Bio 108 Exam combination
DNA and RNA have several different properties. For each property below, indicate whether it is a typical property of DNA, RNA, or both. 1. contains uracil as one of the nitrogenous bases. 2. the sugar present is deoxyribose 3. forms polymers with a sugar-phosphate backbone.
1. RNA 2. DNA 3. Both DNA and RNA
A couple has three children, all with brown eyes and blond hair. Both parents are homozygous for brown eyes (BB), but one is a blond (rr) and the other is a redhead (Rr). The genes are both autosomal and are not linked. What is the probability that their next child will be a brown-eyed redhead?
1/2
Consider the following sequence on one strand of DNA. What is the sequence on the opposite strand of the double helix? 5'- AGCTGCCA -3'
3' TCGACGGT 5'
If a zygote has 4 chromosomes, the somatic cells formed from it have [response1] chromosomes. (number only)
4.0
Natural selection would predict the occurrence of ____________ due to common ancestry.
All of the listed occurences. (homologous structures, conserved gene and protein sequences, similar features in early embryology, vestigial organs
What is the effect of elevated atmospheric CO2 levels on water use by plants? Explain.
Because stomatal opening times decrease in response to elevated CO2 levels, the plant loses less water.
A red blood cell has been placed into three different solutions. One solution is isotonic to the cell, one solution is hypotonic to the cell, and one solution is hypertonic to the cell. A. water flow in the cell B. same in and out of the cell C. water from the cell is moving out
C- the solution in the breaker is hypertonic to the cell A- the solution in the breaker is hypotonic to the cell B- the solution in the beaker is isotonic to the cell.
If you need to isolate the enzymes in the Calvin Cycle, which component below would you need?
The stroma of the chloroplast.
which cell would be able to diffuse substances from the interior of the cell to the exterior more rapidly?
a cell with a high surface area to volume ratio.
An investigator demonstrates that a certain yeast strain is able to grow and consume glucose in a closed chamber in the absence of oxygen. The investigator notices that when the chamber is opened to air, the cells grow but the consumption of glucose by the yeast decreases dramatically. This indicates the yeast strain is ______.
a facultative anaerobe
Evaluate these statements describing differences between bacteria, plant, and animal cells. Which is an accurate statement?
a nucleus is found in plant and animal cells, a nucleoid is found in bacteria cells.
What is the general term for a change in gene frequencies due to chance events when a population is small? (We are looking for the general term, not an example. One to two words only.)
genetic drift (or drift)
what are the monomers in starch?
glucose
Which of the following produces genetic variation in sexual reproduction?
independent assortment, random fertilization, and crossing over
Koalas have long, sharp nails on their fingers and toes. Koalas born with longer and stronger nails were able to climb trees faster. Because they could evade predators and reach food more readily, they were more successful in reproducing and leaving more offspring
natural selection
What evolutionary theory postulates that phenotypes providing an advantage to an organism in its interaction with its environment will be more likely to survive and reproduce and therefore will increase the relative frequencies of this phenotype in the population? (one to two words only)
natural selection
Consider these illustrations of different modifications of chromosomes. The letters represent different regions of a chromosome. Option 1: LMNOP-QRS-> LMNMNOP-QRS Option4:LMNOP-QRS-> LMABCNOP-QRS Which of these options illustrates duplication?
option 1
In a population undergoing natural selection, what type of selection is illustrated here, in which selection favors one of the homozygotes? (porabela moves to the right)
directional selection
a hydrogen atom can form a hydrogen bond when covalently bonded to which of the following atom(s)?
oxygen nitrogen
For the following descriptions of animal cells, indicate whether they are characteristic of gamete or somatic cells. cells are either sperm or ova cells- cells have two set of chromosomes-
- gamete cells - somatic cells
Select the correct cellular locations for the following pathways. the kreb's cycle- glycolysis- fermentation-
- mitochondrial matrix - cytosol - cytosol
A Punnett square ___________.
predicts the result of genetic crosses between organisms of known genotypes
of the following, which is the most common route for membrane flow in the endomembrane system?
rough ER to vesicles to Golgi to the plasma membrane
What kinds of molecules pass through a cell membrane most easily?
small and hydrophobic
During DNA replication, what is the strand that is synthesized continuously and in a direction toward the replication fork?
the leading strand
If all the lysosomes within a cell suddenly ruptured, what would be the most likely result?
the macromolecules in the cytosol would begin to break down
What is meant by the term "alternation of generations"? Do animals as well as plants exhibit an alternation of generations? Explain your answer,
"Alternation of generation" refers to the fact that plants and some algae have both multicellular haploid and diploid stages. The multicellular diploid generation (termed the sporophyte generation) produces the gametophyte as its "offspring" and the haploid gametophyte generation produces the next sporophyte generation. Since animals do not have a multicellular haploid generation, the term does not apply.
Spinal and bulbar muscular atrophy (SBMA) is an X-linked recessive disorder. Mary does not have SBMA, but her father does. John does not have SBMA. What is the probably that Mary and John will have daughters who have SBMA?
0
In humans, free ear lobes is a dominant trait. Those homozygous for the e allele have attached ear lobes. Free ear lobes is observed in heterozygotes or those homozygous for the E allele. In a population in Hardy-Weinberg equilibrium, in which only E and e alleles are present, 25 of 100 individuals have attached ear lobes. What is the frequency for the allele for attached ear lobes (e)? What is the frequency for the allele for the dominant, free ear lobes (E)?
