Exam 2 Online HW

Considering only the 2 genes A & B, how many genetically distinct gametes can this individual produce, if genetic recombination results from independent assortment ONLY?

two

During which part of the cell cycle is the likelihood highest that a mutational event occurs?

S-phase

What was the last phase of the cell cycle that this cell has fully completed?

S-phase

The patient's EDA gene sequence has a SNP located at nucleotide number ____ . The mutation that caused this SNP was a _____ mutation by cause and a _____ mutation by effect and affects the _____st codon of the EDA gene.

- 993 - substitution - missense - 331

Consider the wild-type DNA sequence: 3' ATACTTTCA 5'. (Only the transcribed strand is shown). Which of the following shows an indel mutation of the wild-type DNA sequence shown above that does NOT result in a frameshift mutation?

- A[''']TTTCA - ATA[''']TCA

Years pass, and Jessica and Tom just had a kid, and they send you a picture of the three of them. You are surprised to see that the baby has thin eyebrows and attached earlobes. What does this tell you?

- At least some of Jessica's direct ancestors must be carriers for the recessive allele of gene F, including at least one of her parents. - Jessica's genotype must be Ee Ff. - Given what you know now about Jessica and Tom's genotypes after seeing their first baby, you realize that prior to inception, the chances of their child showing the thin eyebrow, attached earlobe phenotype was only 1/16.

Which cellular processes require chromosomes to be in their uncondensed state?

- DNA replication - Transcription

Which of the following statements about mutations are true?

- Mutations are the only source for the origin of new alleles. - Both substitution and indel mutations could result in a non-sense mutation in the affected codon following the mutational event.

Which of the following predictions of when this algal species reproduces via its asexual versus its sexual cycle would be consistent with hypotheses on the costs and benefits of sexual versus asexual (via mitosis only) reproduction?

- The alga begins reproducing sexually when the present environment of mature cells becomes less conducive to growth. - The alga reproduces asexually during summer months in the pond when conditions are favorable for growth.

Which of the following groups of gametes CANNOT be produced by the SINGLE shown oöcyte undergoing ONE set of meiosis (meiosis I plus meiosis II) divisions?

- gamete assemblage A - gamete assemblage D - gamete assemblage F

The diagram of a gamete below depicts a single chromosome within a gamete. The bars spanning the chromosome indicate 2 genes. Considering only the two genes shown, which of the following processes was NOT capable to produce genetic diversity among the gametes of an individual?

- independent assortment - fertilization - sex linkage

Most of the genetic material of eukaryotes is located in the _____ of the cells. The _____ of the organism is organized on linear pairs of _____ , each of which consist of a long, unbroken _____ molecule of _____ whose sequence of _____ carries the genetic information to make _____. Hence, it is the action of the proteins encoded by your _____ that links your unique set of genetic information, your _____, to your physical, observable _____.

- nucleus - genome - chromosomes - double-stranded - DNA - nucleotide bases - proteins - genes - genotype - phenotype

What is the probability that George VI who is the ancestor of today's British Royals was a carrier for hemophilia B and hence could have passed the condition on to the modern royal family members?

0

A particular recessive genetic disorder is polygenic. It is caused by 2 separate, unlinked genes (Genes A and B). To have the disorder, a person must be homozygous recessive for BOTH of these genes. A mother is heterozygous for Gene A and homozygous recessive for Gene B. The father is heterozygous for gene Gene A and homozygous dominant for Gene B. If they have 2 children, what is the probability that 1 of them will have this disorder?

0.0

A woman is about to deliver triplets. If each child is the product of an independent fertilization event (i.e. fraternal twins, not identical twins), what is the probability that all of her babies will be of the same gender (i.e., she will deliver EITHER all girls OR all boys)? Question 4

0.25

If your inferences based on their known pedigrees are correct, what is the probability that Jessica's and Tom's first baby will have free earlobes and thin eyebrows?

0.25

Gaucher's disease is an inherited metabolic disorder in which harmful quantities of a fatty substance called glucocerebroside accumulate in the spleen, liver, lungs, bone marrow, and sometimes in the brain. Two healthy parents know from DNA sequencing of their gene that each must be a carrier for the recessive allele responsible for Gaucher's disease. 1) What is the probability that the mom will donate a recessive allele to any of her offspring? 2) What is the probability that the dad will donate a dominant allele to any of his offspring? 3) If their first three children have the disease, what is the probability that their fourth child will not? 4) If instead we assume that they have not yet had any children but will have 4 children in the future, what is the probability that all four children will have phenotypic symptoms of the disease?

1) 1/2 2) 1/2 3) 3/4 4) 1/256

In the Morse code, a series of two signal types (dots and dashes) code for 26 different letters of the alphabet. How is this analogous to the genetic code?

The bases of DNA code for the more complex amino acid sequence of the proteins in cells.

