Biology 211 Exam 1 - Iowa State University Questions And Answers Rated A+

Are energy sources electron donors or acceptors? In aerobic respiration, is oxygen the electron donor or acceptor. Explain. - Energy sources are electron acceptors. Anaerobic respiration is the formation of ATP without oxygen, which is the donor instead of the acceptor. Are science and religion in conflict with one another? What types of questions are answered by each? - No, they are able to explain things to people when one fails to do so. Compare and contrast conjugation, transduction, and transformation. Is conjugation in bacteria a form of sexual reproduction? Why or why not? - -Conjugation: When genetic information is transferred by direct cell to cell contact -Transduction: When viruses pock up DNA from one prokaryotic cell and transfer it to another -Transformation: When bacteria and archaea naturally take up DNA from the environment that has been released by cell lysis or secreted -Conjugation is a form of sexual reproduction because of the swapping of DNA between the two organisms. Compare and contrast prokaryotic and eukaryotic cells. What are 3 key differences between the 2 cell types? - 1. Eukaryotic chromosomes are inside a nucleus and linear. 2. Eukaryotic cells are much larger. 3. Eukaryotic cells contain extensive amounts of internal membrane. Eukaryotic cells feature a complicated cytoskeleton. Compare and contrast sexual and asexual reproduction. What are the advantages and disadvantages of each mode of reproduction? What is the relationship between reproductive mode and environmental stress? Does a stressful environment favor sexual or asexual reproduction? Explain. - Sexual: Production of new living organisms by combining genetic information from 2 individuals of different types. Advantage: More variation to assist with survival. Disadvantage: Requires 2 parents.Asexual: Offspring arise from a single organism and inherit the genes of that parent only. Advantage: Allows plants to reproduce quickly Disadvantage: No variations The more environmental stress there is, the more likely that there will be more sexual reproduction and vice versa with asexual reproduction. A stressful environment favors sexual reproduction because more variation gives the new organism the chance to survive. Compare and contrast the protective structures found in diatoms, dinoflagellates and foraminiferans. Why are these protists used to study fossils (forams) and dead bodies (diatoms)? - -Diatoms: Surrounded by cell wall made of silica (hydrated silicon dioxide) -Dinoflagellates: Surrounded by cell wall made of cellulose. -Foraminiferans: Cell wall is made of shells that are commonly divided into chambers that are added during growth. These are extremely useful in age-dating, correlation and paleoenvironmental reconstruction. Compare and contrast Unikonta and Bikonta. Which structural feature distinguishes these two groups? - Unikonta are formed by amoebozoa and the opishokonta (fungi and animals) - form a monophyletic group. The other 5 major lineages form a monophyletic group called bikonta. Define haploid and diploid. Which is 2n and which is 1n? What does n mean in this context? - - Haploid: A cell that contains a single set of chromosomes; 1n -Diploid: Having paired sets of chromosomes in a cell or cell nucleus; 2n N refers to the ploidy level of the organisms. The ploidy level is the number of sets of chromosomes. Describe the DNA found in a bacterial cell? (Is it single or double stranded? Is it circular or linear? Where is it found?) How does a plasmid differ from a chromosome? Would you expect the genes for a plasma membrane to be on the chromosome or plasmid? Why? - The DNA is a double helix that is coiled in on itself to fit into the tiny space within the nucleoid. Plasmids contain genes but are physically independent of the cellular chromosomes.Describe three distinct methods used by protists to obtain carbon (food). Can protists with a cell wall feed by phagocytosis? How does absorptive feeding differ from phagocytosis? Which type of organism feeds on detritus? - 1. Protozoa: Heterotrophic 2. Algae: Photosynthetic 3. Fungus-like: Endocytosis (Wrap around it's prey and takes it in through it's membrane.) No, protists with a cell wall cannot feed by phagocytosis. Bacteria and fungi feed on detritus. Describe two different methods scientists use in bioremediation. - Scientists fertilize contaminated sites to encourage the growth of prokaryotes that degrade toxic compounds, and they add specific prokaryotes to the ground to help as well. Diagram the central dogma of genetics. Label the 3 steps in order, from DNA to protein. - Molecular machinery makes copies of DNA in a closely related molecule known as RNA, which is translated into protein. Diagram the life cycle of Plasmodium. Indicate the sexual and asexual stages of this life cycle. Which stage (sexual or asexual) increases the diversity of the offspring produced? Which stage greatly increases the total number of offspring produced? What disease