biology for non science majors chapter 7 8 9 10
Select all of the following that are true about autosomal recessive inheritance of a human disorder.
-Heterozygous individuals are called carriers. -Both parents of an affected individual carry at least one copy of the disease-causing allele.
Why do recessive X-linked traits occur more frequently and with greater severity in human males than in human females? (Select all that apply.)
-Males don't have a second X chromosome to mask the effects of the first one. -Only females who inherit two X-linked recessive alleles fully express the recessive phenotype.
Drag a label to identify what stage of meiosis each image represents.
-Metaphase II -Anaphase I -Anaphase II -Telophase I -Metaphase I
Which of the following statements is/are true about meiosis? Select all that apply.
-The daughter cells of meiosis have half as many chromosomes as the parent cell. -Meiosis produces gametes. -Meiosis produces four haploid cells. -Meiosis produces nonidentical cells.
Select all of the following that can result from nondisjunction of the X chromosome.
-XXX female -Klinefelter syndrome -turner syndrome
Consider the image below, which shows a cell nucleus with one pair of homologous chromosomes that has not undergone crossing over. Then, click on all of the true statements.
-chromatids C and D carry the same alleles -this could be a homologous pair of autosomes -if this cell undergoes meiosis, the daughter cells will each contain one chromosome -if this cell undergoes mitosis, the daughter cells will each contain two chromosomes
Select all of the following that describe the inheritance of an autosomal dominant disorder.
-typically present in every generation -expressed in homozygous dominant individuals and heterozygous individuals
Suppose the second male from the left in row III had a child with the female on the far right side of row III. What percentage of their offspring will be affected?
0%
In Mendel's experiments, a true-breeding pea plant with yellow seeds (YY) was mated with a true-breeding pea plant with green seeds (yy). What was the genotypic ratio of the F1 generation?
0% YY, 100% Yy, 0%yy
The Punnett square below represents a cross between two parents that are heterozygous for the F gene. The parents have already had three offspring. The first had genotype FF and the second and third had genotype Ff. What is the probability that the fourth child has genotype ff?
0.25
Put the following steps in the order that they occur during transcription initiation in eukaryotes, beginning with the first step at the top.
1. A transcription factor binds to the TATA box of the promoter. 2. The TATA binding protein attracts other transcription factors, including transcription factors bound at enhancers. 3. RNA polymerase is able to bind to the promoter at the start of the gene and begin transcription.
Put the following events of translational elongation (the stage in translation that occurs after initiation) in the order that they occur, beginning with the first step at the top.
1. After the first amino acid has been brought to the ribosome, A tRNA carrying the second amino acid of a protein binds to the second codon. 2. A covalent bond forms between the first and second amino acids. 3. The ribosome releases the first tRNA. 4. The ribosome moves down the mRNA by one codon, and a tRNA carrying the third amino acid comes into place. 5. A covalent bond forms between the second and third amino acids. 6. The ribosome releases the second tRNA.
Click and drag on elements in order Place these mitotic events in the order that they occur, beginning with the earliest event at the top.
1. chromosomes condense and become visible. 2. nuclear envelope breaks up and spindle fibers attach to chromosomes. 3. chromosomes line up along the equator of the cell. 4. sister chromatids separate. 5. nuclear envelopes re-froms.
Put the events of the human life cycle in the correct order, starting with what happens right after a pair of gametes comes together. Some labels describe events that do not occur in the human life cycle; these labels will not be used.
1. fertilization occurs 2. a zygote undergoes mitosis 3. a baby's cell divide mitotically 4. meiosis produces the sex cells that will participate in fertilization
Place the stages of mitosis in order of occurrence, beginning with the first stage at the top.
1. prophase 2. metaphase 3. anaphase 4. telophase
Place the steps of DNA replication into the correct order, beginning with the first step at the top.
1.Helicases unwind and unzip the DNA double helix 2.DNA polymerase adds new, complementary nucleotides to the exposed single strands or DNA 3.Ligase enzymes form covalent binds between adjacent DNA segments
Rank the hereditary components from smallest at the top to largest at the bottom.
1.Nucleotide 2.gene 3.chromosomes 4.gamete
Achondroplasia is a common form of dwarfism caused by autosomal dominant mutation in the fibroblast growth factor receptor 3 (Fgfr3) gene. If a person with achondroplasia (Aa) married and had children with a person of normal height, what is the probability that both their first child and second child would have achondroplasia?
1/4
Mendel mated a pea plant of true-breeding round, yellow seeds (RR YY) with a pea plant of true-breeding wrinkled, green seeds (rr yy). A Punnett square analysis shows that ____ % of the F1 generation has round, yellow seeds.
100
Mendel mated a pea plant of true-breeding round, yellow seeds (RR YY) with a pea plant of true-breeding wrinkled, green seeds (rr yy). A Punnett square analysis shows that ____% of the F1 generation has round, yellow seeds.
100
In a cross between two traits, Mendel mated a pea plant of true-breeding round, yellow seeds (RR YY) with a pea plant of true-breeding wrinkled green seeds (rr yy). What is the genotypic ratio of the F1 generation?
100% Rr Yy
Human diseases like cystic fibrosis show similar patterns of inheritance as that of Mendel's garden peas. For instance, cystic fibrosis is a recessively inherited trait that is the most common lethal genetic disease among Caucasians. Individuals with cystic fibrosis produce a mutated Cl- channel protein that results in abnormal ion and water transport across epithelia such as that lining the lung, often making it difficult to breath. Individuals who are heterozygous for the cystic fibrosis gene are carriers but do not exhibit the disease. The wild type or normal gene is designated Cf, and the cystic fibrosis gene is designated cf. Drag the individual crosses to their appropriate phenotypic outcome.
100% normal: CfCf x CfCf, CfCf x Cfcf, CfCf x cfcf 25% cystic fibrosis, 75% normal: Cfcf x Cfcf 100% cystic fibrosis: cfcf x cfcf
Mendel mated true-breeding pea plants that had yellow seeds (YY) with true-breeding pea plants that had green seeds (yy). In the F1 generation, ______% of the plants had yellow seeds, and ______% of the plants had green seeds.
100;0
A pea plant is heterozygous for the genes for seed form (Rr) and seed color (Gg). It is crossed with a pea plant of the genotype rrgg. How many of the 60 offspring of this mating are predicted to show the dominant trait for both genes? (The genes are not linked.)
15
A cell that has four pairs of chromosomes is undergoing meiosis. What is the number of possible chromosome combinations in the gametes produced by that cell?
16
A diploid cell has ______ alleles for each gene, one on each homologous chromosome.
2
Arrange the following events in the proper order in which they occur during meiosis I. 1 = Separation of homologous chromosomes 2 = Coming together of homologous chromosomes 3 = Crossing-over 4 = Random orientation of homologous chromosomes at cell equator
2,3,4,1
There are a total of ______ pairs of chromosomes in a human diploid cell.
23
In a monohybrid cross, Mendel mated two F1 generation (Yy) pea plants. What was the genotypic ratio in the F2 generation?
25% YY, 50% Yy, 25% yy
Mitotic divisions yield ______ daughter cells, and meiotic divisions yield ______ daughter cells.
2; 4
Cytokinesis occurs ____ time(s) during the process of meiosis, whereas cytokinesis occurs ____ time(s) during the process of mitosis.
2;1
A diploid cell is indicated by what abbreviation?
2n
When Mendel mated two F1 generation yellow-seeded (Yy) pea plants, what was the phenotypic ratio in the F2 offspring? (Green-seeded pea plants are genotype yy.)
3 yellow seeds: 1 green seed
Match the number of chromosomes in a human diploid cell with the correct description.
46: total number of chromosomes 22 pairs: autosomes 1 pair: sex chromosomes
If a female was a carrier for sex-linked color blindness, what percentage of her male children would also be color blind?
50%
If you cross RrYy and RRyy pea plants, what fraction of the offspring will have yellow peas? R = round, r = wrinkled, Y = yellow, y = green
50%
The Punnett square below represents a cross between two parents that are heterozygous for the F gene. What percentage of the offspring are predicted to be heterozygous for the F gene?
