Biology (Photosynthesis - Plant Structure)

Which of the following is the most possible outcome of cell division that does not undergo the cytokinetic phase?multinucleated cellsabsence of cytokinetic phase during cell divisionabnormal sized cells and chromosomal destructionWhat quality best describes an allele?can be expressed as a phenotype enzymes regulate the rate of the replication of the DNAWhich of the following applications of genetic engineering did people use prior to the in-depth study of DNA use?Selective breedingWhat nitrogenous base of the DNA is the partner of guanine?CytosineGenetic engineering has increased the efficiency and productivity of farms, poultry, and other agricultural industries. What statement explains why genetic engineering is more easily applied in plants than in animals?somatic planet cells can produce a complete plantA paleontologist has obtained the 600-year-old preserved skin tissues of an extinct mammal. Which of the following methods is most likely to be useful in increasing the amount of DNA of the recovered tissue for further investigation?Polymerase chain reactionWhich of the following components is most likely to be able to serve as a vector in the process of recombinant DNA?PlasmidA biologist is examining the cells of a leaf and the cells of a caterpillar under a microscope. Which of the following is a difference the biologist might notice?leaf cell has chloroplasts, caterpillar cells do not. Plants do not consume glucose but make their own.Which of the following accurately describes the steps involved in protein synthesis?Dna is transcribed into mRNA, which is translated into proteinAt a certain stage during mitosis, chromatids are pulled to opposite ends of the cell. This stage is called .Anaphase 1: Prophase (chromosomes bunch up) 2: Metaphase (chromosomes line up) 3: AnaphaseThe central dogma of biology states that what chemical compound is transcribed into RNA?DNA to RNA to a proteinAfter RNA is transcribed, it translates into what?ProteinWhat theory suggests that organelles such as the mitochondria were once free-roaming prokaryotes and over time eventually became eukaryotes?Endosymbiotic theoryA leaf gets its green pigmentation from what?Chlorophyll (stroma inside chloroplasts) (somata are pores through which CO2 enters the leaf and O2 exits)The Calvin cycle (light independent convert CO2 into carbs and sugar) and light reactions are the 2 stages of .PhotosynthesisThe change in the frequency of alleles throughout generations is known as which of the following?Genetic driftProcess by which genes are passed through populationsGene flowalteration of an orgs DNAGenetic mutationGenes moving from population to population is known as which of the following?Gene flowGenetic recombinationhappens in meiosisWhat is the process through which different organisms develop similar physical characteristics (such as homologous structures)?Convergent evolutioncharactized by a portion of a species that is separated from the rest of the by physical barriers and eventually adapts new characteristics fit for their new envt.Divergent evolutionAt times, groups of a particular species can get separated by a physical barrier (e.g., rivers, mountains). This is known as which of the following?Divergent evolutionProcess through which closely related but still distinct species develop similar traitsParallel evolutionThe sister chromatids are pulled apart by microtubules in which phase of mitosis?AnaphaseA freshwater plant is placed in a salt marsh. Which of the following predicts the direction in which water will move across the plant's cell wall and the effect of that movement on the plant?Water would move out of the plants cells, resulting in a decrease in the turgor pressure Plants wiltIdentical lengths of potato cores were cut and massed. One potato core was then placed in 100 mL of each of the following solutions; 0M sucrose, 0.2M sucrose, 0.4M sucrose, 0.6M sucrose, 0.8M sucrose, and 1M sucrose. These were left to equilibrate overnight, then the potato cores were removed, patted dry, and massed again. Data is recorded in the table below. Refer to the image. What is the most likely cause of the potato core gaining mass when placed in the 0M sucrose solution?water moved down its concentration gradientWhen a ligand binds to a G protein-coupled receptor, ___ on Gα is phosphorylated to activate the signaling pathway.GDPWhich of the following hypothetical studies support the hypothesis that genetic mutations are random? Select all that apply.A study on genetic mutations observed to be beneficial, neutral, and harmful in a small species A study on antibiotic resistance in the bacteria E Coli concluding that