TAMU Bio 111-Final Review-KEMP
How many electrons pairs does carbon share to fill its valence shell
A 2 B 4 C 8 D 1 E 3
About 25 of the 92 natural elements are known to be essential . Which of these make up 96% of living matter?
A C, Na, H, N B C, O, P, H C C O N Ca D C H N O E O H Ca N
Thylakoids, DNA and ribosomes are all components found in
A chloroplasts B vacuoles C mitochondria D nuclei E lysosomes
Research indicates that ibuprofen, a drug used to relieve inflmmation and pain, is a mixture of two entatiomers; that is molecules that
A differ in the location of their double bonds B exist in either linear chain or ring forms C have identical chemical formulas but differ in the branching of their carbon skeletons D differ in the arrangements of atoms around their double bonds E are mirror images of one another
Which of these molecules is not formed by dehydration reactions
A disacchardies B DNA C amylose D fatty acids E protein
Which type of bond must be broken for water to vaporize
A hydrogen bonds B both hydrogen bonds and ionic bonds C both polar covalent bonds and h bonds D polar covalent bonds E ionic bonds
Why does ice float in liquid water?
A ice always has air bubbles that keep it afloat B the ionic bonds between the molecule in ice prevent the ice from sinking C the crystalline lattice of ice causes it to be denser than liquid water D hydrogen bonds stabilize and keep the molecules of ice farther apart than the water E the high surface tension of liquid water keeps the ice on top
Which organelle is the primary site of ATP synthesis in EUK cells?
A mitochondria B peroxisome C lysosome D Golgi apparatus E vacuole
What aspects of protein structure are stabilized or assisted by H bonds?
A primary B tertiary C secondary D secondary tertiary and quaternary E quaternary
The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in this process and therefore abundant in liver cells?
A rough ER B nuclear envelope C transport vesicles D smooth ER E Golgi apparatus
If a salamander relied on H bonds to cling to surfaces what type of surface would cause the most problems for this animal
A surface coated with a thin film of water B a surface made with carbon, H, N and O covalently bonded together C a surface made with silicon and oxygen atoms covalently bonded together D surface made with C, H and O covalently bonded E. surgace made with C and H atoms covalently bonded together
Which of the following statements correctly describes cis-trans isomers?
A they have variations in arrangement around a double bond B their atoms and bonds are arranged in different sequences C they have an asymmetric caron that makes them mirror images D they have diff molecular formulas E they have same chemical properties
Which of these provides evidence of the common ancestry of all life>
A ubiquitous use of catalysts by living systems B structure of chloroplast C structure of nucleus D near universality of genetic code E structure of cilia
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by
A van der waals interactions B hydrogen bonds C ionic bonds D nonpolar covalent bonds E polar covalent bonds
How many molecules of water are needed to completely hydrolyze a polymer that is 11 monomers long?
A. 12 B. 10 C 8 D 11 E 9
A particular triplet of bases in the template strand of DNA is 5` AGT 3`. The corresponding codon for the mRNA transcribed is
A. 3`UGA 5` B. 3` ACU 5` C. 3` UCA 5` D. 5` TCA 3` E. either UCA or TCA
An atom has 6 electrons in its outer shell. How many unpaired electrons does it have?
A. 6 B. 2 C. 2 or 4 D. 4 E. 0
Black fur in mice (B) is dominant to brown fur (b). Short tails (T) are dominant to long tails (t). What fraction of the progeny of crosses BbTtxBBtt will be expected to have black fur and long tails?
A. 9/16 B. 1/16 C. 3/8 D. 1/2 E. 3/16
Which of the following is true of a species that has a chromosome number of 2n=16?
A. A gamete from this species has four chromosomes B. The species is diploid with 32 chromosomes per cell C. Each cell has 8 homologous pairs D. The species has 16 sets of chromosomes per cell E. During the S phase of the cell cycle there will be 32 separate chromosomes
Which of the following is characteristic of the lytic cycle?
A. A large number of phages are released at a time B. Many bacterial cells containing viral DNA are produced C. the virus-host relationship usually lasts for generations D. viral DA is incorporated into the host genome E. the viral genome replicates w/out destroying the host
In an analysis of the nucleotide composition of DNA, which of the following will be found?
