BIO Final Exam Review
A male is heterozygous for the trait that produces freckles on the skin, and he has freckles. If he marries a woman who is also heterozygous for freckles, ________ percent of their children are predicted to be freckled. Also, of all their children, ________ percent are predicted to be heterozygous.
75%, 50%
Which of the following could not result from mutations?
A fish in a stream dies from a poison that blocks cellular respiration.
What would result from a single nucleotide deletion (point mutation) within the coding sequence of a structural gene?
A frameshift mutation, producing a completely different amino acid sequence
What type of plant would be least affected by the loss of the guard cell function that closes stomata?
A rainforest plant.
Which of the following base pairs would be targeted and repaired by a mismatch repair system?
A-G
The purpose of the light reaction is to produce __________.
ATP and NADPH
Which best explains the role of plant pigments in photosynthesis?
Absorb light energy
Without the work of Rosalind Franklin, Watson and Crick would not have known
All of the choices are correct.
What is a feature of woody stems (in temperate regions) but not of herbaceous stems?
Bud scale scars
Which adaptive root type do tropical trees have?
Buttress roots
Which relationship about nucleotide composition in DNA is correct?
C+A=G+T
In which organelle of the plant does photosynthesis takes place?
Chloroplast
Where does the Calvin cycle occur?
Chloroplast stroma
Normally, crossing over occurs between homologous regions of homologous chromosomes. Sometimes mistakes happen, and crossing over occurs between non-homologous regions of homologous chromosomes, resulting in duplications and deletions. What characteristic of a chromosome would make non-homologous recombination more likely?
Chromosomes that have duplicated regions within them
Griffith first proposed the "transformation principle" through his studies on Streptococcus pneumoniae bacterium. What molecule was later found to be responsible for this phenomenon?
DNA
Which of the following best describes transcription?
DNA -> RNA
Which molecule is responsible for separating double-stranded DNA into single strands?
DNA helicase
If you have a double-stranded synthetic piece of DNA that you want to attach to a PCR product, which enzyme would be used to join together two molecules.
DNA ligase
After a fragment of DNA containing the gene of interest has been inserted into a vector, how are the gaps between the two pieces of DNA sealed together?
DNA ligase catalyzes the formation of covalent bonds in the DNA backbone.
What is the closest parallel in animal structural levels of complexity to the branches, buds, flowers, seeds, and fruits of flowering plants?
Digestive system, reproductive system, skeletal system.
In germline cells, when does DNA replicate?
During S phase
Non-disjunction of chromosome 1 occurs in a cell undergoing Meiosis II. At the end of Meiosis, what would you expect to see in the four gametes?
Four daughter cells, two normal, one that is missing chromosome 1, one with two copies of chromosome 1
In humans, the trait of freckles exhibits simple Mendelian inheritance patterns. The allele for freckles is dominant (F), and the allele for no freckles is recessive (f). An individual who is heterozygous for freckles would have which of the following phenotypes?
Freckles
A cell that is an environment that has an abnormally low pH will NOT pass through which checkpoint?
G1
Using the chart at the beginning of the animation and your knowledge of cells, in what stage of the cell cycle do most cells spend the majority of their lives?
G1
Which of the following represents the correct order of the phases of the cell cycle?
G1 -> S -> G2 -> M
The cell cycle is regulated by checkpoints during the _______ phases.
G1, G2, and M
DNA repair enzymes will be highly active during what phase of the cell cycle?
G2
The success of DNA replication is assessed during the ______ phase.
G2
Following treatment with restriction enzymes, what procedure would be used to separate DNA fragments of different lengths?
Gel electrophoresis
Which feature of DNA represents the highest (or most complex) level of structure?
Genome
Assuming the plant survives, predict what would occur if you removed the shoot apical meristem of a plant embryo.
Growth would only occur at in the roots.
Identify a reactant in the light reaction of photosynthesis.
H2O
A diploid parent cell with genes H, T, and Q has a maternal genotype HTQ and paternal genotype htq. What would be the most likely daughter cell genotype if independent assortment does NOT occur?
