BIO 148 EXAM2 PRACTICE TEST 63 Questions with Verified Answers,100% CORRECT

BIO 148 EXAM2 PRACTICE TEST 63 Questions with Verified Answers . A doctor is trying to identify the mutant gene that causes her patient to be colorblind. To do this she takes a swab of the patient's cheek cells to send off for DNA sequencing. Did she sample the correct cells? a. No, because the cells of the eye have different genes than the cells of the cheek. b. No, because the cells of the eye have different chromosomes than the cells of the cheek. c. Yes, because both cells have the same genes d. Yes, because both cells express the same genes - CORRECT ANSWER C 2. RNA polymerase...... a. Starts transcribing at the first intron b. Starts transcribing at the start codon c. Transcribes the coding strand 5' to 3' d. Synthesizes a nucleic acid that is complementary to the template strand e. Answers (a), (c) and (d) are all correct - CORRECT ANSWER D For most multicellular organisms, how can the cells of a single organism have different shapes and actions? a. They express different genes b. They have different gene switches (enhancers) c. They have different genes d. They have different chromosomes e. Both a and b - CORRECT ANSWER A An individual has a mutation in the gene that encodes a switch activator protein. The mutation prevents the activator protein from binding to the switch that controls the expression of the lactase gene. What will the ultimate outcome of this mutation be? a. The lactase gene will be transcribed but the mRNA will not be translated b. The lactase gene will be transcribed but the RNA will not be processed c. The lactase gene will not be transcribed so the mRNA will not be translated d. The lactase gene will be translated but the mRNA will not be transcribed - CORRECT ANSWER C Within the eukaryotic cell, transcription occurs in the __________ and RNA splicing occurs in the _____. a. Nucleus; nucleus b. Cytoplasm; nucleus c. Cytoplasm; cytoplasm d. Nucleus; cytoplasm - CORRECT ANSWER A The DNA molecules in eye cells contain which of the following? a. Genes that encode eye color and skin color, and switches that control both eye color and skin color b. Genes that encode eye color and skin color, and switches that control eye color only (not skin color) c. Genes and switches that encode eye color only (not skin color) d. Genes that control eye and skin color, but not switches for either of these genes. - CORRECT ANSWER A Which of the following is a part of a DNA molecule? a. Promoter e. A and C only b. Switch c. Gene d. All of the above - CORRECT ANSWER D Use the diagram above to answer the next two questions. 8. Transcription will occur from right to left in the diagram above. Which DNA strand is the coding strand? a. X b. Z c. Impossible to determine - CORRECT ANSWER B 9. Which of the following is present in the DNA sequence above? a. a 5' cap b. a 3' poly (A) tail c. Untranslated regions (UTRs) d. switch activators e. All of the above - CORRECT ANSWER C How might a single base change (substitution) in the sequence of an exon affect the protein encoded by the gene? a. A single amino acid could change b. The length of the polypeptide could change c. It is possible that the change would have no effect on the protein d. All of the above e. A and C only - CORRECT ANSWER D 5' UCUGAUGGGCUUU... 11. Beginning with the start codon, which amino acids, in order, are coded for by this section of mRNA? a. serine, aspartic acid, glycine, leucine b. methionine, glycine, phenylalanine c. methionine, valine, glycine, phenylalanine d. threonine, methionine, glycine - CORRECT ANSWER B A peptide has the sequence phe-pro-lys-gly-phe-pro. Which of the following sequences in the coding strand of the DNA could code for this peptide? a. UUU-CCC-AAA-GGG-UUU-CCC b. AUG-AAA-GGG-TTT-CCC-AAA-GGG c. TTT-CCC-AAA-GGG-TTT-CCC d. GGG-AAA-TTT-AAA-CCC-ACT-GGG e. ACT-TAC-CAT-AAA-CAT-TAC-UGA - CORRECT ANSWER C Which of the following contains information that determines the amino acid sequence of the protein encoded by this gene? a. The gene's promoter b. Nucleotides between +1 and the start codon c. Nucleotides in exons d. All of the above e. B and C only - CORRECT ANSWER C A possible sequence of nucleotides in the template strand of DNA that would code for a portion of a polypeptide with the amino acid sequence Phe-Ile would be _____. a. 3' TTG-CTA 3' b. 3' AAC-GAC 5' c. 3' AUG-CTG 3' d. 3' AAA-AAT 5' e. 3' AAA-TAA 5 - CORRECT ANSWER E Which of the following is TRUE about translation in eukaryotes? a. The first amino acid added during translation of all mRNAs is the same b. Translation begins at the +1 nucleotide c. Translation terminates (stops) after the polyA tail is translated into amino acids d. Each mRNA nucleotide encodes one amino acid e. The mRNA strand is translated 3' to 5' to synthesize a polypeptide from N terminus to C terminus - CORRECT ANSWER A Which of the following about switch activators is TRUE? a. They bind to 3' poly A tails b. They are essential for proper RNA splicing