A. A+C=G+T B. A=C C. G+C=A+T D. A=G and C=T
Which of the follwoing are products of the ligth reactions of photosynthesis that are utilized in the Calvin cycle?
A. ADP, P and NADP B. CO2 and glucose C. ATP and NADPH D. H2O and O2 E. electrons and H+
The difference between ATP and the nucleoside triphosphates used during DNA synthesis is that
A. ATP contains three high energy bonds the nucleoside triphosphates have two B. the nucleoside triphosphates have the sugar deoxyribose and ATP has sugar ribose C. ATP is found only in human cells the nucleoside TP are found in animal and plant cell D. TP monomers are active in the nucleoside TP but not in ATP E. the NT have two phosphate groups; ATP has three
Figure 9.3 Which of the following most accurately describes what is happening along the electron transport chain?
A. ATP is generated at each step B. Chemiosmosis is coupled with electron transfer C. each electron carrier alternates between being reduced and being oxidized D. molecules in the chain give up some of their potential energy E. energy of the electrons increases at each step
Figure 10.2 If ATP used by this plant is labeled with radioactive phosphorus, which molecule or molecules of the Calvin cycle will be radioactively labeled first?
A. B and E B. B, C and D C. B, C, D and E D. B only E. B and C only
Viruses with single-stranded RNA that acts as a template for DNA synthesis are known as
A. Bacteriophages B. Retroviruses C. Lytic phages D. Proviruses E. Viroids
What is meant by the description "antiparallel" regarding the strands that make up DNA?
A. Base pairings create unequal spacing between the two DNA strands B. One strand contains only purines and the other contains only pyrimidines C. The 5`to3` direction of one strand runs counter to the 5`to 3` direction of the other strand D. one strand is positively charged and the other is negatively charged E. The twisting nature of DNA creates nonparallel strands
Eukaryotic telomeres replicate differently than the rest of the chromosome. This is a consequence of which of the following?
A. DNA polymerase that cannot replicate the leading strand template to its 5` end B. gaps left at the 5` end of the lagging strand C. the evolution of telomerase enzyme D. the "no ends" of a circular chromosome E. gaps left at the 3` end of the lagging strand bc of the need for a primer
What was the most significant conclusion that Gregor Mendel drew from his experiments with pea plants?
A. Genes are composed of DNA B. Recessive genes occur more frequently in the F1 generation than do dominant ones C. There is considerable genetic variation in garden peas D. Traits are inherited in discrete units, and are not the results of "blending" E. An organism that is homozygous for many recessive traits is at a disadvantage
If nondisjunction occurs in meiosis II during gemetogenesis, what will be the result at the completion of meiosis?
A. Half of the gametes will be n+1 and half will be n-1 B. there will be three extra gametes C. 2 of the 4 gametes will be haploid, the other 2 diploid D. All gametes will be diploid E. 1/4-n+1; 1/2-n; 1/4 n-1
A sexually reproducing animal has two unlinked genes, one for head shape (H) and one for tail length (T). Its genotype is HhTt. Which of the following genotypes is possible in a gamete from this organism>
A. Hh B. tt C. T D. HhTt E. HT
What kinds of molecules pass through a cell membrane most easily?
A. Ionic B. Monosaccharides such as glucose C. Small hydrophobic D. Large and Hydrophobic E. Large polar
Living organisms increase in complexity as they grow, resulting in a decrease in the entropy of an organism. How does this relate to the second law of thermodynamics?
A. Living organisms do not obey the second law of thermodynamics, which states that entropy must increase with time B. Living organisms are able to transform energy into entropy C. Living organisms do not follow the laws of thermodynamics D. As a consequence of growing, organisms cause a greater increase in entropy in their environment than the decrease in entropy associated with their growth E. Life obeys the second law of thermodynamics bc the decrease in entropy as the organism grows is exactly balanced by an increase in the entropy of the universe
Virulent phages unergo an _______ life cycle, whereas temperate phages are capable of undergoing a(n)________ cycle
A. Lytic; lysogenic B. infective; retroviral C. infective, benign D. lysogenic; lytic E. retroviral; infective
Why did the F1 offspring of Mendel's classic pea cross always look like one of the two parental varieties?