HTQ
Eyelash length is an inherited trait. In the human population, there is an eyelash length gene. There are two possible variants of this gene—an allele for long eyelashes (>1cm) and an allele for short eyelashes (1 cm or less). The allele for long eyelashes is dominant (L) and the allele for short eyelashes is recessive (l). An individual who is heterozygous for eyelash length would produce which of the following gametes?
Half of the gametes would have the L allele and half of the gametes would have the l allele.
Which of these organisms consume organic molecules to live?
Heterotrophs
In which pair of organisms would you predict the DNA sequences of the β-globin gene family are the most similar?
Human and chimpanzee
Place the following events of mitosis in the correct order. I. Sister chromatids align on the metaphase plate .II. The cleavage furrow forms .III. The nuclear membrane breaks up. IV. Sister chromatids begin to condense. V. Sister chromatids separate.
IV, III, I, V, II
What is a difference between DNA replication and RNA transcription?
In DNA replication the helix is never closed after it is opened by helicase, but once RNA polymerase has finished transcribing a region, the double helix closes
What is a dominant allele?
In a heterozygous individual, the allele that determines the phenotype
________ occurs when 50% of a protein produces a different phenotype than that produced by 100% or 0% of the protein.
Incomplete dominance
Which function of genetic material allows for the expression of proteins?
Information storage
How does crossing over increase variation in a population?
It produces offspring with combinations of alleles that neither parent carried.
Docetaxel is a drug that is used in the treatment of cancer. It interferes with cell division by inhibiting microtubule depolymerization. Specifically, what effect will this have on mitosis?
It will prevent sister chromatids from separating during anaphase.
The fact that maternal and paternal chromosome pairs line up randomly during metaphase of meiosis supports Mendel's __________.
Law of Independent Assortment
Which molecule catalyzes covalent bond formation between fragments of DNA?
Ligase
Crossing over often occurs during prophase. How could scientists use an easy-to-measure trait that is linked to the gene responsible for a certain genetic condition to locate the disease-causing gene?
Linked traits occur very close together on a chromosome, so they are not usually separated by crossing over.
Eyelash length is an inherited trait. In the human population, there is an eyelash length gene. There are two possible variants of this gene—an allele for long eyelashes (>1cm) and an allele for short eyelashes (1 cm or less). The allele for long eyelashes is dominant (L) and the allele for short eyelashes is recessive (l). An individual who is heterozygous for eyelash length would have which of the following genotypes?
Ll
Eyelash length is an inherited trait. In the human population, there is an eyelash length gene. There are two possible variants of this gene—an allele for long eyelashes (>1cm) and an allele for short eyelashes (1 cm or less). The allele for long eyelashes is dominant (L) and the allele for short eyelashes is recessive (l). An individual who is heterozygous for eyelash length would have which of the following phenotypes?
Long eyelashes
Why must the life cycle of sexually reproducing species alternate between haploid and diploid stages?
Meiosis must occur at some point in the life cycle to prevent a doubling of chromosomes in each generation.
Which of the following statements about cancer is FALSE?
Most cancers involve genetic changes that are passed from parent to offspring.
Why do chromosomes condense during prophase?
So that they will not be damaged when they are moved around the cell
In pea plants, a single gene controls pea texture. Smooth (S) peas are dominant over wrinkled (s) peas. A plant with smooth peas is crossed with a plant with wrinkled peas. Of the progeny, 252 are smooth and 247 are wrinkled. What are the genotypes of the parent plants?
Ss and ss
You cut a plasmid with a restriction enzyme that cuts it into three pieces—one fragment is 240 base pairs, one fragment is 600 base pairs, and one fragment is 1200 base pairs. You carry out electrophoresis of the digested sample. Which of the fragments will be closer to the top of the gel where the sample was inserted?
The 1,200 base pair fragment.
