EXAM3
Thalidomide was sold as "racemic mixture" to pregnant women to treat morning sickness during pregnancy but the drug was found to harm fetus in the womb. It was banned in 1962. Which of the following reasons is the best explanation of the harmful effects of the drug?
(+)(R)-thalidomide is a sedative, but (-)(S)-thalidomide is a teratogen (a drug that is toxic in nature).
What is the general formula for all the shown biomolecules?
(CH2O)n
A research team used a culture of lymphocytes with radioactively labeled T nucleotides to study the cell cycle. They found that the lymphocytes incorporated the labeled nucleotide at a significantly higher rate after a pathogen was introduced into the culture. Which of the following conclusions is most consistent with the results?
!!
Cells from a diploid protist with n=1 are followed through mitosis and meiosis. The drawings in the figure below represent the chromosomes. Refer to the drawings and answer the following question.
!!
If a plant biologist succeeds in generating a single plant with a particularly desirable flower, which of the following approaches would be the most efficient way to generate more plants with this trait?
!!
In a certain species of diploid fish a single gene controls skin color. Researchers have found four different alleles of this gene within the fish population. How many different gamete genotypes are possible in an individual of this species?
!!
In cats, an X-linked locus is responsible for fur color. There are two known alleles at this locus. One results in black fur color; the other results in orange fur color. A heterozygote animal has patches of orange and black fur (tortoiseshell). Which of the following explains the patches of color in female heterozygote cats?
!!
In chloroplasts, the photosynthetic electron transport chain acidifies which of the following cellular compartments?
!!
In the process of spermatogenesis, each _________ cell undergoes meiosis II, resulting in the production of two __________ cells.
!!
When attempting to associate a region of the genome with a specific phenotype, researchers look for single nucleotide polmorphisms (SNPs) that are shared between individuals with that specific phenotype. If the SNP is associated what would you expect?
!!
Which of the following processes is most directly driven by light energy?
!!
Which of the following scenarios describes an example of epistasis?
!!
Which of the following statements best describes homologous chromosomes?
!!
Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism?
!!
A (hypothetical) diploid organism has different genes that control wing color and wing length. A female of this species has a paternal chromosome set containing one orange-wing allele and one long-wing allele and a maternal set containing one blue-wing allele and one short-wing allele. Which of the following types of eggs would she be expected to produce after meiosis?
!!!
In which cellular structure are the enzymes of the Calvin cycle localized?
!!!
When Mendel crossed yellow-seeded and green-seeded pea plants, all the offspring were yellow-seeded. Which of the following genotypic ratios was expected when Mendel crossed the F1 yellow-seeded plants with green-seeded plants?
!!!
Which of the following statements about ribozymes is/are correct?
-A ribosome can be regarded as one large ribozyme. -Ribozymes are RNA molecules that function as enzymes. -In some genes, intron RNA functions as a ribozyme and catalyzes its own excision.
Exposure to the UV radiation in sunlight causes DNA changes in skin cells. What results when they occur in an individual with xeroderma pigmentosum (XP) but not in an individual who does not have this disorder?
-Compared to XP individuals, non-XP individuals have more effective nucleotide excision repair enzymes. -Compared to non XP individuals, XP individuals must be screened more frequently for cancer
How are genes coordinately controlled in eukaryotic cells?
-Coordinately controlled genes in eukaryotic cells share a set of control elements. -Coordinately controlled genes in eukaryotic cells are activated by the same chemical signals. Submit
Which one of the following statements is true of tRNAs?
-Each tRNA binds a particular codon. -tRNAs are double-stranded. -tRNAs carry special sequences known as codons. -There are four types of tRNA. -*None of the listed answers are correct.*
Which statement(s) about inducible operons is/are correct?
-In an inducible operon, the repressor is synthesized in an active form. -In an inducible operon, an inducer inactivates the repressor.
Which noncoding RNAs are correctly matched with their function?
-Piwi-associated RNAs (piRNAs) reestablish appropriate methylation patterns in the genome during gamete formation. -MicroRNAs (miRNAs) bind to complementary sequences in mRNA and block its translation. -Small interfering RNAs (siRNAs) bind to complementary sequences in mRNA and block its translation.
Which of the following molecules is/are produced by translation? Include molecules that are subject to further modification after initial synthesis.
-RNA polymerase -Aminoacyl-tRNA synthetase
Post-translational modifications of proteins may include which of the following processes?
-addition of carbohydrates to form a glycoprotein -addition of lipids for formation of lipoprotein -addition of phosphates by phosphorylation
Which of the following scenarios describes an example of epistasis?
In many mammals one genotype (ee) prevents any fur color from developing.
Which of the following statements best describes a characteristic feature of osmosis?
In osmosis, water moves across a membrane from areas of lower solute concentration to areas of higher solute concentration. You Answered
Which answer best describes the role of telomerase in replicating the ends of linear chromosomes?
It catalyzes the lengthening of telomeres, compensating for the shortening that could occur during replication without telomerase activity.
Which of the following statements about the law of independent assortment is correct?
It describes the inheritance of different genes relative to one another. For instance A and a behave with no respect for B and b.
Which of the following statements about the 5′ end of a polynucleotide strand of RNA is correct?
It has a phosphate group attached to the number 5 carbon of ribose.
Which of the following is true of oxygen that has 8 protons, 8 neutrons, and 8 electrons
It has an atomic number of 8.
Which of the following statements correctly describes the function of a signal peptide?
It helps target a protein to the ER.
Which of the following describes the normal function of the p53 gene product?
It inhibits the cell cycle.
In a Drosophila experiment a homozygous wild-type female was crossed with a yellow-bodied male. All of the resulting F1 flies were phenotypically wild type. Crossing the F1 flies resulted in F2 flies having the characteristics shown in the figure. Which of the following statements best describes the location of the yellow body locus?
It is X-linked.
Which of the following statements accurately describes the structure of a eukaryotic chromosome?
It is a single linear molecule of double-stranded DNA plus proteins.
Which of the following statements correctly describes a ribozyme?
It is an RNA with catalytic activity.
A recessive allele on the X chromosome is responsible for red-green color blindness in humans. A woman with normal vision whose father is color blind has children with a color-blind male. What is the probability that this couple's first son will be color blind?
1/2
Having polydactyly (extra digits on hands and feet) is a dominant trait. A man has polydactyly. His wife and oldest daughter do not have polydactyly. The couple's second child has polydactyly. What is the probability that their next (third) child will have extra digits?
1/2
Black fur in mice (b) is dominant to brown fur (b). Short tails (S) are dominant to long tails (s). What fraction of the progeny of crosses BbSs × BBss will be expected to have black fur and long tails?
