WGU C190 INTRODUCTION TO BIOLOGY STUDY GUIDE PRACTICE EXAM QUESTIONS AND CORRECT ANSWERS 2026

WGU C190 INTRODUCTION TO BIOLOGY STUDY GUIDE PRACTICE EXAM QUESTIONS AND CORRECT ANSWERS 2026 What item would be classified as Biotic? - Correct Ans-Fungus What Item is an atom? - Correct Ans-Nitrogen Largemouth bass have recently been introduced into ponds that previously did not contain any large, predatory fish. Which adaptation would help the existing population of small, prey species of fish avoid predation from the largemouth bass? - Correct Ans Faster average swim speed If global climate change continues (as predicted) to increase the average temperature of habitats around the world, how would populations of spadefoot toads likely evolve in response to an increase in pond temperatures? - Correct Ans-Spadefoot toads would likely evolve to have a higher percentage of toads become carnivorous. Male peacocks compete with one another to mate female peacocks. Males with more colorful tail feathers attract female mates at a higher rate than those without. Therefore, male peacocks have colorful tail feathers, whereas female peacocks do not. What is this an example of? - Correct Ans-Sexual selection A gardener maintains a species of rose that produce either yellow flowers (the dominant phenotype) or white flowers (the recessive phenotype). One day, the gardener observes that a cross between two yellow rose bushes has led to a single rose bush with orange flowers. What evolutionary mechanism is involved in the change in the gene pool of this species? - Correct Ans-Mutation Which two characteristics are found in organism C? - Correct Ans-Jaw and Lungs Where is the ancestor of wolves and gorillas, but not frogs, depicted on this cladogram? - Correct Ans-Point E Which organism has neither bones nor a jaw? - Correct Ans-Lamprey Which two organisms have eggs with shells? - Correct Ans-Crocodilians and Amphibians WGU C190 WGU C190 Which organisms have four limbs and produce amniotic eggs without shells? - Correct Ans-Primates and Rodents and Rabbits Which species on the following cladogram has the most similar DNA sequence to species E? - Correct Ans-D A subatomic particle has a negative charge and is found in a shell of the atom. What is this particle? - Correct Ans-An electron What is the charge of a proton? - Correct Ans-+1 (positive) A molecular bond results from an electron being transferred from one atom to another. Which type of bond holds these atoms together? - Correct Ans-Ionic Which situation describes covalent bonding? - Correct Ans-An atom shares an electron with another atom. After a rainy day, a leaf has small droplets of water on its surface. Which property of water is this an example of? - Correct Ans-Cohesion A plastic water bottle is filled with water and placed in the freezer. The next day the frozen water has expanded, causing the plastic bottle to rupture. Which characteristic of water is this an example of? - Correct Ans-Density A biological polymer consists of 358 amino acids linked together covalently. What is this polymer? - Correct Ans-A protein A molecule consists of a chain of glucose monomers linked together. What is the function of this molecule within the cell? - Correct Ans-To store energy Which substance is found in ATP? - Correct Ans-nitrogenous base During the Calvin cycle, a sugar molecule is formed as ATP is converted into ADP and a free phosphate group. What is happening to energy in this second step of photosynthesis? - Correct Ans-Energy is being released from ATP to power the conversion of a sugar molecule. Which of these is an output of the light-dependent reaction of photosynthesis? - Correct Ans-ATP Which molecule is an input to the Calvin-Benson cycle? - Correct Ans-Carbon dioxide Which stage of cellular respiration releases carbon dioxide as a product? - Correct Ans Krebs cycle WGU C190 WGU C190 Which stage of cellular respiration releases the most energy and, therefore, produces the most ATP molecules? - Correct Ans-Electron transport chain In the human body, muscle fibers metabolize sugars to produce energy. Fast-twitch muscle fibers, like those used during short-term, vigorous exercise, carry out an anaerobic process that produces less energy per sugar molecule processed. Which metabolic process do fast-twitch muscle fibers carry out? - Correct Ans-Fermentation Fermentation uses sugar in the absence of which molecule? - Correct Ans-O2 What is the function of the flagellum? - Correct Ans-Locomotion and sensing What is true of a