Type S Streptococcus pneumoniae bacterium is lethal and will kill its host. If heat inactivated, the S strain dies and becomes nonlethal. Type R Streptococcus pneumoniae is a nonvirulent strain of bacteria. What would occur if one were to inject both the R strain and heat-killed S strains into a host organism such as the mouse?
The R strain would be transformed into the virulent S strain and the host would die.
What quality of the traits that Mendel chose to study allowed him to establish the basic laws of inheritance?
The alleles that he studied were either dominant or recessive.
A chromosome has undergone a translocation that has completely deleted its centromere region, preventing association with spindle fibers. Other than this loss of sequence, the remaining DNA of this chromosome is undamaged. What will be the fate of this cell?
The cell will not pass the M checkpoint because its chromosomes will not all associate with spindle fibers.
In order to produce human insulin in bacteria what must be done first?
The coding sequence of the genes which produce human insulin must be isolated.
Two identical cells heterozygous for gene Q are undergoing meiosis. What is the probability that two haploid gametes selected from the products of meiosis both contain a recessive allele for gene Q?
0.25
Which of the following sequence pairs is a palindrome?
5′-TCCGGA-3′ 3′-AGGCCT-5′
If a DNA template strand has a sequence of 3′ TACAATGTAGCC 5′, the RNA produced from it will be which sequence?
5′AUGUUACAUCGG3'
What is the overall equation for photosynthesis?
6 CO2 + 12 H2O + Light energy → C6H12O6 + 6 O2 + 6 H2O
The process by which haploid cells are produced from diploid cells is called
meiosis.
During which stage of meiosis would you find a cell with a diploid chromosome number and recombinant chromosomes?
metaphase I
When cancer cells have the ability to migrate to other parts of the body, they are said to be
metastatic.
Centromeres divide in
mitosis and meiosis II.
The life cycle of a sexually reproducing multicellular organism must include which processes?
mitosis, meiosis, and fusion of the gametes.
A eukaryotic cell that receives a "go-ahead" signal at the G1 checkpoint of the cell cycle will
move into the S phase and continue the cell cycle.
A crossover in meiosis is an exchange of genetic material between
non-sister chromatids of homologous chromosomes.
The building blocks of DNA are
nucleotides.
A cell secretes a growth factor that binds to receptors on neighboring cells causing them to proliferate. This is an example of
paracrine signaling.
The nucleotides within DNA are composed of a
phosphate group, deoxyribose sugar, and nitrogenous base.
The organisms that most specifically utilize light energy to make organic molecules from inorganic molecules are __________.
photoautotrophs
When a single-gene mutation can have phenotypic effects at multiple stages of development, it is
pleiotropic.
In a eukaryotic cell, the direct product of transcription is
pre-mRNA.
A tumor suppressor gene normally functions to
prevent development of cancer.
A plant performing photosynthesis will __________.
produce oxygen and consume carbon dioxide
The segment of the DNA molecule where messenger RNA synthesis begins is called the
promoter region.
The arms of the sister chromatids dissociate from each other during ________ of mitosis.
prophase
Which of the following represents the correct order of the phases of mitosis?
prophase -> metaphase -> anaphase -> telophase
A substrate binding to an enzyme is most similar to a signal molecule binding to a
receptor.
The mechanism of DNA replication is
semiconservative.
Human males produce
sperm, half contain an X chromosome, half contain a Y chromosome.
The main structure for gas exchange in plants is called the __________.
stomata
What serves as the "translator" or intermediary between an mRNA codon and an amino acid?
tRNA
Photorespiration __________.
tends to occur under dry and hot conditions
During the G2 phase, the cell is preparing for mitosis. Using your knowledge of cellular organelles and molecules, which molecule is produced in the highest quantity during the G2 phase?
tubulin, the microtubule proteinCorrect
Mendel's Principle of Segregation states that
two alleles of a gene separate during gamete formation such that every gamete receives only one allele.
Meiosis I produces ________ cells, and meiosis II produces ________ cells.
two haploid, four haploid
A tetrad is made up of
two homologous chromosomes, each consisting of two chromatids.