1/2 Submit
Albinism is a recessive trait where an individual does not produce the pigment melanin. A man and woman both produce melanin, but both have one parent with albinism. What is the probability that their first child will have albinism?
1/4
How many electrons are present in the neutral atom represented in the Periodic Table block in the figure? Correct!
18
Rank the following mutations with respect to their likelihood of affecting the structure of the polypeptide (from most likely to affect structure to least likely). 1.insertion mutation in the middle of an intron 2.deletion of 3 bases crossing an intron-exon border 3.substitution mutation at the third position of a codon 4.substitution mutation at the second position of a codon
2, 3, 4, 1
A sample of double-stranded DNA contains 28% thymine. Approximately what percent of the nucleotides in this sample will be guanine?
22%
Given a DNA molecule with the sequence of bases 5'-ATTGCA-3', what would be the sequence of the complementary strand? (It will be helpful to draw the DNA molecule when answering the question.)
3'-TAACGT-5'
Which of the sequences below best describes the sequential steps (numbered 1-5) in a signal transduction pathway that utilizes a G protein-coupled receptor? 1.The signal-receptor complex activates a G protein. 2.Protein kinases are activated. 3.A signal molecule binds to a receptor. 4.Target proteins are phosphorylated. 5.cAMP is produced.
3, 1, 5, 2, 4
Based on the accompanying figure, which of the following wavelengths of light is most effective in driving photosynthesis?
440 nm
Which molecule has both hydrophilic and hydrophobic properties and is found in plasma membranes?
5
Which of the following sequences is most likely to be cut by a restriction endonuclease?
5' -AATATT-3'3' -TTATAA-5'
The following question refers to the figure of a family's pedigree chart, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle. What is the likelihood that a future child of IV-3 and IV-4 will have the trait?
50% Submit
A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain? See Concept 12.1 (Page)
92
Which component in the figure above represents a protein fiber of the extracellular matrix?
A
DNA strands are antiparallel. Which of the following statements defines "antiparallel"?
A 5' to 3' DNA strand is paired with the 3' to 5' DNA strand.
Which of the following statements best describes a key aspect of a G protein signaling pathway?
A G protein is active when bound to GTP.
Some cases of human melanoma have been shown to result from inhibition of apoptosis in these cells. The human analogue of which of the following defects in C. elegans could cause these cancers?
A ced-3 protein that is always inactive.
Which of the following statements correctly describes the terms monohybrid cross and dihybrid cross?
A dihybrid cross involves organisms that are heterozygous for two characters that are being studied, and a monohybrid cross involves organisms that are heterozygous for only one character being studied.
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true?
A gene from an organism can probably be expressed by any other organism.
The genetic code is essentially the same for all organisms. From this, one can logically assume which of the following statements to be true?
A gene from an organism can theoretically be expressed by any other organism.
What are the products of linear electron flow in the light reactions of photosynthesis? these products are used to drive the Calvin Cycle.
ATP and NADPH
Which of the following structures or molecules is required in order for motor proteins to facilitate movement of chromosomes toward the poles in mitosis?
ATP as an energy source
Some cases of human melanoma have been shown to result from inhibition of apoptosis in these cells. Why can't cancer be cured by causing apoptosis with drugs?
Apoptosis would kill normal cells as well
Which of the shown amino acids has a hydrophobic side chain?
Arginine
Which of the following statements best defines artificial selection?
Artificial selection is a process in which humans decide which plants and/or animals will and will not breed.
How would acidification of seawater affect marine organisms?
It will decrease dissolved carbonate concentrations and hinder growth of corals and shell-building animals.
Consider the following reaction at equilibrium: CO2 + H2O ⇔ H2CO3. What would be the effect of adding additional H2O?
It would drive the equilibrium dynamics to the right.
A 3-year old dog has never been able to tolerate much physical activity. A veterinarian discovers that the dog's mitochondria can use only fatty acids and amino acids for cellular respiration, and its muscle cells produce elevated levels of lactate. Which of the following statements best explains the dog's condition?
Its cells cannot transport pyruvate from the cytosol into the mitochondria.
Which of the following statements best describes a reason that C. elegans is an excellent model organism for investigating apoptosis?
C. elegans undergoes a fixed and easy-to-visualize number of apoptotic events during its normal development.
the light reactions alone
CO2 is fixed or incorporated into organic molecules. Submit
If more CO32- in the ocean causes more calcium to be deposited in reefs, why is CO2 in the air bad?
CO32- is removed from the ocean by lower pH forming bicarbonate ions HCO3-
You have just sequenced a new protein isolated from mice and observe that sulfur-containing cysteine residues occur at regular intervals. "This finding is most consistent with which of the following claims about the protein?
Cysteine residues are involved in disulfide bridges that help form tertiary structure.
Which of the following tools of DNA technology is incorrectly paired with its use?
DNA ligase−−cutting DNA, creating sticky ends of restriction fragments
After DNA replication, the resulting daughter DNA double helix contains one strand of the original parental DNA and one new strand. What is the explanation for this phenomenon?
DNA replication is semiconservative.
Which of the following statements best describes Darwin's theory of evolution by natural selection?
Darwin's theory emphasized that populations vary and change over time.
In some parts of Africa, the frequency of individuals who are heterozygous for the sickle-cell anemia allele is higher than the frequency in North America, presumably because this reduces the frequency of malaria. Such a relationship is related to which of the following?
Darwin's theory of natural selection
Which of the following best compares dehydration reactions and hydrolysis? Correct Answer
Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart.
Which of the following mutations would likely be most dangerous to a cell?
Deletion of one nucleotide
Which of the following conclusions is consistent with the fact that plants can be cloned from somatic cells?
Differentiated cells retain all the genes of the zygote.
Which statement provides the best description of the interphase portion of the cell cycle?
During interphase, a cell is metabolically active.
Which of the following best explains why a neuron and a pancreatic cell isolated from the same individual contain different sets of proteins?
Each cell type contains different regulatory proteins and, therefore, they express different proteins.
Which of the following statements describes one characteristic of each chromosome in a cell during the entire process of meiosis I?
Each chromosome consists of two sister chromatids joined by a centromere.
Which of the following statements correctly describes one of the main differences between embryonic stem cells and adult stem cells?
Embryonic stem cells can give rise to all cell types in the organism, and adult stem cells cannot.
Which of the following statements describes the process of transformation in bacteria?
External DNA is taken into a cell, becoming part of the cell's genome.
Which of the following molecules is the lowest-energy donor of electrons to the electron transport chain?
FADH2
Cells will usually divide if they receive the proper signal at a checkpoint in which phase of the cell cycle?
G1
The mass of DNA per nucleus in a certain fungus ranges from 4 to 10 picograms. Nuclei with 5 picograms of DNA are most likely derived from cells in which of the following parts of the cell cycle?
