AP Bio Final

Muscle contraction depends on ATP hydrolysis. During periods of intense exercise...which of the following correctly uses the data to justify the claim that phosphagen system is an immediate, short-term source of ATP for muscle cells?

ATP production by the phosphagen system increases and decreases rapidly following the start of the exercise period

Damaged tissue releases chemicals that activate platelets and stimulate the formation of blood clots. Which of the following predictions about the activity of platelets best describes a positive feedback mechanism?

Activated platelets releases chemicals that activate more platelets

Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's___

Activation energy

A researcher claims that increased atmospheric carbon dioxide levels cause increased growth rates in plants.Which of the following statements best supports the researcher's claim?

Atmospheric carbon dioxide is the raw material for photosynthesis, which plants rely on for producing sugars and other organic compounds.

Water potential is generally most negative in which of the following parts of the plant?

Mesophyll cells of a leaf

The O2 released during photosynthesis comes from

H2O

A model of plasma membrane showing several biological molecules, including a transmembrane protein, is shown in figure 1. Which statement best explains why correct protein folding is critical in the transmembrane protein shown above?

Interactions of the hydrophobic and hydrophilic amino acids help to anchor the protein in the membrane

Process in which O2 is released as a by-product of oxidation-reduction reactions?

Light-dependent reactions of photosynthesis

Glycolysis can be used in both aerobic cellular respiration and fermentation

True

Which of the following is not a product of fermentation?

O2

Most cells that have become transformed into cancer cells have which of the following characteristics when compared to normal, healthy cells?

Shorter cell cycle

Which of the following statements best supports the claim that certain organelles within eukaryotic cells evolved from free-living prokaryotic cells?

Some organelles contain their own DNA that is more similar to prokaryotic DNA in structure and function than to the eukaryotic DNA found in the cell's nucleus.

CAM plants keep stomata closed in the daytime, thus reducing loss of water. They can do this because they

fix CO2 into organic acids during the night

A student placed 20 tobacco seeds of the same species on moist paper towels in each of two petri dishes. Dish A was wrapped completely in an opaque cover to exclude all light. Dish B was not wrapped. The dishes were placed equidistant from a light source set to a cycle of 14 hours of light and 10 hours of dark. All other conditions were the same for both dishes. The dishes were examined after 7 days, and the opaque cover was permanently removed from dish A. Both dishes were returned to the light and examined again at 14 days. The following data were obtained. According to the results of this experiment, germination of tobacco seeds during the first week is?

increased by exposure to light

A student used microscopy to investigate the relative lengths of the different stages of mitosis. The student prepared slides of cells isolated from a growing onion root tip...Based on the data, the percent of the mitotic cells that were in metaphase is closest to which of the following?

18%

Based on the model, what will be the mean diameter of the phytoplankton cells that are found 25 kilometers from shore?

650 micrometers

A cell culture commonly used in research was selected to study the effect of a specific virus on the timing of cell cycle phases...which of the following most accurately describes an observation and an effect of the viral infection indicated by the data in table 1?

75% of the virus-infected cells are found in mitosis? The virus stimulates frequent cell division

Put the steps of the process of signal transduction in the order they occur:

1. A conformational change in the signal-receptor complex activates an enzyme. 2. Protein kinases are activated. 3. A signal molecule binds to a receptor. 4. Target proteins are phosphorylated. 5. Second messenger molecules are released.

Scientists have estimated that it takes yeast cells approximately 20 hours to complete the entire cycle. Table 1 shows the amount of time in each phase of the life cycle for yeast cells. Based on table 1, what percent of the life cycle of yeast cells is spent in DNA replication?

25 percent

The diagram below shows a developing worm embryo at the four-cell stage. Experiments have shown that when cell 3 divides, the anterior daughter cell gives rise to muscle and gonads and the posterior daughter cell gives rise to the intestine. However, if the cells of the embryo are separated from one another early during the four-cell stage, no intestine will form. Other experiments have shown that if cell 3 and cell 4 are recombined after the initial separation, the posterior daughter cell of cell 3 will once again give rise to normal intestine. Which of the following is the most plausible explanation for these findings?