If you wanted to install lights to grow plants indoors, the type of light would you want to use is __________.
visible light, because it has low energy wavelengths
Oncogenes and tumor-suppressor genes have the shared property that
when either type of gene is mutated, cancer can result.
If there is an error during the transcription of a gene, what will be the consequence?
The final protein might not be functional.
What do you predict would happen if flower growth became indeterminate?
The flowers would be enormous.
Which of the following is most likely to be true about the mouse and rat myosin genes?
The genes are similar in sequence, but not identical.
How do you know that the gene being transcribed in the animation is in a prokaryote?
The initiation of transcription involves a sigma factor.
What can be said about the leading versus the lagging strand in DNA population?
The leading strand is replicated continuously for the entire length of the chromosome, while the lagging strand is replicated in pieces.
What is the function of the poly A tail?
The poly A tail increases mRNA stability in eukaryotes.
Two identical twins were separated at birth, one grew up in a prosperous home with ample food and time for rest. The other twin was tragically abandoned and grew up in and out of foster homes and living on the streets. After more than 20 years, the two twins were reunited, but despite their identical genomes, the twins looked very different. The most noticeable difference was their difference in stature, the prosperous twin was tall and well built, while the abandoned twin was short and scrawny. How can you explain these differences?
The poor twin was undernourished as a child, and as a result he was unable to reach the full potential of his genes.
If there is an error during translation of a gene, what will be the consequence?
The protein might not be functional.
Mitosis results in the formation of two genetically identical daughter cells. This is because
all the genetic material is duplicated then segregated equally to the daughter cells.
The two-factor crosses performed by Mendel support the observation that
alleles of one gene are distributed randomly among an individual's gametes, independent of the alleles for other genes.
The production of second messengers in signal transduction offers at least two advantages, speed and
amplification.
A ribozyme is _____.
an RNA that catalyzes a chemical reaction
Most human embryos that are aneuploid
are spontaneously aborted in the first trimester.
A cell secretes a growth factor that binds to receptors on its own membrane preventing it from proliferating. This is an example of
autocrine signaling.
A comparison of mitochondria and chloroplast shows that __________.
both generate ATP via a H+ electrochemical gradient
A carcinogen is a chemical or treatment that
causes mutations that can affect gene activity.
The process through which cells can detect and respond to signals in their extracellular environment is called
cell communication.
Should a genetic abnormality arise, ________ prevent a cell from progressing uncontrollably through the cell cycle.
checkpoint proteins
The law or theory that inheritance patterns of traits can be explained by the transmission of chromosomes during meiosis and fertilization is the
chromosome theory of inheritance.
Which of the following events do NOT occur in prophase of mitosis?
chromosomes are replicated
A vascular bundle
contains xylem and phloem tissue
The formation of the bivalent during meiosis
contributes to the genetic diversity of a species.
The division of the cytoplasm is called
cytokinesis.
The most common eukaryotic ribosome carries out its function in the
cytosol.
Because more than one codon can specify the same amino acid, the genetic code is said to be
degenerate.
Sodium ions move from one cardiac muscle cell to an adjacent cell causing them to contract in unison. This is an example of
direct intercellular signaling.
The major role meiosis plays in chromosomal inheritance is to
double the amount of DNA and reduce the chromosome number in daughter cells from 2N to 1N.
The processes of transcription and translation are collectively known as
gene expression.
An organized unit of DNA sequences that enables a segment of DNA to be transcribed into RNA and ultimately results in the formation of a functional product is called a
gene.
During interphase, a eukaryotic cell would be expected to
grow, replicate its DNA, and prepare for mitosis.
The major way that meiosis II differs from mitosis is that
in meiosis II, the cells are haploid.
If a pink snapdragon is self-fertilized, the offspring are red, pink, or white. What type of inheritance pattern does flower color exhibit in this example?
incomplete dominance
Intervening sequences that are transcribed, but not translated into protein are called
introns.
The centromere
is a region of DNA where sister chromatids associate.
