BIOLOGY 1500 FULL EXAM WITH GUARANTEED ACCURATE ANSWERS 2024, Exams of Nursing

Download BIOLOGY 1500 FULL EXAM WITH GUARANTEED ACCURATE ANSWERS 2024 and more Exams Nursing in PDF only on Docsity! BIOLOGY 1500 FULL EXAM WITH GUARANTEED ACCURATE ANSWERS 2024 Which of the following is the best modern definition of evolution? A) inheritance of acquired characters B) change in allele frequencies in a population over time C) survival of the fittest D) descent without modification - correct answer ✔✔B Which of the following is not a correct version of one of Darwin's four postulates? A) some of variability in traits in a population are heritable. B) individuals with certain heritable traits are more likely to survive and reproduce. C) in each generation, only as many offspring that can survive are produced. D) individuals in a population vary in their traits. - correct answer ✔✔C Evolution in a population island finches can be caused by the following agent(s): A) genetic drift B) natural selection C) gene flow D) all of the above E) both natural selection and genetic drift - correct answer ✔✔D Biological fitness is best defined as: A) similar reproductive success among individuals in a population B) relative the ability of an individual to produce offspring that survive and reproduce C) competition among individuals for resources that allow them to have more offspring D) a heritable trait that increases the match of an individual to its environment E) variability in the population for a trait that increases survival - correct answer ✔✔B Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. You believe that having longer hair is adaptive to these males. To prove that this is an adaptation, you next should ________. A) conclude that natural selection will lead to males with longer hair in your population B) determine if hair length is heritable C) conclude that longer haired males survive better than their shorter haired counterparts D) conclude that there is not enough variation in hair length for natural selection to act - correct answer ✔✔B Which of the following statements describes natural selection best? A) Individuals with the most favorable alleles survive and reproduce. B) Natural selection causes irreversible changes. C) Selection causes changes of individuals that make them more likely to survive. D) Natural selection is a random process that leads to more complex traits. - correct answer ✔✔A Speciation occurs when populations become genetically isolated and then diverge due to evolutionary mechanisms. Which of the following could be a dispersal event that would lead to genetic isolation for populations in that habitat? A) Some insects get blown in a storm to a new mountain range, where they lay eggs. B) Radiation near a nuclear spill increases mutation rate, causing an increase in new alleles. C) The level of water in a lake recedes, creating two lakes where there used to be one. Genetic drift occurs in a population. Which of the following statements might be true? A) Genetic drift increased the population's fitness. B) Genetic drift decreased the population's fitness. C) The population was relatively small. D) The population experiences a decrease in genetic variation. E) Any of the above statements might be true. - correct answer ✔✔E Which of the following is the most predictable outcome of decreased gene flow between two populations? A) increased genetic drift B) decreased genetic difference between the two populations C) higher average fitness in both populations D) lower average fitness in both populations E) increased genetic difference between the two populations - correct answer ✔✔E Three-spined stickleback fish (Gasterosteus aculeatus) show substantial heritable variation in gill-raker length. Fish caught in open water tend to have longer gill rakers and eat different foods than do those caught in shallower water. Longer gill rakers appear to function better for capturing open-water prey, while shorter gill rakers function better for capturing shallow-water prey. Which of the following types of selection is most likely to be found in a large lake (open water in middle and shallow water around the sides) with a high density of these fish? {not that it matters for the answer to the question, but gill rakers in fish are bony or cartilaginous processes that project from the gill arch and are involved with filter feeding tiny prey.} A) no selection B) stabilizing selection C) directional selection D) disruptive selection - correct answer ✔✔D Which of the following describes the most likely order of events in an allopatric speciation event? A) divergence, genetic drift, genetic isolation B) divergence, genetic isolation, genetic drift C) genetic isolation, divergence, genetic drift D) genetic isolation, genetic drift, divergence E) genetic drift, genetic isolation, divergence - correct answer ✔✔D There is an island in the middle of a large river that houses a large population of ants. Damming of the river causes the island to flood and only the highest points of the island are now above water. The ants cannot swim, so are now in multiple isolated populations. Which of the following best describes this event? A) Speciation will not occur in this case because of gene flow. B) This situation represents isolation by dispersal. C) This situation represents a form of sympatric speciation. D) This situation represents isolation by vicariance. E) Only a rare development of polyploidy could lead to speciation in this case. - correct answer ✔✔D A small number of birds arrive on an island from a neighboring larger island. This small population begins to adapt to the new food plants available on the island, and their beaks begin to change. About twice a year, one or two more birds from a