Download DAT Bootcamp Biology Exam #1 – Full-Length Practice Test with Detailed Explanations and and more Exams Biology in PDF only on Docsity!
DAT Bootcamp Biology Exam #1 – Full-Length
Practice Test with Detailed Explanations and
High-Yield Questions for the 2025 Dental
Admission Test
Which of the following does not occur during telophase? A. Reassembly of the nuclear envelope B. Reappearance of the nucleoli C. Uncoiling of the chromosomes D. Centromere division E. Dismantling of the spindles - - correct ans- - D. Centromere Division Explanation: Centromere division occurs during anaphase of mitosis and during anaphase II of meiosis Enzymes which catalyze the phosphorylation of organic molecules are called A. Lipases B. Kinases C. Mutases D. Amylases E. Esterases - - correct ans- - B. Kinases Explanation: Lipases digest fats; Mutases remove erroneous nucleotides from DNA; Amylases break down starches into disaccharides; Esterases cleave ester bonds The primary transmitter of the parasympathetic nervous system is
A. Norepinephrine B. Epinephrine C. Acetylcholine D. Cholinesterase E. Amylase - - correct ans- - C. Acetylcholine According to the first law of thermodynamics, A. Energy transfer leads to less organization B. A system that is isolated from any energy source increases in entropy C. Evolution is possible through the absorption of energy D. Energy is balanced by living things E. Total energy in an isolated system remains constant - - correct ans- - E. Total energy in an isolated system remains constant Explanation: The first law of thermodynamics states "in any process, the total energy of the universe remains constant," or in other words, energy can neither be created nor destroyed. This also applies to any isolated system, i.e., any system that does not exchange mass or energy with its surroundings The myeline sheath is NOT A. Produced by Schwann cells in the peripheral nervous system B. Found surrounding all vertebral axons C. Produced by the fusion of many lamellae of plasma membrane D. Mostly lipid in composition E. Used to increase the speed of an action potential - - correct ans- - B. Found surrounding all vertebral axons Explanation: The myeline sheath only surrounds certain axons, but not all of them
Which of the following decreases during cellular cleavage? A. Nuclear-to-cytoplasmic-material ratio B. Surface-to-volume ratio of each cell C. Nutrient and gas exchange D. Cell size E. Number of cells - - correct ans- - D. Cell Size Explanation: Since the amount of cytoplasm in the group of cells does not change with these rapid divisions, the volume of the cells decreases, increasing the surface-to- volume ratio and therefore the amount of nutrient and has exchange that each cell can participate in. It also increases the nuclear-to-cytoplasmic ratio, not because the amount of nuclear material is changing, but because the amount of cytoplasmic material present in each cell continues to decrease while the amount of nuclear material remains relatively consistent between cells In the process of glycolysis A. NAD+ is reduced to NADH B. The final product is acetyl coenzyme A C. Oxygen is required for maximal ATP production D. There is a net production of 4 ATP per glucose molecule E. Fructose-1,6-bisphosphate is converted into acetyl coenzyme A - - correct ans- - A. NAD+ is reduced to NADH Explanation: The final product of glycolysis is pyruvate, not Acetyl-CoA. Glycolysis does not require oxygen, it is anaerobic. There is a net production of 2 ATP per glucose molecule. Glycolysis is an anaerobic series of reactions that occurs in the cytoplasm that oxidizes glucose to pyruvate The raw materials of the earth's primitive environment (the "primordial soup" did not include A. Phosphorus
B. Salts C. Methanol D. Water E. Ammonia - - correct ans- - A. Phosphorus Explanation: Organic molecules such as sugars and amino acids were synthesize in a primordial environment that contained simple inorganic and organic compounds including salts, methane, ammonia, hydrogen, and water Muscle movement on the cellular level is initiated by the release of Ca2+ from the terminal cistern. Terminal cistern are associated with A. Sarcoplasmic reticulum B. Myosin cross-bridges C. Myoglobin D. Canaliculi E. Thin filaments - - correct ans- - A. Sarcoplasmic reticulum Explanation: Muscle fibers store Ca2+ in the sarcoplasmic reticulum during contraction. The SR, analogous to the endoplasmic reticulum, runs extensively throughout the fiber so that released Ca2+ will come into immediate contact with each sarcomere and cause a uniform contraction. The Ca2+ is released from the terminal cisternae of the SR Non-cyclic photophosphorylation during the light reaction produces A. ATP only B. ATP and NADPH C. ATP and glucose D. NADPH and glucose E. Glucose and water - - correct ans- - B. ATP and NADPH
