Bio Exam 3
Identify the key structural features of a DNA molecule.
-DNA strands are antiparallel and include a 5′5′ end and a 3′3′ end. -DNA bases are always paired purine with pyrimidine. -The backbone of DNA is made of a sugar and a phosphate molecule.
Where does translation start? What is a ribosome? What is the role of tRNA? WHAT IS AN ANTICODON AND WHERE IS IT LOCATED
AUG
Which mRNA codon functions as the start codon, directing the ribosome to begin translating the mRNA from the correct end?
AUG
Identify the definition and example for each term. Allele Genotype Phenotype
Allele -A variation of a gene - B or b Genotype -The allele combinations an organism has -BB Phenotype -The physical expression of a gene -Freckles
Which enzyme unzips the DNA molecule?
DNA helicase
Classify each description as true of introns only, true of exons only, or true of both introns and exons.
Introns only -generally absent from bacterial genomes -removed from initial mRNA strand prior to translation Exons only -code for a protein -part of the final mRNA strand Both introns and exons -present in the DNA used as the template for transcription -present in eukaryotic genomes
Label each level of DNA packaging and the eukaryotic chromosome with the appropriate term
Left to right: Chromosome Supercoil Tight helical fiber Nucleosome Histone protein DNA double helix
What are the monomers of DNA?
Nucleotides
The diagram depicts the molecular structure of DNA. Label the diagram with the names of the three components and we're kind
O-P=O : Phosphate group Connecting Lines : Deoxyribose N-N-N: Nitrogenous base
How are DNA fragments separated using gel electrophoresis?
Smaller DNA fragments move through the gel more quickly than larger‑fragments.
What are the sex chromosomes? What combination of the chromosomes determines if an individual is male? Female?
The sex chromosomes are referred to as X and Y, and their combination determines a person's sex. Typically, human females have two X chromosomes while males possess an XY pairing.
Before DNA synthesis begins, a short RNA nucleotide sequence that is paired to a template strand of DNA must be synthesized. What is the name of that RNA nucleotide sequence?
primer
What the function of telomeres?
to cap the chromosome ends to minimize the loss of DNA during rounds of cell replication
The first step in gene expression is
transcription
The codon table identifies the amino acid sequence that can be translated from a human mRNA sequence. This chart can also be used to identify amino acid sequences for other organisms. Select all of the organisms that use the codon assignments shown in the codon table.
whale shark rose bush cat Staphylococcus aureus rattlesnake (ALL ANSWERS)
At the end of your biology class, your professor asks you to develop a project to determine the genotype of a plant with red flowers. Red petal color (R) is dominant to pink flower color (r). To accomplish this task, you cross the plant with the unknown genotype with heterozygous red‑flowered plants. Which ratios are valid predictions of flower colors in the offspring?
- All redflowers - 3 red : 1 pink flowers
During his experiments with pea plants, Gregor Mendel crossed plants that were heterozygous for two traits with one another in order to determine laws of inheritance. The Punnett square shows the results of this cross. Select the statements that are true about Mendel's law of independent assortment.
-A dihybrid cross between heterozygous individuals will result in exactly nine genotypes. -Allele pairs do not influence one another during segregation for gamete formation.
In meiosis, a diploid cell divides into reproductive cells called gametes. The provided diagram shows chromosome separation during gamete production. Using the diagram, select the statements that are true about Mendel's law of segregation.
-Each parent provides one allele for each gene. -Each gamete carries one version of each gene.
Using the codon table, what conclusions can be drawn about the genetic code?
-Many amino acids are encoded by multiple codons. -Three codons do not code for amino acids.
An analysis is performed to determine the proportions of each of the four nucleotide bases in the DNA of several tissue samples from various species. The results appear in the table. Which conclusions can be drawn from this data?
-The proportion of purines is roughly equal to the proportion of pyrimidines. -The proportion of C is roughly equal to the proportion of G. -The proportion of T is roughly equal to the proportion of A.
Consider the amino acid sequence: Serine−Alanine−Proline−Aspartic acid Identify the mRNA codon sequences that would be translated into this amino acid sequence.