G1
Which of the following correctly matches a phase of the cell cycle with its description?
G1, follows cell division
Which of the following statements best describes the relationship between an enzyme and its function?
GTPase: hydrolysis of GTP
One predicted aspect of climate change is that levels of precipitation and temperature will become more variable. Given this information, which of the following describes the best strategy for genetically engineering crops?
Genetically engineer individuals with different phenotypes within a single crop type.
Which of the following observations suggests that a second messenger is required for the activation of glycogen phosphorylase by epinephrine?
Glycogen breakdown occurs only when epinephrine is administered to intact cells.
Which of the following sequences correctly represents the flow of electrons in photosynthesis?
H2O → NADPH → Calvin cycle
Which of the following statements correctly describes the structure of chromatin?
Heterochromatin is highly condensed, whereas euchromatin is less compact. Submit
Human civilizations developed practices regarding inheritance before the scientific grounding of the practices had been determined. Which of the following genetic principles provides scientific support for the societal taboo against closely related people having children?
Heterozygous loci can mask harmful traits in an individual.
Which of the following events happens at the conclusion of meiosis I?
Homologous chromosomes of a pair are separated from each other.
A diploid animal is dihybrid at the Head shape (H) and Tail length (T) loci. Which of the following gamete genotypes can it produce?
Ht
Why can humans digest starch but not cellulose?
Humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose.
What is the role of hydrogen in the synthesis of "hardened fats" from vegetable oil?
Hydrogen reduces the number of carbon-carbon double bond.
For the following question, match the key event of meiosis with the stages listed below.I.Prophase IV.Prophase IIII.Metaphase IVI.Metaphase IIIII.Anaphase IVII.Anaphase IIIV.Telophase IVIII.Telophase IIHomologous chromosomes are aligned at the middle of the spindle. For the following question, match the key event of meiosis with the stages listed below.I.Prophase IV.Prophase IIII.Metaphase IVI.Metaphase IIIII.Anaphase IVII.Anaphase IIIV.Telophase IVIII.Telophase IIHomologous chromosomes are aligned at the middle of the spindle.
II
Amount of DNA per nucleus over the cell division cycle. This diagram shows two mitosis events. Which numbered regions of the accompanying figure represent the DNA content associated with cells at metaphase?
III only
Which of the following explanations correctly describes a reproductive approach?
In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes.
What is the name of the cytoskeletal element visible in all cells, which duplicates and organizes the spindle during cell divison?
MTOC
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 molecules are produced by transcription?
Messenger RNA Ribozymes
Genomic imprinting is generally due to the addition of methyl (-CH3) groups to cytosine nucleotides to silence a given allele of a gene. If this process depends on the sex of the parent who transmits the gene, which of the following statements must be true?
Methylation must be reversible in ovarian and testicular cells.
What do you call a mutation that converts GUC to AUC?
Missense
Which of the following statements is generally true of aneuploidies in newborns?
Monosomy X is the only viable monosomy known to occur in humans.
Which of the following best describes the redundancy in the genetic code?
More than one codon can specify the addition of the same amino acid.
The figure displays the relationship between initial rate of product formation and reactant concentration in an enzyme-catalyzed reaction with a fixed amount of enzyme. Which of the following statements best explains the shape of the rate curve at high reactant concentration?
Most enzyme molecules are occupied by substrate at high reactant concentrations.
One of two major forms of neurofibromatosis results from inheriting a dominant allele of a gene with affected individuals having phenotypes that range from mild to very severe. Which of the following is the best explanation for why a young child is the first in her family to be diagnosed with a severe form of the condition?
One of the parents has a mild expression of the gene.
If cell Q enters meiosis, and nondisjunction of one chromosome occurs in one of its daughter cells during meiosis II, how will this affect the gametes at the completion of meiosis?
One-quarter of the gametes descended from cell Q will be n + 1, one-quarter will be n - 1, and half will be n.
In animals, what is the difference between reproductive cloning and therapeutic cloning?
Only therapeutic cloning supplies cells for repair of diseased or injured organs.
Which answer correctly compares prokaryotic and eukaryotic codons?
Organisms utilize codons that are nearly universal among all organisms.
Which of the following conditions is required for a target organ to respond to a particular hormone?
The target organ must have receptors that recognize and bind the hormone molecule.
Which of these descriptions of the behavior of chromosomes during meiosis explains Mendel's law of segregation?
The two alleles for each gene separate as homologous chromosomes move apart during anaphase I. Submit
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.
A species of mouse that is preyed on by owls (which can see color) at dawn and dusk varies in coat color between dark and light brown. Under which of the following conditions will NO evolution occur if climate change results in the soil color becoming darker?
There is no variability in the genes that control coat color.
Which of the following describes the function of the pigment molecules in a light-harvesting complex in the thylakoid membranes?
They absorb and transfer light energy, acting like antennae for the light reactions to split water.
Which of the following statements best describes a characteristic of C4 plants?
They are able to fix CO2 in warmer, drier conditions than C3 plants
Which of the following statements best describes a characteristic feature of integral membrane proteins?
They are amphipathic, with at least one hydrophobic region.
The cell walls of bacteria, fungi, and plant cells, and the extracellular matrix of animal cells are all external to the plasma membrane. Which of the following characteristics is common to all of these extracellular structures?
They are constructed of materials that are synthesized in the cytoplasm and then transported out of the cell for assembly.
Which of the following characteristics best support using yeast cells instead of bacterial cells to express mammalian proteins via cloning?
They are eukaryotic cells.
Which of the following statements best describes homologous chromosomes?
They are similar but not identical, carrying alleles of the same genes
Which of the following describes how steroid hormones regulate gene expression?
They bind to intracellular receptors and alter transcription of specific genes.
Which of the following functions are characteristic of general transcription factors in eukaryotes?
They bind to other proteins or to the TATA box.
When a dominant allele coexists with a recessive allele in a heterozygote individual, how do they interact with each other?
They do not interact at all.
Which of the following statements correctly describes a characteristic of tumor-suppressor genes?
They encode proteins that help prevent uncontrolled cell growth.
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 role do phosphatases play in signal transduction pathways?
They inactivate protein kinases to turn off signal transduction.
Which of the following statements best describes steroid receptors?
They may be inside the nucleus of a target cell.
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.
Which of the following describes the role typical proto-oncogenes have when they are expressed in cells that are not cancerous?
They stimulate normal cell growth and division.
Which of the following statements best explains the ability of C4 plants to perform photosynthesis with no apparent photorespiration?
They use PEP carboxylase to initially fix CO2.
