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Answer each question in APA formatting using the read section. 150-word count minimum for each question. 1. Describe the rabies experiment of Louis Pasteur discussed in the story. Research how Pasteur’s injections cured Andre. How do rabies immunizations work today? 2. Name three characteristics of viruses. Are viruses living or nonliving? Defend your answer. 3. List the three groups of archaebacteria. How are they different from bacteria? Which would most likely be found in a hot liquid with a pH of 3? Why? 4. Describe four pieces of evidence used to support the theory of evolution (7.6) 5. Explain the process by which moth species declined in England in the past decades? How did some species of moths increase at the same time? (7.1; 7.3) 6. Name the type of speciation that results when a species cannot mate due to a change in their use of a habitat. Explain how it results in speciation. 7. Diseases due to viruses are plentiful. Name three diseases caused by viruses in humans. Which are not species specific? Why? 8. A disease destroying mycorrhizae in forest concerns a group of biologists. Why are they worried about the effects on the ecosystem? On humans? Unit 3 We Are Not Alone! Chapter 7 Chapter 8 Chapter 9 Chapter 10 C H Evolution Gives Our Biodiversity R I Before Plants and Animals: Viruses, Bacteria, Protists, andSFungi T I Getting to Land: The Incredible Plants A M  oving on Land and N in the Sea: Animal Diversity, M A R K 6 5 3 5 B U 233 ch07.indd 233 11/12/15 4:39 pm C H R I S T I A N , M A R K 6 5 3 5 B U ch07.indd 234 11/12/15 4:39 pm 7 Evolution Gives our Biodiversity Bats evolved echolocation to prey on insects such as moths 6 5 3 5 B U © JHVEPhoto/ M A R K The island once had many moths ©Stephen Rees/ ©Panaiotidi/ C H R I S T I A N , Father and Son Sailing © bikeriderlondon/ Essentials Island without moths; Ecosystem low in diversity…today © Kendall Hunt Publishing Company 235 ch07.indd 235 11/12/15 4:39 pm 236 Unit 3: We Are Not Alone! Check In From reading this chapter, students will be able to: • • • • • • • • • Explain the relationship between evolution, biodiversity, and society’s role. Use moth population changes as an example of evolution and species changes over time. Discuss the history of how life’s origins were discovered, using ideas on spontaneous generation. Describe how natural selection leads to species changes. Define the types of natural selection. Examine the role of speciation as a cause of biodiversity. Describe extinction and its role in biodiversity changes throughout Earth’s history. Discuss and evaluate the evidence for evolution. Use sexual selection to explain the developmentC of organisms over time. H R I The Case of the Quiet Island S I was a young student studying biology in Wales when I talked with my father into sailT ing with me. I had seen my friend sail a small boat earlier in the season, and it looked I fairly easy. So my father and I set off to visit an island that our family once vacationed on when I was a child. The wind A was at our backs, so we zipped along toward the island with ease. I thought, “I should buy N a sailboat and make this my new hobby; I am really great at sailing.” , We docked the boat within a few minutes and began walking the island. It was just a few miles around On an earlier trip I had noticed that the island had many different creatures – plants, birds, bats, and M lots of moths, one of my least favorite insects. My father noticed that it was very quiet – very peaceful and a great place to read – I think he A was telling me I should get away to this island and quit bothering him with my studies. R took leaves and plants for study. We noticed that We hiked up its small hills and there were very few insects buzzing K around us. “How great,” I thought, “no bugs around to bother us.” I had always disliked the arthropods, all of the insect classes, in fact. I recalled times when deer flies bit through a shirt into my neck when I was gardening. 6 “They are good for nothing,” I reminded myself, happy to be relieved of them for at least this walk. There were only small 5 farms on the island, which consisted of quiet countryside cottages. Oddly though, on our walk there were neither birds nor insects to make 3 noise–well, peace at last. 5 deal of farming, and the crops looked very healthy. The island had developed a great My father commented, “This is B what England needs, productivity. Big farms like this one will make Britain strong again!” I had read in a journal article that two-thirds of BritU ain’s 337 large moth species are in significant decline. It was evening, and I again appreciated that there were no moths buzzing around our heads by the lamplights on the road. “A nice quiet night but where were the moths that I once watched in the lamps along the road?,” I envisioned, recalling their bulbous bodies. As a biology student, I knew that moths were an insect class, Lepidoptera, with 150,000 known species. Moths were not beautiful like butterflies and were pretty gangly, throwing themselves at lights. I would never be an entomologist, who studies arthropods for a living. My teacher made us read an article reporting that there had been a 99% decline in common garden moths, Marcaria wauaria, in the past few decades. The total number of large moths was down by almost 50% in southern England. Three species of