eukaryotic cell? - Correct Ans-It contains a mitochondrion. Choose the two substances that are the main components in most eukaryotic cell membranes. - Correct Ans-Lipids and proteins Some cells need to maintain a set concentration of Na+ and K+ ions. These cells are able to do this with the help of the Na/K pump, which transports these ions from areas of low concentration to areas of high concentration (against their concentration gradient). Na+ is pumped out, and K+ is pumped in. Which type of membrane transport is involved in this action? - Correct Ans-Active transport Chromosomes are structures that contain hereditary material that will be passed from one generation to the next. According to this information, which organic molecule must be present in chromosomes? - Correct Ans-DNA A cell has divided its chromosomes into two new nuclei. The cytoskeleton of the cell is currently pinching the cell in the middle to form two new cells. In which stage of the cell cycle is this cell? - Correct Ans-Cytokinesis What is the function of the histones during S phase? - Correct Ans-Organizing and helping to unwind the DNA so the replication enzymes can access it How is DNA structured during the metaphase stage of mitosis? - Correct Ans-The centromere at the center keeps DNA lined up at the cell's equator. What is true regarding the transition from metaphase to anaphase during mitosis? - Correct Ans-Sister chromatids are aligned along the center of the cell and then pulled apart into separate chromatids. Which stage of mitosis is depicted? - Correct Ans-prophase Sister chromatids are being separated and moving towards opposite poles of the cell. Which stage of mitosis is this? - Correct Ans-Anaphase WGU C190 WGU C190 A cell undergoing meiosis is currently dividing. The two new daughter cells will be haploid, but the DNA they contain is still replicated. The homologous chromosomes have separated and are ready to start the second division, but they have not yet begun the second round of division. Which stage of the cell cycle is this cell in? - Correct Ans Telophase I Homologous pairs of chromosomes have separated into two cells. Sister chromatids in each cell have not yet lined up in the middle of the cell. Which stage of the cell cycle is this? - Correct Ans-Prophase II Which type of cell division results in sex cells? - Correct Ans-meiosis Which characteristic describes both meiosis and mitosis? - Correct Ans-Sister chromatids separate What is a characteristic of DNA but not RNA? - Correct Ans-It is intertwined with histone proteins. A fly is heterozygous for wing length, carrying one allele for the dominant long-winged appearance and one allele for the recessive short-winged appearance. Which percentage of the fly's gametes will carry the short-winged allele? - Correct Ans-50% Black (B) is the dominant color, and red (b) is the recessive color in a species of beetle. Two beetles that are both Bb are crossed. What percentage of the offspring will be red? - Correct Ans-25% A species of fish can either have dominant red fins (R) or recessive white fins (r). Fin lengths can either be dominant long (L) or recessive short (l). A dihybrid cross is performed on two of these fish. Each fish is heterozygous for the traits of fin color and fin length. Which four gamete genotypes can be produced by a parent fish? - Correct Ans-Rl, rl, RL, rL Consider the results of a dihybrid cross, where Y refers to black fur, y refers to white fur, S refers to short fur, and s refers to long fur. Capitalized letters refer to dominant traits, and lowercase letters refer to recessive traits. The following are the results: YYSS, YYSs, YySS, YySs, YYSs, YYss, YySs, Yyss, YySS, YySs, yySS, yySs, YySs, Yyss, yySs, yyss How many offspring have white fur? - Correct Ans-4 Which pattern of inheritance is described when a phenotype results from the interaction of many genes? - Correct Ans-Polygenic inheritance A dog breeder mates two black Labrador retriever dogs. The breeder is surprised by the offspring produced by this crossing. In addition to offspring with beautiful black coats, there are dogs with brown, gray, and tan coats. Which form of inheritance is this an example of? - Correct Ans-Polygenic WGU C190 WGU C190 A cutting is taken from a mature hydrangea plant with blue flowers. The cutting is planted in acidic soil and produces red flowers. What caused the flower color in this hydrangea cutting to change? - Correct Ans-An interaction between the genes and the soil A recessive mutation in the DFN3 gene causes deafness. A mother with DFN3 deafness will have sons who all have deafness. How did the sons inherit the gene for deafness? - Correct Ans-On the X chromosome from the mother Which set of chromosomes shows an abnormality that leads to a disorder? - Correct Ans-18 Place the steps of DNA replication in the order of occurrence. Select your answers from the pull-down list. - Correct Ans-1. DNA molecule unwinds. 