0.5 0.5
Consider this reaction in fermentation: acetaldehyde + NADH + H+ → ethanol + NAD+ 1. Which endproduct molecule is in oxidized form? 2. Which endproduct molecule is in reduced form?
1. NAD+ 2. ethanol
Human DNA contains about 30% adenine (A). According to Chargaff's Rules, there should be [Note: only enter the number, not the '%' sign.]
30% thymine 20% cytosine 20% guanine
DNA polymerase catalyzes the elongation of DNA in the __________ direction. RNA polymerase catalyzes the elongation of RNA in the ____________ direction.
5' to 3'
What is the sequence of the mRNA generated if this is the DNA sequence read by RNA polymerase? 5'-TAGGCCATT-3' Label each end as either 5'- or -3'
5'-AAUGGCCUA-3'
Consider these four rabbits with different phenotypes. Propose two parental rabbits and the offspring that could illustrate codominance. A. Identify by letter, two parents. B. Identify by letter the offspring. [rabbit A brown and white; rabbit B white; rabbit C dark brown; rabbit D caramel color]
A Parents- B and C B children- A
This pedigree chart follows eye-color in three generations of Mendaliens. Green eyes, G, are dominant to black eyes, g. The gene is not sex-linked. Black-eyes are indicated by filled circles and squares. Generations are indicated by letters, individuals in a generation are numbered left to right. A. Indicate the most probable genotype for individual A-1 B. List all individuals in generation B who most likely have a genotype of gg. If none, enter 'none', if more than one individual, separate by commas and one space: example: B-7, B-9.
A. Gg B. B-2, B-3
This reaction has a ΔG of -3.9 kcal mol-1. glutamic acid + ammonia + ATP → glutamine + ADP + Pi A. This is an example of an ____________ reaction. B. The hydrolysis of _________ is used to drive the reaction.
A. coupled reaction B. ATP
Recombination frequencies measured between three genes known to reside on the same chromosome are shown. Recombination frequency E to G 0.12 A to E 0.35 A to G 0.47 What is the best relative arrangement of these genes on a chromosome?
AEG
With the lac operon as your model, what molecule would you identify as comparable in function to that of a eukaryotic enhancer? Explain your reasoning.
CAP protein. Like a eukaryotic enhancer, CAP binding to the promoter increases the affinity of RNA polymerase for the promoter leading to enhanced expression. 2 points for identifying CAP 4 points for indicating that both CAP and a eukaryotic enhancer increase the affinity of RNA polymerase for the promoter.
Distinguish between a dehydration reaction and a hydrolysis reaction. Provide an example of each.
Dehydration- a more complex molecule is formed from two simpler ones (monomers), and a water molecule is lost as each bond forms i.e., a disaccharide is formed from two monosaccharides. Hydrolysis- the breakdown of a more complex molecule into its building blocks (monomers . A water molecule is added to each bond, the bond is broken, and simpler molecules are formed in the process, i.e., a disaccharide is broken down to a monosaccharide.
Sea water has a pH of 8. The pH indicates the concentration of __. (one to two words only) Is sea water acidic, basic, or neutral? ( one world response ___.
H+, basic
Most of the drug treatments for AIDS caused by HIV do not involve traditional immunization by vaccines. Instead drugs have been designed to target the unique protein products of the HIV genome. Which of the following provides the strongest reason for this approach?
HIV infects cells involved in the human immune system. Because vaccines function by triggering an immune response, HIV is able to circumvent the protection by vaccines.
Why do histones bind tightly to DNA?
Histones are positively charged, and DNA is negatively charged.
What happens at the conclusion of meiosis I?
Homologous chromosomes are separated.
A woman has been diagnosed with Mickey D syndrome (MDS), described as a predilection for Big Macs and fries. Her husband does not have the syndrome. Of their four children, one of their two sons and one of their two daughters also suffers from the affliction. Can MDS be an autosomal recessive disorder? Explain.
It can because, the father could be heterozygous, there for they could be a carrier. Also children of both genders have the same probablity of getting it.
While analyzing the properties of a protein purified from a cell, it is determined that there are large numbers of ubiquitin's attached to the proteins. What is the expected fate of a protein that has ubiquitin covalently attached to it?
It will be degraded by proteosomes.
What is meant by the term "non-disjunction"? Identify one human disorder that can be attributed to non-disjunction.
Non-disjunction refers to the failure of a pair of homologous chromosomes to move apart to opposite daughter cells during meiosis I or sister chromatids to separate properly during meiosis II. Down syndrome Trisomy 21, Klinefelter syndrome Trisomy X (XXX), Turner syndrome Monosomy X (X0) and XXY, XYY.
F.C. Steward conducted a series of experiments where he demonstrated that a complete carrot plant can be grown from a single cell obtained from a differentiated carrot root. Which of the following statements is a false conclusion from Steward's work?
None of the above, all the statements are valid conclusions of these experiments.
This diagram is the only figure in C. Darwin's "Origin of Species". The figure was used to explain all of the concepts below except ______________.
Only the physically strong survive to the next generation.
Consider the statement below regarding the naked mole rat (shown here). They are mammals found in Africa that have large top incisors and sealed lips.
Over time the naked mole rat population evolved to having long top incisors, this was genetically favored due to the fact that it made it easier to burrow through compacted soil.