A. No genes interacted to produce the parental phenotype B. Different genes interacted to produce the parental phenotype C. One phenotype was completely dominant over another D. Each allele affected phenotypic expression E. The traits blended together during fertilization
The fact that all seven of the pea plant traits studied by Mendel obeyed the principle of independent assortment most probably indicates which of the following?
A. None of the traits obeyed the law of segregation B. The formation of gametes in plants occurs by mitosis only C. all of the genes controlling the traits behaved as if they were on different chromosomes D. all of the genes controlling the traits were located on the same chromosome E. The diploid number of chromosomes in the pea plants was 7
What are the products of linear photophosphorylation?
A. P700 and P680 B. ATP and NADPH C. heat and fluorescence D. ATP and P700 E. ADP and NADP
Proto-oncogenes can change into oncogenes that cause cancer. Which of the following best explains the presence of these potential time bombs in eukaryotic cells?
A. PO first arose from viral infections B. PO normally help regulate cell division C. PO are genetic "junk" D. PO are mutant versions of normal genes E. Cells produce PO as they age
Which of the following is most similar in structure to ATP?
A. Pentose sugar B. Phospholipid C. a DNA nucleotide D. a RNA nucleotide E. An amino acid with 3 phosphate groups attached
Viral envelopes contain proteins with covalently attached cars groups called
A. Peptidocarbs B. Proteosugars C. Carboproteins D. Glycoproteins E. Carbopeptides
Which of the following is true of integral membrane proteins?
A. They lack tertiary structure B. They are loosely bound to the surface of the bilayer C. They are usually transmembrane proteins D. They sere only a structural role in membranes E. They are not mobile within the bilayer
The golgi appartus has a polarity of sidedness to its structure and function. Which of the following statements correctly describes this polarity?
A. Transport vesicles fuse with one side of the Golgi and leave from the opposite side B. Soluble proteins in the cisternae (interior) of the Golgi may be sorted an modified as they move from one side of the Golgi to the other C. Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the golgi to the other D. proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other E. All of the above
In glycolysis, for each molecule of glucose oxidized to pyruvate
A. Two ATP used and Six ATP produced B. Two ATP used and four ATP produced C. Six of ATP are used and Six ATP produced D. Two are used and Two are produced E. Four are used an two are produced
Which of the following is least related to the others?
A. Ubiquitin B. Protein degradation C. Tumor suppression D. Cyclins E. Proteasomes
Viruses are referred to as obligate parasites bc
A. Viral DNA alwyas inserts itself into host DNA B. They can incorporate nucleic acids from other viruses C. They cannot reproduce outside of a host cells D. They must use enzymes encoded by the virus itself E. They invariably kill any cell they infect
Males are more often affected by sex-linked traits than females bc
A. X chromosomes in males generally have more mutations than X chromosomes in females B. males are hemizygous for X chromosome C. female hormones such as estrogen often compensate for the effects of mutations on the X chromosome D. mutations on the Y chromosome often worsen the effects of X linked mutations E. Male hormones such as testosterone often alter the effects of mutations on the X chromosome
Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. What are the genotypes of the parents?
A. XCXc and XCY B. XcXc and XCY C. XCXC and XcY D. XCXC and XCY E. XcXc and XcY
Which of the following is most likely to have a small protein called ubiquitin attached to it?
A. a cyclin that usually acts in G1, now that the cell is in G2 B. a cell surface protein that requires transport from the ER C. an mRNA that is leaving the nucleus to be translated D. a regulatory protein that requires sugar residues to be attached E. an mRNA produced by an egg cell that will be retained until after fertilization
SRY is best described in which of the following ways?
A. a gene present on the X chromosome that triggers female development B. a gene required for development and males or females lacking the gene do not survive past early childhood C. an autosomal gene that is required for the expression of genes on the X chromosomes D. a gene region present on the Y chromo that triggers male deveplopment E. an autosomal gene that is required for the expression of genes on the Y chormosome
Which of the following is true for all exergonic reactions?