A gene on human chromosome 15 is expressed throughout the body. However, in the brain, only the maternal copy of the gene is expressed, whereas the paternal copy of the gene is silent and not transcribed. What accounts for this pattern of expression this gene displays in the brain?
Through genomic imprinting, methylation regulates expression of the paternal copy of the gene in the brain.
Which of the following statements is accurate if we view evolution both as a pattern and a process?
To study evolution as a pattern we draw on information from many other scientific fields, while to study evolution as a process we study factors that cause changes in populations.
According to the data table, the most dangerous food group for coronary health is?
Trans fat
The data can best be used to address which of the following questions?
What is the impact of plowing soil on the number of earthworms?
What does a mutagen cause?
a change in the sequence of DNA
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
When nucleotides polymerize to form a nucleic acid, ________.
a covalent bond forms between the sugar of one nucleotide and the phosphate of a second
Which of the following changes in conditions results in an increase in cAMP receptor protein (CRP) mediated initiation of transcription?
a decrease in glucose and an increase in cAMP
Which of these is currently considered the best definition of a gene?
a gene codes for either a polypeptide or an RNA molecule
Being able to amplify specific DNA fragments is critical our ability to study genes because ________.
a gene may represent only a millionth of the cell's DNA
Which of the following statements best describes a cleavage furrow?
a groove in the plasma membrane between daughter nuclei
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
Which of the following types of mutation would convert a proto-oncogene into an oncogene?
a mutation that greatly increases the amount of the proto-oncogene protein
Which of the following types of mutation would convert a proto-oncogene into an oncogene?
a mutation that greatly increases the amount of the proto-oncogene protein Submit
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely ________.
a plant cell in the process of cytokinesis
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely
a plant cell in the process of cytokinesis.
In DNA technology, the term vector can refer to
a plasmid used to transfer DNA into a living cell.
The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codo
a polypeptide missing an amino acid
A replication error results in a zygote that has inactive telomerase, which of the following characteristics would you expect to see in the organism that develops?
a reduction in chromosome length in gametes
Frederick Griffith heat-killed a culture of pathogenic bacteria. He split the sample and injected half of it into mice. The mice lived. He then mixed the other half with a living, nonpathogenic bacteria strain and injected the mixture into mice. The mice died. These results best support which of the following conclusions.
a substance had been transferred from pathogenic to nonpathogenic bacteria
Which of the following events results in X-inactivation in female mammals?
activation of the XIST gene on the X chromosome that will become the Barr body
Which of the following responses is stimulated by cell signaling the formation of biofilms?
aggregation of bacteria
What types of cells carry out ATP synthesis by chemiosmosis?
all respiring cells, both prokaryotic and eukaryotic, using either oxygen or other electron acceptors
High levels of citric acid inhibit the enzyme phosphofructokinase, a key enzyme in glycolysis. Citric acid binds to the enzyme at a different location than the active site. This is an example of which of the following?
allosteric regulation
Prokaryote's ability to regulate patterns of gene expression most likely promotes the organism's survival by ________.
allowing an organism to adjust to changes in environmental conditions
Using the CRISPR-Cas9 system to correct a genetic defect in a mouse brins with it which of the following risks?
altering non-target mouse genes needed for cell function
Refer to the following figure to answer the questions below.3H2 + N2 ↔ 2NH3Which of the following is true for the above reaction?
ammonia is being formed and decomposed simultaneously
An obstetrician knows that her patient's fetus is at risk for a serious disorder that is detectable biochemically in fetal cells. The obstetrician would most reasonably offer which of the fol
amniocentesis or CVS
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
Which of the following processes will most likely produce a human zygote with 45 chromosomes?
an error during anaphase II while the sperm was produced
In which phase of mitosis do the sister chromatids become daughter chromosomes?
anaphase
A defect in which of the following molecules would dramatically reduce the rate of diffusion of water across cell membranes?
aquaporins
This is a space filling model of the enzyme lysozyme found in your tears and saliva. Tears and saliva are the ______________ for this _______________.
aqueous solvent; protein
The figure shows the structures of glucose and fructose. Which of the following describes a difference between the two molecules?
arrangement of carbon, hydrogen, and oxygen atoms
The figure shows the pedigree of a family. Dark-shaded symbols represent individuals with one of the two major types of colon cancer. Numbers under the symbols are the individual's age at the time of diagnosis. Males are represented by squares, females by circles.
as a dominant trait
Movement of amoebae across a surface requires which of the following activities by components of the cytoskeleton?
assembly of actin filaments to form bulges in the plasma membrane
Many G protein-coupled receptors contain seven transmembrane α-helical domains. If the amino terminus of such a protein is located on the extracellular side of the membrane, where would you expect to find the carboxyl terminus of the protein?
at the cytosolic surface of the plasma membrane
Many G protein-coupled receptors contain seven transmembrane α-helical domains. If the amino terminus of such a protein is located on the extracellular side of the membrane, where would a coupled G protein most likely interact with this receptor?
at the loop between helix 5 and helix 6
miRNAs can control gene expression by what action?
binding to mRNAs and degrading them or blocking their translation
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
How does breakdown of glucose inhibit transcription of the lac operon?
by reducing the levels of intracellular cAMP
Which two functional groups are always found in amino acids?
carboxyl and amino groups
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
In the cells of some organisms, mitosis occurs without cytokinesis. This will result in
cells with more than one nucleus.
The term insoluble fiber on food packages refers to which of the following molecules?
cellulose
Which polysaccharide is an important component in the structure of many animal and fungal cells? Correct!
chitin
Which of the following structures is independent of the endomembrane system in eukaryotic cells?
chloroplast
Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol prevents microtubule depolymerization, which interferes with which of the following processes? This is the drug you experimented with in the lab simulation for mitosis.
chromosome separation
The drug cytochalasin B blocks the polymerization of actin microfilaments. Which of the following events of the cell cycle in animal cells would be most directly disrupted by cytochalasin B?
cleavage furrow formation and cytokinesis
Which of the following responses is stimulated by cell signaling during the formation of biofilms?
clumping and replication of bacteria
Which of the following methods are used by eukaryotes to control gene expression but are not used by bacteria?
control of both RNA splicing and chromatin remodeling
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
Which of the following is a molecule that helps to "turn off" the expression of genes in a cell?
corepressor
The synthesis of ATP by oxidative phosphorylation is an example of which of the following processes?
coupling of an endergonic reaction to an exergonic reaction
Which curves on the graphs most likely represent the temperature and pH profiles of an enzyme taken from a bacterium that lives in a mildly alkaline (basic) hot springs at temperatures of 70°C or higher?
curves 3 and 5
Researchers discovered that carbon fixation in spinach leaves utilizes 45,000 molecules of ATP and 30,000 molecules of NADPH in an hour. The deficit in ATP required for carbon fixation is most directly made up for by which of the following processes?