Gene cloning
is the process of making multiple copies of a gene.
The mitotic spindle fibers attach to chromosomes via special structures termed
kinetochores.
NADPH is produced by __________.
light reactions alone
Which of the following is an overgrowth of cells that serves no useful purpose?
Tumor
If a homologous pair of chromosomes fails to separate during meiosis I, what will be the result?
Two gametes will have 2 of the affected chromosomes and 2 gametes will have 0 of the affected chromosomes.
Why is Taq polymerase used in a polymerase chain reaction (PCR)?
Unlike other DNA polymerases, Taq polymerase is heat stable and survives the 94 degree denaturation step in PCR.
Which characteristic of genetic material accounts for viruses that cause different diseases, such as the common cold and polio, in humans?
Variation within and between species
At what point in gene expression do molecules go from being information storage molecules to metabolic and structurally functional molecules?
When RNA is translated into protein.
All of the following are chemical mutagens EXCEPT
X-rays.
Consider a diploid cell that contains genes Y, R, and Z on separate chromosomes. What is one likely genotype of a daughter cell if the parent cell with genotype YyRRZz undergoes meiosis?
YRZ
A DNA library is
a collection of recombinant vectors containing DNA fragments of a given organism.
An X-linked gene is
a gene on the X chromosome.
What features of meiosis allow for independent assortment of chromosomes?
Random alignment of homologous chromosomes on the metaphase plate
Which factors are utilized by the cell to recognize the stop codon and disassemble the translation machinery?
Release factors
Chromosomes are replicated during the ______ phase.
S
DNA polymerase can be described as and enzyme that ____.
adds nucleotides to the 3′ end of a growing DNA strand.
Ionizing radiation can produce which of the following?
free radicals
The structure that causes the synthesis of RNA to cease is known as the
transcription terminator.
The process that produces mRNA from DNA is called
transcription.
The complimentary messenger RNA strand that would be synthesized from the DNA base sequence of 5'-CTGAC-3' would be _______.
3'-GACUG-5'
Consider an organism whose diploid karyotype shows it to have a total of 60 chromosomes. How many chromosomes would be contained in the sperm of this organism?
30
Which DNA strand is complementary to 5′-ATTCGGTGA-3′?
3′-TAAGCCACT-5′.
Red-green colorblindness in humans is caused by a sex-linked recessive allele. A color-blind man marries a woman with normal vision whose father was color-blind. The couple has a son. What is the probability that he is colorblind?
1/2
If a house cat has 76 total chromosomes, how many sister chromatids would it have at the end of metaphase of Meiosis I?
152
Cells from the fruit fly Drosophila melanogaster contain four pairs of chromosomes. What is the number of possible chromosome orientations in that cell?
16
Which of the following describes meiosis II in humans?
1N -> 1N
If crossing over occurs between two chromatids on a single pair of homologous chromosomes, how many gametes will have a recombinant chromosome?
2 of the 4
Which sequence of events CORRECTLY describes the initiation and elongation steps of translation in prokaryotic cells? (1) Initiator tRNA binds start codon on mRNA (2) Small ribosomal subunit binds to mRNA (3) Large ribosomal subunit binds( 4) tRNA entry and peptidyl transfer reaction (5) Translocation of ribosome and release of tRNA
2, 1, 3, 4, 5
Arrange the following events in the proper order. In which they occur during meiosis I. 1 = Separation of homologous chromosomes 2 = Synapsis 3 = Crossing-over 4 = Independent assortment
2, 3, 4, 1
A DNA specimen that contains 30% guanine has ________ thymine.
20%
Humans have __________ different pairs of autosomes.
22
How many nucleotides are contained in a single codon?
3
Which statement describes a reason ribosomal genes are useful for comparing evolutionary relationships among organisms?
All organisms possess these genes and they can be compared with each other.
What would be a likely outcome if the alignment of maternal and paternal chromosomes during metaphase of meiosis did not adhere to Mendel's Law of Independent Assortment?