A. a net input of energy from the surroundings is required for the reactions to proceed B. the reaction proceeds with a net release of free energy C. the reactions are rapid D. the products have more total energy than the reactants E. the reaction goes only in a forward direction: all reactants will be converted to products, but no products will be converted to reactants
Testosterone functions inside a cell by
A. acting as a signal receptor that activates tyrosine kinases B. Acting as a steroid signal receptor that activates ion channel proteins C. binding with a receptor protein that enters the nucleus and activates specific genes D. Becoming a second messenger that inhibits adenylyl cyclase E. coordination a phosphorylation cascade that increases spermatogenesis
During DNA replication,
A. all methylation of the DNA is lost at the first round of replication B. DNA polymerase is blocked by methyl groups and methylated regions of the genome are therefore left uncopied C. methylation of the DNA is maintained bc methylation enzymes act at DNA sites where one strand is already methylated and thus correctly methylates daughter strands after replication D. methylation of the DNA is maintained bc DNA polymerase directly incorporates methylated nucleotides into the new strand opposite any methylated nucleotides in the template E. methylated DNA is copied in the cytoplasm, and unmethylated DNA in the nucleus
A human cell containing 22 autosomes and a Y chromosome is
A. an egg B. a somatic cell of a male C. a zygote D. a somatic cell of a female E. a sperm
What is a ribozyme?
A. an enzyme that synthesizes RNA as part of the transcription process B. an enzyme that catalyzes the association between the large and small ribosomal subunits C. an enzyme that uses RNA as a substrate D. an enzyme that synthesizes RNA primers during DNA replication E. an RNA with enzymatic activity
Which of the following is the smallest closed system?
A. an organism B. an ecosystem C. Earth D. a cell E. the universe
At which phase are centrioles beginning to move apart in animal cells?
A. anaphase B. metaphase C. prometaphase D. prophase E. telophase
Tumor suppressor genes
A. are frequently overexpressed in cancerous cells B. can encode proteins that promote DNA repair or cell-cell adhesion C. often encode proteins that stimulate the cell cycle D. are cancer causing genes introduced into cells by viruses E. All of the above
One difference between cancer cells and normal cells is that cancer cells
A. cannot function properly bc they are affected by density-deendent inhibition B. are arrested at the S phase of the cell cycle C. continue to divide even when they are tightly packed together D. are always in the M phase of the cell cycle E. are unable to synthesize DNA
Which two functional groups are always found in amino acids
A. carbonyl and amino B. amino and sulfhydrxl C. hydroxyl and carboxyl D. carboxyl and amino E. ketone and methyl
Motor proteins provide for molecular motion in cells by interacting with that types of cellular structures?
A. cellulose fibers in the cell wall B membrane proteins C ribosomes D sites of energy production in cellular repiration E cytoskeletal structures
Which of the following occurs in meiosis but not mitosis?
A. chromosome replication B. production of daughter cells C. synapsis of chromosomes D. condensation of chromatin E. alignment of chromosomes at the equator
Organisms interact with their environments, exchanging matter and energy. For example, plant chloroplasts convert the energy of sunlight into
A. co2 and water B the energy of motion C potential energy of chemical bonds D oxygen E kinetic energy
A carbon atom is most likely to form what kind of bond(s) with other atoms?
A. covalent B. covalent bonds and hydrogen bonds C. ionic bonds, covalent and hydrogen D. ionic E. hydrogen
Where are the proteins of the ETC located?
A. cytosol B. mitochondrial matrix C. mitochondiral intermembrane space D. mitochondrial outer membrane E. mitochondrial inner membrane
Where does glycolysis take place in eukaryotic cells?
A. cytosol B. mitochondrial matrix C. mitochondrial outer membrane D. mitochondrial inter-membrane space E. mitochondrial inner membrane
A cell that remains entirely flexible in its developmental possibilities is said to be
A. determined B differentiated C. totipotent D. Epigenetic E. genomically equivalent
The ATP made during glycolysis is generated by
A. electron transport B. oxidatioin of NDAH to NAD C. photophosphorylation D. substrate-level phosphorylation E. chemiosmosis
Which of the following is a statement of the first law of thermodynamics?
