membrane would likely be impaired in which of the following functions?

cell-cell recognition

Which of the following organelles often occupy the majority of the volume of a plant cell?

central vacuole

Which of the following correctly matches an organelle with its function?

central vacuole with storage

Bacteria that live around deep-sea, hot-water vents obtain energy by oxidizing inorganic hydrogen sulfide belched out by the vents. They use this energy to build organic molecules from carbon obtained from the carbon dioxide in seawater. These bacteria are __________.

chemoautotrophs

An organelle in a newly discovered cell contains thylakoids, DNA, and ribosomes. These findings suggest that this organelle is most likely similar to which of the following organelles?

chloroplast

Which of the following structures is independent of the endomembrane system in eukaryotic cells?

chloroplast

Which of the following types of molecules are most likely to lack hydrophilic domains?

cholesterol

The _____ is composed of DNA and protein.

chromatin

Penicillin is an antibiotic that kills bacteria by binding to the active site of an enzyme involved in synthesis of the bacterial cell wall. Which of the following phenomena best describes the mechanism of action of penicillin?

competitive inhibition

Motor proteins provide for molecular motion in cells by interacting with which of the following cellular structures?

components of the cytoskeleton

Chitin is a long-chain polymer derived from glucose. It strengthens cell walls of fungi and the outer covering (exoskeleton) of arthropods (including crabs, shrimps, and insects). The presence of chitin in these groups is likely the result of which of the following processes?

convergent evolution

An enzyme is composed of four identical subunits. Binding of substrate to one subunit stimulates more rapid binding of substrate to each of the other three subunits. This enzyme is most likely regulated by which of the following mechanisms?

cooperativity

The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Because phosphate import depends on a pH gradient across the membrane, phosphate transport is most likely an example of which of the following transport processes?

cotransport

The movement of glucose into a cell against its concentration gradient is most likely to be accomplished by which of the following?

cotransport of the glucose with a proton or sodium ion that was pumped across the membrane using the energy of ATP hydrolysis

In some cells, there are many different ion electrochemical gradients across the plasma membrane even though there are usually only one or two types of proton pumps present in the membrane. The gradients of the other ions are most likely established by which of the following?

cotransport proteins

Which of the following is least likely to be important in holding the components of a biological membrane together?

covalent interactions between the phospholipid and protein components of the membrane

Photosynthesis that releases O2O2 occurs in

cyanobacteria

A failure in which of the following processes can result in the formation of a supercell that is characteristic of plasmodial slime molds?

cytokinesis

The figure illustrates the energy states associated with the reaction A + B → C + D. Which of the lower-case letters in the figure represents a free energy change that would be the same in either an enzyme-catalyzed or a noncatalyzed reaction?

d

Most fungi are _____.

decomposers

Based on the figure above, which of these experimental treatments would increase the rate of sucrose transport into a plant cell?

decreasing extracellular pH

Movement of phloem sap from a source to a sink

depends ultimately on the activity of proton pumps.

A cell has formed a food vacuole as it ingested a food particle. Which of the following events is associated with the breakdown of that food particle?

digestion of the food particle occurs in a vesicle enclosed by a membrane that separates the digestion from the cytoplasm Submit

Fruits evolved primarily as structures specialized to _____.

disperse seeds

Which component in the figure above represents cholesterol?

e

Which of these is the double membrane that encloses the nucleus?

e

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

embedded in a lipid bilayer.

The pointer is indicating a diploid cell that develops into the _____.

embryo

Some plant species produce male and female individuals in which the males have an XY genotype and the females have an XX genotype. After double fertilization, what would be the genotypes of the embryos and endosperm nuclei?

embryo XX/endosperm XXX or embryo XY/endosperm XXY

Which of the following terms best describes a chemical reaction for which ΔG is positive?

endergonic

An early step in the evolution of eukaryotic cells most likely involved which of the following events?

endosymbiosis of an oxygen-using bacterium in a larger bacterial host cell-the endosymbiont evolved into mitochondria

If you were shipping green bananas to a supermarket thousands of miles away, removing which of the following chemicals from the plants' environment will best prevent premature fruit ripening?

ethylene

Which process provides the main force driving water within xylem vessels?

evaporation of water through stoma

The relationship between the breakdown of macromolecules and the biosynthesis of macromolecules is most similar to the relationship between which of the following pairs of terms?