-UCC-GCU-CCU-GAC -UCG-GCG-CCC-GAU -UCU-GCA-CCA-GAC
Determine which statements describe silent mutations. The adenine of the start codon is position +1.
-a substitution from G to T in the arginine codon of the antisense stand -a transition at position +6 in the sense strand
In the lower half of the interactive, change the template DNA strand such that the sequence ...AACCTG......AACCTG... is changed to ...AACTTG......AACTTG... Which of the terms correctly describes this type of mutation? If this mutation occurred in a protein‑coding gene, how would it be classified?
-substitution -nonsense mutation
Diploid organisms, such as humans and other mammals, have two copies of their genetic material in the form of homologous chromosomes. One copy of each homologous chromosome is passed to the organism from each of its parents during the process of fertilization. For many genetic traits, a diploid organism is said to be either homozygous or heterozygous at a particular locus, depending on whether its parents passed down two of the same or two different alleles for that specific sequence. Which describes a homozygous locus?
-the alleles at a particular position on homologous chromosomes of an individual who expresses a recessive trait -two of the same alleles are found in a particular position on homologous chromosomes
Earwax type is a Mendelian human trait. Specifically, wet earwax (W) is a dominant allele, and dry earwax (w) is a recessive allele. Given parents with WW and ww genotypes, what is the probability that their child will have a dry earwax phenotype? Enter your answer as a percentage.
0%
Questions about the structure of the DNA molecule: 1.what holds the two strands of the molecule together? 2.If you think of a DNA molecule as a ladder, what represents the steps of the ladder and what represents the side supports of the ladder? 3.What does it mean to say that the strands of a DNA molecule are antiparallel? 4.How do you define the 5' end of a DNA strand 5.The 3' end? 6.What are the complimentary base pairing rules? 7.What is the complimentary strand to this DNA sequence: 5'-ACGTCCGGCTGACT-3'?
1. Hydrogen bonds 2. Steps-Nitrogenous bases Sides-phosphate backbone 3. two molecules that are side by side but run in opposite directions 4."5 prime end" has a free hydroxyl (or phosphate) on a 5' carbon 5.3 prime end" has a free hydroxyl (or phosphate) on a 3' carbon 6. a-u t-a g-c c-g (no t) in rna in dna a-t t-a g-c c-g 7. 3' -TGCAGGCCGACTGA-5'
In a hypothetical mouse species, brown fur (B) is completely dominant to white fur (b), and long fur (L) is completely dominant to short fur (l). If two mice heterozygous for both traits mate and produce a litter of pups, what is the probability that an individual pup will have white, short fur?
1/16
If you were to toss the three coins shown in the air, what is the probability that all three would land with the heads side up?
1/8
Each codon on the mRNA represents an amino acid. How many codons could be formed if each codon was two bases long?
16
If the new DNA strand is synthesized in the 5'-3' direction which direction does DNA polymerase read the template strand
3'-5'
Translation practice: 5'-CCAUGGGGUUUAGCGCAUAGAGA-3'
3'-GGTACCCCAAATCGCGTATCTCT-5'
During replication the new DNA strand is synthesized in the
5'-3' direction
Which direction are the new strands of DNA synthesized? Which direction is the template strand read?
5-3 3-5
A couple that already has two daughters wants to have another child. The couple is hoping for a son. What is the probability that the couple's third child will be a boy? Record your answer as a percentage.
50%
The segment of DNA is unwound in preparation for transcription. 5′ GTGCTGGTA 3′5′ GTGCTGGTA 3′ 3′ TAGGCATCA 5′⟵template strand Identify the mRNA transcript that would be produced from this DNA sequence.
5′ AUCCGUAGU 3′
In pea plants, the allele for red flower color, F, is completely dominant to the allele for white flower color, f. Complete the Punnett square showing the genotypes possible among the offspring when two heterozygous individuals are crossed. Use the information from the Punnett square to answer the second question. In this cross between two heterozygous pea plants, what are the chances that an offspring with red flowers will be produced?
75%
What is a promoter sequence?