c. They are proteins that bind to DNA sequences d. They regulate the number of times a RNA molecule is translated - CORRECT ANSWER C A mutation in a gene changes every amino acid in the encoded protein except for the first amino acid. What is the most likely type of mutation that would cause this change? a. silent b. frameshift c. nonsense d. missense - CORRECT ANSWER B Which of the following would you expect to find in a mature mRNA? a. Introns b. Promoters c. Codons d. Amino acids e. Switches - CORRECT ANSWER C The level of protein structure at right is caused by which of the following? (alfa helix) a. Hydrogen bonding between groups along the backbone. b. Specific types of peptide bonds c. Interactions between the R group and other R groups d. Multiple polypeptides interacting with each other - CORRECT ANSWER A Which of the following statements regarding mutations is true? a. Mutations are responsible for the creation of new alleles of genes. b. Only mutations in exons can affect the amount of protein produced in a cell c. Mutations arise when the DNA is being transcribed into mRNA d. Mutations are always harmful to an organism e. Both A and B are true - CORRECT ANSWER A Which part(s) of different amino acids is/are different? a. the central carbon b. the amino group c. the carboxyl group d. the R group e. All of the above - CORRECT ANSWER D Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that do not have a known function. The crab tail is an example of _____. a. convergent evolution b. a transitional feature c. an atavism d. a vestigial trait - CORRECT ANSWER D 0. Each of the following observations provides evidence that support the idea of common ancestry and evolution. Which one is a STRUCTURAL homology? a. Two closely related, but distinct, species of squirrels inhabit the north and south rims of the Grand Canyon. b. The cells in embryos of both birds and mammals divide in the same pattern c. The analysis of a protein sequence reveals that humans and yeast differ by 44 amino acids, whereas the human and monkey differ by 1 amino acid. d. Forelimbs of humans, cats, and whales have different functions, but very similar internal bone anatomy. - CORRECT ANSWER D Snakes do not have limbs but evolved from reptiles. You find a snake that has two front legs. The front legs on this snake would be considered ____. a. a vestigial trait b. an atavism c. evidence against evolution by natural selection d. evidence for artificial selection - CORRECT ANSWER B A child has an ear infection and is treated with an appropriate antibiotic. A week after being cleared of infection by the doctor, the child develops another ear infection. Which of the following is the best explanation for this scenario? a. Some of the original bacterial population responded to the antibiotic by mutating to become resistant, and they caused a second ear infection. b. The first course of antibiotics did not kill any bacteria, so they remained and caused a second infection. c. Some bacteria in the initial bacterial population were resistant to the antibiotic, survived the antibiotic treatment, and caused a second infection. d. All of the bacteria in the original bacterial population developed a temporary resistance while the antibiotics were applied, and they caused a second infection - CORRECT ANSWER C Tapeworm species tend to have simple morphologies. Which of the following statements best explains this observation? a. Tapeworms are lower organisms, and this is why they have simple morphologies. b. Tapeworms do not live long enough to inherit acquired characteristics. c. Simple morphologies convey some reproductive advantage in most tapeworms. d. Tapeworms have not yet had time to progress, because they are evolutionarily young species. - CORRECT ANSWER C 4. Pseudogenes... a. are a result of incorrect transcription b. cause atavisms c. are genes that were once functional in ancestors d. are evidence of gene flow - CORRECT ANSWER C Many salmon species swim from the ocean to the river to reproduce, and then die. The offspring do not require parental care. Which of the following salmon is most likely to have the highest fitness? a. A salmon who lays 1500 eggs and gets eaten by a raccoon b. A salmon who lays 1500 eggs and dies from the exhaustion of swimming upriver from the ocean c. A salmon who lays 2000 eggs and gets eaten by a bear d. A salmon who has the genes to lay 2500 eggs that gets eaten by a bear on her way upriver before she can lay eggs. - CORRECT ANSWER C In order for new functions to arise, what must happen after gene duplication events? a. Mutations must occur in one copy of the gene or in its regulatory region b. Both copies of the gene must become non-functional c. Both copies of the gene must stay the same as each other d. One copy of the gene must be passed on, but the other must not e. One copy of the gene must be transcribed, but the other copy must not - CORRECT ANSWER A Possessing pelvic spines is a trait that is a fitness advantage in stickleback that live in the presence