exergonic and endergonic

The figure illustrates the energy states associated with the reaction A + B ↔↔ C + D. Which of the following terms best describe the forward reaction in the figure?

exergonic, ΔGΔG < 0

Choose the pair of terms that correctly completes this sentence: Catabolism is to anabolism as _______ is to _______.

exergonic; endergonic

Which of the following statements correctly describes exotoxins and endotoxins produced by various bacteria?

exotoxins are secreted into the environment while the bacteria is still alive

Pancreatic cells, which secrete a large amount of digestive enzymes, are labeled with radioactive leucine and then chased for several hours with nonradioactive leucine. Photographic emulsions are prepared at different times during the chase. Where would the black spots appear on an emulsion prepared 3 hours after the pulse?

exterior of the cell

A mutation that disrupts the ability of an animal cell to add polysaccharide modifications to proteins would most likely cause defects in which of the following structural elements?

extracellular matrix

The prokaryotic organisms most likely to be found living in salt ponds are the __________.

extreme halophiles

True or false? Fruits provide food to the developing plant.

false

True or false? In most fungi, fertilization is complete after the cells fuse together.

false

True or false? Proteins produced during the "chase" phase of a pulse-chase experiment are labeled with radioactive material.

false

True or false? The endosperm in a seed develops into the embryo.

false

True or false? The endosperm tissue that nourishes the developing plant has the same nutritional characteristics regardless of the plant species

false

Which of the terms below best describes a regulatory mechanism in which the end product of a metabolic pathway inhibits an enzyme that catalyzes an early step in the pathway?

feedback inhibition Submit

Which of the following generations in the conifer life cycle directly produces the megasporangium of pine ovules?

female sporophyte

Which of the following generations in the conifer life cycle most directly produces the integument of a pine seed?

female sporophyte

A botanist discovers a new species of plant in a tropical rain forest. Investigation of its anatomy and life cycle shows the following characteristics: flagellated sperm, xylem with tracheids, separate gametophyte, sporophyte generations with the sporophyte dominant, and no seeds. To which of the following groups does this plant most likely belong?

ferns

Which feature seen in chytrids supports the hypothesis that they diverged early in fungal evolution?

flagellated spores

Which of the following types of flowers are incapable of self-pollination?

flowers lacking anthers

A porous test (shell) of calcium carbonate, through which pseudopodia protrude, is characteristic of which of the following groups of organisms?

foraminiferans

Which of the following factors most likely helped early plants colonize land?

formation of mutualistic associations with fungi

When a mycelium infiltrates a recently killed mouse carcass, which of the following is most likely to appear within the tissues of the mouse soon thereafter?

fungal enzymes

Which answer arranges the characteristics of plants in the order in which they evolved, from most ancient to most recent?

gametophyte dominance, sporophyte dependence; sporophyte dominance, gametophyte independence; sporophyte dominance, gametophyte dependence Submit

Which one of the following hormones stimulate(s) rapid stem elongation (straight growth) and pollen tube growth?

gibberellins

Which of the following best predicts the effect of removal of oxygen from a facultative anaerobic organism's environment?

glucose consumption increases, while the growth rate decreases

Identify Structure A.

glycoprotein

Compared with a cell with few aquaporin proteins in its membrane, a cell containing many aquaporin proteins will

have a faster rate of osmosis.

One difference between eukaryotic and prokaryotic cells is that eukaryotic cells?

have membrane-enclosed organelles, which are lacking in prokaryotic cells.

Farmers traditionally kept some of the seeds from their best plants in one season to plant the following year. Now that farmers mostly plant hybrid seed this practice is no longer effective because ________.

hybrid seeds are heterozygous and not true-breeding

Several epidemic microbial diseases of earlier centuries incurred high death rates because they resulted in severe dehydration due to diarrhea. Today these diseases are usually not fatal because of the development of which of the following types of treatments?

hydrating drinks with high concentrations of salt and glucose

This cell is in a(n) _____ solution.

hypertonic

If a red blood cell is placed in a salt solution and bursts, what is the tonicity of the solution relative to the interior of the cell?

hypotonic

Is the solution outside the cell isotonic, hypotonic, or hypertonic?

hypotonic

You know that this cell is in a(n) _____ solution because the cell _____.

hypotonic ... swelled

Under which conditions will plant cell mitochondria actively oxidize pyruvate and carry out oxidative phosphorylation?

in all cells, with or without light

Root apical meristems are found

in all roots.