separate population on the neighboring island arrive. These new arrivals _____. A) tend to promote adaptation to the new food plants B) speed up the process of speciation C) tend to slow the adaptation to the new food plants D) represent a colonizing event - correct answer ✔✔C What is the process caused by the birds from the neighboring island described in Question 20 called? A) Gene flow B) Genetic drift C) Vicariance D) Polyploidy - correct answer ✔✔A According to the biological species concept, what must two members of the same species be able to do? A) Mate B) Produce live offspring C) Produce offspring capable of reproducing D) All of the above - correct answer ✔✔D A diploid organism inherits two different alleles of a given gene, A and a, from its parents. However, only the trait associated with allele A is seen in the offspring. How would you describe the relationship of these two alleles? A) Allele A and a and co-dominant. B) Allele a is recessive with respect to allele A. C) Alleles A and a show incompete dominance. D) Allele a is dominant with respect to allele A. - correct answer ✔✔B Which of the following is least likely to be a molecular mechanism for the dominance relationships between alleles A and a in Question 23? A) Both of the protein products for A and a are made appropriately, and both function normally, but there is just a litle more of protein A made. B) Allele A is made appropriately, while the protein for allele a is not folded correctly by the molecular chaperones and does not function. C) Both of the protein products for A and a are made appropriately, but the a protein gets trapped in the endoplasmic reticulum and never makes it to where it exerts a function. D) Allele A has a functional promoter, while allele a has a mutation in its promoter that prevents it from being transcribed. - correct answer ✔✔A A peptide bond _____. A) does not play a role in maintaining the tertiary structure of proteins B) forms between the central carbon and the amino group of a single amino acid C) forms the primary structure of proteins D) forms between the functional groups of different amino acids - correct answer ✔✔C What is the most important contribution of the plasma membrane to cellular biochemical processes? A) By integrating proteins in the membrane, the cell has a storage space for amino acids to use in subsequent biochemical reactions. B) Because cell membranes can spontaneously form from phospholipids, it requires less energy to make a new cell. C) The selective permeability of the bilayer and its transmembrane proteins enable cells to create an internal environment that is specifically maintained separate from the external environment for optimal biochemical conditions. D) The membrane causes diffusion to happen, which is a crucial transport process for many reactions. - correct answer ✔✔C The function of a protein is dependent on the shape it ultimately folds into. Many different kinds 34) of chemical bonds are responsible for maintaining the protein shape. If you isolate a protein from an organism and treated it with a chemical that breaks only the hydrogen bonds of the protein, how would this affect the protein's shape? A) The protein wil not change; once the protein is folded, the hydrogen bonds are no longer necessary. B) The protein will lose only its quaternary structure, but the remainder will stay intact. C) The protein will only have its primary structure remaining. D) The protein will be broken down into its individual amino acids. - correct answer ✔✔C Which of the following is true regarding the structure of the basic components involved in the central dogma? A) All organisms (with few exceptions) use the same 20 essential amino acids to synthesize all of the functional proteins in their cells. B) All organisms (with few exceptions) use the same 4 deoxyribonucleotides to encode their DNA. C) All organisms (with few exceptions) use the same 4 ribonucleotides to encode their RNA. D) All of the above are true. - correct answer ✔✔D What does it mean when we say the genetic code is redundant? A) The genetic code is universal (the same for all organisms). B) A single codon can specify the addition of more than one amino acid. C) The genetic code is different for different domains of organisms. D) More than one codon can specify the addition of the same amino acid. - correct answer ✔✔D Which of the following is most responsible for the fact that DNA is double-stranded? A) covalent phosphodiester bonds B) molecular chaperones join the two strands together C) hydrogen bonding between complementary base pairs D) disulfide linkages between nitrogenous bases - correct answer ✔✔C You take a human brain, a bird muscle, a blade of grass and a colony of Salmonella bacteria, and extracted all of the DNA from these samples. You then denature all the secondary structure and break down all of the polymers into their constituent monomers for the four different samples. Which of the following statements would be accurate regarding these samples? A) You would be able to distinguish the bacteria sample because bacteria only use purines in their DNA. B) The resulting pool of nucleic acids would be different in the plant and bacterial samples, but the same in the two animal samples (human and bird). C) The samples would be completely indistinguishable (you couldn't tell them apart). D) You could sort the samples based on which has the most adenine nucleotides. - correct answer ✔✔C Why are enzymes considered catalysts? A) Because they can make their own form of energy to fuel chemical reactions. B) Because they break down larger molecules into smaller molecules. C) They lower the activation energy of a chemical reaction. D) They allow reactions to go forward with no input of energy