Why does photorespiration occur on hot days?
Oxygen cannot leave the cell and is used as an alternative substrate by Rubisco in the Calvin cycle.
a phosphorus atom bonded to four oxygen atoms.
Phosphate
You are monitoring the hydrolysis of sucrose to glucose and fructose in the presence and absence of the enzyme sucrase, which catalyzes the reaction. Which explanation provides the best rationale for the results shown here?
Sucrase is added at 10 seconds, which decreases the activation energy and more fructose is formed. (that is when fructose apears)
If a population is in Hardy-Weinberg equilibrium, which of the following statements would be false?
The allele and genotype frequencies would be changing from generation to generation.
Which population is most evolutionarily fit?
Turtles who lay 100 eggs, of which 30 survive and reproduce.
In metabolic processes, a pathway that breaks down large molecules into smaller molecules is generally called _____________ pathway.
a catobolic
The cell cycle is controlled in most cells by ______.
a series of checkpoint molecules
An adaptation is _____.
a trait that gives an organism a reproductive advantage in the current environment
list one functional group that can raise the pH of a solution. (one to two words only)
amino acid
a transmembraneprotein in which a hydrophobic region spans that hydrophobic interior of a lipid bilayer is __.
an integral membrane protein
Short-haired cats were tested with humans who were allergic to cats. Breeders crossed cats that caused the least allergic reactions with each other. This was continued until hypoallergenic cats were produced
artificial selection
Which of the following was not an observation Darwin used to make inferences that were important in formulating his theory on descent by modification.
The greatest source of heritable variation is through independent assortment during meiosis.
The folded structure of a protein is more ordered than the denatured structure of the protein. In the cell, proteins are normally folded. How is this observation reconciled with the second Law of Thermodynamics?
The increase in entropy of the cell is greater than the decrease in entropy of the protein when it folds.
The majority of animal viruses have capsids surrounded by a membranous envelope. By contrast, few bacteriophages are enveloped. What is the basis for this difference?
The membranous envelope of animal cells provides a means of entry of the viral capsid into the host cell by the fusion of the envelope with the cell membrane of the host. Since bacteria have a cell wall, this approach would not work. Hence, few bacteriophages are enveloped.
Aphids are insects that attack rose bushes. A gardener sprays roses with an insecticide to kill the aphids. One month later the plants are sprayed again, but there is little effect and the aphid population is back to original numbers very rapidly. Which of the following is the best explanation?
The original surviving aphids were genetically resistant to the insecticide; most of their offspring inherited the trait.
While on a trip to the desert, an individual was bitten by a rattlesnake and nearly died from hemolysis. This is the breakage (lysis) of red blood cells. The snake venom was analyzed and three enzymes were identified: phospholipase, which degrades phospholipids; neuraminidase, which removes cell surface carbohydrates; and protease which degrades proteins. Which of these enzymes do you think was responsible for his near fatal red blood cell hemolysis?
The phospholipase would degrade the phospholipids, the component of a membrane creating a barrier.
All of the events listed below occur in the light reactions of photosynthesis except _____.
carbon dioxide is incorporated into G3P
a carbon double-bonded to an oxygen atom and to a -OH group.
carboxyl
Prions are thought to propagate by __________.
causing normal brain proteins to fold into an abnormal version
When eukaryotic chromosomes are replicated in preparation for either mitosis or meiosis, the two copies of the chromosome are connected at the _____.
centromere
Inheritance in which a heterozygote exhibits both alleles and both phenotypes are present is ___________________. (one or two words only)
codominance
a nucleus__.
contains most of the DNA in a cell
The ostrich, native to Africa and shown on the left, and the emu, native to Australia and shown on the right, look very similar and live in similar habitats; however they are not very closely related. This is an example of ______.
convergent evolution
If two genes are linked, how can recombinants occur? (This answer should be in one to two words)
crossing over
The presence of stripes on a fish is a dominant phenotype and no-stripes is the recessive phenotype. If a test cross is carried out on a homozygous striped fish, what is the expected outcome if there are 100 offspring? If a test cross is carried out on a heterozygous striped fish, what is the expected outcome if there are 100 offspring? (Note: This question can, but does not need to, be answered in one sentence.)
homozygous stiped fish: 100/100 will be stripped. heterozygous striped fish: 3/4 of the offsprings will have stripes and 1/4 will have no stripes.
In a pathway that breaks large molecules into small compounds, one would expect many of the enzymes in the pathway to use __ reactions. In breaking five monomer linkages of a large molecules, these reactions would__ molecules of water.
hydrolysis.... use 4
An aquatic environment has numerous rocks and crevices. Fish that were able to force themselves into the crevices were able to hide from predators. The fish became thinner by continually squeezing between rocks. Their offspring were thinner and over time the fish became long and thin.
inheritance by acquired characteristics
The segments of eukaryotic mRNA that are removed during splicing?
introns
A proton motive force __________________.
is a form of potential energy generated by a gradient of H+ across a membrane
if two solutions, solution A and solution B, have the same solute concentration, then solution A is __ to solution B.
isotonic
Charles Darwin was influenced by the work of James Hutton who developed the geologic theory of gradualism. This theory proposes that _______________.