Which of the following areas in bacterial cells best describes where chromosomal DNA is generally localized?

in the nucleoid

"Bt maize"

includes bacterial genes that produce a toxin that reduces damage from insect pests. Submit

Enzymes are described as catalysts, which means that they __________.

increase the rate of a reaction without being consumed by the reaction

"Golden Rice" is a GM crop designed to enhance which of the following traits?

increase vitamin A content, a common dietary deficiency in developing countries

Most scientists agree that climate change is underway; thus, it is important to know how plants respond to heat stress. Which of the following would b

increased production of heat-shock proteins

Which of the following would increase the rate of the reverse reaction?

increasing the concentration of ammonia

Which of the following best describes the growth of most plant structures, except for flowers?

indeterminate

Endocytosis moves materials _____ a cell via _____.

into ... membranous vesicles

Diffusion of ions across membranes through specific ion channels is driven by ________.

ion electrochemical gradients

Onions are monocots with certain parts adapted for storage. From which of the following plant parts is the main storage structure formed?

leaf sheaths

In addition to activating or inhibiting enzymes through allosteric regulation, which of these mechanisms do cells also use to control enzymatic activity?

localization of enzymes into specific organelles or membranes Submit

Which organelle plays a role in intracellular digestion?

lysosome

Asbestos is a material that was extensively used in construction for decades. One risk from working in a building that contains asbestos is the development of asbestosis caused by the inhalation of asbestos fibers. Cells will take up asbestos by phagocytosis, but are not able to degrade it. Toxicity most likely results from accumulation of asbestos in which of the following organelles?

lysosomes

Which of the following organelles plays a primary role in the digestion of bacteria engulfed by white blood cells?

lysosomes

Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of which of the following molecules out of the nucleus?

mRNA

Plasmodesmata can change in number and, when dilated, can provide a passageway for which of the following?

macromolecules

Which one of the following elements plays a critical role in the structure of chlorophyll?

magnesium

Which of the following plant structures most directly produces the pollen tube of angiosperms?

male gametophyte

The female gametophyte develops in the ovule from diploid (2n) tissue that undergoes meiosis and eventually forms the haploid (n) megaspore. What is the name of the diploid tissue that gives rise to the female gametophyte?

megasporangium

What are the products of meiosis in the life cycle of a seed plan

megaspores or microscopes

Basidia produce spores by a process known as _____.

meiosis

The voltage across a membrane is called the ________.

membrane potential

In angiosperms, which of the following is correctly paired with its chromosome count?

microspore−n−n Submit

The cilia and flagella of eukaryotic cells are composed of _____.

microtubes

Which of these are hollow rods that shape and support the cell?

microtubules

A young child who suffers from a metabolic disease is always tired and fatigued. Which of the following organelles is most likely malfunctioning in this disease?

mitochondria

Which of the following characteristics is functionally important in gametophyte cells of both angiosperms and gymnosperms?

mitochondria

Energy released from the electron transport chain is used to pump H+ ions into which location in eukaryotic cells?

mitochondrial intermembrane space

Disruption of the function of which of the following organelles would result in a dramatic decrease in ATP synthesis in eukaryotic cells?

mitochondrion

Which of the following structures is common to plant and animal cells?

mitochondrion

Which of these organelles carries out cellular respiration?

mitochondrion

Which structure is common to plant and animal cells?

mitochondrion

Stamens, sepals, petals, carpels, and pinecone scales are types of which of the following structures?

modified leaves

Why are micronutrients needed in only very small amounts?

most micronutrients serve mainly as cofactors of enzymes

Which of the following membrane activities requires energy from ATP hydrolysis?

movement of Na+ ions from a lower concentration in a mammalian cell to a higher concentration in the extracellular fluid

A type of bacteria colonizes on the surface of a leaf, where it obtains nutrition from the leaf's nonliving, waxy covering without harming the plant, and inhibits the growth of other microbes that are plant pathogens. If this bacteria gains access to the inside of a leaf, however, it causes a fatal disease in the plant. Once the plant dies, the bacterium and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here?