A cell surface protein on cell 4 signals cell 3 to induce formation of the worm's intestine.

The diagram above illustrates feedback control as exerted by the hormone thyroxine. Following surgical removal of the thyroid gland, the level of TSH in the blood will increase. Which of the following best explains this increase?

A decrease in thyroxine levels means a loss of inhibition to the hypothalamus and anterior pituitary, leading to increased TSH secretion

Cancer can result from a variety of different mutational events. Which of the following is least likely to result in the initiation of a cancerous tumor?

A defect in a cell-cycle checkpoint prevents a cell from entering the S phase?

Thyroxin is a hormone that increases metabolic activities within various tissue targets. Low levels of circulating thyroxin trigger the secretion of TSH from the anterior pituitary...Based on the info provided, which of the following can most likely be concluded about the TSH thyroxin loop?

A person taking thyroxin to supplement low thyroxin secretion will produce more TSH

A series of enzyme catalyze the reaction X->Y->Z->A. Product A bonds to the enzyme that converts X to Y at a position remote from its active site. This binding increases the activity of the enzyme. What is substance X?

A substrate

What molecule will form when hydrogen ions flow down the electrochemical gradient through ATP synthase complexes in mitochondria?

ATP

The energy required to run the Calvin cycle reactions of photosynthesis comes from which two substances produced during the light-dependent reactions?

ATP and NADPH

What substance is produced by the oxidation of pyruvate and feeds into the citric acid cycle?

Acetyl-COA

A study was conducted to understand the factors controlling the rate at which molecules or ions travel across cell membranes. An artificial membrane was created that was composed of a phospholipid bilayer only. The speed at which various substances crossed this membrane was measured. Some substances can pass through an actual cell membrane much faster than they passed through an artificial membrane in this study. Which of the following statements best explains this finding?

Actual cell membranes have a variety of proteins embedded in the membrane that are absent in the artificial membrane.

Figure 1 shows a model of how a channel protein influences the movement of a particle across a cell's plasma membrane. An investigator wants to understand whether a newly found membrane protein is involved in membrane transport of a certain particle. Which investigation will help determine whether the new membrane protein is s channel protein involved in membrane transport?

Add more of the proteins to the plasma membrane and measure the rate of the particle movement

What is the major structural difference between starch and glycogen?

Amount of branching

What event accompanies energy absorption by chlorophyll (or other pigment molecules of the antenna complex?

An electron is excited

For following group of questions first study the description of the situation or data and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet.In the first step of an experiment, rat liver cells were exposed for 5 minutes to amino acids labeled with a radioactive isotope. The cells were then washed to stop any further incorporation of radioactive amino acids. The cells were sampled periodically thereafter, and the radioactivity of a certain protein (protein X) was measured in various cell components, as shown below.

An enzyme that participates in the degradation and recycling of cell components.

Both myoglobin and hemoglobin are proteins that bind reversibly with molecular oxygen. The graph below shows the oxygen-binding saturation of each protein at different concentrations of oxygen. Strenuous exercise lowers the blood pH, causing the curved for both hemoglobin and myoglobin to shift to the right. This shift results in

An unloading of O2 at higher partial pressures

An antigen can induce an immune response in a host organism. Antigens are targeted by antibodies that are produced by the organism's immune system in response to contact with the antigen. Antibodies are specific to antigens. Many different cell types are involved in immune responses.Which of the following best describes the role of cell-to-cell communication during a response to an invasion of antigens?

Antigens attaching to receptors on memory B cells stimulate the memory B cells to become plasma cells.

Which of the following best describes the numbered areas?