cyclic electron flow
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
Which of the following factors is a primary contributor underlying cause of familial hypercholesterolemia?
defective LDL receptors on the cell membranes
Which of the following correctly lists the processes in order for one cycle of polymerase chain reaction (PCR)?
denature DNA; anneal primers; extend primers
Catabolism of fatty acids produces two-carbon molecules that are converted to acetyl CoA. The acetyl CoA molecules will most likely be metabolized in aerobic cellular respiration by which of the following mechanisms?
directly entering the citric acid cycl
What is true of covalent bonds which is not true of ionic or hydrogen bonds
electrons are shared between atoms
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
DNA methylation and histone acetylation are examples of which of the following processes?
epigenetic phenomena
Why is ethanol soluble in water (liquid) and starch is not?
ethanol has available -OH groups
A characteristic 9 + 2 arrangement of microtubules, consisting of nine doublet microtubules surrounding a pair of single microtubules describes the ultrastructure of which of the following cellular structures?
eukaryotic flagella and motile cilia
Forms of the Ras protein found in tumors usually cause which of the following events to occur?
excessive cell division
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, ∆G < 0
Muscle cells differ from nerve cells mainly because they
express different genes.
Abnormal chromosomes are frequently found in malignant tumors. Errors such as translocations may place a gene in close proximity to different control regions that could result in which of the following events?
expression of genes that lead to inappropriate cell division
PCR and cellular DNA replication share which of the following characteristics?
extend new strand by adding to 3' OH
PCR and cellular DNA replication share which of the following characteristics?
extend new strand in 5 to 3 direction
Many diploid organisms produce haploid gametes for reproduction. Which of the following best describes how the diploid number of chromosomes is restored in the offspring of these organisms?
fertilization combines chromosomes from each parent into resulting zygote
Hemoglobin, when subjected to 40% acetonitrile at pH 10.0, loses its quaternary structure, which means the ________.
four α and β polypeptides dissociate
A section of DNA has the base sequence shown in #1. A mutation in this DNA strand results in the base sequence shown in #2. What type of mutation does this change represent?#1 5' - AGCGTTACCGT-3'#2 5'-AGGCGTTACCGT-3'
frameshift mutation
In chemiosmosis, the most direct source of energy used to convert ADP + i to ATP is energy released ________.
from movement of protons through ATP synthase, down their electrochemical gradient
Which of the shown carbohydrates is a monosaccharide?
fructose
In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated?
genes involved in control of the cell cycle
Which of the following sequences describes the path by which electrons move from high-energy to lower-energy molecules in aerobic respiration?
glucose → NADH → electron transport chain → oxygen
An amino acid is to a protein as a glucose molecule is to _______.
glycogen
Which of the following metabolic processes normally occurs in most cells regardless of oxygen (O2) availability?
glycolysis
Which of the following metabolic processes take place in the cytosol of a eukaryotic cell?
glycolysis and fermentation
Carbon dioxide (CO2) is readily soluble in water, according to the equation CO2 + H2O ↔ H2CO3. Carbonic acid (H2CO3) is a weak acid. If CO2 is bubbled into a beaker containing pure, freshly distilled water, which of the following graphs correctly describes the results?
going down
Dried, purified lysozyme has no activity. Lysozyme in water must
have many partial positive and partial negative atoms that hydrogen bond to water
Which of the following is a similarity between a mature human sperm and an ovum that has completed meiosis? Both gametes ________.
have the same number of chromosomes
Which of the following is a similarity between a mature human sperm and an ovum that has completed meiosis? Both gametes ________.
have the same number of chromosomes Submit
What element does not react with other elements?
helium
In humans, the hormone testosterone enters cells and binds to specific proteins, which in turn bind to specific sites on the cells' DNA. What is the probable action of these proteins?
help RNA polymerase transcribe certain genes
What kind of bonds are responsible for the unique cohesion, surface tension, and adhesion properties of water molecules?
hydrogen bonding
Which of the following types of bond is broken when water evaporates?
hydrogen bonds
Two amino acids have the carbonyl group, how would you predict they would act with water?
hydrophilic
What effect does phosphorylating a protein have on that protein?
Phosphorylation changes the shape of the protein, most often activating it.
Which of the following statements accurately describes differences between DNA replication in prokaryotes and DNA replication in eukaryotes?
Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many.
If a bacteria contained a mutant aminoacyl-tRNA synthetase that attaches a lysine instead of the normal phenylalanine to tRNAs with the anticodon AAA which of the following would occur?
Proteins in the cell will include lysine instead of phenylalanine at amino acid positions specified by the codon UUU.
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.
Which of the following processes destroys RNA molecules if they have a sequence complementary to an introduced double-stranded RNA?
RNA interference
Which of the following processes occurs as part of transcription?
RNA is synthesized
Which of the following is a reason that the low error rate of DNA replication is important to evolution?
Rare errors are the source of variation.
Which of the following statements about RNA processing is correct?
Ribozymes may function in RNA splicing.
Which of the following cell cycle phases does not have a checkpoint?
S
Which of the following statements is most accurate in comparing scientific theories and scientific hypotheses?
Scientific theories are supported by, and make sense of, many observations, whereas scientific hypotheses are narrow, testable ideas.
The atomic structures of Hydrogen and Oxygen are shown. When water is formed is the first or second shell of oxygen
Second
Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Which of the following statements best represents the connection between reproduction and evolution?
Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.
Which of the following is an ethical question regarding the use of CRISPR-Cas9 gene editing in humans?
Should we be able to select and control the genetic makeup of the human population?
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.
Which answer best describes why does ice float in liquid water?
Stable hydrogen bonds keep water molecules of ice farther apart than water molecules of liquid water.
Which of the following reasons explains why a steam burn is more severe than a hot water burn?
Steam contains more energy than water.
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.
What information is critical to the success of polymerase chain reaction (PCR)?
The DNA sequence of the ends of the DNA to be amplified must be known.
What information is critical to the success of polymerase chain reaction (PCR)?
The DNA sequence that flanks the DNA to be amplified must be known.
Which of the following statements correctly describes a characteristic of genetically engineered plants?
The alterations can be made in a somatic cell then grown into a whole plant with new traits.
Select the most accurate statement describing the basic function of the light reactions of photosynthesis.
The basic function of the light reactions of photosynthesis is the conversion of solar energy to chemical energy. Submit
Which of the following conditions is most likely to result in transcription of the lac operon?
The cAMP and lactose levels are both high within the cell.
What is the best evidence telling you whether this cell is diploid or haploid?
The cell is diploid because it contains two sets of chromosomes.
Which of the following statements regarding gene linkage is correct?