ch07.indd 236 11/12/15 4:39 pm Chapter 7: Evolution Gives our Biodiversity 237 moths had disappeared from southern England in the past decade: Orange upperwing, Jodiacroceago; Bordered gothic, Heliophobus reticulate; and Brighton wainscot, Oria musculosa. “Good riddance, life goes on without them; but I wonder why so many were gone?” I pondered. When we started back to the coast, I realized the wind was against us. I didn’t really know what to do when the wind did not have our sail. My father and I struggled to keep the sail straight and steered helplessly through the waves that had developed while we were on the island. It had become a nightmare. I frantically tried to steer and pull as the boat went out of control. The boom hit my father’s head in the confusion. He yelled, “You idiot, you’ll kill us yet! Why didn’t you tell me you had never sailed?” He was bleeding and I felt terrible. How was I supposed to know that sailing could get so out of control? It seemed easy when the conditions were just right. It dawned on me that the slight shift in wind direction, much like one fluctuation in moth populations, could usher C in significant change leading to disastrous effects. Moths are an indicator species, meaning that the H state of the environment is first indicated by moth population health. Fewer moths mean R less food for birds and bats, which eat moths. Those organisms eating birds and bats also are affected. One change in I the environment can have profound impacts on the whole ecosystem. The island was quiet like the sea when we arrived.SThere were few insects and few birds to make sounds, but the quiet island had spoken –Tand it was quiet no more. I A Check UpNSection , In the story, our character is at first happy about the loss of biodiversity on the island. By the end of the story, it dawns on him or her that there may be more to the quiet island. Changing environmental M factors, much like sailing conditions, can be unpredictable and get out of control. Moths in England A declined in numbers in part due to habitat loss: large-scale farming destroyed hedges lining smaller farms, an area where moths thrive; pesticides also were shown to kill off many moths. R Study the life history of the Marcaria wauaria, noting its prevalence, habitat use, and the purported ­reasons for its decline in southern England.KSome species of moths saw population increases in ­southern England. The least carpet moth increased by 75,000%. Research why this occurred: How might changes in moth prevalence impact on our society? Do you think the narrator in the story had a 6 change of heart about moths, about the environment? 5 3 5 What Are the Origins of Life? B U to the great diversity of organLife originated about 3.5–4.1 billion years ago, giving rise isms we see today. The origins of our biodiversity emanate from a small set of species of prokaryotes. Stacks of sediment made by colonies of bacteria, called stromatolites, are evidence of our primitive ancestors. Found in Africa, Australia, and the Bahamas, stromatolite layers contain carbon from bacteria dating back to early Earth. Since Earth was formed 4.6 billion years ago, life began relatively early in Earth’s history. How did life originate from our molten ball of Earth chemicals? Early scientific thinkers believed that life originated from nonliving matter. The idea that life appeared from nowhere, called spontaneous generation, was held firmly by scientists for many centuries. ch07.indd 237 Spontaneous generation The idea that states that life appeared from nowhere. 11/12/15 4:39 pm 238 Unit 3: We Are Not Alone! The 17th-century scientists hypothesized that organic matter in food automatically generated maggots and all associated life when coming into contact with air. (You can make the same observation if you leave food at room temperature for a long-enough period of time; you will likely see mold and flies at the least.) Then, Francesco Redi (1636–1697), an Italian naturalist, became the first to disprove spontaneous generation. Redi devised an experiment that involved placing a piece of meat into a glass jar. The jar was covered with gauze, which allowed air flow to the meat but no other agents larger than the holes in the gauze. A second control jar was left uncovered to allow contact with any external agent. Redi’s experiment is shown in Figure 7.1. Redi’s results showed that the gauze-covered jar did not have maggots, but that the uncovered jar did. Realizing that some other agent had caused maggots and not the meat itself, Redi’s experiment was the first to disprove the idea of spontaneous generation. We now understand that flies were the cause of new life on decaying meat, with maggots C growing from eggs laid on the organic material. H the 1600s to view the developing fly eggs on meat. There were no microscopes in The mechanism for new species growth on food was therefore unknown. However, Redi R was criticized because new growth spoiled foods in both his control and his experiI mental jars – we now know the bacteria of decay cause the food to spoil. Thus, debate continued on whether life could S arise spontaneously. Scientists also sparred over what caused milk and beer to sour. French T biologist, Felix Pouchet (1800–1873) believed that microorganisms spontaneously arose in some foods, such as milk and beer, which had I the right combinations to create life. Pouchet heated