the resistance is linked to pre existing gene sequences activated in the bacteria due to antibiotic exposureWhat DNA repair mechanism is most similar to chromosomal crossover in meiosis with respect to replication machinery?homo recomdinationOrder the following steps in the process of protein biosynthesis.RNA is made from DNA RNA splicing removes introns mRNA is formed from remaining exons Ribosome binds to mRNA Ribosome matches tRNA anticodon sequences to the mRNA codon sequence Amino acids are added to polypeptide chain Ribosome releases the chain of proteinsTranscription is the process of DNA being copied into RNA. Translation is the process of a ribosome taking the transcribed mRNA and translating it, matching it to form a complementary base sequence molecule known as tRNA. It is then used to code for proteins. Assuming that the DNA sequence does not include introns, what is the tRNA base sequence that corresponds to the DNA base sequence (AGG)?AGGWhich of the following statements are correct about plant pigments in relation to the process of photosynthesis?pigments are molecules that absorb specific wavelengths of light Chlorophyll a is more abundant than chlorophyll b and evolved first cartotenoids protect the plant from free radicals formed from UVA molecular biology graduate student is studying a new signaling molecule: annokine. The student discovers that if they add it to cells, those cells start to divide rapidly. When they first treat these cells with a pan-G-protein-coupled receptor (GPCR) inhibitor, however, annokine treatment does not provoke a response from the cells.GTPase activity is necessary for annokine's cell division inducing effectHistorically, HIV treatments have largely aimed at interfering with viral replication or other aspects of the viral life cycle, but they have not been able to target cells in which HIV successfully integrates into the genome but remains quiescent. As a result, these treatments are never able to cure patients of HIV entirely. Which of the following treatment strategies has the potential to cure infected individuals of HIV (eliminating viral DNA from all cells in the body) when combined with current treatments?Activating HIV viral production in all latently infected cells, allowing the immune system to destroyOver the course of 1 month, a doctor has 12 patients visit his practice with a previously unknown disease. With the help of a virologist, he discovers that these patients have 2 unique viruses: Virus A and Virus B. When he extends this research further, he makes a few observations: There are many people in the general population who seem to be infected with Virus A but show no symptoms of disease. No humans can be found that are only infected with Virus B. Infecting mice with Virus A leads to infection, but not disease. Infecting mice with Virus B does not lead to infection or disease. Infecting mice with both Virus A and Virus B leads to infection with both viruses and disease. Question What can be concluded about Viruses A and B?Virus B is a virusoid (satellite virus) incapable of replication on its own and dependent on another virus for its replicationA graduate student studying cancer has discovered a new anti-cancer drug and wants to determine how it kills cancer cells. The student discovers that cancer cells treated with this drug die due to issues with DNA replication. Further examination reveals that the DNA of dead cancer cells is filled with small single- and double-stranded breaks after treatment with this drug. Assuming the new drug is an enzyme inhibitor, what DNA replication enzymes may be inhibited by this drug based on these observations?DNA toposiomerase creating single stranded breaks in DNAScientists identify a strain of bacteria with an intriguing property: any time the bacterial DNA codes for a leucine amino acid, there is a 55% chance that the resultant proteins will instead contain a serine at that position and only a 45% chance that a leucine will be present.The bacteria have a mutation in the serine tRNA anticodon, changing tis sequence to resemble the leucine anticodon.Antibiotic resistance is on the rise in clinical settings, and many doctors are concerned that in the future there will not be any antibiotic drugs available to combat bacterial infections. An alternative to antibiotics has been the subject of recent research interest: the use of engineered bacteriophages to target and kill infectious bacteria in sick individuals. Which of the following are potential limitations to phage therapy? Select all that apply.Bacteria can evovle resistance to phages Bacteriophages can facilitate transduction the immune system detects viruses as invadersThe RNA