A. energy cannot be created or destroyed B. the entropy of the universe is decreasing C. the entropy of the universe is constant D. kinetic energy is stored energy that results from the specific arrangement of matter E. energy cannot be transferred or transformed
Muscle cells differ from nerve cells mainly because they
A. express different genes B. contain different genes C. use different genetic codes D. have unique ribosomes E. have different chromosomes
During aerobic respiration, electrons travel downhill in which sequence?
A. food-citric acid cycle-ATP-NAD+ B. glucose-ATP-ETC-NADH C. food-glycolysis-citric acid cycle-NADH-ATP D. food-NADH-ETC-Oxygen E. glucose-pyruvate-ATP-Oxygen
What does the chemiosmotic process in chloroplasts involve?
A. formation of glucose, using CO2, NADPH and ATP B. establishment of a proton gradient across the thylakoid membrane C. diffusion of electrons through the thylakoid membrane D. movement of water by osmosis into the thylakoid space from the stroma E. reduction of water to produce ATP energy
Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
A. gap junctions B. peroxisomes C. tight junctions D. extracellular matrix E. desmosomes
Genomic imprinting, DNA methylation and histone acetylation are all examples of
A. genetic mutation B. chromosomal rearrangements C. karyotypes D. epigenetic phenomena E. translocation
Hydrolytic enzymes must be segreagated and packed to prevent general destruction of cellula components. Which of the following organelles contains these hydrolytic enzymes in animal cells?
A. glyoxysome B lysosome C chloroplast D peroxisome E central vacuole
If you were to observe the activity of methylated DNA, you would expect to
A. have turned off or slowed down the process of transcription B. be very active in translation C. induce protein synthesis by not allowing repressors to bind to it D. Be replicating E. Be unwinding in prep for protein synthesis
Which enzyme catalyzes the elongation of a DNA strand in the 5`-3` direction?
A. helicase B. primase C. DNA ligase D. DNA polymerase III E. topisomerase
Eukaryotic cells can control gene expression by which of the following mechanisms?
A. histone acetylation of nucleosomes B. DNA acetylation C. RNA induced modification of chromatin structure D. repression of operons E. Induction of operators in the promoter
When a molecule of NAD gains a hydrogen atom (not a proton) the molecule becomes
A. hydrolyzed B. dehyrogenated C. redoxed D. oxidized E. reduced
In order for a protein to be an integral membrane protein it would have to be
A. hydrophilic B. exposed on only one surface of the membrane C. completely covered with phospholipids D. hydrophobic E. amphipathic, with at least one hydrophobic region
Which of the following is a true statement about sexual vs asexual reproduction?
A. in asexual reproduction, offspring are produced by fertilization without meiosis B. Sexual reproduction requires that parents be diploid C. Asexual reproduction but not sexual reproduction is characteristic of plants of fungi D. Asexual reproduction produces only haploid offspring E. In sexual reproduction, individuals transmit 50% of their genes to each of their offspring
Alternative RNA splicing
A. increases the rate o transcription B. is due to the presence or absence of particular snRNPs C. is a mechanism for increasing the rate of transcription D. can allow the production of similar proteins from different RNAs E. can allow the production of proteins of different sizes from a single mRNA
What would occur if the repressor of an inucible operon were mutated so it could not bind to the operator?
A. irreversible binding of the repressor to the promoter B. reduced transcription of the operon's genes C. buildup of a substrate for the pathway controlled by the operon D. continuous transcription of the operons genes E. overproduction of catabolite activator protein (CAP)
Absence of bicoid mRNA from a Drosophilia egg leads to the absence of anterior larval body parts and mirror image duplication of posterior parts. This is evidence that the product of the bicoid gene
A. is transcribed in the early embryo B. normally leads to formation of tail structures C. normally leads to formation of head structures D. is a protein present in all head structures E. leads to programmed cell death
What is the function of the release factor?
A. it separates tRNA in the A site fro the growing polypeptide B. it binds to the stop codon in the A site in lace of a tRNA C. it supplies a source of energy for termination of translation D. Releases the ribosome from the ER to allow polypeptides into the cytosol E. It releases the amino acid fro its tRNA to allow the amino acid to form a peptide bond
Which of the following is true for the signaling system in an animal cell that lacks the ability to produce GTP?