large geologic changes are cumulative products of slow, continuous changes
Which class(es) of macromolecules can be described by both of the following properties? - they are predominantly hydrophobic or amphiphilic compounds. - they often form vesicles or membranes when in aqueous solutions
lipids
the cytoskeleton is composed of three different filament types. put the three filament types in order from smallest to largest diameter. smallest to largest
micro filament, intermediate filaments, micro tubules
Name two organelles that fit this description: - it is involved in energy metabolism - it possesses an inner and outer membrane - it has characteristics resembling prokaryotic cells - it contains DNA that is replicated along with the organelle
mitochondria and chloroplasts
in animals, somatic cells are reproduced by
mitosis
ATP is required in the transport of __.
molecules to areas of higher concentrations
cells containing membrane-enclosed organelles are__.
eukaryotic
Two populations of moths are separated by 100 miles and 500 ft in altitude. A nature trail is built that connects the two populations. The moths frequently fly into hikers backpacks and are transported away from their initial populations. Over time, the allele frequencies of the two populations change. Which of the following is the most likely cause of this allele frequency change.
gene flow
What energy-rich organic compound is produced as a result of the Calvin cycle?
glyceraldehyde-3-phosphate (G3P)
An example of a degradative pathway is _____________.
glycolysis
Identify the labels in this structure of a virus.
glycoproteins RNA or DNA capsid envelope
the chemical reaction illustrated in the figure results in a __ bond. the -R group indicated by the dashed line is __?
glycosidic bond......nonpolar
The recombination frequency between two gene loci is _____.
greater as the distance between the two loci increases
the cooling effect of sweat or perspiration in humans is due to what property of water?
high heat vaporization
When a glucose molecule is metabolized to release energy, ~40% of the energy is converted into usable energy, while ~60% is lost as heat. What property of water acts to keep temperature levels in the cell from raisin to dangerous levels?
high specific heat
The component of chromatin that can be regulated by methylation are _________ Acetylation usually results in _________ in transcription.
histones an increase
Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from common ancestry. What do biologists call these features?
homologous structures
Forelimb bones seen in wings, general forelimbs, and in flippers are shown. They exhibit striking similarity in bone structure. This is an example of ____. The structural similarities between the flippers of seals and the wings of bats are used to show that the _____.
homologous structures bat species and seals have a common ancestry
Consider the following phylogenetic tree. Which of the six dots in the tree corresponds to the most recent common ancestor of lizards and mammals?
e
Consider the following 3 populations of turtles. Assume HW equilibrium. With these turtles brown coloring is recessive, while green is dominant. Population 1 has 20 turtles, of which 2 are brown and 18 are green. Population 2 has 200 turtles, of which 50 are brown and 150 are green. Population 3 has 500 turtles, of which 125 are brown and 375 are green. Which population is least susceptible to an alteration of allele frequencies due to an accident? Which population is most likely to be subject to a bottleneck effect? Which population has the highest frequency for the brown allele?
population 3 population 1 population 2 and 3
In chemiosmosis, a H+ gradient is formed. What is the dominant type of energy this gradient possess? (one to two words only)
potential energy
At what stage of mitosis does the nuclear envelope fragment (disappear)?
prometaphase
When observing cells undergoing cellular division, you observe tetrad formation and chiasmata formation. You conclude the cells are in __________.
prophase I of meiosis
In which of the following stages will homologous pairs of chromosomes not be present in a dividing animal cell?
prophase II of meiosis
A new flower species has a unique photosynthetic pigment. The leaves of this plant appear to be reddish yellow. What wavelengths of visible light are not being absorbed by this pigment?
red and yellow
Consider this diagram of an integral membrane protein. Select the region, labeled A-C, you expect to most likely find each amino acid listed below.
region A and C (not the middle)
The terms alpha helix and beta-sheets are used to describe the __ structure of proteins.
secondary
In prokaryotes, DNA is replicated in a _______________ manner. In eukaryotes, DNA is replicated in a ______________ manner.
semi-conservative semi-conservatice
Which factor is the most important in producing the variability that occurs in each generation of sexually reproducing populations?
sexual recombination
Use this phylogenetic tree. The labeled dots indicate ancestors. Consider the relationship between the snowy owl, bald eagle, and golden eagle. Of these three species, which are the two most closely related species? Which ancestor is the most recent common ancestor of all three species?
snowy owl and bald eagle b
A green-skinned, yellow-spotted frog and a black-skinned, red-spotted frog have 20 offspring. Most of the offspring are green-skinned and yellow spotted or are black-skinned and red spotted. It is known the genes controlling these two phenotypes obey a dominant inheritance pattern. About 15% of the offspring exhibit recombinant phenotypes. A possible explanation is that the genes controlling skin color and spot color are __________.
the genes are linked, and do not obey the Law of Independent Assortment
An organelle that prepares, modifies, and identifies molecules for transport within and outside the cell is __.
the gogli apparatus
the figure below shows two monosaccharides, ribulose on the right and ribose on the left. Ribose in the sugar in RNA and ribulose is important in photosynthesis. Which of these statments correctly indicates a relationship between these sugars?
the molecules are structural isomers
The Darwinian fitness of an individual is measured by ____________.
the number of its offspring that survive to reproduce
Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?
the phosphodiester linkage between deoxyribose sugars would be broken
Why is the concept of a population important in studying evolution?
the population is the smallest unit of evolution. individuals do not evolve; it is a population that changes over generations evolution is the change in frequency of alleles in a population
For the trp operon ..... What molecule does tryptophan (trp) bind? What part of the operon does this trp complex bind?