A DNA sequence that is the initial binding site of RNA polymerase during transcription.
The bacteria Streptococcus pneumoniae has a virulent S strain and a nonvirulent R strain. The S strain is lethal to mice. The S strain contains a chemical factor that can transform the R strain to be virulent. The diagram shows a series of experiments conducted by injecting combinations of these strains into mice to identify the transforming factor. A R strain (nonvirulent) B S strain (virulent) C Heat‑treated S strain D R strain and heat‑treated S strain E R strain and heat‑treated S strain with polysaccharides, lipids, RNA, and proteins destroyed F R strain and heat‑treated S strain with polysaccharides, lipids, RNA, proteins, and DNA destroyed If DNA is the transforming factor, match the expected results of each experiment by placing the appropriate mouse image.
A R strain (nonvirulent) - Alive B S strain (virulent) - Dead C Heat‑treated S strain - Alive D R strain and heat‑treated S strain - Dead E R strain and heat‑treated S strain with polysaccharides, lipids, RNA, and proteins destroyed - Dead F R strain and heat‑treated S strain with polysaccharides, lipids, RNA, proteins, and DNA destroyed - Alive
What is monohybrid cross?
A cross between individuals heterozygous for a single character. A cross between two individuals who are heterozygous for one trait
Which scenario is an example of epistasis?
A horse with a dominant allele at the B gene is black. A horse with a dominant allele at the G gene is gray. However, a horse with dominant alleles at both the B gene and G gene is gray.
What is the difference between how the lagging strand and the leading strands are replicated? What are Okazaki fragments?
A leading strand is the strand which is synthesized in the 5'-3'direction while a lagging strand is the strand which is synthesized in the 3'-5' direction. The leading strand is synthesized continuously while a lagging strand is synthesized in fragments which are called Okazaki fragments
Which event occurs during eukaryotic translation termination?
A protein recognizes the stop codon, and the ribosome dissociates from the mRNA.
Why did this substitution mutation have the greatest impact?
A stop codon was changed to one encoding an amino acid, elongating the polypeptide.
Which of the events occur during eukaryotic translation elongation?
A tRNA binds a codon and the ribosome adds amino acids from each tRNA to the polypeptide chain.
In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (A) is dominant over albinism (a). For this question, assume it is a single gene with two alleles. If both parents display the albino phenotype, what possible phenotypes may be observed in their offspring?
Albinism only
Mendel formulated the law of independent assortment to explain the basic rules of inheritance based on his experiments with pea plants. With the modern understanding of chromosomes, alleles, and the process of gamete formation, what is the physical basis for the law of independent assortment?
Alleles on nonhomologous chromosomes separate randomly into gametes during meiosis.
How did Mendel use self‑pollination and cross‑pollination techniques in his experiments with flower color to observe the basic patterns of inheritance?
By cross‑pollinating a parental generation of plants with different‑colored flowers and allowing the F1 generation to self‑pollinate, Mendel observed the basic patterns of inheritance in the F2 generation.
Classify each example as either a character or trait of a pea plant.
Character -Flower color -Seed color -Seed shape -Pod color -Stem length Trait -Purple flower -Yellow seed -Round seed -Yellow pod -Short stem
The dominance pattern of a gene can be determined from the phenotypes of the parents and offspring. In the examples below, assume that each parent is homozygous for the specific allele and that the progeny are heterozygous. Classify each example as either: complete dominance incomplete dominance codominance.
Complete dominance\ -A pea plant with smooth seed and a pea plant with wrinkled seeds produce a pea plant with smooth seeds Incomplete dominance -A red snapdragon and a white snapdragon produce a pink snapdragon -A moth with red wings and a moth with yellow wings produce a moth with orange wings Codominance - A mother with type A blood and a father with type B blood have a daughter with type AB blood
In a particular species of octopus, long arm length is completely dominant over short arm length. If an octopus of this species has long arms, what is its genotype?
DD or Dd
Which enzyme opens up the DNA helix for replication
DNA helicase
Which enzyme replicates DNA
DNA polymerase
The central dogma of biology states that information in the cells flows from
DNA->RNA->Protein
How does DNA polymerase prevent errors during synthesis?