A. it would employ a transducion pathway directly from an external messenger B. it would be able to carry out reception and transuction but would not be able to respond to a signal C. it would use ATP instead of GTP to activate and inactivate the G protein on the cytoplasmic sid eof the plasma membrane D. It would not be able to activate and inactivate the G protein on the cytoplasmic side of the plasma membrane E. It could activate only the epinephrine system
Which of the following might result in a human zygote with 45 chromosomes?
A. lack of chiasmata in prophase I B. fertilization of a 23 chromosome human egg by a 22 chromosome sperm of a closely related species C. an error in either egg of sperm meiotic anaphase D. failure of the egg nucleus to be fertilized by the sperm E. an error in the alignment of chromosomes on the metaphase plate
Which of the following intermediary metabolites enters the citric acid cycle and is formed, in part, by the removal of a carbon (CO2) from one molecule of pyruvate?
A. lactate B. citrate C. oxaloactate D. acetyl CoA E. glyceraldehydes-3-phosphate
What are scaffolding proteins?
A. ladderlike proteins that allow receptor-ligand complexes to climb trough cells from one position to another B. microtubular protein arrays that allow lipid-soluble hormones to get from teh cell membrane to the nuclear pores C. large molecules to which several relay proteins attach to facilitate cascade effects D. relay proteins that orient receptors and their ligands in appropriate directions to facilitate their complexing E. proteins tat an reach into the nucleus of a cell to affect transcription
At which phase(s) is it preferable to obtain chromosomes to prepare a karyotype?
A. late telophase B. anaphase C. late prophase or metaphase D. early prophase E. late anaphase or early telophase
In a human karyotype, chromosomes are arranges in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common?
A. length, cenromere position, staiing pattern and DNA sequences B. Length and position of the centromere only C. They have nothing in common except X shape D. Length, centromere position, and staining pattern only E. Length, centromere position, staining pattern, and traits coded for by their genes
Which of the following is an example of potential rather than kinetic energy?
A. light flashes emitted by firefly B. the flight of an insect foraging for food C. muscle contractions of a person mowing grass D. water rushing over Niagara Falls E. a molecule of glucose
Large numbers of ribosomes are present in cells that specialize in producting which of the following molecules>
A. lipids B nucleic acids C glycogen D cellulose E proteins
Which type of organelle or structure is primarily involved in the synthesis of oils, phospholipids and steroids?
A. lysosome B. contractil vacuole C. ribosome D. smooth ER E. mitochondria
Which plant cell organelle contains its own DNA and ribosomes
A. mitochondria B. glyoxysome C. peroxismoe D. golgi apparatus E. vacuole
Which of the following are involved in embryonic development
A. morphogenesis B. cell differentiation C. cell division D, A and B only E. A, B and C
Which of the following statements about the DNA in one of your brain cells is true?
A. most of the DNA codes for protein B. the majority of genes are likely to be transcribed C. each gene lies immediately adjacent to an enhancer D. many genes are grouped into operon-like clusters E. it is the same as the DNA in one of your heart cells
Hydrophobic substances such as vegetable oil are
A. polar substances that have an affinity for water B. nonpolar substances that repel water molecules C. charged molecules that hydrogen-bond with water molecules D. nonpolar substances that have an attraction for water molecules E. polar substances that repel water molecules
The nitrogenous base adenine is found in all members of which group?
A. proteins, carbs and ATP B. alpha glucose, ATP and DNA C. proteins, ATP and DNA D. ATP, RNA and DNA E. proteins, triglycerides, and testosterone
In many ways, the regulation of the genes of a particular group of viruses will be similar to the regulation of the host genes. Therefore, which of the following would you expect of the genes of the bacteriophage?
A. regulation via acetylation of histones B. positive control mechanisms rather than negative C. control of more than one gene in an operon D. reliance on transcription activators E. utilization of eukaryotic polymerases
In general, a signal transmitted via phosphorylation of a series of proteins
A. requires phosphorylase activity B. cannot occur in yeasts bc they lack protein phosphates C. requires binding of hormone to a cytosol receptor D. allows target cells to change their shape and therefore their activity E. brings a conformational change to each protein
Prokaryotic and eukaryotic cells generally have which of the following features in common?