the repressor the operator
Which of these nitrogenous bases is found in DNA but not in RNA?
thymine
The most important means of controlling gene expression is at the level of _______.
transcription
What is the term used to describe the conversion of mRNA to its protein product? (one to two words only)
translation
If a cell is placed in a hypotonic solution and becomes firm, but does not burst, that cell is likely a ___.
turgid plant cell
Compared to cells in the nose of a mouse in Missouri, the cells in the nose of an arctic fox in Alaska will most likely have an increased concentration of which of these molecules?
unsaturated phospholipids
An adipose cell stores large quantities of lipids. The lipids that are stored are synthesized primarily in the liver. Which of the following organelles do you expect to find in abundance in adipose cells?
vacuoles
This graph represents growth of bacteriophages in a culture of host bacteria cells. The number of virus particles per milliliter were determined over a four hour time period. What type of virus does this data indicate? How many lytic cycles were observed?
virulent phage 3
Consider this image of the Tobacco Mosaic Virus. Does this virus contain a capsid? does this virus contain an envelope?
yes no
During protein synthesis, an aminoacyl-tRNA recognizes the codon and binds to _____.
A site of the ribosome
In a population of 100 turtles, 16 have sharp beaks and 84 have rounded beaks. The shape of the beak is due to one gene with two alleles; a recessive allele, r, which results in a sharp beak, and a dominant allele, R, that results in a rounded beak. The population is in Hardy-Weinberg equilibrium. Complete the table below. These are numerical answers, no words or fractions. Frequencies are greater than or equal to 0 and less than or equal to 1. How many is greater than 1. What is the frequency of the dominant allele in the population? What is the frequency of the recessive allele in the population? What is the frequency of the homozygous dominant genotype in the population? What is the frequency of the heterozygous genotype in the population? What is the frequency of the homozygous recessive genotype in the population? In this population of turtles, how many are heterozygous?
0.6 0.4 0.36 0.48 0.16 48
In the year 2500, four male space colonists and four female space colonists from Earth settle on an uninhabited Earth-like planet in a galaxy far, far, away. The colonists and their offspring randomly mate for generations. All eight of the original colonists had smooth hair lines, and two are heterozygous for that trait. The allele for smooth hair lines, S, is dominant to the allele for a widow's peak, s. What is the frequency for the S allele in the founding population? What is the frequency for the s allele in the founding population? If one assumes that Hardy-Weinberg equilibrium applies to the population of colonists on this planet, about how many people will have a widow's peak when the planet's population reaches 1,000? If three of the original colonists die due to poisoning before they produced offspring, the population will likely experience _______.
0.875 0.125 16 a bottleneck effect
Correctly identify the description to the Law of Thermodynamics. 1st Law- 2nd Law-
1- energy is neither created nor destroyed 2- entropy of the universe always increases
Consider this figure of a phospholipid. Two regions of the molecule are labeled 1 and 2. Carbon atoms are black, hydrogen atoms are gray, orxygen atoms are red, phosphate atoms yellow, and nitrogen is blue. region labeled "1" is hydrophilic region labeled "2" is hydrophobic
1-hydrophilic 2- hydrophobic
Calculate the allele and genotype frequencies in a population of 800 morning doves, of which 200 are white and 600 are dark grey (The white color is due to a recessive allele, w and dark grey is due to a dominant allele, W. The population is in Hardy-Weinberg equilibrium. How many of the dark grey morning doves are heterozygous? 1. Frequency of the dominant allele in the population: 2. Frequency of the recessive allele in the population: 3. Frequency of the homozygous dominant genotype in the population: 4. Frequency of the heterozygous genotype in the population: 5. Frequency of the homozygous recessive genotype in the population: 6. The number of dark grey morning doves in the population that are heterozygous:
1. 0.50 2. 0.50 3. 0.25 4. 0.50 5. 0.25 6. 400
In the glycolysis pathway, the net production is 1.___pyruvate 2.___ATP 3.___NADH
1. 2 2. 2 3. 2
A group of cells is assayed for DNA content immediately following mitosis and found to have 22 picograms (pg) of DNA per nucleus. 1. At the end of the G1 phase, it is expected that the cells would have___ picograms of DNA per nucleus. 2. At the end of the G2 phase, it is expected that the cells would have___ picograms of DNA per nucleus.
1. 22 2. 44
For the production of one molecule of glyceraldehyde-3-phosphate (G3P) by the Calvin cycle, indicate the number of input molecules needed. (for each question, one number response only) 1.How many CO2 2. How many NADPH? 3. How many ATP?
1. 3 2. 6 3. 9
In a eukaryotic diploid cell with six chromosomes, identify the figures that best represent the stages of mitosis or meiosis requested below. 1.Prophase I 2.Anaphase
1. B 2. H
In certain snakes green coloration is dominant to brown coloration. The allele for large black spots is dominant to small black spots. They are not sex-linked genes. Dihybrid green, large-spotted snakes are crossed with brown, small-spotted snakes. Of the 661 offspring, there are : 314 green, large-spotted snakes 300 brown, small-spotted snakes 22 green, small-spotted snakes 25 brown, large-spotted snakes 1. Among the offspring, which two combinations are recombinant phenotypes, not the parentals? 2. what is the recombination frequency? 3. do these results support a conclusion that the genes for coloration and for spot size are on the same chromosome?