World Hypothesis posits that prior to the development of DNA, earlier living organisms and proto-organisms relied upon RNA as their genetic material for information storage and transmission. Which of the following pieces of evidence support the RNA World Hypothesis? Select all that apply.DNA is synthesized from ribose precursors Synthetic autocatalytic RNA polymerases have been generated by researchersA scientist is studying a novel protein (Cambromangen) in human immune cells, comparing its activity in children and adults. The scientist discovers that if they compare the amount of Cambromangen mRNA between groups, then there is no difference in its expression with age. In contrast, if they measure the amount of Cambromangen protein, then adults have significantly higher levels in their immune cells than do children.https://pa-cat.exammaster.com/learning/6907051#:~:text=RNA%20is%20flexible,of%20the%20complex%3FX ray crystallographyTranscription is the very first step of gene expression. However, this process is tightly regulated by a group of proteins called transcription factors. FoxO1 is a transcription factor that is pivotal for cardiac development. Dr. Holland has generated a mouse model with FoxO1 gene deletion.Incomplete vascular development overexpression will lead to reduced heart sizeChloroplasts are the site of photosynthesis in the cell. A plant biologist is studying the effect of salt stress on the expression of chloroplast proteins. Which of the following statements is true?study nucleus encoded genes since chloroplasts have a limitied coding capacityCase Plant cells are composed of many complex organelles. The chloroplast is the organelle in which photosynthesis occurs in plants. Question Malfunction of what part of the chloroplast would prevent the light reaction from occurring?Thylakoid membrane (light reactions) Calvin cycle is the stromaCase Antibiotic resistance is a major public health concern. Indiscriminate and pervasive use of antibiotics has led to the existence of multi-drug resistant organisms, sometimes referred to as "superbugs." One such organism is called vancomycin-resistant Staphylococcus aureus (VRSA), which is formed after transfer of a plasmid encoding for vancomycin resistance from vancomycin-resistant Enterococci (VRE) to methicillin-resistant Staphylococcus aureus (MRSA). Question Assuming that this process occurs via conjugation, a compound with what mechanism would theoretically prevent the formation of VRSA?Disruption of the mating bridgeCase Highlights Chronic myeloid leukemia (CML) is a myeloproliferative disorder that occurs because of a chromosome translocation that results in the formation of BCR-ABL1 gene. This gene encodes the BCR-ABL1 fusion protein, a mutant tyrosine kinase that is constitutively active. Imatinib is a drug used to treat CML and results in long-term control of the disease in most patients. Question Highlights What is the most likely mechanism of imatinib?Inhibition of phosphorylationThe DNA sequence 5'-ATGGTAGC-3' will pair with which of the following RNA sequences?5'-GCUACCAU-3'.Case Frontotemporal dementia is a form of dementia characterized by cognitive decline and changes in personality, behavior, and language. Research has shown that there is a genetic component to this disease. Specifically, the MAPT gene, which encodes for the tau protein, has been implicated. Several mechanisms have been proposed, one of which is an altered ratio of tau isoforms caused by defects in splicing at exon 10 of MAPT. Question Patients with frontotemporal dementia due to this mechanism have a defect in the processing of what type of moleculeCase Parkinson's disease is a neurologic disorder characterized by resting tremor, slow movements, unstable posture, and rigidity. A pathologic finding that characterizes the disease is Lewy bodies, which are abnormal protein aggregates that accumulate in neurons. These abnormal proteins are believed to contribute to the disease process and accumulate due to problems with protein degradation. Pathologic examination of brain tissue often shows immunoreactivity for ubiquitin. Question Highlights Dysfunction of what cellular component would most likely explain the aggregation of abnormal proteins seen in Parkinson's disease?Proteasome degradation of proteinsCase At puberty, human growth hormone (HGH or GH) is produced in the pituitary gland and released into the bloodstream. The growth hormone receptor (GHR) is located on the surface of a number of cells throughout the body, including cells in the liver. When bound to HGH, liver GHRs form dimers that are phosphorylated by the protein JAK2. This phosphorylation causes GHR to phosphorylate proteins