DAT Domain 1.1: Survey of the Natural Sciences, Biology Welcome to your DAT Domain 1.1: Survey of the Natural Sciences, Biology 1. DAT: Survey of the Natural Sciences, Biology Which of the following describes the role of the sodium-potassium pump during action potential generation in neurons? It pumps sodium ions out and potassium ions in, restoring the resting membrane potential. It pumps potassium ions out and sodium ions in, initiating depolarization. It increases the permeability of the membrane to sodium ions, causing repolarization. It decreases the permeability of the membrane to potassium ions, preventing hyperpolarization. None 2. DAT: Survey of the Natural Sciences, Biology During meiosis, when does crossing over occur and what is its significance? Prophase I, contributing to genetic diversity. Metaphase I, ensuring equal distribution of chromosomes. Anaphase II, preventing nondisjunction. Telophase II, facilitating chromosome separation. None 3. DAT: Survey of the Natural Sciences, Biology In the context of enzyme kinetics, what does the Michaelis-Menten constant (Km) indicate? The maximum reaction speed at saturating substrate concentration. The substrate concentration at which the reaction speed is half the maximum. The rate at which an enzyme is degraded in the cell. The affinity of an enzyme for its substrate at zero substrate concentration. None 4. DAT: Survey of the Natural Sciences, Biology What role does the p53 gene play in cell cycle regulation? It promotes the transition from G2 phase to M phase. It functions as a tumor suppressor by initiating cell cycle arrest and apoptosis. It enhances DNA replication in the S phase. It facilitates cytokinesis during the M phase. None 5. DAT: Survey of the Natural Sciences, Biology In a eukaryotic cell, where does the Calvin cycle take place? Mitochondrial matrix Chloroplast stroma Cytoplasm Endoplasmic reticulum None 6. DAT: Survey of the Natural Sciences, Biology Which of the following best describes the function of the rough endoplasmic reticulum? Synthesis and modification of lipids Detoxification of drugs and poisons Synthesis and processing of proteins Packaging of proteins for secretion None 7. DAT: Survey of the Natural Sciences, Biology Which process is responsible for the independent assortment of alleles during gamete formation? Synapsis during prophase I of meiosis Random fertilization Segregation during anaphase I of meiosis Crossing over during prophase I of meiosis None 8. DAT: Survey of the Natural Sciences, Biology In the Lac operon, what role does the repressor protein play when lactose is absent? It binds to the operator, preventing transcription. It enhances the binding of RNA polymerase to the promoter. It undergoes a conformational change, allowing transcription. It degrades lactose, preventing its use as an energy source. None 9. DAT: Survey of the Natural Sciences, Biology What is the primary structure of a protein determined by? Hydrogen bonding between amino acids The sequence of amino acids Disulfide bridges between cysteine residues The alpha-helix and beta-sheet structures None 10. DAT: Survey of the Natural Sciences, Biology In eukaryotic gene regulation, what role do enhancer sequences play? They degrade mRNA to control gene expression. They facilitate the binding of RNA polymerase to the promoter. They act as binding sites for proteins that increase the likelihood of transcription. They prevent transcription by binding repressor proteins. None 11. DAT: Survey of the Natural Sciences, Biology In a population adhering to Hardy-Weinberg equilibrium, what is true about the allele frequencies? They change in response to natural selection. They remain constant from one generation to the next in the absence of evolutionary influences. They are not influenced by random mating. They decrease with genetic drift. None 12. DAT: Survey of the Natural Sciences, Biology What is the primary function of the Golgi apparatus in a cell? Protein synthesis ATP production Modification, sorting, and packaging of proteins and lipids Breakdown of cellular waste None 13. DAT: Survey of the Natural Sciences, Biology Which of the following best describes the relationship between photosynthesis and cellular respiration? Photosynthesis occurs in animal cells, while cellular respiration occurs in plant cells. The products of photosynthesis serve as the reactants in cellular respiration. Cellular respiration produces glucose, which is then used in photosynthesis. Photosynthesis and cellular respiration are unrelated processes. None 14. DAT: Survey of the Natural Sciences, Biology How does a competitive inhibitor affect enzyme activity? It binds to the enzyme and changes its structure. It increases the enzyme's affinity for the substrate. It binds to the active site, preventing substrate binding. It binds to a site other than the active site, changing the enzyme's shape. None 15. DAT: Survey of the Natural Sciences, Biology What role do ribosomes play in a cell? They synthesize lipids. They synthesize proteins. They generate ATP. They package DNA. None 16. DAT: Survey of the Natural Sciences, Biology In the context of molecular biology, what is the central dogma? DNA replicates itself, then synthesizes RNA, which then produces proteins. Proteins synthesize RNA, which then creates DNA and replicates it. RNA replicates DNA, which then synthesizes proteins directly. Proteins are synthesized directly from DNA without the need for RNA. None 17. DAT: Survey of the Natural Sciences, Biology What is the primary outcome of the light-dependent reactions in photosynthesis? Production of glucose Absorption of carbon dioxide Conversion of light energy into chemical energy stored in ATP and NADPH Release of oxygen as a by-product None 18. DAT: Survey of the Natural Sciences, Biology Which cellular organelle is responsible for producing ribosomal RNA (rRNA) Nucleus Ribosome Endoplasmic reticulum Nucleolus None 19. DAT: Survey of the Natural Sciences, Biology In genetic terms, what is an operon? A set of genes in prokaryotes that are transcribed together. A segment of DNA that codes for a single protein. A structure that aids in chromosome pairing during meiosis. A mobile genetic element that can cause mutations. None 20. DAT: Survey of the Natural Sciences, Biology What is the primary function of mitochondria in cells? Protein synthesis Photosynthesis ATP production Lipid metabolism None 1 out of 20 Time is Up! Time's up
