BI101J, UNSEEN LIFE ON EARTH, QUIZ 2 Darwin and Wallace's ideas about evolution include life had a common origin. there is variation within populations. the environment constantly changes and competition between individuals results in the selection of favorable traits within the environment. * all of the above none of the above Critique this sentence: Most mutational changes damage a protein's function. * True; a change in the sequence of DNA, called a mutation, will result in a change in the sequence of amino acids in the protein coded for by that gene. And yes, most changes are harmful. True; mutations are changes in the amino acid "language" found in our genes and they result in changes to the nucleic acid sequence found in proteins. False; most mutations are beneficial. False; mutations don't have anything to do with protein function. none of the above Critique this sentence: We expect the microbial world to be rich and complex. True; the incredible diversity of bacterial shape is truly astounding; there are millions of different-appearing microbes. * True; microbes have been fine-tuning and evolving for billions of years, and regardless of their apparent similarity in shape, they have many important internal differences that allow them to exploit all different environments on Earth. False; based on our current understanding of microbial life, we think there are only a small handful of different bugs out there. False; we don't know what to expect, because we are just beginning to learn about microbes. none of the above The first photosynthetic organisms were bacteria. * True False Many species of bacilli, spirilli , and a few cocci move by means of legs. arms. tentacles. suckers. * flagella. Bacterial nuclear material is surrounded by mesosome. nucleus. * cytoplasm. pilus. granule. The correct sequence of bacterial structures, starting from the outside and moving in is mesosome, nucleosome, granules, cytoplasm. * capsule, cell wall, cell membrane. cell membrane, cytoplasm, cell wall, nucleus. granule, endoplasmic reticulum, ribosome, cytoplasm. none of the above In asexual reproduction, bacteria and other microorganisms must * duplicate their DNA and other cell structures. join with another of the same species to exchange genetic material such as plasmids. synthesize new cytoplasm, but not DNA - the bug just splits what DNA it has, and later on will replenish what it lost from its food. none of the above Penicillin acts to disrupt bacterial cell division by stopping synthesis of cytoplasm. stopping synthesis of new DNA - it's a DNA synthase inhibitor. stopping production of additional cytoplasm. * inhibiting production of cell wall material. all of the above Aerobic bacteria prefer to live where oxygen is ________; anaerobic bacteria prefer ________ oxygen. * plentiful; little or no little or no; plentiful combined with iron; free combined with carbon; carbon-free none of the above Endospores of the genus Clostridium can survive in boiling water and the organism can grow in very low oxygen levels. So what? The rascal may grow in improperly canned food and produce botulism poisoning in people, that's what! The organism can grow in deep wounds, even if thoroughly washed and can cause gas gangrene or tetanus. The organism can live in soils and mud that are very low in oxygen. * all of the above Critique this sentence: We could expect to find thriving, growing populations of bacteria commonly found on Earth in outer space. * Most unlikely! Most bacteria on earth soon die if deprived of food or water, although a few will form tough, resistant stages called endospores that do indeed resist long periods of harsh conditions. We might find resting stages of bacteria in space, but there's no liquid water, so none could grow and thrive. It's not impossible, because we've found bacteria that live in extremes of temperature, pressure, and acidity. Certainly! I saw it on the X-files just last week! none of the above All organisms in this nutritional class of microorganisms harvest energy (electrons) and carbon from the same source. autotrophs * heterotrophs chemotrophs phototrophs none of the above Exponential growth of a population occurs in the ________ phase. death lag * log stationary end Using a closed container (such as a brewer's tank) for microbe cultivation means that four stages of population growth do not occur. nutrients are continually supplied. * four stages of population growth will occur. metabolic byproducts are continually removed. the brewmaster must carefully vent away the build-up of oxygen inside the tank. The term macromolecules refers to * large, complex molecules. large, complex gases, such as hydrogen or helium. smaller molecules, such as CO2. larger organisms, such as mushroom-forming fungi. smaller organisms, such as Bacillus or Clostridium. In the absence of oxygen, ________ occurs in the muscle tissue of animals. * lactic acid fermentation alcohol fermentation (can you get drunk by holding your breath?) anaerobic respiration metabolism does not proceed; the tissue dies none of the above ________ are the producers in deep sea ocean vent ecosystems. Phototrophs * Chemolithotrophs Organotrophs Heterotrophs There are no producers, only decomposers and detritivores (eaters of dead stuff). Bacteria reproduce by or when playing the lottery. accumulating DNA from others. * binary fission. they've been exposed to the proper chemical messengers. producing gametes that then fuse together. The three kinds of RNA are * messenger, transfer, and ribosomal. amino acids, phosphorylation, nucleic acids. sugar, salt, fat (also known as the three major food groups). deoxyribose, serotonin, uracil. regulatory, promoter, operons.