called STATs. The STATs go to the nucleus, acting as transcription factors and causing proteins to be transcribed. This results in the liver cells producing the hormone IGF-2, which causes bone growth. Question Highlights What type of signaling does HGH send to the liver cells?Endocrine (release of chemical signals into the bloodstream) Autocrine:signaling cell and target cell are the same Juxtacrine: cells touch each other Paracrine: diffusion of chemical signals rather than bloodstreamCase At puberty, human growth hormone (HGH or GH) is produced in the pituitary gland and released into the bloodstream. The growth hormone receptor (GHR) is located on the surface of a number of cells throughout the body, including cells in the liver. When bound to HGH, liver GHRs form dimers that are phosphorylated by the protein JAK2. This phosphorylation causes GHR to phosphorylate proteins called STATs. The STATs go to the nucleus, acting as transcription factors and causing proteins to be transcribed. This results in the liver cells producing the hormone IGF-2, which causes bone growth. Question What liver GHRs are these?Receptor kinases (form dimers and are phosphorylated to reach active state) G protein require a G protein on the intracellular side Intracellular completely inside the cell rather than cell surfaceCase Highlights At puberty, human growth hormone (HGH or GH) is produced in the pituitary gland and released into the bloodstream. The growth hormone receptor (GHR) is located on the surface of several cells throughout the body, including cells in the liver. When bound to HGH, liver GHRs form dimers that are phosphorylated by the protein JAK2. This phosphorylation causes GHR to phosphorylate proteins called STATs. The STATs go to the nucleus, acting as transcription factors and causing proteins to be transcribed. This results in the liver cells producing the hormone IGF-2, which causes bone growth. Question Highlights What would happen if the GHR gene were mutated so that the protein was pre-dimerized and always had a phosphate group?IGF-2 would be constantly producedCase In observing DNA replication in the lab, you notice that in some cells, a defect occurs where DNA replication proceeds, but the RNA primers are not removed and replaced with DNA. Question What enzyme is most likely to be defective in this system?DNA polymeraseCase During transcription, RNA polymerase creates a small RNA segment that is complementary to the region in the sequence below shown in bold. 5'-CACAGCAGAAACCTACAACTCATG-3' Question What is the RNA sequence?5-GUUGUAGGUUUC-3 antiparallel to each otherCase Histones are proteins involved in the packaging of DNA so that nearly 2 meters of DNA can fit inside the nucleus of a single cell. The DNA molecule is wrapped around the histones to form nucleosomes. Histone proteins are among the most highly conserved of all eukaryotic proteins, with the majority of the protein's sequence being identical from yeast to humans. Question Until recently, mutations in the human genes coding for histones had not been observed. Why are histone mutations so rare?Mutations likely change the charge on histones, preventing DNA binding.Which illness is caused by a virus?Rabies Chlamydia (bacteria) Cellulitis (bacteria)Case A 36-year-old man who actively uses intravenous (IV) drugs comes into the clinic due to unintentional weight loss in the past month and worsening sore throat and fatigue in the past 2 weeks. Question For what virus should he be tested?HIV Coronavirus and flu: res viruses Hep A: through food or fluidsA bacteriophage is a ______ that inserts its ______ into a host ______, resulting in the production of new DNA.Virus , DNA, baceteriaDuring what phase of mitosis are the sister chromatids separated to opposite sides of the cell?Anaphase (3) Prophase (1): chromosomes condense metaphase(2): lined up in middle Telophase (4): final stage , mit spindle breaks downWhat occurs during the uncoating phase of viral replication?genome is released from the capsid of the virusThe mRNA has what responsibility?Encoding genetic info from the DNA to the ribosome carries the genetic info in form of amino acid sequence rRNA converts amino acid into proteinsAmino acids are brought to the ______ by the ______ to form a polypeptide during translation.ribosome, TRNA to form polypeptideDNA is composed of bases that pair together to form a double helix. What type of bond is responsible for holding base pairs together?Hydrogen bondsWhat process is considered an accurate high-fidelity double-strand break (DSB) repair pathway?Homo recomboWhat is the only type of cellular RNA to be translated into a functional protein?mRNA piRNA: gene silencing