A. ribosomes B. linear chromosomes made of DNA and protein C. a membrane-bounded nucleus D. a cell wall made of cellulose E. flagella or cilia that contain microtubules
Accuracy in the translation of mRNA into the primary structure of a polypeptide depends on specificity in the
A. shape of the A and P of the ribosomes B. bonding of the anticodon to the codon and the attachment of amino acids to tRNAs C. bonding of the anticodon to the codon D. binding of ribosomes to mRNA E. attachment of amino acids to tRNAs
Taxol is an anticancer drug extracted from the Pacific yew tree. IN animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precurson, tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect
A. the S phase of the cell cycle B. chromatid assembly C. anaphase D. the formation of the mitotic spindle E. formation of the centrioles
Which of the following is an example of post-transcriptional control of gene expression?
A. the addition of methyl groups to cytosine bases of DNA B. the binding of transcription factors to a promoter C. The removal of introns and splicing together of exons D. gene amplification during a stage in development E. the folding of DNA to form heterochromatin
Hydrangea plants of the same genotype are planted in a large flower garden. Some of the plants produce blue flowers and others pink flowers. This can be best explained by which of the following>
A. the alleles being codominant B. the allele for blue being completely dominant C. environmental factors such as soil pH D. the fact that a mutation has occured E. the knowledge that multiple alleles are involved
If a particular operon encodes enzymes for making an essential amino acid and is regulated like the trp operon, then
A. the amino acid inactivates the repressor B. the enzymes produced are called inducible enzymes C. the repressor is active in the absence of the amino acid D. the amino acid acts as a corepressor E. the amino acid turns on transcription of the operon
Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells?
A. the animal cell is in a hypertonic solution and the plant cell is in a hypotonic solution B. the animal cell is in an isotonic solution, and the plant cell is in a hypertonic solution C. the animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution D. the animal cell is in a hypertonic solution and the plant cell is in an isotonic solution E. the animal cell is in a hypotonic solution, and the plant cell is an isotonic solution
Within a cell, the amount of protein made using a given mRNA molecule depends partly on
A. the degree of DNA methylation B. the rate at which the mRNA is degraded C. the presence of certain transcription factors D. the number of introns present in the mRNA E. the types of ribosomes present in the cytoplasm
Which of the following is a reasonable explanation for why unsaturated fatty acids help keep any membrane more fluid at lower temperatures?
A. the double bonds form kinks in the fatty acid tails, preventing adjacent lipids from packiong tightly B. the double bonds block interaction among the hydrophilic head groups of the lipids C. the double bonds result in shorter fatty acid tails and thinner membranes D. unsaturated fatty acids have a higher cholesterol content and therefore more cholesterol in membranes E. unsaturated fatty acids are more polar than saturated fatty acids
The leading and the lagging strands differ in that
A. the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together B. the leading strand is synthesized at twice the rate of the lagging strand C. 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 D. the leading strand is synthesized by adding nucleotides to the 3` end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5` end
The centromere is a region in which
A. the nucleus is located prior to mitosis B. new spindle microtubules form at either end C. metaphase chromosomes become aligned at the metaphase plate D. chromatids remain attached to one another until anaphase E. chromosomes are grouped during telophase
What is the reason that linked genes are inherited together?
A. the number of genes in a cell is greater than the number of chromosomes B. genes align that way during metaphase I of meiosis C. chromosomes are unbreakable D. they are located close together on the same chromosome E. Alleles are paired together during meiosis
Knowing just the atomic mass of an element allows inferences about which of the following
A. the number of protons in the element B. both the number of protons and the chemical properties of the element C. the number of neutrons in the element D. the number of protons plus neutrons in the elements
The oxygen consumed during cellular respiration is involved directly in which process or event?
A. the oxidation of pyruvate to acetyl CoA B. glycolysis C. the phosphorylation of ADP to form ATP D. accepting electrons at the end of the ETC E. the citric acid cycle
Cell differentiation always involves
A. the production of tissue specific proteins, such as muscle actin B. the movement of cells C. the transcription of the myoD gene D. the selective loss of certain genes from the genome E. the cell's sensitivity to environmental cues, such as light or heat
Replication in prokaryotes differ from replication in eukaryotes for which of the following reasons?