50%
If a diploid cell has 14 chromosomes, it will have
7 pairs of homologous chromosomes.
Using this Punnett Square, predict the phenotypic ratios in the offspring that result from a cross of two pea plants that are heterozygous for both seed color and seed shape
9:3:3:1 Yellow and round : Yellow and wrinkled : Green and round : Green and wrinkled seeds
Suppose these two chromosomes are found in a cell nucleus during prophase. What is the relationship between chromatids A, B, C, and D? Select all that apply.
A is identical to B C is identical to D
Why are some cells in the onion root tip undergoing mitosis?
A root tip is a plant tissue that is growing
What disease results when HIV causes such an immense loss of T cells that the body's immune system is defenseless against infections and cancer?
AIDS
The DNA sequence ATGCCGTAC would be transcribed into what complementary RNA sequence?
AUGGGCUAC
If nondisjunction occurs during meiosis I, as shown in the image below, what are the possible gametes that can be produced? Click on all the boxes that apply.
Abnormal (n+1) Abnormal (n-1)
If an animal has 6 chromosome pairs in its cells, then 64 combinations of chromatids are possible for a gamete. If both male and female gametes have 64 possible chromosome combinations, how many genetically unique zygotes could be produced due to random fertilization? (Assume crossing over does not occur.)
About 4,000
RNA differs from DNA in many ways, including
All answers are correct. -DNA contains deoxyribose and RNA contains ribose -DNA contains thymine and RNA contains uracil instead of thymine -DNA is double stranded and RNA is single stranded -RNA can catalyze some chemical reactions and DNA cannot.
Consider the types of mutations and the circumstances in which mutations arise to select those TRUE statements below. (Select all that apply.)
All mutations are harmful to the organism's genome. Mutations can be useful to the organism.
Alternative forms of a gene are called ____
Allele
At what phase can nondisjunction occur?
Anaphase I or II
What is the inheritance pattern of the disorder shown in the pedigree?
Autosomal recessive
A pair of what chromosomes are the same size and contain the same genes in both males and females?
Autosomes
Identify each of the following as characteristics of living organisms, viruses, or both.
BOTH: Contain nucleic acids to relay genetic information. Genetic material mutates LIVING ORGANISMS: Cellular, reproduce on their own VIRUSES: *virus pic* consists of genetic material surrounded by protein coats
Genes A, B, C, and D are linked. The crossover frequency between the genes in each column and row are listed in the table below. Use the table to determine the order of the genes. Click on the one correct answer.
C-A-B-D
Select all of the following that are true about cancer risk.
Cancer risk increases with age. Chemicals or radiation in the environment can cause mutations that lead to cancer. Mutated genes that cause cancer can be inherited. Genetic mutations can cause cancer.
Long strands of DNA and their associated proteins are called
Chromosomes
Which of the following events do NOT occur in prophase of mitosis?
Chromosomes are replicated.
Following mitosis, what process splits the organelles, cytoplasm, duplicated nuclei, and macromolecules into two daughter cells?
Cytokinesis
______ splits the cell into two cells after telophase I.
Cytokinesis
During transcription, the template strand of ______ contains the nucleotide sequence that is transcribed into RNA.
DNA
The instructions in ______ encode the information that a cell needs to produce proteins, which are vital to living things.
DNA
Match each eukaryotic regulatory mechanism with where it would act within the "central dogma."
DNA availability- Occurs before transcription. mRNA processing, mRNA exit from the nucleus- Occurs after transcription but before translation. Protein degradation- Occurs after translation. Transcription factors- Occurs at initiation of transcription.
Epigenetics is the study of ______ that affect gene expression but do not change the DNA sequence.
DNA modifications
What enzyme adds complementary bases to exposed single strands of DNA during DNA replication?
DNA polymerase
What enzyme has proofreading and repair functions during DNA replication?
DNA polymerase
In ______, two DNA double helices are synthesized from one DNA double helix molecule when it unwinds and complementary nucleotides are added to the exposed unpaired bases.
DNA replication
What process is illustrated in this picture?
DNA replication
In order for a cell to divide, all of its genetic information has to be duplicated through a process called
DNA replication.
The process of reading a DNA strand and making a complementary DNA copy of that strand is called
DNA replication.
In living organisms, information for making proteins flows from
DNA to RNA to protein.
All viruses contain genetic material, which is either RNA or ______, and a(n) ______ coat that surrounds the genetic material.
DNA; protein
In the section "Investigating Life: Evolutionary Strategies in the Race Against Cancer," what did the researchers conclude?
Declining dose therapy led to the smallest tumors.
A human ______ cell has 46 chromosomes, 23 chromosomes from each parent.
Diploid
How are diploid cells, homologous chromosomes, and alleles related?
Diploid cells have homologous pairs of chromosomes, which carry the same genes as one another but not necessarily the same alleles.
An extra copy of chromosome 21 causes
Down syndrome
Why is DNA replication called semi-conservative?
Each daughter DNA molecule is composed of one parental strand and one new strand
What is the purpose of the meat tenderizer?
To digest associated proteins that bind the DNA
Why is it important to be able to differentiate between male and female flies?
To ensure that you have the appropriate mix of male and female flies in your cross.
_____ are portions of mRNA that get spliced together to form mature mRNA before translation occurs in eukaryotes.
Exons
Select all of the following that act as controls of cell division.
External growth factors Cell cycle checkpoints
In a frameshift mutation, all of the amino acids before the shift are changed.
FALSE
True or false: Complementary base pairing rules state that in DNA, A pairs with G and T pairs with C.
False
True or false: During the G1 phase of interphase, the cell replicates the DNA.
False
True or false: The daughter cells of mitosis have half as many chromosomes as the parent cell.
False
True or false: The phase of the cell cycle called interphase is a time of inactivity and rest for the cell after mitosis.
False
True or false: The younger the mother, the higher the chance of producing a child with Down syndrome.
False
Meiosis produces cells for which of the following processes?
Fertilization
What process occurs when gametes from two parents fuse?
Fertilization
______ is the merging of a sperm and an egg to create a diploid zygote.
Fertilization
In the ______ phase of the cell cycle, the cell grows, carries out basic functions, and produces new organelles.
G1
Select all of the following that are part of interphase.
G2 G1 S
______ are haploid sex cells which combine to form new offspring.
Gametes
How are "gamete," "chromosomes," and "zygote" related?
Gametes unite, forming zygotes with two sets of chromosomes.
The genotype of a heterozygous individual is ______, of a homozygous dominant is ______, and of a homozygous recessive individual is ______.
Gg; GG; gg
Of all the people who have studied inheritance, the person who made the most lasting impression on the science of genetics is
Gregor Mendel.
Who discovered the basic principles of inheritance using traits of pea plants?
Gregor mendel
What virus is responsible for the disease AIDS?
HIV
Arrange the following parts and processes of eukaryotic gene expression in chronological order.
Transcription enzymes find gene. Transcription is initiated. Transcription elongation occurs. mRNA is produced. Introns are removed. Translation occurs. Functional protein appears.
The most common cause of Down syndrome is
Trisomy 21
The resulting portion of the polypeptide has this sequence (using the 3-letter codes): ____________ .
Trp-Arg-Thr-Ala-Leu
Two chromosomes with the same size, centromere location, and gene sequence are called a(n) ____ pair.
Homologous
What correctly describes metaphase I of meiosis I?
Homologous chromosomes line up as pairs along the center of the cell.
Match the following genotypes with their appropriate description
Homozygous Dominant: Upper case T Lower case t Heterozygous: lower case t lower case t Homozygous recessive: upper case T upper case T
What is the genotype of the right-most individual in row II?
Homozygous dominant
Select all of the following that are true with respect to genomes.
In prokaryotic cells, the genome usually consists of just one circular DNA molecule. In eukaryotic cells, the genome is usually divided up into multiple chromosomes.
