BIOD 171 Microbiology Module 1 – 6 Exam Questions and Answers2025/2026

BIOD 171 Microbiology Module 1 – 6 Exam Questions and Answers BIOD 171 Microbiology Module 1 – 6 Exam Questions and Answers Microbiology -Answer-The study of microbes and their biological processes at the micro (microscopic) level. Microbes -Answer-1. A general term that includes microorganisms and viruses; an organism or virus too small to be seen without a microscope 2. Beneficial when aiding in food digestion to protecting us when we are exposed to potentially harmful foreign invaders to helping crops grow 3. Detrimental when harmful strains of bacteria, fungi, protozoa, and viruses kill millions of people each year and sicken even more Microorganisms -Answer-1. Usually consist of a single cell 2. Examples: bacteria, archaeons, fungi, protozoa, and algae Prokaryotic or eukaryotic -Answer-1. The most common distinction between living organisms 2. Prokaryotic cells (before kernel) lack a nucleus, whereas eukaryotic cells (true kernel) have a defined nuclear region 3. Difference: size, complexity, unicellular or multicellular, abundance, examples, nucleus & DNA, and membrane-bound organelles 4. Similarity: macromolecules, plasma membrane, cytosol, chromosomes, and ribosomes 3 classifications of life -Answer-1. Bacteria, Archaea, and Eukarya 2. The first two categories are prokaryotic microorganisms that are different in cellular composition Bacteria (Prokaryotes) -Answer-1. Morphologies: coccus (round/spherical), bacillus (rod), vibrio (curved rod), or spirillum (spiral/corkscrew). 2. Cellular organization: isolated (individual) cells, in chains, or in clusters 3. Examples: Streptococcus (round chains); E. coli (rod); Mycobacterium tuberculosis (a unicellular bacterium) Archaea (Prokaryotes) -Answer-1. Also referred to as extremophiles 2. Survive in extremely harsh environmental conditions, such as high salt levels, acid conditions, high temperatures, and oxygen-poor conditions Eukarya -Answer-Animalia, Plantae, Fungi, and Protista Animalia -Answer-1. Multicellular eukaryotic organisms includes animals and humans 2. Heterotrophic and the general characteristic of motility Heterotrophic -Answer-Incapable of producing one's own energy, must absorb (consume) nutrients from the environment Plantae -Answer-1. Multicellular eukaryotes with cell walls made of cellulose 2. Obtain most energy from sunlight via photosynthesis - autotrophic Photosynthesis -Answer-A process that converts light energy (sunlight) into chemical energy (sugars) within the organism and fuels its activities. The process of capturing sunlight and converting it into the usable energy sources ATP and NADPH. Fungi -Answer-1. Either multicellular or unicellular microorganisms 2. Heterotrophic and the presence of chitin (a derivative of glucose) in cell walls 3. Examples of multicellular fungi are molds and mushrooms; the most common unicellular fungus is yeast Protista -Answer-1. Unicellular microorganisms 2. May form as colonies (seemingly multicellular but do not form tissue layers and thus retain the unicellular classification) 3. Examples: amoeba (motility); algae (plant-like characteristics); mold (fungi-like properties). Viruses -Answer-1. Neither prokaryotic nor eukaryotic 2. Not considered living and do not replicate on their own (only within a host) 3. Contain a capsid, a membrane-like structure that contains genetic material, similar to the nucleus Cell membrane/plasma membrane/cytoplasmic membrane -Answer-1. A semi- permeable barrier surrounding the cytoplasmic space of a cell acts as a barrier to the outside environment while also retaining and preventing the intra (within) cellular components from being lost to the surrounding environment 2. A bilayer composed primarily of amphipathic phospholipids that contain a polar hydrophilic (water loving) head group and a non-polar hydrophobic (water fearing) tail region 3. A relatively high degree of fluidity dependent on the types of lipids, the temperature, and additional molecules (proteins) 4. Sterol lipids (such as cholesterol), which play a major role in eukaryotic membrane composition Cell walls/outer membrane -Answer-1. Found in bacteria, plants, fungi, and algae and help to form the shape of the cell, providing support, structure, and protection 2. Peptidoglycan for bacterial wall: a peptide-polysaccharide matrix; vary in thickness to protect the cell from potentially damaging environmental stresses 3. Surface-layer proteins (S-layer) for archaea cell: physical and chemical protective barrier to the harsh surrounding environments 4. Cellulose and chitin for fungi 5. Mannoproteins (highly glycosylated polypeptides called mannan and mannose) and chitin for yeasts 6. Silica (main component in glass) for Diatoms (algae) : very rigid 7. Some eukaryotic cell walls may contain polysaccharides, like cellulose and pectin Cell envelope -Answer-The combination of the cell membrane and the outer membrane (cell wall) Cytoplasm -Answer-1. Constitutes the open volume within a cell; 2. Comprised mostly of water containing dissolved substances important to the functioning of the cell. Organelles -Answer-Membrane-enclosed structures within the cytoplasm that perform specific functions. Nucleus -Answer-1. A porous double lipid bilayer that contains the genomic content of the cell (DNA) 2. The command center of the cell 3. The defining organelle of all eukaryotic cells Nucleolus -Answer-Within the nucleus, the site of ribosome synthesis Ribosomes -Answer-1. Responsible for protein synthesis. 2. Located in the cytoplasm of prokaryotic cells and attached to the endoplasmic reticulum in eukaryotic cells Endoplasmic Reticulum (ER) -Answer-1. A series of membrane-enclosed sacs and interconnected tubes (lumen) 2. Composed of the smooth endoplasmic reticulum (SER) and the rough endoplasmic reticulum (RER with ribosomes stud the surfac