Which of Mendel's laws describe the behavior of genes on non homologous chromosomes? A. Law of Dominance B. Law of Segregation C. Law of Definite Position D. Law of Recessiveness E. Law of Independent Assortment - - correct ans- - E. Law of Independent Assortment Explanation: Mendel's Law of Independent Assortment states that if traits are on different chromosomes, then the alleles of these different traits should separate independently of each other into different gametes. The likelihood of two genes on the same chromosome separating independently of each other increase with the distant between two genes. Law of Dominance states that one factor (gene) of a pair may mask or inhibit the expression of the opposite member (recessive) of the pair. The Law of Segregation states that the members of a pair of genes are separate, or segregate, at the time of segregation Cellular respiration produces A. 2 ATP/mol of glucose B. 4 ATP/mol of glucose C. 12 ATP/mol of glucose D. 32 ATP/mol of glucose E. 36 ATP/mol of glucose - - correct ans- - E. 36 ATP/mol of glucose Explanation: Cellular respiration, consisting of glycolysis, Krebs cycle, and oxidative phosphorylation, yields approximately 36 ATP per mole of glucose Prokaryotes are fond in the kingdom A. Protista B. Plantae C. Fungi
D. Monera E. Animalia - - correct ans- - D. Monera Explanation: Prokaryotes are found only in the kingdom Fonera. The members include bacteria and cyanobacteria (blue-green algae) During development, the solid ball of dividing embryonic cells develops a fluid-filled cavity in the middle. What is this cavity called? A. Morula B. Blastula C. Blastocoel D. Protoplasm E. Blastopore - - correct ans- - C. Blastocoel Explanation: The solid ball of embryonic cells is referred to as the morula. With the development of the fluid-filled cavity inside the morula, the ball of cells is referred to as a blastula. The blastula contains a fluid-filled cavity referred to as the blastocoel. Protoplasm is the cytoplasm within the cell. The blastopore is not formed until gastrulation and refers to the invagination of the embryo that occurs as the germ layers are formed Which of the following is characteristic of humans and fungi, but not bacteria? I. Eukaryotic II. Ribosomes III. Cell wall IV. Asexual reproduction A. I only B. II only C. I and II
E. Simple diffusion - - correct ans- - B. Facilitated diffusion Explanation: Facilitated diffusion provides the means for substances that are impermeable to the lipid bilayer to diffuse across through a protein channel along its concentration gradient. Simple diffusion is the movement of a substance across a permeable membrane along the substrate's concentration gradient. No protein carrier molecule is necessary. For example, CO2 can diffuse across the cell membrane, while Na+ would require a carrier molecule In a Hardy-Weinberg population where the frequency of the dominant allele B equals the frequency of the recessive allele b, what is the frequency of the heterozygotes in the population? A. 0 B. 0. C. 0. D. 0. E. 1.00 - - correct ans- - C. 0. Explanation: The HWE states p2 +2pq + q2 and p+q=1. If the frequency of the dominant allele is equal to the frequency of the recessive allele b then p=q=0. During recovery from oxygen debt, which of the following does not occur? A. Glucose is converted to pyruvate B. Pyruvate is converted to lactate C. Lactate is transported to the liver D. Lactate is converted to pyruvate - - correct ans- - B. Pyruvate is converted to lactate Explanation: During oxygen debt, the need for ATP exceeds the capacity of the mitochondria for oxidative phosphorylation. As a result, cells resort to anaerobic respiration in order to increase ATP yields. It is during this process that pyruvate is converted to lactate, not during recovery from oxygen debt
A scientist wants to detach a peripheral membrane protein from the exterior of a cell membrane. Which is the best method to do so? A. Change the salt concentrations. B. Perform a light centrifuge. C. Add a detergent. D. Change the temperature of the solution. E. Run a small current through the solution. - - correct ans- - A. Change the salt concentrations. Glycolysis is best described as what type of process? A. Exergonic B. Endergonic C. Isotonic D. Hypertonic E. Hypotonic - - correct ans- - A. Exergonic This micrograph was most likely taken with which of the following microscopes? (scale bar = 200 nm) Picture is of a 2-D cocci A. Compound Light Microscope B. Stereo Microscope C. Transmission Electron Microscope D. Fluorescence Microscope E. Scanning Electron Microscope - - correct ans- - C. Transmission Electron Microscope
Oligodendrocytes are best associated with: A. Beta cells of the pancreas B. G cells of the stomach C. Nerves in the peripheral nervous system D. White matter of the brain E. Spermatogonia of the testes - - correct ans- - D. White matter of the brain The main extracellular buffer system in humans consists of: A. amphipathic proteins B. phosphate C. sulfate D. bicarbonate E. histamines - - correct ans- - D. bicarbonate Blood in the pulmonary vein would be best characterized as which of the following? A. High in CO B. Low in O C. High in O D. Low in iron E. High in NaCl - - correct ans- - C. High in O Which of the following is a method marine fish use to maintain homeostasis? A. Swim towards freshwater. B. Rarely drink water.