at all - correct answer ✔✔C From where is the energy source used by most enzymes to catalyze chemical reactions A) Enzymes get energy directly from glucose molecules to fuel chemical reactions. B) Phosphate groups from ATP molecules that are bound to the enzymes during the process of phosphorylation. C) Enzymes use free kinetic energy inherent in all molecules to drive chemical reactions. D) Amphipathic membrane proteins are broken down to release energy for chemical reactions. - correct answer ✔✔B What is the most important contribution of the plasma membrane to cellular biochemical processes? A) The selective permeability of the bilayer and its transmembrane proteins enable cells to create an internal environment that is specifically maintained separate from the external environment for optimal biochemical conditions. B) Because cell membranes can spontaneously form from phospholipids, it requires less energy to make a new cell. C) The membrane causes diffusion to happen, which is a crucial transport process for many reactions. D) By integrating proteins in the membrane, the cell has a storage space for amino acids to use in subsequent biochemical reactions. - correct answer ✔✔A Where would you most likely find an integral membrane protein? C) electrons D) H+ (protons) - correct answer ✔✔B Meiosis involves the creation of haploid cells from diploid cells. The haploid chromosome number in gametes is created when _____. A) homologous chromosomes separate B) crossing over occurs C) gametes go through their maturation processes following meiosis D) sister chromatids separate - correct answer ✔✔A Mendel's law that describes the process of creating haploid gametes in diploid organisms is called _____ . A) the Law of Segregation B) the Law of Independent Assortment C) gene mapping D) the Law of Linkage - correct answer ✔✔A Which of the following describes Crossing Over during meiosis? A) Homologous chromosomes exchange the same portions of their DNA before separating B) Both alleles of the same gene in a diploid organism end up on the same chromosome during meiosis. C) A portion of one chromosome breaks off and is attached to the end of a different chromosome. D) Homologous chromosomes separate during meiosis - correct answer ✔✔A Which of the following statements about the DNA in one of your liver cells is true? A) All of the genes of the genome are likely to be transcribed in your liver cells. B) All of the DNA in your liver cells codes for protein. C) It is the same as the DNA in one of your skin cells. D) Each gene on a pair of homologous chromosomes in liver cells is identical. - correct answer ✔✔C How might the addition of a single base (for example adding a G or a C) in the sequence of a gene affect the amino acid sequence of a protein encoded by the gene, and why? A) It is not possible for a single base addition to affect protein structure, because each codon is three bases long. B) Only a single amino acid could change, because the reading frame is unaffected. C) The amino acid sequence could be substantially altered, because the reading frame would change with a single base addition. D) All of the promoters of the genes following the substitution would be affected, because the reading frame would be shifted. - correct answer ✔✔C To which part of a gene do the regulatory transcripton factors bind? A) The promoter-proximal elements B) The coding sequence C) The core promoter itself (with the TATA box) D) The transcription termination sequence - correct answer ✔✔a The reason for differences in the sets of proteins expressed in a liver cell and a skin cell of the same individual is that nerve and pancreatic cells contain different _____. A) transcription factors B) promoters C) promoter-proximal elements D) genes - correct answer ✔✔A If cells of an individual contain the same set of genes, how do these cells become different from each other during development? A) Different cell type-specific regulatory elements in DNA are selectively lost during development. B) Differences in cell-signaling cascades can lead to the activation of different transcription factors in each cell. C) Different cell type-specific regulatory elements in DNA are created during development. D) Differences develop in promoter sequences that lead to different signals being produced by each type of cell. - correct answer ✔✔B Basal transcription factors _____. A) open the two strands of DNA so RNA polymerase can begin transcription B) influence the degree of unwinding of DNA at the replication fork C) influence the assembly of the regulatory transcription factor complex D) influence the binding of RNA polymerase to DNA - correct answer ✔✔D If you wanted to artificially express a foreign gene only in a limited type of cell in the target organism, how would you go about engineering the recombinant DNA construct? A) Alter the target cells so that they express only the transcription factors responsible for the expression of the foreign DNA. B) It is impossible to limit expression to only a limited target cell type inan organism. C) Engineer the foreign DNA gene with a promoter region that was identical to that of a gene found naturally only in the target cells. D) Engineer the foreign DNA gene with start codons that are specific to those found only in the target cells. - correct answer ✔✔C You want to engineer bacteria to produce a human clotting factor protein called Factor 7 so that you can purify the protein and use it to treat people with hemophilia (an inabiltiy to clot blood). If you want to B) Stabilizing selection C) Directional selection - correct answer ✔✔C What is the most likely new genotype frequency to arise from this selection event? [make sure you carefully read the information in question #37 before