Micro RNA: gene expressionWhat is true about transfer RNAs (tRNAs)?tRNAS are specific to their target codon sequence carry an anticodon sequence composed of three bases involved in translationProteins routinely undergo post-translational modifications (PTMs). What PTM involves adding a phosphate group to a protein to alter its activity?Phosphorylation Acetylation: addition of an acetyl group to a protein Alkylation: addition of an alkyl groupHow do small interfering RNAs (siRNAs) inhibit expression of a target protein?siRNAS directly bind the mRNA of their target gene to induce degradationWhere would you expect to find telomerase activity?At the end of a chromosome in a cancerous eukaryotic somatic cell allow cancer cells to continue to replicate indefinitelyWhy do different cells in the same organism express different genes?different gene regulatory proteins are activatedInterest has recently increased in phage therapy to treat bacterial infections. What would be a likely advantage of phage therapy over current treatments?Bacteriophages would target specific bacteria better than antibioticsA research investigating the distribution of certain fleshly-fruited species was conducted. One of the findings was that the distribution of the fleshly-fruited species can be influenced by the climatic factor. The researchers observed that a great proportion of fleshly-fruited species is higher in warmer and more moist climates. One other finding was that the distribution of the fleshly-fruited species can be influenced by animals that are responsible for seed dispersal. The seed dispersal has altitudinal patterns resulting from seed-dispersing animal migrations. What is the main function of the plant that was examined in this research?Reproduction Reproduction is the main function of the plant that was examined. An important clue is that the research mentioned "seed" and "fruit", and seed and fruits are reproductive organs of plants. The other reproductive organ of plants is the flower. Another clue is that the research mentioned a "warmer and more moist climate" can facilitate the growth and distribution of the fleshly-fruited species. When warmth and moisture are mentioned, one can associate them with temperature and water. Temperature and water conditions are vital for plant reproduction. Lastly, seed dispersal by animals is one of plant's reproduction strategies. After the animals eat the fruits, they excrete the seeds of the fruits and disperse them along their way, helping plant reproduction. One other well-known plant reproduction strategy is seed dispersal by wind, as in dandelions. The extent of seed dispersal is proportional to plant reproduction. Photosynthesis is a plant function, but it is not a major function associated with the research. Light and oxygen production would be important topics to be discussed for photosynthesis, and light and oxygen production were not discussed. Transpiration is a plant function, but it is not a major function associated with the research. Transpiration is the process when water is absorbed from plant roots, then moves toward the pores (called stoma, plural "stomata") under the leaves, eventually evaporating out of the pores. Transpiration mainly influences the growth of individual plants, and less likely the greater aspects such as the distribution of plants as mentioned in the research. Glycogenesis is a function in animals, and not in plants. Plants produce starch as their carbohydrate resource, while for animals it is glycogen, generated by glycogenesis.Case Podophyllotoxin is an antineoplastic agent formulated as a topical application to treat external genital warts. Podophyllotoxin was forbidden to use during pregnancy due to possible toxicity to the embryo development, even though the studies showed that it had minimal toxicity. To examine the toxicity of the podophyllotoxin, research was conducted on mice by exposing them to podophyllotoxin, and the podophyllotoxin's effect on embryonic development was studied. The results showed podophyllotoxin exposure led to inhibition of mouse oocyte maturation. The meiotic spindle formation was disrupted, affecting the spindle dynamics and chromosomal alignment. Question Highlights Which stage of meiosis is most relevant to the antineoplastic effect of podophyllotoxin?Metaphase Prophase: involves initial formation of spindlesWhat distinguishes the sugar of RNA from that of DNA?Hydroxyl group attached to the 2' carbon of the sugar ring The sugar of RNA is ribose, while the sugar of DNA is deoxyribose. These two sugars differ in their 2' carbon position; ribose of RNA has the -OH (hydroxyl) group, while deoxyribose of DNA has the H atom (thus the