Below are the wild-type sequence of a gene, as well as four alleles that originated from the wild-type allele via mutational events at some time in the past. Nucleotides that differ compared to the wild-type allele as a result of a mutation are shown in bold and underlined. A missing nucleotide is indicated by a '. a) Label each allele by cause and by effect of the mutation that caused it. b) Identify the severity of the mutation on the functioning of the protein end-product compared to the wild-type. 1) Allele 1 2) Allele 2 3) Allele 3 4) Allele 4

1) Allele 1 - Mutation type by cause: substitution - Mutation type by effect: missense - Severity: not enough information 2) Allele 2 - Mutation type by cause: substitution - Mutation type by effect: nonsense - Severity: non-functional protein product 3) Allele 3 - Mutation type by cause: deletion - Mutation type by effect: frameshift - Severity: non-functional protein product 4) Allele 4 - Mutation type by cause: substitution - Mutation type by effect: silent - Severity: no effect

Below are images taken at different time points of a cell undergoing mitosis. You do not need to know the names of the phases of mitosis. But we walked through the main events during mitosis (simple cell division) as they affect how sister chromatids of replicated chromosomes are moved into the two daughter cells to produce two genetically identical daughter cells.

1) Chromosomes are uncondensed in nucleus of cell 2) Replicated chromosomes condense & nuclear envelope dissolves 3) Spindle fibers attach to centromere and pull chromosomes to metaphase plate 4) Sister chromatids separate and are pulled by spindle fibers toward poles of cell 5) Nuclear envelope reforms, chromosomes decondense, & cytokensis.

Correctly label the structures, and place the missing alleles at the correct gene loci for gene A and gene B, assuming that this individual is heterozygous for gene A (this individual has the two alleles A and a for this gene), but is homozygous for gene B (ONLY has allele b for this gene).

1) Field 1: A 2) Field 2: a 3) Field 3: a 4) Field 4: b 5) Field 5: b 6) Field 6: b 7) Field 7: b 8) Field 8: Gene locus 9) Field 9: Centromere 10) Field 10: homologs (homologous chromosomes) 11) sister chromatids

Match the correct hypothesis to the predicted phenotypic ratios for the cross of two F1 individuals described in the previous question. Evaluate each of these hypotheses with respect to the data you collected from real crosses of canaries in the previous question.

1) Hypothesis 1: 1-gene trait with co-dominance Reject 2) Hypothesis2 : 2-gene trait, both display complete dominance with epistasis Reject 3) Hypothesis 3: 2-gene trait, one displays complete the other co-dominance with epistasis Fail to reject 4) Hypothesis 4: 2-gene trait, both sex-linked and gene A shows incomplete dominance, gene B co-dominance

For each gene you found in the previous question, find its location along the length of the chromosome (see the karyotype window to see which chromosome your genome browser zoomed into. Find the exact gene locus by finding the blue highlighted field along the chromosome layer out at the very top of the genome browser window.

1) NGF and ACTA 1 3) RHO 11) INS 16) HBA1 22) MB

Hypothetically, brown color (B) in naked mole rats is dominant to pink color (b). Suppose you ran across a brown, male naked mole rat in class and decided to find out if he was genotype BB or Bb. You investigate this question by crossing this male with a female and observe the phenotypic ratio of offspring. 1) What would be the best mole rate phenotype and genotype to mate with the male so you can make a reliable determination of the genotype of the father? 2) What is this cross called? 3) What are the expected genotypic ratios from this cross? 4) What are the expected phenotypic ratios from this cross?

1) Phenotype: pink Genotype: bb 2) Test cross 3) if the brown male is genotype BB: 1:0 if the brown male is genotype Bb: 1:1 4) if the brown male is genotype BB: 1:0 if the brown male is genotype Bb: 1:1

The offspring of one mated pair of mammals included three males, all of which showed an X-linked recessive trait. The fourth offspring was a female. Consider whether the following statements about her are definitely true, possible, or false. 1) Even if the father shows the trait, she will not. 2) She can only show the trait, if her father shows it phenotypically as well. 3) If the father does not show the trait, she can still phenotypically show the trait. 4) She can only show the trait, if her mother shows it phenotypically as well.

1) Possible 2) Definitely true 3) Definitely false 4) Definitely false

Match each of the shown phases of Meiosis to the the correct effect it has.