mutualist, pathogen, nutrient recycler

Which structure allows the growing mushroom to nourish itself?

mycelium

Which structure is not directly involved in the reproduction of at least one major group of fungi?

mycelium

A particular cell contains the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. Based on this composition, it could be a cell from which of the following organisms?

nearly any eukaryotic organism

Vines in tropical rain forests must grow toward large trees before being able to climb toward the sun. Which of the following responses would promote vine growth towards a tree?

negative phototropism

Which elements are most often the limiting nutrients for plant growth?

nitrogen, potassium, phosphorus

The 3-D structure of an enzyme composed of a single polypeptide chain includes a large substrate-binding domain. It also has a separate binding site for a regulatory molecule. Based on these structural observations the enzyme is most likely regulated by which of the following mechanism?

noncompetitive inhibition

Hydrophobic substances like salad oil are

nonpolar molecules that do not have an affinity for water molecules. Submit

Ribosomal subunits are manufactured by the _____.

nucleolus

Which of the following can be used to determine a twig's age?

number of apical bud scar rings

What name is given to the process by which water crosses a selectively permeable membrane?

osmosis

Which of the following are present in angiosperms but not in gymnosperms?

ovaries

Which part of a flower develops into the seed?

ovule

Which of the following processes is most directly driven by light energy?

oxidation of chlorophyll molecules

Which of the following particles could diffuse easily through a cell membrane?

oxygen

Facilitated diffusion is a type of _______.

passive transport

Which term describes the portion of a peach that can be eaten by humans?

pericarp

Which of these organelles produces H2O2 as a by-product?

peroxisome

Which part of a plant attracts pollinators?

petals

A white blood cell engulfing a bacterium is an example of _____.

phagocytosis

An organism with a cell wall would most likely be unable to take in materials through which of the following processes?

phagocytosis

Which of the following processes is used by white blood cells when engulfing bacteria?

phagocytosis

Identify Structure D.

phospholipid bilayer of membrane

Which of the following detects light during de-etiolation (greening) of a tomato plant?

phytochromes

Which of the following statements best describes the difference between pinocytosis and receptor-mediated endocytosis?

pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity

Which term describes the fusion of cytoplasm from two individuals?

plamogamy

Mitochondria are found in __________.

plant and animal cells

The _____ is a selective barrier, regulating the passage of material into and out of the cell.

plasma membrane

Which of the following is a key feature of seed plants facilitating life on land?

pollen

Which term describes the male gametophytes of flowering plants?

pollen grains

Which structure formed by the male gametophyte allows sperm to reach the ovary of a flowering plant?

pollen tube

Which process involves the transfer of pollen grains from an anther to a stigma?

pollination

Which of the following could best be investigated by measuring fruit production in plants?

pollination success

What would enhance water uptake by a plant cell?

positive pressure on the surrounding solution

Energy is observed in two basic forms: potential and kinetic. Which of the following correctly matches these forms with a source of energy?

potential energy with the covalent bonds of a sugar molecule

Which of the following describes a difference between wind-pollinated angiosperms compared with animal pollinated plants? Wind pollenated plants ________.

produce much more pollen because winds disperse pollen randomly

A cell with a predominance of rough endoplasmic reticulum is most likely involved in which of the following processes?

producing large quantities of proteins for secretion

Trypanosome infections evade attacks by host immune systems through which of the following mechanisms?

production of new cell-surface proteins with a different molecular structure by each new generation

What is the oxidizing agent in the following reaction? Pyruvate+NADH+H+→Lactate+NAD+

pyruvate

Which of the following processes occurs in the Calvin cycle?

reduction of CO2

Look at the graph of reaction rate versus substrate concentration for an enzyme. In which region does the reaction rate remain constant?

region C

Refer again to the graph. In which region is the enzyme saturated with substrate?

region C

Disruption of nuclear pore complexes in a eukaryotic cell will most likely interfere with the transport of which of the following molecules into the nucleus?

ribosomal portions

Which of the following is present in a prokaryotic cell?

ribosome

Which of the following structures are found in plant, animal, and bacterial cells?

ribosomes

_____ are the sites of protein synthesis.

ribosomes

Which of the following plant parts absorbs most of the water and minerals taken up from the soil?