prefix "deoxy").Case Mutated or overexpressed receptor tyrosine kinases are frequently observed in tumors. For example, the epidermal-growth-factor receptor (EGFR) is overexpressed in some human epithelial cancers, including breast cancer. Because a small portion of the receptors can dimerize and activate the signal transduction pathway even without binding to epidermal growth factors (EGF), overexpression of the receptor increases the likelihood that an activation signal will be improperly sent to the cell, making the cells grow and divide uncontrollably, as observed in most cancers. Question What is the most practical strategy to control this kind of offending signal transduction pathway?Inhibiting EGFRThe emergence of multicellular organisms was associated with the stabilization of cell-cell adhesions and other kinds of spatial and complexity developments. The cell-cell adhesions involve many adhesive junctions that can support multicellular structures. What structure has the most significant contribution to support multicellularity?Desmosomes Desmosomes are calcium-dependent adhesive junctions that mediate cell-cell contact and strong adhesion. They pin adjacent cells together, forming a strong sheet of cells that resist mechanical stress. This feature can unite single cells and support multicellularity. Hemidesmosomes are similar to desmosomes in that they both have adhesion property, but hemidesmosomes function to attach cells to the extracellular matrix, or basal lamina, rather than to adjacent cells. Plasmodesmata are plants' cell-cell junctions, but they promote cell-cell communication rather than cell-cell adhesions. Connexins are membrane proteins that form connexons, lining the gap junctions between animal cells. The gap junctions function in cell-cell transports, and not adhesions. Although the connexins have some level of adhesion quality, they adhere to each other rather than pinning adjacent cells together.How does E. coli DNA replication compare to human DNA replication?Human and E Coli replications both involve DNA repair E coli has one circular chromosome Humans have 23 pairs pf linear chromosomesWhich component of genetic material is the smallest?Nucleic Acid To make genes which make an allele to make a chromosomeWhat is the term for a gene located with another gene on the same chromosomes?Linked gene genome: entirety of the genes an organism has Autosomes: not sex linkedWhat part of messenger RNA is excised from pre-mRNA in the making of a mature messenger RNA molecule?Intron exon: will code for the protein promoter region: important in transcription sigma factor: protein that participates in transcriptionWhich part of the messenger RNA molecule is directly coded into a protein molecule?Exon Intron: gets spliced out 5 prime cap: helps RNA molecule attach to the ribosome poly A tail: helps the RNA molecule exit the nucleusPoly(ADP-ribose) polymerase-1 (PARP-1) is an enzyme involved in DNA repair, and PARP-1 inhibitors are a promising therapeutic target in many types of cancer. PARP signaling at single-stranded breaks in DNA causes DNA repair proteins to be recruited to the damaged sites. Recent data shows that unligated Okazaki fragments are responsible for the majority of PARP-1 activity in normal cells. Where does the most PARP-1 activity occur?Lagging strand of DNA Okazaki fragments are formed on the lagging strand of DNA during DNA synthesis because DNA synthesis can only proceed in the 5' to 3' direction. Okazaki fragments are not formed on the leading strand of DNA due to its directionality. Newly synthesized mRNA and tRNA are not involved in DNA synthesis.Some viruses use RNA as their genetic material and must synthesize DNA from their RNA. Antiviral medications can exploit this fact by inhibiting what enzyme?Reverse transcriptase Reverse transcriptase is the enzyme responsible for the synthesis of DNA from an RNA template. DNA polymerase replicates DNA using a DNA template, and RNA polymerase uses a DNA template to synthesize RNA. tRNA synthetase attaches cognate tRNA molecules to the corresponding amino acids.Unlike transcription where RNA is synthesized from a DNA template, translation refers to the synthesis of a protein from what kind of RNA?mRNA Translation is the process by which ribosomes synthesize proteins from mRNA. rRNA make up ribosomes within ribosomal proteins. tRNA bring amino acids to ribosomes. snRNA form complexes within proteins found only in eukaryotes.If sister chromatids are unable to form, which phase of the cell cycle is affected?S phase S phase involves the formation of sister chromatids, which are two identical copies of each chromosome. G0 phase is a mitotically inactive