Areas 1 &3 are polar, since the membrane molecules are aligned with water molecules

ADH is important in maintaining homeostasis in mammals...The amount of hormone released is controlled by a negative feedback loop. Based on the model presented, which of the following statements expresses the proper relationship between osmolarity, ADH release, and urine production?

As tissue osmolarity rises, less ADH is released, causing less water to be excreted as urine

Both myoglobin and hemoglobin are proteins that bind reversibly with molecular oxygen. The graph below shows the oxygen-binding saturation of each protein at different concentrations of oxygen. Which of the statements is true?

At 40 mm Hg partial pressure, myoglobin has a greater affinity for oxygen than hemoglobin has

The alternative pathways of photosynthesis using the C4 or CAM systems are said to be compromises. Why?

Both minimize photorespiration but expend more ATP during carbon fixation.

Catabolic processes. . .

Break down complex molecules into simpler ones

How might a change of one amino site , distant from the active site of an enzyme , after an enzyme's substrate specificity?

By changing the enzyme's pH optimum

Aldosterone (a steroid hormone) is a small, nonpolar, hydrophobic molecule that enters a target cell by moving across the plasma membrane, down a concentration gradient. Based on info presented, how does aldosterone most likely enter target cells?

By simple diffusion

Which temperature and pH profile curves on the graphs were most likely generated from the analysis of an enzyme from a human stomach where conditions are strongly acidic? (REFER TO THE GRAPHS)

Curves 1 & 4

Which curves on the graphs may represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildy alkaline hot springs at temperatures of 70C or higher?

Curves 3 & 5

Which of the following equations represents aerobic cellular respiration?

C6H12O6 + 6O2 -----> 6 CO2 +6H2O + energy

Which of the following pathways does NOT occur in aerobic cellular respiration?

Calvin Cycle

Process in which carbon from CO2 is incorporated into organic molecules?

Calvin cycle (light-independent reactions of photosynthesis)

A cell culture was supplied with radioactively labeled O2. The cells were monitored. In a few minutes the radioactive oxygen atoms were present in which of the following compounds:

Carbon Dioxide

Which of the following molecules will diffuse out of the cell, enter the bloodstream, and be released from the lungs during aerobic cellular respiration?

Carbon dioxide

Some cells, such as intestinal cells, exchange a lot of material with their surroundings. The surface to volume ratio of these cells affects the efficiency of material exchange. The table provides measurements of four different eukaryotic cells. Based on the data, which cell is likely to be most effective in the exchange of materials?

Cell 2

Two different models of a living cell are represented in the figure, which would likely be more efficient at exchanging substances with the surrounding environment?

Cell A because it has the larger surface area to volume ratio

Cells from malignant tumors often have very abnormal chromosomes and an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities?

Cell cycle checkpoints are not in place to stop cells with chromosome abnormalities

During a fight-or-flight response, epinephrine is released into the body's circulatory system and transported throughout the body. Some cells exhibit a response to the epinephrine while other cells do not.Which of the following justifies the claim that differences in components of cell signaling pathways explain the different responses to epinephrine?

Cell signaling depends on the ability to detect a signal molecule. Not all cells have receptors for epinephrine. Only cells with such receptors are capable of responding

Carbohydrate-synthesizing reactions of photosynthesis directly require?

Chlorophyll and CO2

What component of amino acid structure varies among different amino acids?

Components of the R-group

Which of the following does not occur during mitosis?

Condensation of chromosomes

Which of the following is true of enzymes?

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

Researchers investigating the regulation of neurotransmitter release from presynaptic neurons proposed a model (Figure 1) in which CDK5, a protein expressed in axon terminals, inhibits the movement of synaptic vesicles to the presynaptic membrane.To test their model, the researchers used a modified version of green fluorescent protein (GFP*). In slightly alkaline conditions, GFP* exhibits a bright green fluorescence. In acidic conditions, GFP* exhibits no fluorescence. Using standard techniques, the gene encoding GFP* is easily introduced into living cells. By engineering the expression of GFP* in laboratory-cultured nerve cells, the researchers found that a bright green fluorescence was exhibited only when a presynaptic neuron was given a certain stimulus.Based on the model, which of the following best explains how regulation of neurotransmitter release might increase the range of responses to a stimulus in the nervous system?