root hairs

Estimate the average root and hyphal length in soils of 35∘∘C.

root length: 0 cm/g; hyphal length: 0.4 m/g

Estimate the average root length and hyphal length in soils of 25∘∘C.

root length: 5 cm/g; hyphal length: 1.3 m/g

Under which of the following conditions would guttation be most likely to occur?

root pressure exceeds transpiration pull

A newly synthesized protein destined for secretion from a eukaryotic cell will generally follow which of the pathways listed below?

rough ER →→ Golgi →→ transport vesicle →→ plasma membrane

Which of these organelles manufactures proteins bound for secretion out of the cell?

rough endoplasmic reticulum

Which of the following structures is correctly paired with its function?

sclerenchyma-supporting cells with thick secondary walls

Which of the following statements describes a difference between seed plants and ferns?

seed plants produce two kinds of spores

If pollen from a plant with the S1S2 genotype is recognized and allowed to germinate on the stigma of the same plant with the S1S2 genotype, the plant is mostly likely ________.

self-compatible and can self-pollinate

Which of the following statements best describes the relationship between the solutions on both sides of the U-tube?

side A is isotonic to side B

Which of the following types of molecules are least likely to diffuse through the phospholipid bilayer of a cell membrane?

small ions

The liver is involved in detoxification of many poisons and drugs. Which of the following structures is abundant in liver cells and primarily responsible for detoxification processes?

smooth endoplasmic reticulum

Where is calcium stored?

smooth endoplasmic reticulum

Structure A is a _____.

solute

Which of the above species have a cell wall that consists partly of an outer membrane of lipopolysaccharide?

species 3, 4, and 5

The oxygen released by photosynthesis is produced by which of the following processes?

splitting water molecules Submit

Which of the following statements is correct regarding the structure of a fern?

sporangia are found on the sporophylls

What is the function of Structure E?

stabilization of the phospholipids

A plant mutant that shows normal gravitropic bending but does not store starch in its plastids would require a reevaluation of the role of ____________ in gravitropism.

statoliths

Evergreen trees lose their leaves _____.

steadily all year

Which of the following structures is a modified horizontal shoot growing along the soil surface?

stolon

Which of the following accurately describes the structure of a leaf?

stomata can occur on both sides of a lea

Photosynthesis ceases when leaves wilt, mainly because

stomata close, preventing CO2CO2 from entering the leaf.

Which type of mutant is most likely to produce a bushier phenotype?

strigolactone underproducer

Which of the following best describes why water flows into the source end of a sieve tube?

sucrose has been actively transported into the sieve tube, making it hypertonic

Which one of the following nutrients plays a critical role as a component of proteins?

sulfur

Fungi release digestive enzymes into their _____.

surroundings

An ecological relationship between organisms of different species that are in direct contact can best be described as __________.

symbiotic

A cell with a predominance of smooth endoplasmic reticulum is most likely specialized to carry out which of the following processes?

synthesis of large quantities of lipids

A flask containing photosynthetic green algae and a control flask containing only water are exposed to a cycle of 12 hours of light and 12 hours of darkness. Which of the following statements best describes how the relative dissolved oxygen concentration in the flask with algae will compare to the control flask?

t will be lower in the control in the light, but higher in the control in the dark.

Most cells cannot harness heat to perform work because

temperature is usually uniform throughout a cell.

Which of the following statements is the reason that most cells cannot harness heat to perform work?

temperatureis usually uniform throughout a cell

What do the multiple branching points at the root of the eukaryotic phylogenetic tree indicate about the evolution of eukaryotes?

that eukaryotes are all descended from a common ancestor

The evolution of vascular tissue in plants facilitated which of the following changes?

the ability to grow taller

Which of the following is NOT a way in which an enzyme can speed up the reaction that it catalyzes?

the active site can provide heat from the environment that raises the energy content of the substrate

You can recognize the process of pinocytosis when _____.

the cell is engulfing extracellular fluid

Which of the following reactions produces the majority of the CO2 released by the complete oxidation of glucose?

the citric acid cycle Submit

When a cell is deprived of oxygen, which of the following processes will be inhibited first?

the electron transport chain

Which of the following events takes place in the electron transport chain?

the harnessing of energy from redox reactions to generate a proton gradient

Which structure or compartment is part of the symplast?