Analyze the genotypes and phenotypes shown in the Punnett square below. Then, click on the term that describes the expression of the F gene. (Select the one correct answer.)
Incomplete dominance
When is the DNA in chromosomes replicated?
Interphase
Classify the following descriptions of stages of the cell cycle into interphase and mitosis.
Interphase: G₁ S G₂ Mitosis: Cytokinesis Telophase Anaphase Metaphase Late prophase Prophase
What is wrong with the following piece of mRNA? TACCAGGATCACTTTGCCA
It contains T and not U
Select all of the reasons that gene regulation is advantageous in multicellular eukaryotic organisms.
It saves energy. Not all cells need all proteins encoded in the genome.
Select each of the following that is a role of DNA polymerase in DNA replication.
It synthesizes a daughter strand that is complementary to the template strand. It "proof reads" new daughter strands to be sure the bases are in the correct order.
After DNA polymerase adds new nucleotides to replicating DNA, what enzyme forms covalent bonds to join adjacent DNA segments?
Ligase
______ is a specialized type of cell division that produces cells that are genetically different from each other.
Meiosis
What is the difference between meiosis I and meiosis II?
Meiosis I separates homologous chromosomes and meiosis II separates sister chromatids
Translate the following mRNA sequence into the correct amino acid sequence. AUG-GUU-UGC-AGC-GGA-UAG Use the table below to put the amino acids in order for your answer.
Met Val Cys Ser Gly Stop
Match each description with the correct phase of the cell cycle.
Metaphase- Chromosomes align at equator of cell prophase- chromosomes continue to condense and become visible telophase- nuclear envelope forms interphase dna replicates cytokinesis- the cytoplasm divides anaphase- centromeres split
Which statement is NOT true about mitosis?
Mitosis is a process that duplicates and divides the nuclear contents only.
Classify each of the following sentences as relating to binary fission, mitosis, or both.
Mitosis- spindle pulls DNA molecules to separate ends of the cell centromeres split Binary fission- DNA attaches to the cell membrane both- Dna replication occurs before cell division. daughter cells are identical to the original
Classify the following phrases as related to mitosis or meiosis. If it relates to both, then place the label in the "both" dock. Some labels may not be used.
Mitosis: -participates in growth -asexual reproduction uses this process -daughter cells have the same chromosome number as the parent cell Meiosis: -produces gametes -crossing over occurs during this process -daughter cells have half of the chromosome number of parent calls Both: -interphase precedes this process -this process begins with replicated chromosomes -ends with unreplicated chromosomes
Assume that a recessive allele (f) is associated with a severe language disorder. An unaffected male wants to determine the genotypes of his wife, his parents, and himself. His mother has the language disorder. Neither he nor his wife has the language disorder, but one of their five children does. What is the genotype for each individual? Answers may be used more than once or not at all. (Note: the gene associated with this language disorder is on an autosome.)
Mother: ff Father: either FF or Ff Wife: Ff Himself: Ff
________ provides the raw material for evolution because it can create new alleles, which are alternative forms of the same ______.
Mutation; gene
Classify the likely effect of each mutation. The table below has been provided for your reference.
No Protein Produced: Point mutation in start codon Longer Protein: point mutation in STOP codon No change to protein: Point mutation changing the codon UUU to UUC Shorter Protein: Deletion of 12 bases point mutation changing codon UGC to UGA Protein of same size with different sequence: Substitution of all 3 bases in a codon (without creating a stop codon)
What occurs when chromosomes do not separate during meiotic divisions?
Nondisjunction
What produces gametes with a missing or extra chromosome and may result in embryonic, fetal, or infant death or a trisomic individual?
Nondisjunction
What type of gene expression was present in the seven traits Mendel studied?
One allele was completely dominant over the other.
What describes the product of DNA replication?
One strand of a new DNA double helix is newly synthesized and the other strand is from the parent molecule.
What is the first set of individuals mated in a particular cross?
P generation
What occurs during meiosis but not mitosis?
Pairing of homologous chromosomes
In a genetic cross, what does the P generation represent?
Parental generation
True or false: Gene regulation allows cells to produce only the proteins that they need.
True
If nondisjunction occurs during anaphase I, the final product of meiosis II is:
Two cells with an extra chromosome and two cells missing a chromosome.
what is the product if DNA replication
Two daughter DNA molecules
The RNA product of the genetic code above has the sequence ____________ . It binds to the small subunit of the ____________ . It is joined by the large subunit, completing the initiation stage of the process of ____________ .
UGGACGAACGGUGUUA, ribosome, translation
Use the DNA template strand below to create a complementary RNA strand. Type the complementary RNA strand in the box. Template strand: AATACGGCC
UUA UGC CGG LCR
Select all of the following that can increase the risk of cancer.
UV radiation sexually transmitted viruses increased age smoking
HIV is a retrovirus. Label the structures of this retrovirus.
Up to down Envelope protein reverse transcriptee RNA protein coat viral envelope
Use the chromosome image, where the letters represent genes, to match the statements with their answers.
Possible genotype of resulting gamete - FGrm Possible recombinant chromatid genotype-rM Most likely to be separated by crossing over-F and g Smallest crossover frequency-R and M Single dominant allele-M Single recessive allele-f
select all of the following that are functions of mitosis
Produce daughter cells that are genetically identical growth and repair of body tissues produce two daughter cells from one parent cell
which of the following represents the correct order of the phases or mitosis?
Prophase, metaphase, anaphase, telophase
During transcription, what reads the template strand within a gene and adds complementary bases?
RNA polymerase
Select all of the following that are involved in transcription initiation in eukaryotes.
RNA polymerase transcription factors promoter TATA box
Arrange the events of transcription in the order that they occur, beginning with the first event at the top.
RNA polymerase binds to the gene's promoter. RNA polymerase moves down the template strand, producing a complementary RNA molecule. RNA polymerase separates from the DNA and the newly synthesized RNA is released
Only one of the two strands of DNA is transcribed because
RNA polymerase binds to the promoter, intiating transcription on only one strand of DNA.
What results in a random mixture of paternal and maternal genetic material in each daughter cell during meiosis?
Random orientation of chromosome pairs during metaphase I
Where in the cell cycle is DNA polymerase most active? Click the correct box.
S phase (DNA replication)
The ______ are the genetic components that determine whether a mammal develops as a male or female.
Sex chromosomes
What statement correctly describes the result of the experiment discussed in the Investigating Life feature?
Sexual reproduction increased in roundworms exposed to live disease-causing bacteria.
What is the correct way to spool the DNA
Slowly, using a constant motion and pressure to collect the precipitate.
A woman who is heterozygous for the X-linked, recessive hemophilia allele mates with a man who does not have hemophilia. Which of the possible offspring will have hemophilia?
Son: one X chromosome carrying the recessive hemophilia allele and one Y chromosome
Select all of the following that occur in prophase I of meiosis.
Spindle forms from microtubules. Nuclear envelope breaks up. Crossing over occurs. Chromosomes condense.
Which describes the cells at the end of meiosis I when nondisjunction occurs during meiosis II?
The cells are haploid the homologous pairs are in separate cells
Which describes the cells at the end of meiosis I?
The cells are haploid The homologous chromosomes are in separate cells
In Drosophila, white eyes is caused by a recessive allele (r) located on the X chromosome. The dominant allele (R) produces red eyes. Suppose a white-eyed female mates with a red-eyed male. Knowing this, complete the sentences with the correct terms.
The genotype of the male is best represented as ______RY______ . The genotype of the female is best represented as ______rr______ . Among the male F₁ offspring, the predicted proportion with white eyes is _____100%_______ . Among the female F₁ offspring, the predicted proportion with white eyes is ___0%_________ . Among all F₂ offspring, the predicted proportion with white eyes is _____50%_______ .
Read Investigating Life 10.1. As indicated in the image below, the dominant allele (R) confers susceptibility to the Bt toxin, and a recessive allele (r) confers resistance to Bt. Suppose that a resistant female mates with a susceptible male. They have many offspring, the size and survival of which are shown in the graph. What is the genotype of the male parent, and what is the genotype of the susceptible offspring? (Assume complete dominance.)