stage. G1 phase occurs when cells are accumulating energy to replicate each chromosome in the nucleus. G2 phase is the stage in which cells double their amount of DNA.A genome is an organism's complete set of genes. What is a chromosome made of?DNA and proteinCase Within eukaryotes, the process of DNA replication gives rise to duplicated chromosomes that are distributed to daughter cells through mitosis. During this process, eukaryotic chromosomes are assisted by cohesin and condensin systems responsible for uniting and disbanding sister chromatids, respectively. Question In which phase of mitosis is cohesin expected to initiate association?S phase Sister chromatids are synthesized in S phase. Cohesin acts to associate sister chromatids following their formation during S phase.Case Within eukaryotes, the process of DNA replication gives rise to duplicated chromosomes that are distributed to daughter cells through mitosis. During this process, eukaryotic chromosomes are assisted by cohesin and condensin systems responsible for uniting and disbanding sister chromatids, respectively. Question Which phase of mitosis is exemplified by the simultaneous effects of cohesin acting upon the centromere and condensin acting upon the chromatids?Metaphase During metaphase, the two chromatids are connected at the centromere. This is indicative of cohesin association at the level of the centromere and condensin dissociation at the level of the chromatids. During anaphase, chromosomes are separated into independent chromosomes and are not attached by a centromere. During prophase, cohesin is lessened and condensin is increased to support condensation within the nucleus. Telophase is exemplified by genetically identical daughter cellsCase Within eukaryotes, the process of DNA replication gives rise to duplicated chromosomes that are distributed to daughter cells through mitosis. During this process, eukaryotic chromosomes are assisted by cohesin and condensin systems responsible for uniting and disbanding sister chromatids, respectively. Question A process known as sister chromatid resolution is enabled through the simultaneous mediation of condensin and release of cohesin from the chromosomal arms. This event gives rise to visibly discernible chromosomes with sister chromatid pairs. In which phase of mitosis is this condensation mechanism displayed?Prophase Prophase is characterized by disappearance of the nuclear envelope and visible chromosome resolution. Sister chromatid resolution is the mechanism that makes this possible. Anaphase is characterized by separation of sister chromatids rather than display of condensed chromosomes. Metaphase is not characterized by a release of cohesin. Telophase is characterized by genetically identical daughter cells.Case Within eukaryotes, the process of DNA replication gives rise to duplicated chromosomes that are distributed to daughter cells through mitosis. During this process, eukaryotic chromosomes are assisted by cohesin and condensin systems responsible for uniting and disbanding sister chromatids, respectively. Question To enable final separation of sister chromatids, the enzyme separase acts upon cohesin to release chromosome arms. In which phase of mitosis does this reaction occur?Anaphase Anaphase is characterized by chromosome migration to opposite poles. The reaction of separase upon cohesin is supportive of this phenomenon. Metaphase, prometaphase, and telophase are not characterized by the final separation of sister chromatids.Case Within eukaryotes, the process of DNA replication gives rise to duplicated chromosomes that are distributed to daughter cells through mitosis. During this process, eukaryotic chromosomes are assisted by cohesin and condensin systems responsible for uniting and disbanding sister chromatids, respectively. Question Within eukaryotes, formation of anaphase bridges may occur due to failure of chromosome segregation. This is hypothesized to occur during metaphase resolution of sister chromatid association. Deficiency of what molecule is responsible for this manifestation?Condensin Condensin is responsible for the detachment of sister chromatids; a deficiency of condensin is responsible for formation of anaphase bridges. Cohesin is responsible for the association of sister chromatids; a deficiency in cohesin is not responsible for this phenomenon. Chromosomes and chromatin are similarly not responsible for formation of anaphase bridges.DNA is transcribed to RNA, then translated into protein. DNA is not constant, and genes can be silenced. When alternate forms of genes (splice variants) are transcribed, what component can be omitted or used in alternate forms? Answer Choices 