During DNA synthesis, most DNA polymerases "check their work," fixing the majority of mispaired bases in a process called proofreading.
Which of the statements describes what happens during mismatch repair of DNA?
Enzymes identify the recently copied DNA strand, snip out a portion of the DNA strand that contains the mismatched nucleotides, and resynthesize the segment correctly.
DNA damage can occur as a result of exposure to chemicals or ultraviolet radiation. What happens during nucleotide excision repair of damaged DNA?
Enzymes unwind the DNA, cut out a section on one stand that contains the DNA damage, and resynthesize the section with the correct DNA sequence.
Arrange the steps of DNA replication in the order that they occur.
First-Last: -Helicase unwinds the DNA double helix -Single-stranded DNA-binding proteins bind to each template strand -RNA primers are added -DNA polymerase synthesizes DNA -RNA primers are removed -DNA ligase join DNA fragments together
Arrange the steps of DNA transcription in the order in which they occur.
First-Last: -The RNA polymerase attaches to the DNA strand upstream from a gene -RNA polymerase pairs RNA bases with the DNA bases on the template strand -RNA polymerase releases the RNA strand, and they both leave the DNA strand
A ___ is a unit of inheritance passed from parent to child
Gene
You should be able to define the following terms: gene, allele, homozygous, heterozygous, phenotype, genotype
Gene- A segment of DNA on a chromosome that codes for a specific trait Allele- one of a number of different forms of a gene Homozygous- having two identical alleles for a trait Heterozygous- having two different alleles for a trait Phenotype- An organism's physical appearance, or visible traits. Genotype- genetic makeup of an organism
What are the steps of DNA replication? What role do each of the following play in the process? DNA helicase, DNA polymerase, topoisomerase, single stranded binding proteins, DNA primase,
Helicase unwinds the DNA double helix -Single-stranded DNA-binding proteins bind to each template strand -RNA primers are added -DNA polymerase synthesizes DNA -RNA primers are removed -DNA ligase join DNA fragments together
Mendel proposed the law of segregation to explain how hereditary particles are passed down from parents to offspring. With the current understanding of chromosomes, alleles, and the process of cell division, what is the physical basis for the law of segregation?
Homologous chromosomes separate into different daughter cells in anaphase I of meiosis.
What is the offspring of a genetic cross between two purebred organisms with different genotypes called?
Hybrid
a DNA molecule consists of two nucleic acid chains held together by
Hydrogen bonds
Explain the principle of incomplete dominance? What is the relationship between the alleles? What trait do you see in the heterozygote?
Incomplete dominance is a situation in which two alleles in the heterozygote have an intermediate phenotype They end up mixing
DNA encodes the cell's genetic instructions for making proteins. The process of making proteins from DNA is divided into two stages called transcription and translation. Transcription is further divided into three steps called initiation, elongation, and termination. Classify the statements about transcription according to the step in which each occurs. Initiation Elongation Termination
Initiation -The RNA polymerase binds to the group of transcription factors at the promoter -The DNA double helix unwinds and RNA synthesis begins Elongation -The RNA polymerase traverses the DNA template, adding complementary base pairs in the 5'-3' direction Termination -The RNA polymerase detaches from the DNA -The RNA polymerase stops adding base pairs when it reaches a certain DNA sequence that signals the end of the gene -The RNA transcript is released
Modern humans share a small percentage of their DNA with Neanderthals, with the exception of modern humans of African descent. What conclusion can be drawn from this?
Interbreeding between modern humans and Neanderthals occurred after modern humans migrated out of Africa.
Why are linked genes often inherited together?
Linked genes are close together on the same chromosome.
Match each definition to the appropriate term: Locus Interference Linkage Recombination
Locus - The chromosomal site where a specific gene is located Interference - The observed double crossover frequency differs from the expected double crossover frequency Linkage - The tendency for genes located in close proximity on the same chromosome to be inherited together Recombination - The process by which a new pattern of alleles on a chromosome is generated
Match each function to the appropriate type of RNA.