The genotype of the male parent is Rr and the genotype of the susceptible offspring is Rr.
Select the true statement about viral infection of a host cell.
Viral penetration into a host cell may not cause immediate death of the host cell.
What occurs early in embryonic development of female mammals to prevent "double dosing" of proteins from X chromosomes?
X inactivation
What process in females balances the inequality of having a double dose of every gene carried on the X chromosome and leads to the expression of the paternal X allele in some cells and the maternal X allele in other cells?
X inactivation
Duchenne Muscular Dystrophy is encoded by the X-linked recessive allele "h". To demonstrate your knowledge of how to set up a Punnett Square to represent a mating between a XHXh female and a XHY male, indicate which of the following choices could be placed into the boxes indicated by the arrows.
XH Xh
In sexual reproduction, the sex cells of two different parents fuse to form
a genetically different offspring.
Select the two characteristics that all viruses share.
a protein coat that surrounds the genetic material genetic material, either RNA or DNA
In prokaryotes, DNA is contained in ______, and in eukaryotes, DNA is contained in ______.
a single chromosome; multiple chromosomes
According to the image below, a mutation in a gene is analogous to
a typo in a recipe
In humans, the allele for dimples (D) is dominant to the allele for no dimples (d). At another gene locus, the allele for broad eyebrows (B) is dominant to the allele for slender eyebrows (b). These two allele pairs assort independently. A man who is heterozygous for both traits marries a woman who has no dimples and who is heterozygous at the gene locus controlling eyebrow width. Complete the sentences about this dihybrid cross with the correct terms.
The genotype of the man is ______DdBb______ . The genotype of the woman is ___ddBb_________ . The genotype of the gametes produced by the man is _____25% DB, 25% Db, 25% dB, 25% db_______ . The genotype of the gametes produced by the woman is _____50% dB and 50% db_______ . The probability that their first child will have dimples is ______1/2______ . The probability that their first child will have dimples and slender eyebrows is ____1/8________ .
Select all of the following that are true regarding nondisjunction and trisomy 21 (Down syndrome).
The older the mother, the higher than chances of producing a child with Down syndrome. Nondisjunction during sperm production can lead to sperm gametes with abnormal numbers of chromosomes.
In pea plants there is a dominant allele (A) for green pods and a recessive allele (a) for yellow pods. Suppose a heterozygous plant is crossed with a plant that has yellow pods. Complete the sentences about this monohybrid cross with the correct terms.
The phenotype of the heterozygous plant is _____Green pods_______ . The genotype of the heterozygous plant is ______Aa______ . The genotype of the plant with yellow pods is _____aa_______ . The genotype of the gametes produced by the heterozygous plant is ___50%A and 50%a_________ . The genotype of the gametes produced by the plant with yellow pods is _____100%a_______ . The expected frequency of F₁ plants with yellow pods is _____50%_______ . The expected frequency of F₁ plants with the genotype AA is ______0%______ .
Why might it be advantageous for bacteria to prevent transcription of a particular enzyme, unless its substrate is present in the environment?
The steps involved in synthesizing proteins such as enzymes require a considerable amount of energy.
Which of the following best describes the overall process of mitosis?
The type of cell division that separates chromosomes and produces two daughter cells with identical nuclei.
Select all the true statements with respect to benign tumors.
They are usually harmless. They are surrounded by a tough capsule to prevent them from spreading. They grow slowly.
Select all of the following that are true about malignant tumors.
They invade adjacent tissue. They are likely to metastasize.
Select all of the following that can be components of RNA nucleotides.
adenine ribose uracil guanine
Two strands of DNA within the double helix are said to be complementary to each other because ____ on one strand always pairs with thymine on the opposite strand, and cytosine on one strand always pairs with ____ on the opposite strand.
adenine; guanine
Genetic information is passed from one generation to the next through
all of the above
A gene has different versions, or ____, which are carried on homologous chromosomes and encode different versions of the gene's protein product.
allele
A variant of a gene is referred to as a(n)
allele
Different varieties of the same gene, called ______, may arise from mutations.
alleles
What are different versions of a gene?
alleles
Homologous chromosomes are separated, but sister chromatids remain attached at the centromere, during what phase of meiosis?
anaphase I
On a tRNA molecule, the ____ is a three-base sequence that is complementary to and binds to an mRNA codon during translation.
anticodon
What three-base site of a tRNA molecule is complementary to an mRNA codon?
anticodon
In animals, an intentional, programmed death of some cells occurs through a process called ______.
apoptosis
What type of reproduction produces offspring that are identical to the parent (except for mutations)?
asexual
When ______ reproduction occurs in a one-celled organism, the organism replicates its DNA and splits into two genetically identical cells.
asexual
Binary fission is a type of ______ seen in prokaryotes, such as archaea and bacteria.
asexual reproduction
New viral particles ____________ .
assemble
Rank the five steps of viral replication in the order in which they occur during an infection, beginning with the first step at the top.
attachment to host cell penetration synthesis of viral components assembly of new viruses release of new viruses from host cell
The 22 pairs of human chromosomes that are the same in both males and females are called
autosome
Usually, warts and moles are ______ tumors of the skin, meaning they do not invade surrounding tissues or metastasize.
benign
Due to its proofreading accuracy, DNA polymerase incorporates an incorrect nucleotide only about one in a ______ nucleotides.
billion
Select all of the following that are methods of gene regulation found in eukaryotes but not prokaryotes.
blocking mRNA exit from the nucleus adding methyl groups to silence genes splicing exons in alternative ways
Select all the examples of cells that divide constantly to produce new cells.
bone marrow stem cells cells at the tips of plant roots
Select all of the following that describe RNA.
can be single-stranded nucleotides contain the sugar ribose the nitrogenous base uracil is used instead of thymine can catalyze chemical reactions
A class of diseases characterized by malignant cells is called
cancer
Complete the following sentences with the correct labels. Surgery, radiation, and chemotherapy are traditional treatments for ____________ . Directed at specific cancer cells, ____________ treatment involves the excision of a specific tumor, and is most successful before metastasis. Chemotherapy and radiation target rapidly dividing cells, such as those in the ____________ , bone marrow, and hair follicles. Treatment called ____________ is intended to stop cancer cells anywhere in the body and is usually delivered intravenously. In a treatment called ____________ , streams of energy from radioactive isotopes are directed at rapidly dividing cells in limited areas of the body.
cancer surgical removal digestive tract chemotherapy radiation therapy
After a virus attaches to and penetrates a host cell, a virus can enter a phase where symptoms of the infection are delayed or it can
cause immediate cell death.
A single nucleotide deletion during DNA replication
causes the amino acids encoded by nucleotides AFTER the deletion to be incorrect.
The ______ describes the series of events that occur in a eukaryotic cell from cell division, including division of the genetic material and the cytoplasm, through the interval of cell activity before the next cell division.
cell cycle
Paired sister chromatids are joined to each other at the
centromere
The two sister chromatids of a replicated chromosomes attach at a point called the
centromere
In early stages of mitosis, a structure appears and functions to organize the protein subunits of the mitotic spindle. This is the
centrosome
Several internal ______ in the cell cycle ensure that a cell does not enter into the next phase of the cell cycle before completing the previous phase.
checkpoints
A replicated chromosome consists of two attached copies called sister ____
chromatid
DNA and its associated proteins in the nucleus is referred to as the
chromatin
Eukaryotic chromosomes consist of _______, which is composed of uncondensed DNA and associated proteins.
chromatin
A single molecule of DNA and its associated proteins is called a
chromosome.