The closer two genes are on a chromosome, the lower the probability that a crossover will occur between them.
Which of the following statements describes a likely effect of a drug that inhibits testosterone binding to its receptor in human cells?
The expression of certain genes would increase or decrease.
For what purpose(s) might a karyotype be prepared?
The first three answers are correct. Submit
When Thomas Hunt Morgan crossed red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies, but all the white-eyed flies were male. Which of these best explains Morgan's result?
The gene involved is located on the X chromosome. Submit
Mendel crossed true breeding yellow-seeded and green-seeded pea plants and then allowed the offspring to self-pollinate to produce an F2 generation. The results were as follows: 6,022 yellow and 2,001 green (8,023 total). Which of the following statements correctly describes the relationship of the allele for green seeds to the allele for yellow seeds?
The green allele is recessive to the yellow allele.
Exposing inner mitochondrial membranes to ultrasonic vibrations will fragment the membranes and pieces will reseal to form small vesicles that contain the intermembrane space. These vesicles can transfer electrons from NADH to oxygen and synthesize ATP. Which of the following statements best describes what will happen to the vesicles when NADH is added?
The inside of the vesicles will become acidic.
If a researcher moves the repressor gene (lacI) and its promoter, to a position at some several thousand base pairs away from its normal position, which of the following describes the most likely effect on the lac operon?
The lac operon will function normally.
Which of the following statements correctly describes the difference between the leading strand and the lagging strand in DNA replication?
The leading strand is synthesized continuously in the 5'- 3' direction, while the lagging strand is synthesized discontinuously in the 5'- 3' direction.
Which of the following statements correctly describes the difference between the leading strand and the lagging strand in DNA replication?
The leading strand is synthesized continuously in the 5'→ 3' direction, while the lagging strand is synthesized discontinuously in the 5'→ 3' direction.
Which of the following statements correctly describes the difference between the leading and the lagging strands of DNA in DNA replication?
The leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction.
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.
Which of the following best describes a biological concern regarding the use of CRISPR-Cas9 gene editing in humans?
The modifications created by the process may result in unintended effects on non-target genes.
Which of the following characteristics of short tandem repeats (STRs) DNA makes it useful for DNA fingerprinting (genetic profiling)?
The number of repeats at a particular STR is inherited following Mendelian genetic patterns.
Which of the following characteristics of short tandem repeats (STRs) DNA makes it useful for DNA fingerprinting (genetic profiling)?
The number of repeats at a particular STR is very likely to be different between 2 people.
Researchers found a strain of bacteria that had mutation rates one hundred times higher than normal. Which of the following statements correctly describes the most likely cause of these results?
The proofreading mechanism of DNA polymerase was not working properly.
Two of the following are diseases of advanced age, where normal proteins are misfolded and do not get destroyed properly. One disease involves the ingestion or health-care associated contamination of a person with a misfolded protein. Which of the protein folding diseases is communicable in this way?
nvCJD
A covalent bond is likely to be polar under which of the following conditions?
one of the atoms sharing electrons is more electronegative than the other atom
In the following structure where A and B represent two different elements, the valency of A is ________ and B is ________.
one; three
If yeast cells of mating type α with normal mating factor receptors are genetically modified to produce only mating factor a, they will mate with which of the following cells?
only with each other
The results from Stanley Miller's 1953 experiments can best be used to support which of the following hypotheses?
organic molecules can be synthesized abiotically under conditions that may have existed on early Earth
The diagram is reminiscent of Darwin's sketch showing the branching of evolution. The horizontal axis of the diagram is a timeline that extends from 100,000 years ago to the present; the vertical axis represents nothing in particular.
origin of new species and extinction
A type of localized signaling in which a cell secretes a signal molecule that affects neighboring cells is best described as which of the following?
paracrine signaling
Which of the following enzymes essentially reverses the reaction catalyzed by adenylyl cyclase?
phosphodiesterase
Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls?
plasmodesmata
A paleontologist has recovered a bit of tissue from the 400-year-old preserved skin of an extinct dodo (a bird). To compare a specific region of the DNA from the sample with DNA from living birds, which of the following would be most useful for increasing the amount of dodo DNA available for testing?
polymerase chain reaction (PCR)
Ovalbumin, the egg white protein is denatured in scrambled egg. Which of the following is not affected?
primary structure of ovalbumin
In which of the following organisms did the process of photosynthesis most likely originate?
prokaryotes
question 9
review
Which of the following structures are found in plant, animal, and bacterial cells?
ribosomes
In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (CRCW) offspring of red (CRCR) and white (CWCW) homozygotes. Which of the following crosses would produce offspring in the ratio of 1 red:2 roan:1 white? red × white
roan × roan
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
Where are human sperm produced?
seminiferous tubules
The mitotic spindle plays a critical role in which of the following processes?
separation of sister chromatids
Which of the following characteristics of DNA allows it to carry a vast amount of hereditary information?
sequence of bases
When a neuron responds to a particular neurotransmitter by opening gated ion channels, the neurotransmitter is serving as which part of the signal pathway?
signal molecule
Which of the following processes occurs in prokaryotes but not in eukaryotes?
simultaneous transcription and translation of the same mRNA
Which of the following phenotypes is an example of polygenic inheritance?
skin pigmentation in humans
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
Choose the cell which is the final result of meiosis in seminiferous tubules.
sperm
Which of the following processes occurs in meiosis but not in mitosis?
synapsis of chromosomes
Which of the following processes would be most directly affected if a thylakoid membrane is punctured so that the interior of the thylakoid is no longer separated from the stroma?
synthesis of ATP
In DNA polymerization, a phosphodiester bond is formed between a phosphate group of the nucleotide being added and which of the following atoms or molecules of the last nucleotide in the polymer?
the 3' OH
What does the DNA methylation mechanism used by eukaryotes do?
inactivate genes
If the DNA of a mammalian promoter region experiences increased methylation on cytosine (C) which of the following results is most likely to occur?
inactivation of the gene
Which of the following molecules binds with a repressor to alter its conformation and therefore affect its function?
inducer
German scientist Carl Correns found that the inheritance of variegated color on the leaves of certain plants was determined only by the maternal parent. Which of the following phenomena best explains this pattern of inheritance?
inheritance of plastid genes
If the proteins of the electron transport chain were labeled with a fluorescent tag, the fluorescence observed by microscopy will be localized to which of the following regions of the mitochondria?
inner membrane
Why is it difficult to observe individual chromosomes with a light microscope during interphase?
interphase chromosomes are long, thin strands unlike the condensed chromosomes visible in mitosis
ATP is necessary for life because ________.
it is the principle energy carrying molecule in a cell
Where does RNA polymerase begin transcribing a gene into mRNA?