Messenger RNA (mRNA) -contains the codons for the polypeptide sequence Ribosomal RNA (rRNA) -enzymatic amide bond synthesis Transfer RNA (tRNA) -hydrogen bonds with codon -transports amino acids to the ribosome.
Genetics often involves calculating the probability of events, such as the probability of being born with a genetic disorder. To address many types of genetics problems, the multiplication and addition rules of probability are applied depending on the situation. When is the the multiplication rule used? When is the addition rule used?
Multiplication: Independent events Addition: Mutually exclusive events
DNA consists of monomers called
Nucleotides
A man with normal vision, XB Y, and a woman who is a carrier for color blindness, XB Xb, mate. How many total phenotypes result from this cross? What percentage of female offspring will be color‑blind? If the father were color‑blind, what percentage of male offspring would be color‑blind?
Number of phenotypes: 3 Color-blind female offspring: 0% Color-blind male offspring: 50%
What is the relationship between the genotype and phenotype?
Phenotype is the physical trait itself, which may be influenced by genotype and environmental factors.
The observable traits (what you can see) of an individual such as flower color, eye color or heights are called
Phenotypes
Classify each feature as describing prokaryotic DNA structure or eukaryotic DNA structure.
Prokaryotic DNA structure - DNA is circular - condensed only by DNA supercoiling -arranged in a single looped structure -does not have telomere region Eukaryotic DNA structure -DNA is linear - condensed around histone proteins -arranged in multiple chromosomes -has repeating telomere region
The descriptions pertain to either prokaryotic or eukaryotic transcription. Match each description to the appropriate category.
Prokaryotic transcription -can be terminated by rho helicase -promoter includes -35 consensus sequence Eukaryotic transcription -includes spliceosome processing -requires TFIID -promoter includes a TATA box
What is the name of the DNA sequence where transcription begins? What enzyme synthesizes the RNA? What is the role of transcription factors?
Promoter RNA polymerase Proteins involved in the process of converting, or transcribing, DNA into RNA.
What happens during the elongation step of DNA transcription?
RNA polymerase moves along the template strand of the DNA creating an mRNA strand.
What RNA sequence is produced during transcription of the given DNA sequence? 3′ ATTCGGCTA 5′ DNA sequence3′
RNA sequence: 5′ UAAGCCGAU 3'
After transcription the mRNA is processed. The three steps of processing are the addition of a 5'-G cap, a 3' poly A tail and RNA splicing. Understand the process of RNA splicing.
RNA splicing is a process that removes the intervening, non-coding sequences of genes (introns) from pre-mRNA and joins the protein-coding sequences (exons) together in order to enable translation of mRNA into a protein
Consider the set of crosses for hypothetical genes that control eye color and tail length in mice. Diane is working with mice with recessive mutations for the genes that control light eye color (b) and short tail length (t). She knows that these genes display genetic linkage and are found on chromosome III. In her work, she crosses a true‑breeding male with light eyes and a long tail (bbTT) and a true‑breeding female with dark eyes and a short tail (BBtt). She then crosses the resulting heterozygous progeny (BbTt) together in a dihybrid cross. The number of animals of each phenotype of this second cross is shown. dark‑eyed, short‑tailed (𝐵𝐵𝑡𝑡)=24dark‑eyed, short‑tailed (BBtt)=24 dark‑eyed, long‑tailed (𝐵𝑏𝑇𝑡 or 𝐵𝐵𝑇𝑇)=54dark‑eyed, long‑tailed (BbTt or BBTT)=54 light‑eyed, long‑tailed (𝑏𝑏𝑇𝑇)=25light‑eyed, long‑tailed (bbTT)=25 light‑eyed, short‑tailed (𝑏𝑏𝑡𝑡)=2light‑eyed, short‑tailed (bbtt)=2 What is the most likely explanation for why Diane sees light‑eyed, short‑tailed (bbtt) progeny in this cross?