flasks of hay A brews to 100° C. He sealed the flasks, but even though they were sterilized, bacteria formed. N Pouchet thus concluded that organisms could arise from a good mixture of materials, as found in beer and other fermentation environments. , He tried many times to sterilize the flasks, but in every case within a short period of time, he observed a sea of bacteria. Pouchet thus reopened the defense of spontaneous generation. M Louis Pasteur (1833–1895) proposed an alternate hypothesis, arguing that bacteria were everywhere. He claimedAthat Pouchet’s experiment was contaminated when he 6 5 3 5 B U JAR 1 JAR 2 © Kendall Hunt Publishing Company R K Figure 7.1 Redi’s experiment. After covering jars, Redi determined that a covered jar does not lead to maggot formation on meat. It was a first attempt to disprove the spontaneous generation of life. ch07.indd 238 11/12/15 4:39 pm Chapter 7: Evolution Gives our Biodiversity 239 Dust particles, bacteria, and other airborne materials trapped No microorganisms grow Microorganisms thrive Nutrient broth is sterilized C Figure 7.2 Pasteur’s experiment. H R placed lids onto the flasks. Pasteur designed special long-necked flasks to keep broth I placed inside free from bacterial growth as he sterilized its contents. Air was still able S that life might not have air to to get through to the broth; this eliminated the criticism breathe, as in Redi’s sealed jars. The lower part of the T neck of the flask trapped the heavier dust particles and microbes. His flask design isI shown in Figure 7.2. With no external agent, Pasteur reasoned correctly that the “trap” in the neck kept A Pasteur tipped a flask to allow out microbes, and no new life formed in his flasks. When broth to touch the trap, bacteria appeared in the brothNin a few days. His rejection of Pouchet’s results brought Pasteur membership in and an award from the French Acad, emy of Science. Pasteur’s experiment showed how his critical thinking led to a solid disproof of spontaneous generation – and led to the birth of microbiology as a discipline. Personally, Pasteur was a devout Roman Catholic. M He performed the experiment to emphasize the sanctity of life. He reasoned that if spontaneous generation were true, A then there would be no need for a creator God to exist. His disproof of spontaneous generation was actually a movement against atheism. ItRworked toward a resurgence of religious faith in the 1800s. While Pasteur promoted K his work as an example of pure science, it may show how one’s personal beliefs, even as a scientist, influences thinking about scientific research. 6 arguments continue through The Pasteur–Pouchet debate illustrates how scientific the centuries. The germ theory of biology, which places5a focus on sterile techniques to prevent microbial disease spread, led to important improvements in medicine. The wide3 spread use of sterile techniques decreased deaths, especially during childbirth. 5 In 1953, physical chemists The origin of life is of continual interest to scientists. Stanley Miller (1930–2007) and Harold Urey (1893–1981) devised an experiment B demonstrating that precursors to life could have formed from the right mixture of chemicals. Conditions on early Earth were simulated in a U glass tube containing methane, hydrogen sulfide, hydrogen gas, and water vapor. The experiment in Figure 7.3 shows the design of Miller and Urey’s experiment. An electrode was placed in the glass tube which simulated X-rays, ultraviolet light, and lightning of the early Earth. The environment in Miller and Urey’s glass tube was an oxygen-free system, just like on early Earth. When an electric charge was applied to this primordial mixture of chemicals, organic molecules formed. Fats, sugars, proteins, and genetic material were produced from the simulation. Organic molecules make up life, and as discussed in Chapter 2, are able to self-­ assemble based on their chemistry. It is hypothesized that droplets of organic material ch07.indd 239 © Kendall Hunt Publishing Company Airborne bacteria can now reach the broth Germ theory The theory that places a focus on sterile techniques to prevent microbial disease spread, led to important improvements in medicine. 11/12/15 4:39 pm C H Figure 7.3 Miller and Urey apparatus. organic molecules, precursors toRlife. I S T I A N , © Roger Ressmeyer/CORBIS Unit 3: We Are Not Alone! Gases in the glass tubes reacted to form © paulista/ 240 M A R Prebionts. These tiny K spheres share some characteristics of life, including Figure 7.4 a separate membrane to keep it distinct from its environment. 6 Prebiont A sphere of organic material that led to first living cells. formed from the newly made organic products. As shown in Figure 7.4, the droplets 5 formed a sphere that was separate from its environment. This sphere of organic material is called a prebiont and was the3first form of new life. It was capable of replicating, absorbing genetic material, and forming new prebionts. These new “cells” further devel5 oped into prokaryotes found as fossils within stromatolites. But how did so much life B originate from such a simple prebiont? U Natural Selection and Biodiversity Reproductive success Is the number of viable offspring an individual produces. ch07.indd 240 Take a moment to ponder the fact that living organisms, in all their magnificent diversity, emerged from a simple assortment of chemicals on early