it starts after a certain nucleotide sequence called a promoter
Which of the following statements best describes scaffolding proteins?
large molecules to which several relay proteins attach to facilitate cascade effects
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
According to the central dogma, which of the following intermediate molecules correctly completes the flow chart describing the flow of information in a cell blank? DNA - ________ - Proteins
mRNA
Clogging 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? You Answered
mRNA
Which of the following molecules directly participates in the process of translation?
mRNA, tRNA, and rRNA
Males are more often affected by X-linked traits than are females because ________.
males are hemizygous genes on the X chromosomes
Which of the following lists represents the order of increasingly higher levels of organization of chromatin?
nucleosome, 30-nm chromatin fiber, condensed and compressed chromosome
Which of the following is the correct order of organization of genetic material from smallest to largest?
nucleotide, gene, chromosome, genome
As letters are to English language, ________ is/are to genetic information.
nucleotides
Independent assortment of chromosomes is a result of which of the following processes?
the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I
Histone proteins contain internal cores that are hydrophobic and surface amino acids that are positively charged. Which of the following characteristics of DNA would best support tight binding between DNA and histones?
the ring structures in DNA bases that disperse charge promote hydrophobic interactions with histone cores
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
Why do some species employ both mitosis and meiosis, whereas other species use only mitosis?
they need both if they are reproducing sexually
Which of the following is true of benign tumors, but not malignant tumors?
they remain confined to their original site
A codon consists of __________ bases and specifies which __________ will be inserted into the polypeptide chain.
three, amino acid
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
For which of the following processes can dideoxyribonucleotides be used?
to sequence a DNA fragment
In cats, an X-linked locus is responsible for fur color. There are two known alleles at this locus. One results in black fur color; the other results in orange fur color. A heterozygote animal has patches of orange and black fur (tortoiseshell). Which coat color phenotypes are expected from the cross of a black female and an orange male?
tortoiseshell females; black males
Transcription in eukaryotes requires which of the following molecules in addition to RNA polymerase?
transcription factors
Gene expression is often assayed by measuring the level of mRNA produced from a gene. Which of the following levels of the control of gene expression can by analyzed by this type of assay?
transcriptional control
The cloning of Dolly the sheep is an example of which of the following processes?
transfer of an adult cell's nucleus into an enucleated sheep egg, followed by incubation in a surrogate
The chromosomal alteration that results from a chromosome fragment joined to a nonhomologous chromosome is called a ________.
translocation
Male sex determination in mammals is in large part due to the SRY gene found on the Y chromosome. Which of the following scenarios will result in a person with an XX karyotype developing a male phenotype?
translocation of SRY to an X chromosome during gamete formation
Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm?
two
Oogenesis is much more complicated than spermatogenesis. Which thing that is true for female gamete making and not males?
unequal division of the cytoplasm in meiosis I and meiosis II
Catalase is an enzyme that functions in human liver cells where the pH is approximately neutral. Which of the following graphs best reflects the activity profile of catalase from pH 5 to pH 9?
up then. down
Why is the lac operon said to be an inducible operon?
when allolactose is present, it induces the inactivation of the lac repressor
Under what conditions does the trp repressor block transcription of the trp operon?
when the repressor binds to tryptophan
The following question refers to the figure of a family's pedigree chart, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle. What is the genotype of individual II-5?
ww
Match to vocabulary words to their definition. These words are apply to splicing foreign DNA into a plasmid and inserting the plasmid into a bacterium I.Transform bacteria with a recombinant DNA molecule. II.Cut the plasmid DNA using restriction enzymes (endonucleases). III.Extract plasmid DNA from bacterial cells. IV.Hydrogen-bond the plasmid DNA to non-plasmid DNA fragments. V.Use ligase to seal plasmid DNA to non-plasmid DNA.
- cut the plasmid and non plasmid -use a restriction enzyme to recognize and cleave dsDNA -ligate- allow matching -purify DNA -separate plasmids from bacterial cell fragments, and another source -Transform-convince bacteria to take up DNA from the environment
Which statement(s) about repressible operons is/are correct?
-Repressible operons usually contain genes that code for anabolic enzymes. -A repressible operon is on unless a corepressor is present.
A protein kinase is an enzyme that functions in which of the following ways?
-by adding a phosphate group to activate or inactivate other proteins -becoming active after dimerization of RTKs
After DNA replication, each duplicated chromosome consists of two of which of the following structures?
-sister chromatids -centromeres
How is translation initiated?
-the small ribosomal subunit binds to the mRNA -the tRNA bearing methionine binds to the start codon -the start codon signals the start of translation -the large ribosomal subunit binds to the small one -*All of the listed answers are correct.*
Which of the four amino acids has a single methyl group sidechain?
Alanine
Which of the following statements best describes the relationship between autotrophs and heterotrophs?
Autotrophs produce their organic molecules from CO2 and other inorganic molecules, whereas heterotrophs obtain their organic molecules from compounds produced by other organisms.
In human blood types, Rh positive is a trait that shows simple dominance over Rh negative. The Rh phenotype is recorded by stating "positive" or "negative" after the individuals ABO blood type. A woman who has blood type A positive has a daughter who is type O positive and a son who is type B negative. Which of the following phenotypes is possible for the father?
B positive
Which of the following pairs of organism groups consist solely of prokaryotic cells?
Bacteria and Archaea
When attempting to introduce a particular fragment of DNA into the genome of an animal cell which of the following methods would be most successful?
CRISPR/Cas9 recombinatio
Which of the following unique feature of carbon allows it to support life on Earth?
Carbon can form a variety of bonds in nature.
A typical eukaryotic cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen to an individual when they exhaust their ATP supply?
Catabolic processes will be activated to generate additional ATP.
One type of eukaryotic cell (cell line 1) spends 24 minutes in S phase and another type of cell (cell line 2) spends 48 minutes in S phase. Which of the following statements is the best explanation for the difference in time spent in S phase by cell lines 1 and 2?
Cell line 2 contains more DNA than cell line 1
In which of the following ways do the membranes of a eukaryotic cell vary?
Certain proteins are unique to each membrane.
Exposure to the UV radiation in sunlight causes DNA changes in skin cells. Why are these changes more harmful when they occur in an individual with xeroderma pigmentosum (XP) than in an individual who does not have this disorder?
Compared to XP individuals, non-XP individuals have more effective nucleotide excision repair enzymes.
Which of the following results when homologous chromosomes cross over in meiosis?
Corresponding segments of non-sister chromatids are exchanged.
Which molecule shown above contains a functional group that is a part of the principal molecule that stores and transfers energy in cells?
D
Radioactive thymine is added to media containing one actively dividing E. coli bacterium. Which of the following outcomes would be seen after a single cell division?