answering] A)10%RR-10%RN-80%NN B) 75%RR-15%RN-10%NN C) 5% RR - 60% RN - 35% NN D) 25% RR - 50% RN - 25% NN - correct answer ✔✔A Normal hemoglobin protein is called hemoglobin A, but people with Sickle Cell Disease have only hemoglobin S, which turns normal, round red blood cells into abnormally curved (sickle) shapes. This often leads to various acute and chronic complications, several of which can cause death. "Sickle Cell Trait" describes a condition in which a person has one abnormal allele (S) of the hemoglobin gene (is heterozygous, or genotype AS), but does not display the severe symptoms of sickle cell disease that occur in a person who has two copies of the S allele (is homozygous, or gentoype SS). QUESTION: Each hemoglobin protein has a total of four chemical heme groups that can bind oxygen molecules. When you denature the molecule and study its composition, you find that each heme group occurs on a different polypeptide. Which of the following hypotheses does this observation support? A) The protein requires a cofactor to functio - correct answer ✔✔D The hemoglobin HbS mutation is a point mutation. How might this single base substitution (the 69) base changes, but is not deleted) in the sequence of a gene affect the amino acid sequence of a protein encoded by the gene, and why? A) Only a single amino acid could change, because the reading frame is unaffected. B) The protein will be unable to form any peptide bonds, and therefore not be made. C) It is not possible for a single base substitution to affect protein structure, because each codon is three bases long. D) All amino acids following the substitution would be affected, because the reading frame would be shifted. - correct answer ✔✔A Sickle cell disease, which is caused by having two copies of the hemoglobin S allele, leads to substantially decreased fitness in individuals afflicted. Prior to modern medical intervention, mortality was high and people died before they could reproduce. If you could follow the prevalence of the S allele in the population prior to modern medicine, how and why do you expect allele frequencies of hemoglobin A and S to change over time? A) Genetic drift will result in the fixation of the A allele. B) Stabilizing selection will result in no change in A and S frequency in the population. C) Directional selection will result in a decrease in the frequency of the S allele. D) Disruptive selection will result in an increase in homozygous A and homozygous S individuals, but the overall frequency of alleles will not change. - correct answer ✔✔C How would you describe the blood cell content of an individual who is homozygous for the sickle cell mutation (genotype AS)? A) All of the cells will contain a mix of normal (HbA) and mutant (HbS) hemoglobin protein. B) Half of the cells will contain normal (HbA) and half of cells will contain mutant (HbS) hemoglobin protein. C) All of the cells will contain only mutant hemoglobin (HbS). D) All of the cells will contain only normal hemoglobin (HbA). - correct answer ✔✔A What is the underlying cause of malaria in humans? A) A viral infection B) A parasitic protist infection C) Toxicity from eating a plant that produces a chemical defense D) A genetic mutation in the hemoglobin gene - correct answer ✔✔B Malaria affects both liver cells and red blood cells in humans. Red blood cells are derived from cells in the bone marrow that make new red blood cells throughout the life of a person. Clearly liver cells and bone marrow cells are very different in terms of their functions. How can these two cells have such distinct functions even within the same individual? A) Bone marrow cells and liver cells have different sets of regulatory transcription factors that lead to distinct subsets of proteins being made in each cell type. B) Bone marrow and liver cells have all the same proteins, but they are folded differently in each cell type. C) The bone marrow cells contain genes for making red blood cells, while the liver cells have genes that specify liver function. D) Bone marrow and liver cells have all the same genes, but contain different cell-specific promoters that allow for different genes to be turned on in each cell ty - correct answer ✔✔A So the question then arises, if the hemoglobin S allele is so deleterious, why does it persist in human populations? A striking discovery was made by Tony Allison in the 1950's that showed that there is a link between sickle cell and malaria. Remember that sickle cell trait occurs when an individual is heterozygous for the A and S alleles of hemoglobin. It turns out that sickle cell trait provides a survival advantage over people with normal hemoglobin in regions where malaria is endemic. Because of the unique survival advantage, people with sickle cell trait increase in number as more people infected with malaria that have the normal hemoglobin tend to die due to the malaria complications. Also keep in mind, it is never good to have sickle cell disease, which is caused by being homozygous for hemoglobin S. Given this interesting example, how and why do you expect allele frequencies of hemoglobin A and S to change o - correct answer ✔✔C If you wanted to cure someone who was afflicted with sickle cell disease, what would your gene therapy strategy be? A) Make a gene construct that contains the coding sequence of HbA and the promoter region of HbA and introduce it into bone marrow cells of the afflicted person. B) Make a gene construct that contains the coding sequence of HbS and the promoter region of HbA and introduce it into bone marrow cells of the afflicted person. C) Make a gene construct that contains the coding sequence of HbA and the promoter region of from a bacteria and introduce it into bone marrow cells of the afflicted person.