of trout predators. In which region(s) would you expect to see a mutation that allows the stickleback to live to adulthood, but would potentially lower fitness in an environment with trout? a. Region (a) b. Region (b) c. Region (c) d. Region (a) and (c) e. Region (b) and (c) - CORRECT ANSWER C A mutation in what region(s) could potentially prevent a stickleback embryo from living into adulthood? a. Region (a) b. Region (b) c. Region (c) d. Region (a) and (b) e. Region (a) and (c) - CORRECT ANSWER D Cheetahs are the fastest land animal, causing some people to proclaim that they have a perfect body design for running. How would an evolutionary biologist refer to the body design of cheetahs? a. Cheetah bodies have adaptations for running fast but do not represent perfection. b. Individual cheetahs develop a shape for speed as a result of chasing gazelle c. Because of the need for speed, a mutation arose in cheetahs that lead to the streamlined body d. Adaptations in the cheetah's body for high speed running are examples of perfect morphologies. - CORRECT ANSWER A . Mutations..... a. are always bad for fitness b. have no effect on fitness c. result from an organism's evolutionary needs d. can be beneficial in their effect on an organism's fitness - CORRECT ANSWER D If having one or more antibiotic resistance genes in the bacterium Staphylococcus aureus reduces fitness in environments that lack of antibiotics, what is predicted to happen to bacterial populations in environments that lack antibiotics? a. The antibiotic resistance genes would be maintained in the population, in case the antibiotics appear. b. Bacteria with the antibiotic resistance genes would be outcompeted and replaced by bacteria that do not have the genes. c. Bacteria with the antibiotic resistance genes would try to make the cost worthwhile by locating and migrating to environments where antibiotics are present. d. The number of antibiotic resistance genes would increase in these bacteria. - CORRECT ANSWER B Central Dogma - CORRECT ANSWER the flow of hereditary information genes are... - CORRECT ANSWER -A sequence of amino acids in a polypeptide -Segments of a chromosome structure of a protein determines... - CORRECT ANSWER function of proteins switches are ____. activators are _____. - CORRECT ANSWER DNA sequence, proteins three major parts of genes - CORRECT ANSWER 1- promoter 2-transcribed region 3-termination signal 2 DNA strands: - CORRECT ANSWER 1- template for transcription 2-coding(same sequence as mRNA) transcription occurs... - CORRECT ANSWER 5 to 3 amino acids are added together to form a polymer called a ____. - CORRECT ANSWER polypeptide ribosomes are large complexes containing____. - CORRECT ANSWER About 100 proteins and 4 RNAs. tRNAs are___. - CORRECT ANSWER RNAs that act as adapters: they can read the codon and bring the correct amino to the ribosome. amino acids are connected by ___. - CORRECT ANSWER peptide bonds Primary Structure: - CORRECT ANSWER the sequence of amino acids in a polypeptide. Secondary - CORRECT ANSWER the folding of small sections of the polypeptide chain into alfa or beta Tertiary - CORRECT ANSWER the overall folding of the peptide Quaternary - CORRECT ANSWER binding of 2 or more folded polypeptides to form a complex protein mutations change___. - CORRECT ANSWER the DNA sequence of an organism missense mutations - CORRECT ANSWER one amino acid is replaced by another nonsense mutations - CORRECT ANSWER a sense codon is replaced with a stop codon silent mutation - CORRECT ANSWER a change in nucleotide sequence but not the amino acid sequence frameshift mutations - CORRECT ANSWER deletions or insertions 2 main components of evolution - CORRECT ANSWER decent and modification clades are___. - CORRECT ANSWER all taxas and their common ancestor homologies - CORRECT ANSWER similarity due to inheritance from a common ancestor structural homology - CORRECT ANSWER -structures in different species with a common ancestor -non-embryonic structures, usually adult form developmental homology - CORRECT ANSWER studying the embryological development of living things provides clues to present-day organisms genetic homology - CORRECT ANSWER similarities in the sequences of DNA,RNA, or protein due to common ancestry -hox genes vestigial traits - CORRECT ANSWER -show change over time in which complexity decreases -reduced structure of unknown or minimal function related to full, used structures in other species atavisim - CORRECT ANSWER an "evolutionary throwback"; a trait that reappears in a species that is not normally seen in that species but is known to have been present in an ancestral species. Misconceptions about evolution by natural selection - CORRECT ANSWER 1- large phenotypic changes require lots of change at the genetic level 2-natural selection is a random process 3-natural selection results in perfect organism 4-evolution causes changes in individuals 5-adaptations occur in response to a need of an organism 6-evolution always results in more complex organisms