1. The green, small-spotted snakes and the brown, large-spotted snakes. 2. (25+22) / 661 = 0.07 3. yes
Lysosomal storage diseases (LSDs) are a group of inherited metabolic disorders that affect lysosomal function. You have a patient that you believe is suffering from an LSD. Describe 1) what you would look for to determine that your patient is indeed suffering from an LSD and 2) the approach that you would take to either cure or ameliorate the effect of the disease.
1. You would look to see if a particular class of molecules (i.e., a particular type of lipid or protein) is accumulating within the patient's lysosomes. 2. Try to find a mechanism to increase the residual activity of the enzyme that is responsible for breaking down the accumulating molecule, i.e., by stem cell transplantation, enzyme replacement therapy, gene therapy or, taking another tact, by reducing the synthesis of the stored substrate molecule.
1. A three base sequence on mRNA that translates into an amino acid is ___________. 2. The region on tRNA that it corresponds to is the ___________.
1. a codon 2. anticodon
1. An example of a homozygous genotype. 2. In a cross of fish with black stripes and yellow fins (both dominant) and a fish with silver stripes and blue fins (both recessive), the offspring that have black stripes and blue fins are _________.
1. both DD and dd 2. recombinants
Label the DNA replication fork 1. the DNA template for the leading strand. 2. the DNA template for the lagging strand 3. Okazaki fragments 4. the leading strand 5. the letter A represents a 5' end. 6. the letter B represents a 3' end. 7. the letter E represents a 3' end 8. the letter F represents a 5' end 9. The letter G represents a 5' end. 10. The letter H represents a 3' end.
1. c 2. d 3.i 4.j 5.5' 6.3' 7.3' 8.5' 9.3' 10.5'
1. In a prokaryotic cell, translation occurs in the ___________. 2. In a eukaryotic cell, translation occurs in the __________.
1. cytoplasm 2. cytoplasm
Two cells undergoing cell division are viewed under a microscope, as shown here. 1. A cleavage furrow is observed in 2. A plant cell is observed in
1. image A 2. image B
Indicate whether the following statements regarding enzymes are correct or incorrect. 1. the uncatalyzed reaction has a lower energy of activation 2. the reaction will occur at a slower rate in the absence of the enzyme
1. incorrect 2. correct
You are in the process of assembling an artificial membrane. What components will you need to collect before beginning the process? You are thinking of using the membrane in a pulmonary application, i.e., as a respiratory surface. Because such a membrane must be permeable to O2 and CO2, you are concerned about the type of protein channels that should be incorporated into the membrane. Should you be concerned? Why or why not?
1. phospholipids and proteins. 2. No, you should not be concerned because O2 and CO2 being small non-polar molecules can easily diffuse through the lipid bilayer.
Consider the two reactions diagrammed here and answer the following questions. 1. Does the conversion of ADP + Pi to ATP release energy or require energy? 2. Is the reaction of ADP + Pi to ATP endergonic or exergonic? 3. Is the reaction of ATP to ADP + Pi endergonic or exergonic?
1. require energy 2. endergonic 3. exergonic
Predict photosynthesis outcomes when a plant is placed in the conditions described below. 1. A plant is moved from the light into the dark. 2. A C3 plant is exposed to very high temperatures for 20 days with no rain.
1. the light reactions do not occur, the Calvin cycles does occur. 2. the light reactions occur, photo respiration occurs.
A person is described as a carrier for a disease. Indicate whether each of the following statements is true or false, in regard to this carrier. 1. The person is heterozygous for the gene determining the disease. 2. The person does not exhibit the disease. 3. The person is always female.
1. true 2. true 3.false
A goldfish has 94 chromosomes in its somatic cells. Ignoring crossing over, how many different combinations of chromosomes in gametes can be produced during meiosis?
2^47
Summer squash is a vegetable that has three fruit colors; yellow, green, and white. There is one gene for color pigment. Yellow, Y, is dominant to green, y There is a second gene which controls whether either the yellow or the green pigments are expressed. If the dominant C gene is present, then the Y or y gene is expressed. If the recessive is homozygous, cc, then the squash is white, regardless of the presence of the Y or y alleles. What are the expected ratios if these two squash were crossed? (Enter ratios in reduced form.) Yycc x YyCC
3 Yellow 1 green 0 white
If you are asked to identify a cell undergoing binary fission, what would you look for?
A bacteria undergoing cell division.
Which of the genes below would you expect is the most likely to be a proto-oncogene?
A gene that codes for a checkpoint molecule involved in mitosis.
Below are micrographs of cells in different stages of the cell cycle. Select the stage of mitosis that is exhibited in the cell labeled 'A'. Select the stage of mitosis that is exhibited in the cell labeled 'C'.
A- metaphase C- anaphase
Correctly identify each of the organelles indicated by arrows. Each lettered label should be one to three words only. (look at exam 1)
A- mitocondria B- nucleous C- vacuole D- central membrane
This Punnet square shows the F1 generation from a P generation that crossed true-breeding green male turtles with true-breeding brown female turtles. All the F1 turtles are green. In the Punnett square, 1, 2, 3, and 4 represent the genotypes corresponding to each box within the square. For each question below, answers are the numbered boxes, 1-4. Answers may be one, or more numbered box. A. Which of the numbered boxes represents the genotype that is the same as the genotype of the P generation males? B. Assume that instead of being inherited by complete dominance, the turtle color follows an incomplete dominance pattern. Which of the numbered boxes represents the genotype that would be expected to exhibit a different phenotype than the P generation turtles? You MUST number your answers (A or B). Explanations are not needed, your answers just need the box numbers.