Recombination
An alteration in the nucleotide sequence of a gene can alter the gene product. Each sentence is made up of three‑letter words, representing mRNA codons. THE RED ANT RAN THE FOX WAS RED THE DOG RAN The same sentences are written with a substitution, deletion, or insertion, much as a gene may have a substitution, deletion, or insertion mutation. Identify which sentence represents a substitution, which represents a deletion, and which represents an insertion.
Substitution - THE FOX WTS RED Deletion - THE DGR AN Insertion -THE RED ANA TRA N
Why is the genetic code on the mRNA composed of triplet codons instead of doublet codons?
The 64 codons that can be produced with triplets allow at least one codon for each amino acid.
Explain the principle of dominance and recessiveness? What are the possible genotypes of individuals with the dominant phenotype? Individuals with the recessive trait?
The law of dominance states that whenever the dominant allele is present, the dominant allele will express itself. The expression of the recessive allele is suppressed in the presence of dominant allele. The recessive allele does not get lost. AA and Aa for dominant aa for recessive
What is the mechanism of DNA replication?
The process of DNA replication begins when the two strands of DNA separate. An enzyme called helicase unwinds and separates the bonds between the two DNA strands, and both these separated strands act as templates from which new DNA is made. DNA polymerases are a group of enzymes which make new DNA
Which of the events occur during eukaryotic translation initiation?
The small ribosomal subunit binds with a specific tRNA to the mRNA and scans for a start codon.
What contribution did James Watson and Francis Crick make to our understanding of DNA?
They modeled the structure of DNA based on the limited data available.
What generally causes thymine dimers to form in a strand of DNA, and why are thymine dimers a problem?
Thymine dimers, which can be produced by ultraviolet radiation, can lead to cancer‑causing mutations.
Classify each feature as describing either transcription or translation.
Transcription -takes place in the nucleus -produces mRNA Translation -takes place in the ribosome -produces a protein -requires tRNA
Which statement describes the central dogma of biology?
Transcription is the process of synthesizing RNA from DNA. Translation is the process of synthesizing an amino acid sequence from RNA.
The 2 steps of gene expression are transcription and translation. What is the end product of each step?
Transformation :a complimentary strand of messenger RNA Translation: pproteins
What transformation occurs during each of these processes?
Trasnslation: RNA-> protein Transcription: DNA->RNA Replication: DNA->DNA
Complete the transcription of the RNA sequence using the DNA template ATCGAC
UATGCUG A-U T-A C-G G-C
Some characteristics of DNA are shared between all living organisms, whereas other characteristics of DNA differ between organisms. Classify DNA characteristics as either being a universal attribute of DNA or an attribute of DNA that is unique to particular individuals or species.
Universal DNA attribute -Nucleotides A,C,G, and ,T -code for amino acids -triplet codes Unique to individuals or species -DNA sequence -size of genome
The nucleotide found in RNA but not in DNA is
Uracil
What is an x-linked trait? How do the inheritance patterns differ?
X-linked genes have different inheritance patterns than genes on non-sex chromosomes (autosomes). That's because these genes are present in different copy numbers in males and females. What about genes on the Y? Since a female has two X chromosomes, she will have two copies of each X-linked gene.
Explain the principle of codominance? How does it differ from incomplete dominance? What do the heterozygotes look like?
You see both traits
What are codons? Be able to read the genetic code and translate an mRNA sequence.
a sequence of three nucleotides which together form a unit of genetic code in a DNA or RNA molecule.
Which is the definition of a sex‑linked trait?
a trait that is coded by a gene located on a sex chromosome
In eukaryotes where does transcription occur and where does translation occur?
a trinucleotide sequence complementary to that of a corresponding codon in a messenger RNA (mRNA) sequence. Found at one end of a transfer RNA (tRNA) molecule.