C. Absorb salts through gills. D. Constantly urinate. E. Constantly drink water. - - correct ans- - E. Constantly drink water. A marine fish is hypoosmostic to its environment, meaning that it is less salty than the concentrated saltwater surrounding it. Therefore, it will constantly lose water to the environment. To make up for this, the marine fish must constantly drink water. It also rarely urinates to not waste any water, and it secretes the salts it acquires from constantly drinking. Why does cartilage take a considerable amount of time to heal? A. Cartilage does not consist of cells and therefore cannot be healed quickly. B. Cartilage lacks a direct blood supply. C. Similar to bones, cartilage heals slowly because it is a rigid structure. D. Cartilage is a complex tissue that cells cannot quickly synthesize. E. Cartilage can only be formed in utero while the body is flexible. - - correct ans- - B. Cartilage lacks a direct blood supply. Cartilage consists of living tissue in close proximity to bone. However, it does not have its own blood supply. As a result, nutrients can only access cartilage through slow diffusion, hence why it takes a considerable amount of time to heal. It is not as rigid as bone and can continually be formed throughout an organism's life. In mammals, which of the following structures aides the embryo in gas exchange and the disposal of liquid waste? A. Yolk B. Amnion C. Allantois D. Chorionic Villi
All of the following processes result in genetic variation EXCEPT for one. Which one is the EXCEPTION? A. Mutation B. Crossing over C. Meiosis D. Linked genes E. Independent Assortment - - correct ans- - D. Linked genes If genes are linked they travel together during meiosis and are likely to be expressed together in an organism's phenotype. Nondisjunction occurring during meiosis II, followed by fertilization, would result in a zygote with which of the following chromosomal descriptions? A. Aneuploid B. Haploid C. Diploid D. Tetraploid E. Disomic - - correct ans- - A. Aneuploid When non-disjunction occurs during meiosis II the chromosome is not separated and instead one of the resulting cells produced will have two copies of the same chromosome and one cell will be missing a chromosome. This is referred to as aneuploidy, or the occurrence of having an abnormal amount of chromosomes, either more or less than 23. A student observes a population of 100 eagles in Hardy-Weinberg equilibrium. The eagle's allele for a pointed beak is dominant, and the allele for a rounded beak is homozygous recessive. If 9 eagles were found to have a rounded beak in the population, what is the allele frequency of the pointed beak?
A. 0.
B. 0.
C. 0.
D. 0.
E. 0.91 - - correct ans- - C. 0. The equation for the Hardy-Weinberg equilibrium is: p^2 + 2pq + q^2 = 1. We also know that p + q = 1, where p (pointed beak) and q (rounded beak) are the dominant allele and recessive allele frequencies, respectively. Which of the following are best characterized by brackish water? A. A river emptying into an inland lake. B. A mangrove leading to an estuary. C. A stream in a tropical forest. D. A freshwater marsh and lake. E. Seawater washing onto a beach. - - correct ans- - B. A mangrove leading to an estuary. Brackish water means a mix between salt and fresh water, which would be found in an estuary. An estuary is a specific area where freshwater meets seawater. A species of desert plant secretes a chemical into the surrounding soil that kills seeds from any other species of plant that attempts to germinate in that area. What is this an example of? A. Commensalism B. Allelopathy C. Exploitation competition
A. by ingesting contaminated water B. through injuries with contaminated sharps C. through inhalation D. by shaking hands with patients - - correct ans- - through injuries with contaminated sharps What bloodborne disease has the greatest potential for occupational transmission risk to dental professionals? A. Hepatitis B B. HIV C. Hepatitis C D. Hepatitis A - - correct ans- - Hepatitis B The best way for you to avoid contracting a bloodborne disease in the office is to: A. not shake hands with patients B. wear a mask all day long even between patients. C. handle sharps carefully D. disinfected operatory surfaces with undiluted bleach. - - correct ans- - C. handle sharps carefully How does HIV cause AIDS? A. it destroys the liver B. it destroys the body defenses against diseases C. it destroys the ability to control muscle action D. it paralyzes the body - - correct ans- - B. it destroys the body defenses against diseases Which of the following hepatitis diseases seldom, if ever, establishes a chronic infection?
A. Hepatitis A B. Hepatitis B C. Hepatitis C D. Hepatitis D - - correct ans- - A. Hepatitis A Which of the following hepatitis diseases does not have a chronic carrier state? A. Hepatitis A B. Hepatitis B C. Hepatitis C D. Hepatitis D - - correct ans- - A. Hepatitis A HIV makes people sick by: A. damaging the liver B. causing a respiratory infection C. causing food poisoning D. by destroying their immune system - - correct ans- - D. by destroying their immune system HIV disease is not spread: A. to a developing fetus from the infected mother B. by inhalation C. through percutaneous exposure D. from sexual actions - - correct ans- - B. by inhalation A vaccine is available for which of the following types of hepatitis? A. Hepatitis A and Hepatitis C B. Hepatitis B and Hepatitis A C. Hepatitis C and Hepatitis B