Earth. Chapter 1 discussed Darwin’s principles of evolution; we will expand on some of those principles here. When populations have more individuals than an environment can support there is inevitably a struggle for survival. Individuals have varied characteristics, with some better able to survive than others. These more successful organisms reproduce more and thus have better reproductive success (RS), defined as the number of viable offspring 11/12/15 4:39 pm Chapter 7: Evolution Gives our Biodiversity (a) Figure 7.5 ch07.indd 241 5 3 5 B U Evolution The change in gene frequencies in a population, over time. Natural selection The natural selection for or against certain attributes. Outdoorsman/ © Dennis W. Donohue/ an individual produces. The frequency with which genes appear in a population change based upon these different RS rates. Organisms with a successful RS increase their ­relative proportions of genes in a population. The change in gene frequencies in a population, over time, is defined as ­evolution. However, evolution acts only upon phenotypes, or the physical characteristics of one’s genes. Those organisms with traits better adapted for a particular environment will increase in numbers. The driving force behind evolution is thus natural selection, or nature selecting for or against certain attributes. It results from an interaction between organisms and their environments. Consider the polar bear, Ursus maritimus, which has white fur. Over time, those bears with a light color as camouflage were better able to blend in with their snowy surroundings. Contrast the darker colors of the brown bear, Ursus americanus, which blends better within darker forests of North America (Figure 7.5). Their respective environments influence the phenotypic traits that are selected for C and against. To illustrate, the dark color of a brown bear roaming the polar ice caps H its enemies and obvious predwould stand out like a sore thumb, making it easy prey for ators to its prey. Thus, different environmental conditions R favor different phenotypes at different times. If the ice caps were to melt, becoming forests, polar bears would no I longer have an advantage with respect to fur coloration. In our story, the characters witS ness changes in moth populations on the island. Moth species thus experience a change in gene frequencies within their populations, with some T decreasing and some thriving. With declines in the V-moth, Marcaria wauaria and extinctions of three moth species in I England, Orange upperwing, Jodia croceago; Bordered gothic, Heliophobus reticulate; A is at work. Changed environand Brighton wainscot, Oria musculosa, natural selection mental conditions, such as loss of habitats and harmful Npesticides in farming, contributed to moth species changes (Figure 7.6). , Why the changes in moth populations in England? Consider that currants and gooseberries, once very popular and found in many gardens, lost favor across households. ­Currants and gooseberries are a big part of V-moth M diets. Without easy access to these foods, V-moth populations declined substantially. On the other hand, some conA of moth species experienced ditions favored certain species of moths. In fact, one-third R The reason was the improveincreased numbers in the region discussed in our story. ments in air pollution and acid rain led to a rise i ...
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Running Head: Unit 5 Biology Questions



Running Head: Unit 5 Biology Questions
1. Describe the rabies experiment of Louis Pasteur discussed in the story. Research
how Pasteur’s injections cured Andre. How do rabies immunizations work today?
The rabies experiment of Louis Pasteur discussed in the story discusses how
Andre was cured from Pasteur’s injections. Pasteur’s research on rabies-infected dogs
showed him that living infected dogs survived when injected with a vaccine made of
ground up spinal cords from dead rabid dogs. He however, had not tried this drastic and
experimental procedure before. Despite this, he injected Andre with ground up spinal
from a dog. Andre was injected with the spinal cord mixture each day of the three months
that followed. At the end of the treatment, Andre emerged as the first person in history to
ever survive a rabies infection. The spinal cord mixture has a natural antibiotic property
that helps in treating the wound caused by rabid dog. Before Pasteur’s discovery, society
lived in fear of a bite from a rabid animal. Rabies vaccination directly acts on the
rhabdovirus, with special proteins or antibodies that attack viruses, stopping their action.
Rabies vaccine is a form of immunization that acts directly on pathogens and without the
help of a host’s immune system.
2. Name three characteristics of viruses. Are viruses living or nonliving? Defend your
The variety of organisms that are not plants or animals have many important
functions in our ecosystems, but certain forms can also be harmful. Viruses have unique
characteristics that classify them as in-between living and non-living state. Viruses are
intracellular parasites, meaning that they invade host cells and live within them. They are
not cells and are not included in the classification schemes of living organisms. They are
obligatory parasites, unable to live outside of a host. Thus, they are not considered to be

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