the interior of a sieve tube

Tay-Sachs disease is a human genetic disorder that results in cellular accumulation of very large, complex, undigested lipids. Which of the following organelles is most likely defective in Tay-Sachs disease?

the lysosome

Which criteria allow biologists to classify chemicals into macronutrients and micronutrients?

the quantities of each required by plants

Which of the following parameters is most likely to limit the maximum size of a cell?

the ratio of surface area to volume of cytoplasm

A new drug designed for the treatment of lung cancer must specifically enter the cytoplasm of lung cells while not entering the cells of other tissues. Which of the following characteristics would likely enhance the specificity of this drug?

the similarity of the drug molecule to other molecules normally transported lung cells

You are working on a team that is designing a new drug. For this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively

the similarity of the drug molecule to other molecules that are transported into the target cells

The permeability of a biological membrane to a specific polar solute may depend on which of the following?

the types of transport proteins in the membrane

Some bacteria are metabolically active in hot springs because

their enzymes have high optimal temperatures.

If you examined the cut surface at the base of this twig, how many growth rings should be present?

three

Passive leakage of partially digested material from the small intestine into the human abdominal cavity may result from defects in which of the following type of intercellular junction?

tight junctions

In experiments to test whether a protein can enter the nucleus, why would proteins be labeled with fluorescent molecules?

to make the proteins easy to see

Which of the following are water-conducting cells that are dead at functional maturity?

tracheids and vessel elements

Beginning within the nucleus, the first step leading to the synthesis of a polypeptide is _____.

transferring of information from DNA to messenger RNA

What pathways would be necessary to carry you to the leaves of the trees?

transmembrane symplastic apoplastic bulk flow All of the above.

Structure B is a _____.

transport protein

True or false? Most of the cells in a mushroom contain haploid nuclei.

true

True or false? Osmosis is a type of diffusion.

true

True or false? The water-soluble portion of a phospholipid is the polar head, which generally consists of a glycerol molecule linked to a phosphate group.

true

Which of the following molecules is required by cells to assemble cilia or flagella?

tubular

A gardener in Canada wants to surprise his mother on her birthday and make her favorite hibiscus bush flower in May instead of at the end of June. The bush is growing in the greenhouse. Which of the following treatments is most likely to make the hibiscus bush flower early?

turn on the greenhouse lights before dawn in March or April

Which of the following best describes the structure of a biological membrane?

two layers of phospholipids, with proteins either crossing the layers or on the surface of the layers

Additional vascular tissue produced as secondary growth in a root originates from which cells?

vascular cambium

In a meristematic region, the cell plate during mitosis is perpendicular to the side of the stem. In what direction will the stem grow?

vertically in height

What is endosperm?

via cotyledons, a source of food for the embryo

The symplastic route can transport which of the following?

viruses, sugars, and mRNA

Which of the following molecular movements is due to diffusion or osmosis?

when a plant cell is placed in concentrated salt water, water moves out of the cell.

When is the polarity of a plant established?

when the shoot-root axis is established in the embryo

Which of the following clues would tell you if a cell is prokaryotic or eukaryotic?

whether or not the cell is generally partitioned by internal membranes Submit

Which of the following are produced by lateral meristems?

wood and cork

Cytokinins, produced primarily in roots, travel by which of the following structures to influence branching in a recently topped tree (tree whose upper branches have been trimmed off)?

xylem

Which of the following is NOT a pattern of vascular bundles evident in this stem?

xylem toward the outside of each bundle, phloem toward the center

The mathematical expression for the change in free energy of a system

ΔG is the change in free energy.

A chemical reaction occurs between the amino acids alanine (Ala) and glycine (Gly), forming the compound alanylglycine. The simple conversion reaction of alanine and glycine into this compound is endergonic, with a ΔΔG of 6.9 kcal/mol. Therefore, it requires ATP hydrolysis to drive the nonspontaneous reaction. Calculate the free energy change for the whole process, applying what you know about ATP hydrolysis.

ΔΔG = -0.4 kcal/mol

A plant cell with a ΨsΨs of −−0.65 MPaMPa maintains a constant volume when bathed in a solution that has a ΨsΨs of −−0.30 MPaMPa and is in an open container. The cell has a

Ψpof ++0.35 MPa