DNA in both daughter cells would be radioactive.
The "flow of genetic information" in molecular biology follows the following path, ________.
DNA is transcribed into RNA, which is translated into protein
Which of the following statements best describes the mechanism by which testosterone or PPAR Gamma functions inside a cell?
It binds with a receptor protein that enters the nucleus and activates expression of specific genes.
Which of the following processes correctly describes alternative RNA splicing?
It can allow the production of proteins of different sizes and functions from a single mRNA.
Which of the following characteristics of Taq polymerase make it useful in the PCR process? Correct!
It is heat stable and can withstand the heating step of PCR.
Marfan syndrome in humans is caused by an abnormality of the connective tissue protein fibrillin. Patients are usually very tall and thin, with long spindly fingers, curvature of the spine, sometimes weakened arterial walls, and sometimes eye problems, such as lens dislocation. Which of the following would you conclude about Marfan syndrome from this information?
It is pleiotropic.
In a Drosophila experiment, a homozygous wild-type female was crossed with a yellow-bodied male. All of the resulting F1 flies were phenotypically wild type. Crossing the F1 flies resulted in F2 flies having the characteristics shown in the figure. Which of the following statements best
It is recessive.
Folk singer Woody Guthrie died of Huntington's disease, an autosomal dominant disorder. Which statement below must be true? See Concept 14.4 (Page)
It is very likely that at least one of Woody Guthrie's parents also had the allele for Huntington's disease.
What is the role of DNA ligase in DNA replication?
It joins Okazaki fragments together.
Which of the following statements best describes the accompanying figure?
It represents a C4 photosynthetic system
The average length of a transcription unit along a eukaryotic DNA molecule is about 27,000 nucleotide pairs, whereas an averaged-sized protein is about 400 amino acids long. What is the best explanation for this fact?
Most eukaryotic genes and their RNA transcripts have long noncoding stretches of nucleotides that are not translated. Submit
Which of the following statements best describes some aspect of cytoskeleton structure or function in eukaryotic cells?
Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
Which of the following products result from the oxidation of pyruvate to acetyl-CoA?
NADH and CO2
Multiple cells from the same species were isolated, the relative cohesion protein content for each type was determined, and the results were plotted on the graph. Refer to the graph to answer the following question.
NOT. I
Which of the following molecules would likely diffuse through the lipid bilayer of a plasma membrane most rapidly?
O2
The table represents the results of an experiment where the effects of pH buffers on an enzyme found in saliva (amylase) were studied. A spectrophotometer set at 500 nm was used to measure absorbance at the various pH levels every 20 seconds for 2 minutes. The higher absorbance values would indicate greater enzyme activity. All experiments were conducted at the same temperature.Which statement correctly identifies the result that the optimum pH for amylase function is 7?
The pH with the highest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
What does it mean to say that a signal is transduced?
The physical form of the signal changes as it passes from the cell membrane to the ultimate intracellular target.
Which of the following statements describes the interaction of water molecules with phospholipids?
The polar heads interact with water; the nonpolar tails do not.
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.
Which of the following is the most likely effect on the rates of ATP and CO2 production if yeast cells growing in minimal medium lacking glucose are provided with supplemental acetyl-CoA?
The rates of ATP production and carbon dioxide production would both increase.
What would be observed by live-cell fluorescence microscopy immediately after HIV entry if HIV enters the cell by endocytosis first, and then later fuses with the endocytotic vesicle membrane?
The red fluorescent dye-labeled lipids will appear in the infected cell's interior.
Which of the following processes occurs in the Calvin cycle?
Which of the following processes occurs in the Calvin cycle?
For which of the following is the number the same in human males and females?
meiotic divisions required to produce each game
For which of the following is the number the same in human males and females?
meiotic divisions required to produce each gamete Submit
The voltage across a membrane is called the ________.
membrane potential
During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell?
metaphase I of meiosis
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
The pedigree in the figure shows the transmission of a trait in a particular family. Based on this pattern of transmission, the trait is most likely ________.
mitochondrial
Assume that it is possible to label each of the molecules below with 18O a heavy isotope of oxygen. As a result of cellular respiration, water containing 18O would most quickly be detected if cells are provided with which one of the following molecules labeled with 18O?
molecular oxygen (O2)
Researchers investigating the mechanism of vesicle transport assembled a cell-free system that included microtubules, vesicles, and ATP. However, they observed no movement of transport of vesicles because the mixture was missing which of the following components?
motor proteins
If a pair of homologous chromosomes fails to separate during meiosis I, select the choice that shows the chromosome number of the four resulting gametes with respect to the normal haploid number (n)?
n + 1; n + 1; n - 1; n - 1
Which of these provides evidence of the common ancestry of all life?
near universality of the genetic code
The PPAR gamma control element, or the control sequences for any gene's transcription are found in
noncoding DNA
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
Which of the following statements correctly describes the property of hydrophobic substances such as vegetable oil?
nonpolar substances that repel water molecules
Which of the following processes has just occurred when chiasmata can first be viewed under a microscope?
prophase I
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?
proteins
What two types of genes regulate the cell cycle either causing cell divison or stopping it?
proto-oncogenes; tumor suppressor genes
Which of the following occurs in binary fission but not in mitosis with cytokinesis?
question 7
Which of the following processes is directly associated with photosystem I?
receiving electrons from the thylakoid membrane electron transport chain
Which of the following signal transduction proteins typically functions by forming dimers after binding to a signal molecule?
receptor tyrosine kinases
When electrons are passed from one atom to a more electronegative atom, the more electronegative atom is ________.
reduced, and energy is released
A person on a strict diet and exercise regimen lost 7 kg (about 15 pounds) of body fat in just two weeks. In which of the following forms did the lost fat most likely leave the body?
released as CO2 and H2O
Which of the following events would be most likely to produce cells with several nuclei?
repeated mitosis without cytokinesis
Which of the following molecules is a protein produced by a regulatory gene?
repressor
In a healthy eukaryotic cell, the rate of DNA repair is typically equal to the rate of DNA mutation. Which of the following is most likely to result if the rate of repair lags behind the rate of mutation?
the cell can be transformed into a cancerous cell
Which of the following reactions produces the majority of the CO2 released by the complete oxidation of glucose?
the citric acid cycle
When a cell is deprived of oxygen, which of the following processes will be inhibited first?
the electron transport chain
The partial negative charge in a molecule of water occurs because ________.
the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus
What are telomeres?
the ends of linear chromosomes
Which of the following events takes place in the electron transport chain?
the harnessing of energy from redox reactions to generate a proton gradient
In a plant, which of the following reactions produces molecular oxygen (O2)?
the light reactions alone
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