A cell's genetic material is contained in one or more
chromosomes
In eukaryotes, a molecule of genetic material and its associated proteins form a(n) ____ , of which humans have 46 in each cell.
chromosomes
In the nucleus of eukaryotic cells, all of the DNA is divided into multiple ____, which are continuous, long strands of DNA wrapped around proteins.
chromosomes
This image shows two ways that ______ during meiosis I to generate different combinations of chromatids in resulting gametes.
chromosomes can orient
Match each label to the correct cell it describes.
chromosomes condense chromosomes align at equator of cell sister chromatids move toward opposite poles nuclear envelope forms the cytoplasm divides
The first sign of cytokinesis in an animal cell is the formation of a
cleavage furrow
In a type of gene expression called ______, two different alleles are both expressed fully in the phenotype of the offspring.
codominance
Two different alleles of a heterozygous genotype are both fully expressed to produce the phenotype in a type of expression called
codominance
Each mRNA 3-base sequence, called a ____________ , matches with a tRNA sequence called the ____________ . The tRNA also carries the specified ____________ , used as a building block for a protein.
codon, anticodon, amino acid
Why is it important to keep the filtrate and reagents cold?
cold temperature stabilizes DNA
Adaptive therapy aims to combat _______ amongst cancer cells that leads to tumor growth continuing even after therapy treatments.
competition
During transcription, a gene's DNA sequence is transcribed into a
complementary RNA molecule.
DNA's sugar-phosphate backbones are joined with
covalent bonds
During the elongation stage of translation, a _______ bond is formed between the incoming _______ acid and the growing polypeptide chain, and empty tRNAs are released from the ribosome.
covalent; amino
Short segments of DNA are exchanged between homologous chromosomes during prophase I in a process called ____ over.
crossing
In prophase I, allele shuffling between homologous chromosomes occurs in a process called
crossing over.
What cellular event is occurring in this picture?
cytokinesis
Select all of the bases that can be present in DNA nucleotides.
cytosine guanine adenine thymine
Fur color in mice is affected by a gene with two alleles. The B allele causes dark brown fur and is completely dominant over the b allele that causes light brown fur. What is the fur color of a mouse with the genotype, Bb?
dark brown fur
select all of the following that are components of DNA nucleotides
deoxyribose nitrogenous base phosphate group
What was the purpose of mixing cells with sodium chloride and detergent to form the strawberry filtrate?
detergent emulsifies cell and nuclear membranes of cells sodium ions neutralize the negative charge of DNA to facilitate precipitation
An example of a(n) ______ cross is the mating of two rats that both have the genotype Ff Tt for fur color and tail length to examine which of two fur colors and tail lengths their offspring will have.
dihybrid
What type of cross is a mating between two individuals that are both heterozygous for the same two genes?
dihybrid cross
A cell with two complete sets of chromosomes is a ____ cell.
diploid
A(n) ______ cell contains two sets of chromosomes, one set of chromosomes inherited from each parent.
diploid
Located in the ovaries and testes of animals, specialized cells called germ cells are ______ and undergo meiosis to produce ______.
diploid; gametes
Select all of the following that describe meiosis.
divides eukaryotic chromosomes of one cell into daughter cells that contain half as many chromosomes as the parent cell cell division needed to produce gametes, or sex cells
A(n) ____ allele always exerts its effects when present.
dominant
When one or both copies of a gene are the ______ allele, then this allele's form of the trait will be exhibited.
dominant
A DNA molecule consists of two intertwining strands of nucleotides that form a
double helix.
If an individual is homozygous for a particular trait
each parent contributed the same allele for that trait.
Match the symbols to the correct allele combination description.
ee-homozygous recessive JJ-homozygous dominant Bb-heterozygous
The gametes of humans are called
eggs and sperm
Transcription, translation, nucleotide synthesis, and modification of mRNA are all processes that require
energy.
Siamese cats and Himalayan rabbits have light-colored bodies but darker-colored paws, ears, and tail due to an enzyme whose activity varies with temperature. This is an example of ______.
environmental effects
The effect of diet and lifestyle choices on phenotypes in humans is an example of
environmental effects.
Modifications to the DNA, such as methylation, that do not change the nucleotide sequence but do affect gene expression are called ______ modifications.
epigenetic
What are coding regions of eukaryotic mRNA that are translated?
exons
Daughter cells produced in meiosis are identical.
false
Genetic variability will not occur among offspring if crossing over does not occur during prophase I of meiosis.
false
Germ cells are haploid but gametes are diploid.
false
If you found a living Neanderthal, genetic analysis of FOXP2 would show maximal similarity to the homologous gene in mice.
false
Mitosis and meiosis II are similar, except that cells undergoing meiosis II are diploid and cells undergoing mitosis are haploid.
false
Only germ cells have sex chromosomes.
false
The amino acid that starts every protein and that is encoded by ACG is methionine.
false
True or false: For some of the traits Mendel studied, alleles were incompletely dominant or codominant.
false
What is an advantage of sexual reproduction over asexual reproduction?
faster production
X inactivation occurs early in ______ embryonic development and prevents ______ of every gene on the X chromosome.
female; a double dose
In sexual reproduction, the first cell of the next generation (the zygote) is produced by the process of ______, which is the union of the sex cells.
fertilization
In sexual reproduction, the union of sperm and egg occurs in a process called ____
fertilization
The first cell of a new organism is formed from the merging of haploid gametes during
fertilization
The union of gametes to form a zygote occurs during a process called
fertilization
Binary ______ is a type of prokaryotic asexual reproduction in which replicated DNA and other cell parts are distributed into two new daughter cells.
fission
After translation is complete, the newly synthesized protein must ______, as determined by some regions of the amino acid chain.
fold into its functional shape
The end of meiosis II produces:
four haploid cells
At the end of meiosis II, there are
four haploid cells, with each chromosome consisting of a single chromatid.
Drag the labels to their correct locations on the diagram of DNA replication. Some labels may be used more than once.
from left down to right down: Parent DNA Duplex Origin of Replication DNA Polymerase Helicase DNA Polymerase Daughter DNA Strand
Select all the possible results of nondisjunction in sex chromosomes.
gamete is missing a sex chromosome XXX zygote gamete contains an extra X gamete contains an extra Y
Sperm cells and egg cells are also called
gametes
The haploid cells of humans are called
gametes
In sexual reproduction, meiosis results in the production of genetically unique sperm cells and egg cells, which are also called
gametes.
The special haploid cells required for sexual reproduction are called
gametes.
Complete the sentences below about the human life cycle using some of the provided words. Adults produce haploid ____________ through the process of ____________ . The union of these cells occurs during ____________ , forming a ____________ . A type of cell division, called ____________ , now occurs rapidly as the embryo develops. Some events of development also require programmed cell death, or ____________ .
gametes; meiosis fertilization; zygote mitosis; apoptosis
A(n) ______ is a portion of DNA that encodes a protein.
gene
What is a sequence of DNA nucleotides that holds the instructions to make a protein?
gene
Crossing over, random orientation of chromosomes, and random fertilization are mechanisms involved in meiosis and sexual reproduction that generate ____ diversity.
genetic
The chromosomes of offspring are not identical to those of their parents or siblings because ______ is shuffled during meiosis.
genetic information
The genome of an organism is all of its
genetic material
A cell's ____ is defined as all the cell's genetic material (DNA) and consists of one or more chromosomes containing the DNA.
genome
In order for a eukaryotic or prokaryotic cell to divide, it needs to first duplicate its entire ______, which consists of all of its genetic material.
genome
All of the genetic material that is within a cell is called its
genome.
An individual's allele combination for a particular gene is called the
genotype
The genetic makeup of an individual is called the
genotype
If a chromosome in one of your bone cells becomes mutated, you will not pass this mutation onto your children because
germ cells cannot undergo mitosis
In animals, specialized diploid cells that undergo meiosis are called
germ cells.