Different neurons in the same neural network can release different amounts of neurotransmitter.

According to the chemiosmotic theory (chemiosmotic coupling), the energy required to move protons from the mitochondrial matrix to the intermembrane space against a concentration gradient comes directly from

Electrons

A scientist claims that Elysia chlorotica, a species of sea slug, is capable of photosynthesis.Which of the following observations provides the best evidence to support the claim?

Elysia chlorotica grows when exposed to light in the absence of other food sources.

The water loss during transpiration is a side effect of the plant's exchange of gases. However, the plant derives some benefit from this water loss in the form of

Evaporative cooling and mineral transport

____ is a series of enzymatic reactions by which glucose is incompletely metabolized to lactate or carbon dioxide and alcohol

Fermentation

During aerobic cellular respiration, which molecule originates from the digestive system?

Glucose

Which of the following is not a polymer?

Glucose

Which pathway for cellular respiration is located in the cytoplasm of the cell?

Glycolysis

Which of the following statements is not true about glycolysis?

Glycolysis requires oxygen

A cell is treated with a drug that prevents the formation of new lysosomes. The cell continues to transcribe the genes that code for the hydrolytic enzymes that are normally found in lysosomes and continues to translate the mRNAs for those proteins on membrane-bound ribosomes. The hydrolytic enzymes are most likely to accumulate in which of the following cellular structures?

Golgi complex

Which of the following questions is most relevant to understanding the Calvin cycle?

How is ATP used in the formation of 3-carbon carbohydrates?

Which of the following best describes how the properties of water at an air-water interface enable an insect to walk on the water's surface?

Hydrogen bonds between molecules at the surface of the water provide surface tension, which allows the water surface to deform but not break under the insect

Celery stalks that are immersed in fresh water for several hours become stiff. Similar stalks left in a 0.15 M solution become limp. From this we can deduce that the fresh water___

Hypertonic to fresh water but hypotonic to salt concentrations

Signal transduction may result in changes in gene expression and cell function, which may alter phenotype in an embryo. An example is the expression of the SRY gene, which triggers the male sexual development pathway in mammals. This gene is found on the Y chromosome.

If the SRY gene is absent or nonfunctional, the embryo will exhibit female sexual development

Which of the following is true of osmosis?

In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration

The epidermal growth factor receptor EGFR is a cell surface receptor. When a growth factor binds to EGFR, the receptor is activated. The activated EGFR triggers a signal transduction pathway, which leads to increased frequency of cell division. Which of the following best predicts the effect of a mutation that causes EGFR to be active in the absence of a growth factor?

Increased cell division will lead to the formation of a tumor

Water is constantly diffusing into the cytosol of freshwater single cell organisms...Of the following, which additional investigation can be used to determine when the cells are in an isotonic solution

Increasing the salinity of the environment a little at a time until the ATP reaches a minimum

The transport of a substance across a plasma membrane of a specific organelle requires energy...which procedure should be done next to gather data needed to meet the scientist's objective?

Incubate samples containing 1.0 uml/mL of ATP at four temperatures other than 25C

Nucleotides can be radiolabeled before they are incorporated into newly formed DNA and therefore...They concluded that

Infection causes lymphocytes to divide more rapidly

Lipids are___

Insoluble in water

Based on chemiosmosis, hydrogen ions accumulate in the _____

Intermembrane space

If the cytoplasm of a cell is at pH 7, and the mitochondrial matrix is at pH 8, then the concentration of H+ ions.....

Is 10 times higher in the cytoplasm than in the mitochondrial matrix

The usefulness of fermentation as a means of deriving energy is limited because

It cannot generate enough ATP

Which of the following is most directly responsible for water's unique properties?