2. DNA molecule separates into two template strands. 3. Complementary nucleotides are added to each template strand. 4. Two DNA molecules, each with a template strand and a new strand, are formed. Which of the following carries the information that determines which amino acids are used to make a protein? - Correct Ans-Messenger RNA (MRNA) In which eukaryotic organelle does protein assembly and modification occur? - Correct Ans-Endoplasmic reticulum (ER) A gene contains the sequence CGCATACGGTAC that results in the amino acid sequence arg-ile-arg-tyr. A mutated version of this gene has an A in place of the second C and produces the amino acid sequence arg-ile-arg-tyr. What is true regarding this mutation? - Correct Ans-The mutated gene results in the same amino acid sequence and will result in the same phenotype. Biologists estimate that there are 1000 species of bacteria living in the average human stomach. Biologists are studying how these species interact with each other. Which level of ecological organization is being studied? - Correct Ans-Community There are four species of woodpeckers that inhabit the pine forests in the southeastern area of the United States. Individuals of these species utilize many of the same resources for food and nesting. Which level of ecological organization describes the relationship among these four species of woodpecker? - Correct Ans-Community Two species of woodpecker inhabit the same loblolly pine woodland throughout the southeastern United States. Each species requires recently deceased (but still standing) pine trees for reproduction. The woodpeckers excavate their nest cavities in the dead pine trees. In most healthy forests there are generally not enough dead pine trees to provide nests for all the woodpeckers that want to build them. What is the relationship between these two species of woodpecker an example of? - Correct Ans-Competition WGU C190 WGU C190 While abroad, a traveler drinks unclean water containing tapeworm cysts. The tapeworm attaches to the intestinal walls of the traveler, absorbing nutrients from the partially digested food. Over the next few months, the traveler experiences ongoing nausea, loss of appetite, and weight loss due to the presence of the tapeworm in his intestines. What is the interaction between the tapeworm and the traveler an example of? - Correct Ans-Parasitism In the harsh arctic tundra, the survival of one species is often dependent on the actions of another. For example, the arctic bumblebee pollinates the arctic poppy flower and receives energy rich nectar in return. Which interaction is occurring between these species? - Correct Ans-Mutualism A remora (suckerfish) eating food left over by a shark is an example of which interaction between species? - Correct Ans-Commensalism Which organism is a producer in this food web? - Correct Ans-diatoms Which organism in this food web is a primary consumer? - Correct Ans-Copepods Which organism in this food web is a detritivore? - Correct Ans-lobster Which two activities assist in the movement of water through its cycle and take place in living things? - Correct Ans-Photosynthesis and aerobic respiration Prairie ecosystems are common within continental interiors in the Northern Hemisphere. These ecosystems have a thick, nutrient-rich topsoil and are dominated by grasslands and shrubs. Which activity would have a negative impact on biodiversity in a prairie ecosystem? - Correct Ans-Collecting the rich topsoil to sell in surrounding cities Aquatic habitats (e.g., lakes and streams) throughout the northeastern United States have been damaged by acidic rainfall. Airborne pollutants released by coal-fired power plants acidify the rain that falls in these regions, which has led to wide-scale disruptions to ecosystems and a decrease in diversity in these habitats. Which activity would continue to increase the acidity of the rain and negatively impact biodiversity in these aquatic habitats? - Correct Ans-Increasing the use of fossil-fuel dependent electrical power Which action would have a direct negative effect on the environment? - Correct Ans