Select all of the following that are present in a bacterial operon.
group of genes promoter operator
Select all the body and cellular processes that require cell division (mitosis or meiosis) to function.
growth dead cell replacement reproduction
Select all of the following nitrogenous bases that are found in RNA.
guanine uracil cytosine cytosine adenine
Daughter cells produced in meiosis have
half the number of chromosomes as the parent cell
1n is an abbreviation for
haploid
A cell with one set of chromosomes is a(n) ______ cell.
haploid
A(n) ______ cell contains only one copy of each chromosome.
haploid
Gametes, or sex cells, are ____, meaning they contain only one set of chromosomes.
haploid
Gametes, or sex cells, are _____, meaning they contain only one set of chromosomes.
haploid
The abbreviation n or 1n represents a ________ cell.
haploid
Select all of the following that are true about the human immunodeficiency virus (HIV).
has an RNA genome can cause latent infections contains the enzyme reverse transcriptase
A(n) ______ individual has 2 different alleles for a given gene.
heterozygous
If parents contribute different versions of a gene, then the offspring are ______ for that gene.
heterozygous
In Mendel's experiments, the hybrid plants had what genotype?
heterozygous
Match the parts of the chromosome with their description.
histone - proteins around which DNA winds centromere - place where two sister chromatids attach in a replicated chromosome chromatid - replicated copy of a chromosome
To help fit the very long molecules of DNA that compose a eukaryotic genome into the nucleus of a cell, stretches of DNA are wrapped around proteins called ______.
histones
During meiosis I, what do spindle fibers pull apart?
homologous chromosomes
Crossing over is the process in which ______.
homologous chromosomes physically exchange pieces.
A crossover in meiosis is an exchange of genetic material between
homologous chromosomes.
Two matching chromosomes having the same basic structure and same sequence of genes are called a ______.
homologous pair
A ______ individual has two identical alleles for a gene.
homozygous
If both parents contribute identical versions of a gene, then the offspring are ______ for that gene.
homozygous
Select all of the possible genotypes for the true-breeding plants in Mendel's experiments.
homozygous dominant homozygous recessive
The image shows ______, a virus that can cause latent and active infections in ______ of the immune system.
human immunodeficiency virus (HIV); T cells
A ______ organism produces mixed offspring: some that are identical to the parent plant and some that are different.
hybrid
The two strands of nucleotides in a DNA molecule are held together by
hydrogen bonds
In a DNA molecule, ______ bonds form between nitrogenous bases, such that A (adenine) pairs with its complement ______, and G (guanine) pairs with its complement ______.
hydrogen; T (thymine); C (cytosine)
In asexual reproduction, the offspring are genetically ________ to each other.
identical
Select all of the following that are true about meiosis.
includes two cell divisions creates four haploid cells from one diploid cell produces gametes with half the number of chromosomes as compared to somatic cells
In a gene expression pattern called ______, the heterozygote has an intermediate phenotype between the homozygotes.
incomplete dominance
If the heterozygous phenotype is intermediate between that of the homozygotes, this is called
incomplete dominance.
The pink snapdragon flowers in the picture are an example of
incomplete dominance.
In an inherited form of high cholesterol, HH individuals have a blood cholesterol level greater than 500mg/dL, RH individuals are near 300mg/dL, and normal (RR) cholesterol levels should be less than 200mg/dL. The H allele is ________ to the R allele.
incompletely dominant
The risk of giving birth to a child with trisomy 21 ______ age of the mother.
increases with increasing
Although Mendel did not know that random orientation of homologous chromosome pairs during metaphase I leads to random allele combinations of different genes in gametes, he created the law of ____ ____, which deduced this phenomenon.
independent assortment
Genes A and B are on the same chromosome. If a person has one chromosome with the alleles AB and a second chromosome with the alleles ab, how could they produce a gamete with a chromosome containing the alleles Ab or aB?
independent assortment
The picture of gamete production with two genes uninfluenced by each other as they are divided in meiosis I and II supports Mendel's law of
independent assortment.
Match the following steps of transcription with their descriptions. Instructions
initiation: RNA polymerase binds to the gene's promoter elongation: RNA polymerase moves down the template strand, adding nucleotides and producing a complementary RNA molecule. termination: RNA polymerase separates from the DNA and the newly synthesized RNA is released
During a section of the cell cycle collectively called ______, the cell is not dividing, but protein synthesis, cell growth, DNA replication, and basic cell functions are occurring.
interphase
The G1, S, and G2 phases are components of a part of the eukaryotic cell cycle called
interphase
Match the following events of the eukaryotic cell cycle with their description.
interphase-the time between cell divisions in which DNA replication, basic cellular activities, and cell growth take place mitosis-division of the contents of the nucleus cytokinesis-division of the cell itself
A(n) ____ is a portion of mRNA that is about 1,000 nucleotides long and that is removed before translation.
intron
In archaea and eukaryotes, a part of an mRNA molecule that is removed before translation is called a(n)
intron.
In eukaryotic cells, sequences of mRNA removed before translation are called
introns
A malignant tumor is one that
invades surrounding tissue
A test cross is a mating of an individual with an unknown genotype and an individual that
is homozygous recessive.
If you were looking at a set of human chromosomes under the microscope, you would know when you saw the X chromosome in part because it is
larger than the y chromosome
An animal virus can cause a(n) ______ viral infection, in which disease symptoms are not produced immediately, but the viral information remains inside the cell.
latent
This diagram of gamete production from meiosis and gamete fusion in fertilization supports Mendel's ______.
law of segregation
What enzyme forms covalent bonds between stretches of newly added DNA nucleotides and existing segments of nucleotides during DNA replication?
ligase
In the ______ infection cycle, a bacteriophage replicates and then causes the host cell to burst, thus killing it and releasing the new viral particles.
lytic
In what type of bacteriophage infection does the host cell burst open, releasing the new viral particles?
lytic
Match each type of RNA to its correct description.
mRNA: Its codons specify the order of amino acids in translation tRNA: Carries amino acids to ribosomes and binds to codons rRNA: Combines with proteins to form a ribosome
In transcription, the genetic information in DNA is copied into a(n) ______ molecule, and in translation, the "message" in an mRNA molecule is translated into a(n) ______ sequence.
mRNA; amino acid
Would it be more likely for a female or male to show the phenotype for a recessive X-linked mutation?
male
In humans, what is the biological sex of an individual with XY sex chromosomes?
males
X-linked recessive disorders can affect more human males than females because ______ always express the disorder when they inherit the recessive allele from ______.
males; the mother
What is the key feature that classifies a disease as cancer?
malignant cells
Cell division that results in the production of gametes is called
meiosis
What process gives rise to gametes in humans?
meiosis
______ is the cell division process that occurs in diploid germ cells and gives rise to haploid cells.
meiosis
A cell division process called ____ shuffles the genetic information contained in chromosomes and produces cells called gametes. Gametes are ____ cells because they only have one copy of each chromosome. ____ unites sperm and egg to form a zygote, which has two copies of each chromosome and is therefore a(n) ____
meiosis haploid fertilization; diploid
A cell in which homologous chromosomes arrange in pairs along the equator of the cell is in what stage of cell division?
meiosis I
Dividing cells that contain only one chromosome from each homologous pair aligned at the equator of the cell must be undergoing
meiosis II.
______ formulated key principles of genetics before DNA, genes, and chromosomes were discovered.
mendel
In what phase of mitosis are the chromosomes aligned along the equator of the cell?
metaphase
Select the stages of the cell cycle during which each chromosome consists of two chromatids joined at the centromere.
metaphase prophase late interphase
During what phase of meiosis I does the spindle arrange the homologous pairs of chromosomes along the equator of the cell?
metaphase I
Random orientation of homologous chromosomes occurs in ________ of meiosis.
metaphase I
The mitotic spindle is composed of protein fibers called ______ that coordinate the movements of ______ during mitosis.
microtubules; chromosomes
Centromeres divide in
mitosis and meiosis II
Eukaryotic cells produce new cells for growth and repair through a cell division process known as
mitosis.
A ______ cross is a mating between two individuals that are both heterozygous for the same, single gene.
monohybrid
An example of a(n) ______ cross is the mating of two rats that both contain the alleles Ff for fur color. This cross is made to examine which of two fur colors their offspring will have.
monohybrid
Eukaryotic cell division is more complicated than binary fission because eukaryotes house the DNA in
multiple chromosomes.