does Plasmodium cause? What is the global impact of this disease? - The sexual stage increases the diversity of the offspring produced. The asexual stage increases the total number of offspring produced. Plasmodium causes malaria. In 2016, an estimated 445,600 people died of malaria. Distinguish between fitness and adaptation? What organism are the most evolutionarily fit? - Fitness is how well you produce offspring and how well they produce offspring. Adaptation is a trait that increases the fitness of an individual in a certain environment. Do most bacteria cause disease? Diagram Koch's postulates and be able to explain how this process is used. Why are some bacteria pathogenic? Why is antibiotic resistance a growing concern? - No, only a small percentage of bacteria are pathogenic. To establish a causative link between sickness and a certain type of organism, the four criteria must be met. (1.) The microbe must be present in the sick individual and absent in the healthy one. (2.) The organism must be isolated and grown in a pure culture. (3.) The organism from the pure culture must beinjected into a healthy animal to see if the symptoms return. (4.) The organism should be isolated from the diseased animal and cultured again to see if it's the same. Toxins are proteins that are in some bacteria that cause humans to get sick while endospores are released from the bacteria that also make us sick. Both are only present in some bacteria. Toxins are proteins that are in some bacteria that cause humans to get sick while endospores are released from the bacteria that also make us sick. Both are only present in some bacteria. Antibiotic resistance is a growing concern because the pathogenic bacteria is becoming immune to the medicine, meaning that soon it won't work at all. Do protists make up a monophyletic or paraphyletic group? Explain. Is there a synapormorphy that defines protists? - Protists are not a monophyletic and there are not synapomorphies that define protists. Draw a bacterial cell and label the nucleoid region, cytoplasm, flagella, fimbriae, plasmids, cell wall, plasma membrane, and ribosomes. What is the function of each of these structures? - -Nucleoid Region: location of bacterial chromosome - Cytoplasm: Where the functions for cell growth, metabolism, and replication are carried out. - Flagella: locomotion - Fimbriae: (pili) adherence of bacteria to surfaces, substrates, and other cells or tissues in nature. - Plasmids: Small, circular, double-stranded DNA molecule that is distinct from a cell's chromosomal DNA. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance. -Cell Wall: Provide rigidity, tensile strength, structural support, protection against mechanical stress and infection. -Plasma Membrane: Permeability barrier for most molecules and serving as the location for the transport of molecules into the cell -Ribosomes: Workbench for protein synthesis where they receive and translate genetic instructions for the formation of specific proteins. Draw a phospholipid bilayer, labeling the lipids, proteins, the hydrophobic and hydrophilic regions. - Draw a simple phylogenetic tree with 1 outgroup and 3 nodes. Label the root, branches, outgroup, and nodes. -Draw an algal life cycle that has alternation of generations. Label the gameophyte, sporophyte, zygote, gamete and spore stages. Indicate where mitosis, meiosis, and fertilization occur. Label each stage as either haploid or diploid. - A multicellular gametophyte, which is a haploid with n chromosomes, alternates with a multicellular sporophyte, which is diploid with 2n chromosomes. Draw an aquatic food chain, describing how protists influence the carbon cycle. Why would researchers want to add iron to the open ocean? What are some concerns with this plan? - Researchers want to add iron to the ocean to slow global warming by having the protists produce more oxygen. The concern is that too much iron can cause an algal bloom and everything else will die. Draw the endosymbiosis theory of mitochondrial origins. What do mitochondria provide the "host" cell? What do the host cells provide for the mitochondria? How did chloroplasts originate? - Mitochondria provide the host cell with ATP and the host cell provides the mitochondria with protection. Chloroplasts originated from cyanobacteria through endosymbiosis-when a eukaryotic cell engulfed a photosynthesizing cyanobacterium that became a permanent resident in the cell. Give examples of different characters that could be used to construct the data matrix that is used to build a phylogenetic tree. - 1. Cladistic approach: shared derived characteristics 2. Parsimony: least amount of change Given the 3 RNA sequences, draw a phylogenetic tree that accurately represents the relationship between the 3 species. - How are Archaea and Bacteria related to each other? Are Archaea more closely related to Bacteria or to Eukarya? - Archaea and Bacteria are related to each other through LUCA/ They are very similar in their structure but Archaea are more closely related to Eukarya.