Alleles for genes would tend to be inherited together because chromosome pairs would align non-randomly.
What was one of the pieces of evidence most critical to the discovery of DNA structure?
An X-ray diffraction pattern suggesting a double helix shape.
The cellular division that changes the chromosome ploidy number from 2N to 1N occurs during __________.
Anaphase of Meiosis I
Which statement about mitosis and cytokinesis is TRUE?
At the end of cytokinesis there are two daughter cells with a normal complement of diploid genetic material.
You transform bacteria with a plasmid carrying the ampicillin-resistance gene ampR. How would you determine which bacteria took up the plasmid?
Bacteria containing the plasmid would be able to grow in the presence of ampicillin.
Which of the following statements about crossing over is TRUE?
None of these statements are true regarding crossing over.
Beginning with the simplest level of structure, which order of organization of genetic material is CORRECT?
Nucleotide, strand, double helix, chromosome, genome.
The products of photosynthesis are __________.
O2 and carbohydrates
Which is involved in replicating the lagging strand of DNA, but is not involved in leading strand DNA replication?
Okazaki fragments
Which of the following is true concerning a somatic cell mutation?
Only a small group of cells within the organism is affected by the mutation.
The amino acids of a growing polypeptide chain are held together by what kind of bond during the elongation stage of translation?
Peptide
The equation, 6CO2 + 6H2O →C6H12O6 + 6O2, describes which process?
Photosynthesis
Which of the following vectors undergo transformation to get into bacterial cells?
Plasmid
Which adaptive root type do mangrove trees have?
Pneumatophores
A small amount of DNA is collected from a crime scene. However, the amount of DNA collected is insufficient to perform the necessary experiments to link a suspect to the crime. Which method could be utilized to increase the amount of DNA?
Polymerase chain reaction (PCR)
Which of the following best describes translation?
RNA -> Protein
Why is there a need to produce Okazaki fragments on the lagging strand, but not on the leading strand of DNA?
The two parental strands of DNA are antiparallel and DNA polymerase makes DNA in the 5′ to 3′ direction only.
Which statement best describes the value of DNA microarrays to medical research?
They can determine how the environment can regulate genes that cause disease.
What is TRUE of restriction enzymes?
They protect bacterial cells from invasion by foreign DNA.
If you add the plant hormone auxin to one side of a plant, the cells exposed to the auxin elongate. If you measured auxin levels in a plant stem exposed to lateral light, what would you expect to find?
They would be lower on the illuminated side than on the shaded side, causing the plant to bend towards the light.
Which of the following statements about microtubules during anaphase is TRUE?
Those attached to chromosomes shorten, while those that are unattached elongate.
Hormones are released from one cell and act on other cells in distant organs. This is an example of
endocrine signaling.
When insulin is secreted from the pancreas and acts on muscle cells to increase glucose uptake, this is an example of
endocrine signaling.
Root hairs are specialized
epidermal cells.
At the end of meiosis I
the cells are haploid and the homologous pairs are in separate cells.
The color of petunia flower can be changed from red to blue by altering the pH of the soil. This is an example of
the environment influencing the phenotype.
In a haploid dominant species
the multicellular organism is haploid, and only the zygote is diploid.
Incomplete dominance is when
the phenotype of a heterozygote is not the same as either parent, but it is somewhere between the two parents.
In some cases, just a few hormone molecules binding to the surface of a cell can trigger a very large response because
the signal is amplified by activation of enzymes that each catalyze multiple reactions.
The ultimate source of energy for reactions in a plant is __________.
the sun
How can one distinguish between annuals, biennials, and perennials?
the time from seed germination to seed production
The single-factor crosses performed by Mendel support the observation that
the two alleles for a given gene are distributed randomly among an individual's gametes.
The energy for producing organic molecules in plants is directly driven by __________.
the use of light to provide electrons for oxidation and reduction reactions
Restriction enzymes are invaluable tools in gene cloning because
they cut at specific sites within the DNA and produce sticky ends allowing DNA from different sources to be joined together.