A(n) ____ is any external agent, such as X-rays or chemicals, that induces mutations.
mutagen
UV rays, X-rays, some chemicals found in tobacco, and radioactive fallout are all examples of _____, agents that can damage DNA and cause mutations.
mutagens
A change in a gene sequence or a regulatory DNA sequence is called a(n) ______.
mutation
A(n) ____ is a change in a cell's DNA sequence.
mutation
If a haploid cell goes through meiosis it will generate
no answer is correct
A process called ______ is an error in meiosis in which chromosomes fail to separate and a gamete with too many or too few copies of a particular chromosome can be produced.
nondisjunction
Suppose that after the cell below undergoes meiosis I and meiosis II, the result is one gamete with two chromosomes, two gametes with three chromosomes, and one gamete with four chromosomes. What has occurred? (Click on the correct answer.)
nondisjunction during meiosis II
The DNA double helix is made up of two strands of ______ monomers oriented in opposite directions.
nucleotide
Subunits called ______ are the building blocks of DNA.
nucleotides
A DNA molecule consists of two strands of ______ held together in a ______ structure.
nucleotides; double helix
Where would the majority of the DNA be located within a eukaryotic cell?
nucleus
Phenotype means the
observable expression of the genes in an individual
Select all of the following that are true about sexual reproduction.
offspring are genetically different from each other offspring are genetically different from their parents two parents are required
What describes a substitution mutation?
one DNA base is replaced with another
If nondisjunction occurs during anaphase I, then meiosis I produces:
one cell with extra homologous chromosomes and one cell missing a homologous chromosome.
A type of gene expression called pleiotropy occurs when
one gene has multiple effects on the phenotype.
After DNA replication, each new daughter DNA molecule is composed of .
one parental strand and one newly synthesized strand.
In bacteria, a(n) ______ is a group of genes under control of a single promoter.
operon
The 2 meters of DNA that makes up the human genome is able to fit in one cell because the chromatin is ______.
organized around proteins
Diagrams depicting family relationships and phenotypes for a genetic disorder are
pedigree charts
The viral nucleic acids ____________ the host cells.
penetrate
An individual's ____ is its observable characteristics for a particular trait.
phenotype
Is hairline shape, ear shape, and eye color a genotype or phenotype?
phenotype
What are the observable characteristics of an individual's genes?
phenotype
Tobacco mosaic virus (TMV) infects many species of
plants.
A gene that produces a protein important in more than one biochemical pathway is
pleiotropic
Analyze the image below, which shows one protein affecting three biochemical pathways. Then, click on the term that best describes how the gene encoding this protein affects the phenotypes of the individual.
pleiotropy
In ______, one gene encodes a protein that is important in many biochemical pathways or that affects many parts of the body.
pleiotropy
Human eye color is controlled by multiple enzymes encoded by multiple genes; therefore, human eye color is an ______ trait.
polygenic
If the phenotype reflects the activities of more than one gene, it is called a ______ trait.
polygenic
RNA ______ is the enzyme that builds the RNA chain during transcription.
polymerase
The enzyme called DNA ______ adds new complementary DNA nucleotides to a single-stranded DNA template.
polymerase
In the experiment discussed in the Investigating Life feature, what variable was different between the tan bars and the red bars in the graph below?
presence of living bacteria
The ____ rule states that the chance of two independent events occurring is equal to the product of the individual chances that each event will occur.
product
If a couple that are both heterozygous carriers of the cystic fibrosis allele have children, the chance that both their first and their second child are carriers is 0.5 x 0.5, or 25%, as determined by the
product rule.
Select all of the following that take place during interphase preceding meiosis.
production of two identical sister chromatids attached at the centromere replication of DNA synthesis of proteins and enzymes needed for cell division
At the beginning of transcription, RNA polymerase binds to the ______ on the DNA.
promoter
The ______ is a sequence of DNA that signals the start of a gene and also which of the two strands of DNA is the template for transcription.
promoter
The chromosomes condense and become visible under a light microscope during what phase of mitosis?
prophase
The stage of mitosis shown in the picture is called early
prophase
Arrange the phases of mitotic cell division in chronological order. Begin the series with the first step after interphase.
prophase metaphase anaphase telophase cytokinesis
Click on every image that is correctly paired with the phase of the cell cycle that it represents.
prophase metaphase telophase
The exchange of genetic material between nonsister chromatids is called crossing-over and occurs during which phase of meiosis?
prophase I
Crossing over only occurs in
prophase I of meiosis
Rank the steps of meiosis I in the order in which they occur, beginning with the first phase at the top.
prophase I. metaphase I. anaphase I. telophase I.
Rank the steps of meiosis II in the correct order in which they occur, beginning with the first step at the top.
prophase II. metaphase II. anaphase II. telophase II.
Which of the following represents the correct order of the phases of mitosis?
prophase, metaphase, anaphase, and telophase.
Enzymes and chaperone proteins assist in ______ that takes place after translation is complete.
protein folding
In the "central dogma," information flows from DNA to RNA to ______.
proteins
What is produced during translation?
proteins
Select all of the following that are components of chromatin.
proteins for transcription proteins for replication DNA proteins for scaffolding
Use the terms on the left to complete the following sentences. Some terms may be used more than once or not at all. Transcription and translation produce ____________ using the information in ____________ . Some ____________ are chemical signals that regulate the cell cycle by stimulating cell division. When these ____________ bind to ____________ on a cell membrane, they initiate a cascade of reactions that results in ____________ . If the ____________ encoding any of these ____________ have mutations, then cells might receive improper signals to divide. Sometimes, loss of control over cell division results in a ____________ , an abnormal mass of tissue.
proteins; genes proteins proteins; receptors; cell division genes; proteins tumor
A ______ is a diagram that shows how the parental alleles may combine to form possible genotypes of the offspring.
punnett square
Select all of the cancer therapies that are considered to be "blunt tools" because they target rapidly dividing cells, regardless if they are healthy or cancerous.
radiation chemotherapy
Match each type of cancer treatment to its correct description. Instructions
radiation-streams of energy that can be directed on tumors and cells in limited areas surgery-removal of a tumor and surrounding tissues chemotherapy-drugs designed to affect cancer cells, and sometimes other rapidly dividing cells, throughout the body
In sexual reproduction, exactly what egg cell matures and what sperm cell fertilizes the egg is
random and results in genetic variability.
Select all of the mechanisms that generate genetic variability in sexual organisms.
random fertilization random orientation of chromosomes crossing over
The host cells ____________ the new viruses.
release
The host cells ____________ the viral ____________ and produce viral proteins.
replicate; genomes
Select all of the processes involved in asexual reproduction.
replication of the genetic material splitting of one cell into two cells
Some method of cell division is necessary for every organism to
reproduce
What sugar is a component of RNA nucleotides?
ribose
Only producing proteins that are needed allows a cell to
save energy.
Although Mendel did not know that homologous chromosomes separate during meiosis I such that the alleles of one gene are packaged into separate gametes, he developed the law of ______, which deduced this phenomenon.
segregation
Which of the following events occurs during anaphase I?
separation of homologous chromosomes
Review Investigating Life 10.1. The pedigree below shows the inheritance pattern of Bt resistance in three generations of bollworms. How many individuals on this pedigree are definitely heterozygous?
seven
In a human karyotype, there are 22 pairs of autosomes and 1 pair of ____ chromosomes.
sex
The X and Y chromosomes in humans are called ______.
sex chromosomes
Genes that are located on the X or Y chromosome are said to be ______ and often are expressed in one sex more than the other.
sex-linked
Red-green color blindness and hemophilia are examples of ______, which are controlled by alleles on the sex chromosomes.
sex-linked genes
A chromosome is a(n) ______.
single molecule of DNA and its associated proteins
After DNA replication, chromosomes consist of two
sister chromatids
Centromeres attach ______ to each other.
sister chromatids
In meiosis I, homologous chromosomes separate, whereas in meiosis II,
sister chromatids separate.