A. the rate of elongation during DNA replication is slower in prokaryotes than in eukaryotes B. Prokaryotic chromosomes have histones, wehereas eukaryotic chromosomes do not C. Prokaryotes produce Okazaki fragments during DNA replication, but eukaryotes do not D. Prokaryotic chromosomes have telmeres and euk do not E. PRO chromosomes have a single origin of replication, whereas EUK have many
Independent assortment of chromosome occurs
A. the statement is true for mitosis and meiosis II B. the statement is true for mitosis and meiosis I C. the statement is true for meiosis I only D. the statement is true for meiosis II only E. the statement is true for mitosis only
How do we describe transformation in bacteria?
A. the type of semiconservative replication shown by DNA B. the creation of a strand of RNA from a DNA molecule C. assimilation of external DNA into a cell D. the creation of a strand of DNA from an RNA molecule E. the infection of cells by a phage of DNA molecule
Bc most receptors are membrane proteins, which of the following is usually true?
A. they change their conformation after binding with signal polypeptides B. the preferentially bind w/ lipid of glycolipid signal molecules C. they lead to changes in intracellular ion concentration D. they are only attached to one membrane surface: exterior or interior E. they open and close in response to protein signals
Which of the following is (are) true for anabolic pathways?
A. they consume energy to build up polymers from monomers B. they do not depend on enzymes C. they are usually highly spontaneous chemical reactions D. they release energy as they degrade polymers to monomers E. they consume energy to decrease the entropy of the organism and its environment
Which of the following is true of transcription factors?
A. they control gene expression B. they transcribe ATP into cAMP C. they regulate the synthesis of DNA in response to a signal D. they initiate the epinephrine response in animal cells E. they regulate the synthesis of lipids in he cytoplasm
According to the fluid mosaic model of cell membranes, which of the following is a true statement about membrane phospholipids?
A. they occur in an uninterrupted bilayer, with membrane proteins restricted to the surface of the membrane B. they frequently flip-flop from one side of the membrane to the other C. they are free to depart fro the membrane and dissolve in the surrounding solution D. they have hydrophilic tails in the interior of the membrane E. they can move laterally along the plane of the membrane
Where does the Calvin cycle take place?
A. thylakoid membrane B. cytoplasm surrounding the chloroplast C. stroma of the chloroplast D. outer membrane of the chloroplast E. interior of the thylakoid
Why do chromosomes coil during mitosis?
A. to allow the siter chromatids to remain attached B. to increase their potential energy C. to allow the chromosomes to fit within the nuclear enverlpe D. to allow the chromosomes to move w/out becoming entangled and breaking E. to provide for the structure of the centromere
Which of the following is a fxn of a signal peptide?
A. to terminate translation of the messenger RNA B. to bind RNA polymerase to DNA and initiate transcription C. to direct an mRNA molecule into the cisternal space of the ER D. to translocate polypeptides across the ER membrane E. to signal the initiation of transcription
Which of the following does not occur in prokaryotic gene expression, but does in eukaryotic gene expression?
A. transcription can begin as soon as translation has begun even a little B. mRNA, tRNA, and rRNA are transcribed C. RNA polymerase requires a primer to elongate the molecule D. A poly-A tail is added to the 3` end of an mRNA and a cap is added to the 5` end E. RNA polymerase binds to the promoter
The functioning of enhancers is an example of
A. transcriptional control of gene expression B. post-transcriptional mechanism for editing mRNA C. the stimulation of translation by initiation factors D. post-translational control that activates certain proteins E. a eukaryotic equivalent of prokaryotic promoter functioning
In the thylakoid membranes, what is the main role of the antenna pigment molecules?
A. transfer electrons to ferredoxin and then NADPH B. Harvest photons and transfer light energy to the reaction-center chlorophyll C. concentrate photons within the stroma D. split water and release oxygen to the reaction-center chlorophyll E. synthesize ATP from ADP and P
One possible result of chromosomal breakage is for a fragment to join a nonhomologous chromosome. What is this alteration called?
A. translocation B. deletion C. duplication D. inversion E. transversion
Which of the following processes includes all others?
A.passive transport B. diffusion of a solute across a membrane C. osmosis D. transport of an ion down its electrochemical gradient E. facilitated diffusion