1) Prophase 1 - homologs pair up and exchange genetic material among non-sister chromatids 2) Metaphase 1 - independent assortment of homologs along metaphase plate 3) Anaphase 1 - responsible for reducing ploidy by half 4) Telophase 1 - Nuclear envelope forms around haploid nuclei with replicated chromosomes 5) Metaphase 2 - chromosomes align along metaphase plate in a manner most similar to mitosis 6) Anaphase 2 - change from replicated to non-replicated chromosomes

Follow the instructions above to find the first 15 bases of 3'-->5' template sequence of the protein-coding sequence of each of the 5 genes in the table below. 1) Rhodopsin 2) alpha hemoglobin 3) nerve growth factor 4) alpha actin

1) Protein: Rhodopsin - Function: light-sensitive protein in retinal cells of eyes - Gene ID: RHO - [TACTTACCGTGTCTT] 2) Protein: alpha hemoglobin - Function: subunit of adult hemoglobin protein involved in oxygen transport in adults - Gene ID: HBA1 - [TACCACGACAGAGGA] 3) Protein: nerve growth factor - Function: signaling protein involved in the proliferation of nerve cells - Gene ID: NGF - [TACAGGTACAACAAG] 4) Protein: alpha actin - Function: structural protein associated with actin filaments in skeletal muscle cells - ACTA1 - [TACACGCTGCTTCTG]

Based on what you know about the effects of different processes on ploidy and the information on the life cycle of an alga above, associate the most likely ploidy with each life stage of this algal life cycle.

1) Zoospore - haploid 2) Mature individual - haploid 3) Zygospore - diploid 4) Gamete - haploid

In cats, the Manx (M) allele causes a short or absent tail, while a recessive allele (m) confers a normal, long tail. Cats of genotype MM are never born alive, as the M allele is fatal before birth when homozygous, because the spinal cord never develops. If 2 Manx cats mate, what proportion of living offspring will have long tails?

1/3

Use the NCBI Human Genome Browser (right-click for the direct link to open in a new window) to find the specific gene loci for the EDA gene and for the EDAR gene in humans and annotate the human karyotype for each locus below. Center the little CIRCLE of each gene marker on top of the gene locus on the relevant chromosome you identified. BE AS PRECISE AS POSSIBLE.

2) EDAR X) EDA

What is the karyotype formula of the cell shown in the previous question?

2n = 6

Check the mRNA and amino acid sequence in the figure above. Which of the following mRNAs represents an alternative mRNA sequence that would not change the amino acid sequence as a consequence of the redundancy of the genetic code?

5'-AUG-GCU-AAC-GAU-UUC-CAG-UAA-3'

For the Punnett square in the previous question, what proportion of the offspring have a phenotype that is DIFFERENT from the phenotype of either parent? Assume that capital letters represent the dominant allele and that the genes are on different chromosome types.

7/16

What does this structure represent on a molecular level?

A single, double-stranded molecule of DNA in the condensed state

Consider the following wild-type double-stranded DNA sequence: 5' T A T G A A A G T 3' non-transcribed strand (sense strand) 3' A T A C T T T C A 5' transcribed strand In the space below, write ONE of the possible DNA sequences of the transcribed strand shown above that results from BOTH a single substitution mutation of the first codon AFTER the start codon that would also cause a nonsense mutation.

ATACATTCA

Based on the phenotypes of her and her ancestors, what was the genotype of Belquest's Last Laugh?

E_ Bb

Write your answer below as mRNA bases from left to right on the shown mRNA molecule shown above. Do not include spaces or other symbols between the bases.

GUUACCGAU

What was the last phase of the cell cycle or type of cell division that resulted in the karyotype of this cell depicted above?

Meiosis I

After many dozens of crosses and hundreds of offspring, you arrive at the peculiar ratio of: 3/16 green : 6/16 pied : 7/16 yellow Based on these data, what do you conclude about your initial hypothesis?

Reject my initial hypothesis.

What is the amino acid sequence that corresponds to the following abbreviated DNA sequence taken from the middle of a gene? 5'TATGAAAGT3' non-transcribed strand 3'ATACTTTCA5' transcribed strand

YES

Which best describes the mode of inheritance in the pedigree shown below?

autosomal recessive

In order for the four shown gametes to have been produced by meiotic divisions from the SINGLE oöcyte shown in G1-phase to the left (i.e. you are looking at the gametes produced during meiosis from a single parent cell), what must have happened during meiosis?

both non-sister chromatids of the large chromosome type had a crossing-over event between genes H and F

The phenotypic variation in the trait "coat color" in mice is passed from a parent to their offspring via _______________.

differences in DNA sequences in different parents

The different coat colors of the two mouse phenotypes are directly caused by _________.

differences in the protein amino acid sequence

What is the ploidy of the cell shown above?

diploid

Considering only these 2 genes, how many genetically distinct gametes can this individual produce, if genetic recombination results from BOTH crossing over and independent assortment?

four

Which of the groups of gametes show ALL POSSIBLE genotypes after thousands of meiotic divisions starting with the genotype of the oöcyte shown above?

gamete assemblage F

On the given Punnett square, what do the letters used as column and row headings represent (e.g., TB, Tb, tB, and tb)?

gamete genotypes

What is the ploidy of the depicted cell?

haploid

Consider the following mRNA transcript: 5'-UCUGAUGGGCUGAGUA-3' Assuming that this is the complete mRNA molecule, how will ribosomes translate its sequence into a polypeptide chain?

methionine, glycine