DNA replication occurs during interphase. Which image shows the products of replication, if the parent strands are blue and the new strands are red?
solid blue line solid red line solid red line solid blue line
A mutation in a gene would cause a change in the sequence of amino acids in a protein.
sometimes
The _______ consists of microtubule fibers that move the chromosomes during mitosis.
spindle
Select all of the following that are features of both mitosis and meiosis.
spindle fibers made of microtubule proteins prophase, metaphase, anaphase, and telophase steps preceded by interphase
Drag each description on the left to its best placement in the Venn diagram. Descriptors common to more than one category should be placed in the appropriate intersection of circles
starting from top left and going left to right...Mad Cow Disease, Involves proteins, Contains DNA or RNA middle row.. lacks a coat, disease- causing, infects plants. Bottom row.. contains RNA only.
What type of cells may divide constantly throughout their life?
stem cells
What role does DNA play in the cell?
store instructions for making proteins
What type of mutation occurred in the following? Normal allele GGAAUGAAACAGGAACCCMutant allele GGAAUGAAACAGGUACCC
substitution
The replacement of one DNA base with another is called a(n)
substitution mutation.
During meiosis I, homologous chromosomes have completed their movement to opposite poles in
telophase I.
The DNA strand that is "read" during transcription is called the _________ strand.
template
In transcription, the enzyme RNA polymerase builds a strand of RNA along the ________________________ .
template strand of DNA
In a ____ cross, an individual with an unknown genotype is mated with an individual with a homozygous recessive genotype to determine the unknown genotype.
test
To determine if the genotype of a pea plant with a dominant phenotype is homozygous dominant or heterozygous, a ______ may be completed.
test cross
If a diploid sperm fertilizes a diploid egg it will produce a ____ zygote.
tetraploid
Presence of the phenotype of an autosomal recessive disorder in one generation and then absence of the phenotype in the next generation likely means
the allele is present in heterozygotes that are carrying the disorder.
Imagine that one egg cell unites with one sperm cell at fertilization. Nine months later, twin brothers are born. Select all of the true statements about the DNA of these brothers.
the brothers have received identical information from the father the brothers have received identical information from the mother
In a "silent" mutation, the
the codon that mutates does not cause a change in the amino acid specified
The "central dogma" of molecular biology described by Watson and Crick describes
the directional flow of genetic information in cells.
The nucleotide sequence in mRNA is determined by
the nucleotide sequence in DNA.
Review the genetic code, and then complete the sentence below the table. Complete this sentence: If the nucleotides ATT were inserted into the template strand of a gene, then
the resulting protein will be SHORTER and nonfunctional.
A latent viral infection is one in which
the viral genetic information remains inside the cell but does not cause disease symptoms.
What is the purpose of the ice cold 95% ethanol?
to precipitate the DNA from the filtrate
The first virus ever discovered was ______, a virus that infects over 120 plant species.
tobacco mosaic virus
If you wanted to lower your chances of lung cancer, what would be the best factor to avoid?
tobacco use
Study the graphs below. Which trait is most likely influenced by either the environment or multiple genes? (Select the one correct answer.)
trait 3
A TATA box and a terminator sequence would apply to what part of the diagram?
transcription
In a process called ______, an RNA copy of a gene sequence on the DNA molecule is made.
transcription
In eukaryotic cells, proteins called ______ factors bind at specific DNA sequences and form a pocket that allows RNA polymerase to initiate transcription.
transcription
Is transcription or translation shown in the image below?
transcription
The process of forming RNA from a template strand of DNA is called ___.
transcription
Initiation, elongation, and termination are the three main steps in
transcription and translation
In eukaryotes, RNA polymerase cannot bind to the promoter and initiate transcription without the presence of regulatory proteins called
transcription factors.
The gene sequence above undergoes ____________ to produce ____________ with the help of RNA polymerase, and other proteins. This occurs in the ____________ of a eukaryotic cell.
transcription, mRNA, nucleus
Eukaryotic cells can compact their DNA or add methyl groups to make their DNA unavailable for
transcription.
In the "central dogma" describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called ____ , and the information in RNA is used to direct the synthesis of a protein in a process called ____.
transcription; transcription
During ____, the information that is encoded in the DNA base sequence is copied into the complementary language of mRNA. Then, once the mRNA is produced and modified, a process called ____ uses that information to assemble a sequence of amino acids.
transcription; translation
In a process called ______, an RNA molecule is used to produce a protein.
translation
Select all of the following that can result from nondisjunction in humans.
trisomy failed development due to missing genetic material an extra copy of a chromosome
At the end of meiosis I, there are two haploid cells, each with two sister chromatids per chromosome.
true
Both somatic cells and germ cells are diploid, although only germ cells can undergo meiosis.
true
Chromosome duplication occurs prior to both mitosis and meiosis.
true
Crossing over occurs during prophase I of meiosis.
true
Cytokinesis in animal cells occurs by means of a cleavage furrow
true
DNA replication utilizes the base pairing that is part of the basic structure of the DNA double helix.
true
Exposure to UV radiation from the sun can increase the risk of cancer.
true
If the probability of one genetic event is 1/2 and of another 1/6, then the probability of both occurring is 1/12.
true
Mitosis occurs in somatic cells throughout life.
true
A ______ organism always produces offspring that are identical to the parent when self-fertilized.
true-breeding
An abnormal mass of tissue that results from the loss of cell cycle control is called a(n)
tumor
How many rounds of cell division occur in meiosis?
two
If a gene exists in 10 different alleles in a population, how many alleles can be expressed in one diploid cell?
two
If crossing over occurs only between the two alleles of the same gene, as shown in the animation, what allele combinations are present in the gametes?
two gametes with parental combinations of alleles, and two recombinant gametes
Select all of the following that can lead to the formation of a tumor.
uncontrolled cell division lack of programmed cell death
Attachment, penetration, synthesis, assembly, and release are the stages of
viral replication.
A small, infectious agent that is composed of genetic information inside of a protein coat is a called a
virus
A(n) ____ , Correct Unavailable is a noncellular, small, infectious agent that is simply genetic information enclosed in a protein coat.
virus
A ____________ attaches to a host cell by adhering to surface ____________ on host cells.
virus; receptors
Select all the ways that cells can make DNA less available for transcription.
wind or fold DNA in a way that makes it unavailable tag DNA with methyl groups
Nondisjunction of the ______ chromosome during meiosis can produce offspring that are XXX or XXY.
x
The diploid cell created from the fusion of gametes is called a(n)
zygote.
The first diploid cell of a new organism, called a(n) _____ , has a set of chromosomes from each parent.
zygotes
Click on all of the true statements about sexual and asexual reproduction.
- Bacteria, archaea, and some single-celled eukaryotes, such as amoebas, reproduce asexaully - In general, sexual reproduction requires more energy than asexual reproduction. - Asexual reproduction is most advantageous when environmental conditions are constant. - Many animals, such as dogs, reproduce sexually. - Asexual reproduction requires only one parent.
Select behaviors that reduce the risk of cancer. (Select all that apply.)
- Schedule regular doctor visits- Use condoms during sexual activity- Avoid exposure to UV radiation- Eat fruits and vegetables with every meal- Don't smoke- Examine yourself for changes- Exercise regularly- Avoid obesity
If a female with genotype Dd mates with a male of genotype dd, what are the possible genotypes of the haploid gametes they produce? Select all that may apply.
- The male can only produce d gametes. - The female can produce D and d gametes.
Replication creates a complementary strand of DNA. Given the following parental strand of DNA, what would be the nucleotide sequence of the daughter strand? AACTGGCATCGACTAGGG
TTGACCGTAGCTGATCCC
AZT is a drug that is commonly used to fight HIV infection. The active component of AZT is a nitrogenous base that mimics thymine. Normal nucleotides CANNOT covalently bond to the thymine mimic. HIV's reverse transcriptase enzyme will use the thymine mimic instead of using thymine, whereas our DNA polymerase will not make this mistake. What is the most likely explanation for how AZT prevents HIV replication?
The DNA strand produced by reverse transcriptase will stop being synthesized the first time the thymine mimic is inserted.