A. 1 B. 2,3
Consider this figure that depicts tRNA. What is the triplet of bases on the mRNA strand that codes for the amino acid of this tRNA? (Provide your answer in the 5' to 3' direction, do not label the ends, the answer is one letter codes for bases on the mRNA) 5'- [response1] -3'
AUG
Plants synthesize large amounts of glucose and sucrose in green leaves. These sugars are immediately transported out of the chloroplasts into the phloem (the vasculer system in plants). What type of transport process would you expect if the sugars are transported out of the chloroplasts as soon as they are synthesized into the phloem?
Active transport because the sugars are transported from low to high concentration into the phloem.
Consider this image of DNA. The 3' end of the DNA strands is(are) labeled _____. The 5' end has a free __________ group at the end of the polymer.
B and C phosphate
which of the figures illustrates a prokaryotic cell
Cell a (left)
In a cell, the flow of information proceeds from __________.
DNA to RNA to protein
Bacteria are grown in a sealed container. Initially, the culture contained 2.5 % glucose. The glucose and lactic acid content was measured every four hours for 24 hours. The data is shown, with red triangles indicating glucose levels and blue circles indicating lactic acid levels. Which of the following statements are supported by the data shown here? (Select all that apply.)
Fermentation increases as oxygen is depleted from the culture.
The ability of ice to float is of utmost importance to the existence of life on this planet. Explain why? What makes water less dense as a solid than as a liquid?
If ice were more dense than liquid water bodies of water would freeze from the bottom up, extinguishing all life in those waters. Water is less dense as a solid because in ice hydrogen bonds are stabilized. This results in 4 hydrogen bonds to each water molecule. The net effect is that all water molecules are pushed further apart from one another in ice than in liquid water. Hence, there are fewer water molecules per unit volume in ice than in liquid water.
Distinguish allosteric activation from cooperativity.
In allosteric activation, the activator binds to a multi subunit enzyme at a position removed from the active site. Binding at this site by the activator locks in the proper geometry for binding of substrate at all active sites on the enzyme. In cooperativity, substrate binding at one active site of a multi subunit enzyme locks in the proper geometry that facilitates binding of substrate at the remaining active sites of the enzyme.
What is alternative RNA splicing? Does it play a role in the gene expression of both prokaryotes and eukaryotes? Explain.
In alternative RNA splicing a single gene can code for multiple proteins based upon which exons are included or excluded from the final product. Only eukaryotic DNA has introns and exons and so alternative RNA splicing is a process that is restricted to eukaryotes.
If a plant is actively engaged in photosynthesis, how would a chloroplast most likely provide additional ATP if it had sufficient levels of NADPH?
Increase the amount of cyclic electron flow in the light reactions.
An investigator is characterizing a cell that seems to have an unregulated expression of a gene. They sequence the coding region of the gene and the promoter region, and they are both exactly as expected. They are told to sequence the upstream region for at least 2000 nucleotides. What would they be looking for so far from the gene?
Mutations in enhancers.
Which of the following statements about NAD+ is false?
NAD+ transfers electrons to the electron transport chain of cellular respiration.
How does natural selection differ from gene flow? Include in your response the effect of each on the subsequent genetic diversity of the population.
Natural selection selects for those alleles in the population that lead to greater reproductive success in a given environment. Gene flow results from individuals emigrating from or immigrating into a population. Natural selection will reduce the genetic diversity of a population, since those alleles that increase reproductive success will be selected for at the expense of those that don't. Gene flow may increase or decrease diversity depending on the direction of flow (into or out of the population). Gene flow could also lead to an increase or decrease in the relative fitness of individuals in the population, which could also lead to a reduction in genetic diversity via natural selection. 3 points for distinguishing natural selection from gene flow. 3 points for correctly predicting the the affect of each on the genetic diversity of the population.
Recall from our discussion on the catabolism of various food molecules that fat molecules are converted to acetyl CoA (by a process called beta oxidation). Based on your knowledge of the various stages of aerobic respiration and the fermentation process, can a muscle cell use fat as a source of energy during periods of intense exercise when oxygen is lacking? Explain your reasoning.
No, a muscle cell cannot use fat as a source of energy when oxygen is lacking. Fat is converted to CoA, which would enter the TCA cycle. The TCA cycle would continue to function and produce ATP by substrate level phosphorylation until all the NAD+ were converted to NADH, which would occur very rapidly. Without a functioning ETC, the NADH could not be re-oxidized to NAD+.
A sexually reproducing fish has two autosomal, unlinked genes, one for red scales (R) and one for black spots (B). List all possible allele combinations in gametes from an individual who is RrBB. (An explanation is not needed.)
RB, rB
Red-green color blindness is a sex-linked recessive trait in humans. Two people with normal color vision have a color-blind son. Assuming no new mutations, what are the genotypes of the parents?