1 CodonExonsThere are 5 nucleic acid bases, comprised of carbon and nitrogen atoms: adenine, cytosine, guanine, thymine, and uracil. Which 3 are common between DNA and RNA?Adenine, cytosine, guanine Thymine is found in DNA Uracil is found in RNAIntrons and exons can both be found in what molecules?Primary RNA transcripts Mature mRNA and mature rRNA transcripts contain only exons.Contrary to introns, what do exons code for?Proteins Exons code for proteins. Introns are not implicated in protein-coding because introns are removed during RNA splicing. Both introns and exons are found on RNA. Neither introns nor exons are found in DNA. Genomes are a complete set of genetic material.How conserved are exons compared to introns?More conserved than introns Exons are more conserved than introns since their sequences do not change quickly over time. Intron sequences change frequently.During RNA splicing, how is a complete coding sequence formed to allow for mature mRNA to be ready for translation?Introns are removed During RNA splicing, introns are removed and exons are joined together to form a complete coding sequence, allowing mature mRNA to be ready for translation.Which part of the cell cycle is associated with division of replicated genetic material?Mitosis Mitosis is the part of the cell cycle associated with division of replicated genetic material to two daughter cells. Meiosis refers to cell division that creates four haploid cells, each genetically distinct from the parents. Interphase occurs before mitosis and is divided into sub-phases: G1, S, G2. Cytokinesis occurs after mitosis, when the cytoplasmic components of daughter cells are separated.During which phase of the cell cycle are cells inactive?G0 During the G0 phase, the cell is in a quiescent stage, not actively preparing to divide. G2 is the stage in which cells appear to have double the amount of DNA as observed in G1 and chromosomes appear to be diffuse. G1 is when the cell is biochemically accumulating building blocks for cellular components along with energy reserves. Prophase occurs when each chromosome becomes visible with its sister chromatid.What contains the untranslated region 5'-UTR?The first exon The untranslated region 5'-UTR is contained by the first exon. Untranslated regions are not contained by introns. The untranslated region 3'-UTR is contained by the last exon.What is a characteristic of exons?encode an amino acid sequence of a protein Exons encode an amino acid sequence of a protein. Introns are removed during RNA splicing, located between two exons, and are not expressed by proteins.Contrary to introns, where are exons found?Both prokaryotes and eukaryotes Introns are found in eukaryotes only.Most mammals have similar numbers of genes, but what do they have different numbers of?Chromosomes Mammals have different numbers of chromosomes. For example, humans have 46 chromosomes and dogs have 78. Genomes, nuclei, and mitochondria will not vary as much as chromosomes in eukaryotes.What must be removed to make mature mRNA?Introns Introns must be removed to make mature mRNA. Exons code for mature mRNA and are not removed. DNA and histone proteins are components of chromosomes.In which phase of the cell cycle is DNA expressed to make the enzymes necessary for DNA synthesis?G1 G1 phase of the cell cycle is when DNA is expressed to make the enzymes necessary for DNA synthesis. G2 stage is when cells appear to have double the amount of DNA as observed in G1 and chromosomes appear to be diffuse. S stage is when DNA replication results in forming sister chromatids. M (mitotic phase) is when cell growth and protein production stop in the cell cycle.In which phase of the cell cycle are genes expressed for synthesis of enzymes necessary for cell division?G2 G phase of the cell cycle is when genes are expressed for synthesis of enzymes necessary for cell division. G0 phase is a mitotically inactive stage. G1 occurs when cells are accumulating energy to replicate each chromosome in the nucleus. S phase involves the formation of sister chromatids, which are two identical copies of each chromosome.What does semi-conservative replication synthesize?DNA Semi-conservative replication is the synthesis of DNA. Mitochondria are not synthesized by the cell. Protein is synthesized by translation. RNA is synthesized by transcription.What base pair is unique to RNA synthesis rather than being shared with DNA?Uracil Uracil is included in RNA synthesis and is not found in DNA. Adenine, cytosine, and guanine are found in both DNA and RNA. DNA also uses thymine, where RNA does not.

Biology (Photosynthesis - Plant Structure)

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