It forms hydrogen bonds

Why is carbon so important in biology?

It is a common element on Earth

The CFTR protein is made up of 1,480 amino acids linked together in a chain. Some humans produce a version of the CFTR protein in which phenylalanine (an amino acid) has been deleted from position 508 of the amino acid chain. Which of the following best predicts how the amino acid deletion will affect the structure of the CFTR protein?

It will affect the primary, secondary, and tertiary structures of the CFTR protein

Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor?

Lack of appropriate cell death

Researchers grew seedings of corn, zea mays, in loose and compact sand...Based on the sample means, which of the following conclusions about the cells in the growing root tips of Zea mays seedlings is best supported by the results of the experiment?

More cells are produced per unit of time in the root tips growing in compact sand than in the root tips growing in loose sand

In the figure, why does the reaction rate plateau at higher reactant concentrations?

Most enzyme molecules are occupied by substrate at high reactant concentrations

Which coenzyme is used in cellular respiration

NAD+

The final electron acceptor associated with photosystem I is?

NADP

In chloroplasts, ATP is synthesized from ADP plus inorganic phosphate (Pi) in a reaction catalyzed by ATP synthase molecules that are embedded in the thylakoid membrane. Which of the following statements provides evidence to support the claim that no ATP will be synthesized in the absence of a proton gradient across the thylakoid membrane?

No ATP is synthesized when channel proteins that allow the free passage of protons are inserted into the thylakoid membrane.

The carriers for the electron transport system are located

On the cristae of the mitochondria

Stanley Miller's 1953 experiment supported the hypothesis that

Organic molecules can be synthesized abiotically under conditions that may have existed on Earth

Three lab groups carried out an experiment...From that data given, which statement most accurately describes what is occurring in response to a particular unknown solutions?

Osmosis of water molecules from unknown solution A likely caused the increased in mass observed.

During chemiosmosis in aerobic respiration, protons are pumped

Out of the mitochondrial matrix into the inner membrane space of the mitochondria

which molecule is the final electron acceptor in cellular respiration?

Oxygen

A researcher examining a root tip observes a plant cell with condensed sister chromatids, kinetochores with attached microtubules, and individual chromosomes that are aligned at the equatorial plate of the cell. Which of the following best describes what the next process will be in the cell?

Paired chromatids will separate, and the new daughter chromosomes will move toward opposite poles of the cell

Which of the following best explains the processes of passive and active transport?

Passive transport is the net movement of substances down a concentration gradient that does not require metabolic energy. Active transport is the movement of substances up a concentration gradient that requires energy.

What most likely causes the trends in oxygen concentration shown in the graph below?

Photosynthesis produces more oxygen than is consumed by respiration during the day.

Which of the following statements best describes how organisms such as rabbits obtain the carbon necessary for building biological molecules?

Rabbits eat plants and break down plant molecules to obtain carbon and other atoms that they arrange into new carbon-containing molecules

Prokaryotic and eukaryotic cells generally have which of the following features in common?

Ribosomes

The sequence for two short fragments of DNA are shown above. Which of the following is one way in which these two segments would differ?

Segment 1 would become denatured at a lower temperature than would segment 2 because A-T base pairs have two hydrogen bonds whereas G-C base pairs have three

A student analyzed a viral genome and found that the genome had the following nucleotide composition (28% adenine, 20% thymine, 35% cytosine, 17% guanine) *Which of the following best describes the structure of the viral genome?

Single-strand DNA

The relative amounts of DNA present in the nucleus of the cell at four different stages of the life cycle are shown in figure 1, which of the following statements correctly links a stage of the cell cycle with the event occurring at that stage?

Synthesis of sufficient DNA for two daughter cells occurs in stage 2

Students investigated the effect of light on the carbon cycle in aquatic ecosystems...Which of the following graphs is the most appropriate representation of the experimental results documented in the table?