In humans, oculocutaneous (OCA) albinism is a collection of autosomal recessive disorders characterized by an absence of the pigment melanin in skin, hair, and eyes. That is, normal pigmentation (𝐴)(A) is dominant over albino characteristics (𝑎)(a) . For this question, assume the phenotype is determined by a single gene with two alleles. If both parents display the albino phenotype, what are all of the possible genotypes that may be observed in their offspring?
aa only
In humans tongue rolling (T) is dominant to non-rolling (t). What would be the expected phenotypes of the offspring if a homozygous tongue roller was crossed to a heterozygous non-tongue roller
all of the offspring's would be tongue rollers
What is the central dogma of biology? (What is the direction of information flow in the cell?)
an explanation of the flow of genetic information within a biological system dna-rna-protein
Which statement describes dominant alleles?
any allele that can hide the presence of a different allele
Why is a small segment of RNA added before DNA polymerase can start synthesizing the DNA molecule?
because the enzymes that catalyze this process, DNA polymerases, can only add new nucleotides to an existing strand of DNA
Which of the substitution mutations most substantially impacts the resulting polypeptide?
changing A to C within the DNA segment ATC near the 5′5′ end of the template DNA strand
Select the description of an exon.
coding portion of a DNA sequence that is present in mature mRNA
Sickle‑cell anemia is a disease that affects the type of hemoglobin (Hb) a person makes in his or her red blood cells. Consider the case of Martin and Cindy, who are the parents of Mary. Martin has sickle‑cell anemia with abnormal hemoglobin, and his genotype is HbS/HbS. Cindy has normal hemoglobin, and her genotype is HbA/HbA. Their child Mary carries the sickle‑cell trait and produces both normal hemoglobin and abnormal hemoglobin. Mary's genotype is HbS/HbA. What type of dominance pattern would result in Mary's blood producing both normal and abnormal hemoglobin?
codominance
What type of bond holds the monomers together?
covalent bonds
Which type of DNA mutation results in a change in the reading frame of an mRNA?
deletion of a single nucleotide
The process by which the information in DNA is converted into a protein is called _______
gene expression
An anticodon is a sequence of three nucleotides that
is found on transfer RNA and is complementary to messenger RNA codons.
Why does DNA primase add a short RNA during DNA replication
it provides DNA POLYMERASE WITH A 3'oh GROUP TO ADD NUCLEOTIDES TO
Which enzyme joins fragments of DNA into a continuous strand?
ligase
At least three types of RNA are required for protein synthesis. Compare and contrast mRNA, rRNA, and tRNA by moving the descriptions of their structure and function to the appropriate categories. Some phrases may describe all three types of RNA.
mRNA -moves genetic information out of the nucleus and into the cytoplasm -contains nucleotide triplets that code for specific amino acids rRNA -acts as an enzyme for peptide synthesis tRNA -moves amino acids to the site of protein synthesis -has a convoluted structure with a three-base sequence called an anticodon ALL OF THEM -in eukaryotes, can exist outside the nucleus -composed of ribonucleic acid
What are the difference between RNA and DNA? What are the 3 types of RNA and what are their functions?
mRNA is the intermediary between the nucleus, where the DNA lives, and the cytoplasm, where proteins are made. rRNA and tRNA are involved in protein synthesis. Additional RNAs are involved in gene regulation and mRNA degradation.D
Use the diagram to select the correct statement regarding RNA splicing.
noncoding introns are edited out and removed
The lagging strand of DNA is formed in a series of short discontinuous fragments called _______
okazaki fragments
Since DNA is replicated semiconservatively, what does each new daughter cell receive from the parent cell after replication and mitosis?
one of the original strands and one new strand
Select the description of rRNA.
ribonucleotides that assemble with proteins into three‑dimensional complexes on which polypeptide chains are produced
What are telomeres?
the DNA located at the ends of eukaryotic DNA molecules
Which statement describes a genotype?
the pair of DNA sequences an organism has for a trait
Select the description of RNA splicing.
the process by which introns are removed from pre‑mRNA and exons are connected to form mature mRNA
What is a substitution mutation?
the replacement of one nucleotide by another nucleotide in a DNA molecule
There are several methods by which genetic material can be exchanged between bacteria. Which of the terms describes the uptake of DNA from the environment by the host cell?
transformation
In a species of flowers, having long thorns (𝑇^𝑇) is incompletely dominant over not having thorns (𝑇^𝑁). What is the genotype of a flower of this species that has long thorns?
𝑇^𝑇𝑇^𝑇