XCXc x XCY
Two potential devices that eukaryotic cells use to reduce the rate of transcription are histone __________methylation and DNA _____________.
acetylation methylation
hromosome modifications that are used to regulate transcription include histone _______ and DNA ______.
acetylation................ methylation
Which of the following statement indicates similarities between cellular respiration and photosynthesis.
both utilize a proton-motive force by a H+ gradient to produce ATP
The protein shell that encloses a viral genome is the _________.
capsid
Which of the following atoms have an electronegativity value most similar to hydrogen?
carbon
Which of these common elements found in biological molecules has four electrons in the valence shell?
carbon
Hydrophobic interactions___.
can hold two nonpolar molecules together
The cloning of a plant from somatic cells, first demonstrated by F.C. Steward, is consistent with the view that ________.
differentiated cells retain all the genes of the zygote
During embryonic development, the process by which cells specialize is _______; and the process by which form develops is ________.
differentiation ..................... morphogenesis
Consider a hypothetical population of kangaroos. The plants the kangaroos prefer to eat undergo an adaptation that results in taller plants. Kangaroos with longer necks are more successful in foraging for food and exhibit greater reproductive success. Over thousands of years, the necks of the kangaroos of this population increase in length. This is an example of _________ selection.
directional
A man has an autosomal dominant genetic disorder. This means _________.
the gene is not located on a sex chromosome
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as _____.
feedback inhibition
Three populations of squirrels have characteristics as described in this table. All three populations had the same allele frequencies one year ago, the allele A frequency was 0.70 and the allele a frequency was 0.30. Population 1 initially was part of Population 3. Population 2 had a population size of 250 members last year before a flash flood swept through their habitat. Population: initial; 1; 2; 3 Age of population: 1 year; 10 years; 10 years Population size: -, 10, 50, 200 allele A frequency: .70, .30, .60, .70 allele a frequency: .30, .70, .40, .30 Based on this information, population 1 allele frequencies are experiencing genetic drift, likely caused by a ______. Based on this information, population 2 is experiencing genetic drift likely caused by __________. Currently, the population least susceptible to a bottleneck effect is population _____
founder effect bottleneck effects population3
If this cell is permeable to water, glucose, and fructose, but impermeable to sucrose, which of these solutes will exhibit a net diffusion into the cell? Cell- 0.03 M sucross and 0.02 M glucose Environment- 0.01 M sucrose and 0.01 M glucose and 0.01 M fructose
fructose
What phage reproductive cycle is associated with release of new phages and death of the bacterial host?
lytic cycle
Below are five events describing the process of mRNA degradation by miRNA. They are in alphabetical order. Dicer, an enzyme, cleaves the precursor miRNA into small fragments miRNA binds to complementary mRNA mRNA is degraded or translation is blocked at the ribosome one strand of the miRNA binds a protein complex, the other strand is degraded the precursor miRNA forms a hairpin loop Which of these events occurs fifth?
mRNA is degraded or translation is blocked at the ribosome
In plants, haploid cells are produced from diploid cells by
meiosis
in animals, gamete cells are produced b
meiosis
A common feature of all sexual life cycles, is that the chromosome number remains stable over generations because ___ and ____ always alternate.
meiosis ............... fertilization
The protein and carbohydrate composition on the interior and exterior sides of a plasma membrane are asymmetric. One reason for this is that ____.
membrane proteins modified inside of the Golgi end up on the outside of plasma membranes
Cattle and poultry are often treated with high levels of antibiotics to keep the animals from developing sicknesses. Over time the animals have become more susceptible to illness because the bacteria have developed resistance to the antibiotics
natural selection
A proficient engineer can easily design skeletal structures that are more functional than those currently found in the forelimbs of such diverse mammals as horses, whales, and bats. That the actual forelimbs of these mammals do not seem to be optimally arranged is because __________________.
natural selection is generally limited to modifying structures that were present in previous generations and in previous species
For a biologist studying a small fish population in the lab, which Hardy-Weinberg condition is the most difficult to meet?
no genetic drift
the enamal on teeth is resistant to most substances except acids.In regard to enamal on teeth, which of the following should be avoided?
orange juice lemons
transport processes that do not require energy are__ processes.
passive
which of the following macromolecules is not a polymer?
phospholipids
Much of the diversity of macromolecules found in living organisms is due to the polymeric nature of these molecules, which are composed of a limited number of unique monomers. For each monomer listed, identify the polymer it can be a part of. glucose- nucleotides- amino acids-
polysaccharides DNA or RNA proteins
you determine at one of the samples has a linear, unbranched polymeric chain. is this sample starch or glycogen?
starch
which of the samples, starch or glycogen, is obtained from a plant?
statch
The ultimate source of energy for the synthesis of organic molecules by photosynthesis is _______.
sunlight
Which of the following occurs in meiosis but not in mitosis?
synapsis and alignment of tetrads at a metaphase plate
In natural selection, _____ determines which phenotypes are successful.
the environment
You are presented with a sample of an enzyme of unknown function. An enzyme catalyzes a chemical reaction. You test the enzyme in three solutions described below. You measure the average number of monomers present in the polymers in each sample before, and one hour after, adding the enzyme to each solution. Which of the following is a potential explanation for these observations? Solution-A,B,C Solution Contents- DNA, Protein, polysaccharide avg. # of monomers/polymer 0 hr- 3000, 300, 600 avg. # monomers/polymer 1 hr- 300, 300, 600
the enzyme hydrolyzes phosphodiester bonds in DNA
Taxol is an anticancer drug. In animal cells, taxol disrupts microtubule formation and stops mitosis. Specifically, taxol must affect ___________.
the fibers of the mitotic spindle