THIS IS OPTION 2 WITH THE BAR GRAPH

Once a cell completes mitosis, molecular division triggers must be turned off. What happens to MPF during mitosis?

The Cdk component of MPF is degraded and exported from the cell.

Cholesterol is an important component of animal cell membranes...Based on the information presented, which of the following is the most likely explanation for a buildup of cholesterol molecules in the blood of an animal?

The animal's body cells are defective in endocytosis

DNA and RNA are nucleic acids that can store biological info based on the sequence of their nucleotide monomers. Figure 1 shows a short segment of each of the two types of nucleic acids. Which of the following best describes a structural difference between DNA and RNA?

The backbone of DNA contains deoxyribose, whereas the backbone of RNA contains ribose

spherical bacterial cell has a radius of 3um. The human egg has a radius of 100um. Which statement correctly indicates the cell is able to more efficiently exchange materials with the external environment and provides the correct explanation?

The bacterial cell because it has the largest surface to volume ratio

According to the induced fit hypothesis of enzyme catalysts,

The binding of the substrate changes the shape of the enzyme's active site

Some cells have several nuclei per cell. How could such multinucleated cells be explained?

The cell underwent repeated mitosis, but cytokinesis did not occur

Based on the model of eukaryotic cell cycle regulation shown in the figure, which of the following best describes the effect of a drug that blocks the production of the mitotic cyclin?

The cell would be prevented from entering mitosis, and the cell would stop dividing

IV solutions administered to patients are normally isotonic. Which of the following is most likely if an IV of distilled water is administered to a patient?

The cells that are exposed to hypotonic solutions will expand as water moves osmotically into the cells from the blood.

Type 1 diabetes results from the destruction of insulin-producing cells in the pancreas. Individuals with type 1 diabetes produce insufficient amounts of insulin, a hormone that regulates the concentration of glucose in the blood.Which of the following best explains how treatment with a drug that stimulates the production of insulin receptors on target cells will affect the insulin signaling pathway in an individual with type 1 diabetes?

The drug will have little or no effect on the signaling pathway because the receptors will not be activated in the absence of insulin

Cancer cells behave differently that normal body cells. For example, they ignore signals that tell them to stop dividing. Which of the following conditions will most likely cause a normal body cell to become a cancer cell?

The environment lacks a signal that would otherwise tell the cell to stop dividing

Figure 1 represents a common process that occurs in organisms. Which of the following is an accurate description of the process shown in figure 1?

The formation of a covalent peptide bond in a dehydration synthesis reaction

A hydrophilic peptide hormone is produced in the anterior pituitary gland located at the base of the brain. The hormone targets specific cells in many parts of the body.Which of the following best explains a possible mechanism that would enable the hormone to efficiently reach all of the target cells in the body?

The hormone is released into the bloodstream where it can be transported to all cells with the correct receptors

The model below shows the structure of a portion of a plasma membrane in an animal cell. Which statement best explains the orientation of the phospholipid molecules in this model?

The hydrophilic phosphate groups of the phospholipid molecules are attracted to the aqueous internal and external environments

Which of the following is an important difference between light-dependent and light-independent reactions of photosynthesis?

The light-dependent reactions produce ATP and NADPH; the light-independent reactions use energy stored in ATP and NADPH.

Why are hydrocarbons insoluble in water?

The majority of their bonds are nonpolar covalent carbon to hydrogen linkages

An experiment to measure the rate of respiration in crickets and mice at 10C and 25C was performed using a respirometer, an apparatus that measures changes in gas volume. Respiration was measured in mL of O2 consumed per gram of organism over several five-minute trails and the following data were obtained.

The mice at 10C had a higher rate of ATP production than the mice at 25 C

Water and Ammonia interact to form hydrogen bonds, as represented in the figure. Which statement best helps explain the formation of hydrogen bonds represented in the figure?

The nitrogen has a partial negative charge, and the hydrogen attached to the oxygen has a partial positive charge

Vertebrate immune responses involve communication over short and long distances. Which of the following statements best helps explain how cell surface proteins, such as MHC proteins and T cell receptors, mediate cell communication over short distances?

The proteins interact directly with proteins on the surfaces of other cells.

The coagulation cascade controls blood clot formation in response to blood vessel injury...which of the following effects on the coagulation cascade is likely to result from inhibiting thrombin activity with argatroban?

The rate of fibrin formation will decrease

Which of the following best describes how the ratio of the density of stomata per CO2 concentration changes as the CO2 concentrations increases?

The ratio decreases from 0.86 to 0.63 because fewer stomata are needed at higher CO2 concentrations

Figure 1 represents the relative time and sequence of the phases of the cell cycle. Which statement best predicts why a cell's progression through the cell cycle might be halted at the g1/S checkpoint?

There are not enough nucleotides available to construct new DNA

In an experiment, cells were isolated from an aquatic plant and suspended in pond water, a sucrose sugar solution, or distilled water...Which of the following best explains the observations represented in figure 1?

There was a net movement of water out of the cell suspended in the sugar solution and a net movement of water into the cell suspended in the distilled water.

Which of the following statements is true about the Krebs (citric acid) cycle and the Calvin (light-independent) cycle?

They both are carried out by enzymes located within an organelle matrix.

Organelles such as mitochondria and the endoplasmic reticulum have membranes that compartmentalize reactions and other metabolic processes. To function properly, the organelles must move substances across their membranes.Which of the following statements describes a feature shared by mitochondria and the endoplasmic reticulum that increases the efficiency of their basic functions?

They have highly folded membranes.

Which of the following best describes the structures of carbs?

They occur as monomers, chains of monomers, and branched structures

The figure below illustrates a eukaryotic cell. Which of the following best describes how the three structures indicated by the arrows work together?

To synthesize and isolate proteins for secretion or for use in the cell

A tumor suppressor protein p53 binds to DNA and activates target genes, which results in the synthesis of o21, CD95, and other proteins. The p21 protein promotes apoptosis. Which of the following will most likely result from a loss of p53 function?

Uncontrolled cell proliferation

A sample of human blood was placed in a test tube containing a physiological saline solution (0.9% sodium chloride)...which of the following best predicts which diagrammed microscopic view the laboratory worker would see and best explains why?

View 2 because the rate of water movement into the RBCS equals the rate of water movement out of the cells

Ignoring all other factors, what kind of day would result in the fastest delivery of water and minerals to the leaves of an oak tree?

Warm, humid day

The synthesis of a protein or carb polymers always produces which of the following as a byproduct?

Water

Which of the following molecules is NOT formed as a result of the Krebs cycle during aerobic cellular respiration?

Water

The movement of water across biological membranes can best be predicted by

Water potentials

Compared to C3 plants, C4 plants?

can continue to fix CO2 even at lower CO2 concentrations and higher oxygen concentrations

A feature of organic compounds not found in inorganic compounds is the presence of

carbon atoms covalently bonded to each other

The carbon 'that makes up organic molecules in plants is derived directly from?

carbon fixed in photosynthesis

In autumn, the leaves of deciduous trees change colors. This is because chlorophyll is degraded and

carotenoids and other pigments are still present in the leaves

The chemiosmotic hypothesis is an important concept in our understanding of cellular metabolism in general because it explains?

how ATP is synthesized by a proton motive force

In autotrophic bacteria, where is chlorophyll located?

in the infolded plasma membrane

What role does O2 play in aerobic respiration?

it is the final electron acceptor at the end of the electron transport chain

The mitotic spindle is a microtubular structure that is involved in

separating sister chromatids

In a plant cell, where are the ATP synthase complexes located?

thylakoid membrane and inner mitochondrial membrane

Additional observations were made on day 21, and no yellow-leaved seedlings were found alive in either dish. This is most likely because?

yellow-leaved seedlings were unable to convert light energy to chemical energy