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22 Cards in this Set
- Front
- Back
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Why are there so many species of insects? What features among the arthropods have contributed to their success and diversification?
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• When did oxygen concentration first reach about 15 percent of the current level? What type of life was the most complex at the time? • When was the most dramatic increase in oxygen after the Cambrian explosion? What biological feature is most closely associated with this increase in oxygen?• What was the oxygen concentration at the start of the Cambrian period?• Of all the time in which there has been life on Earth, what percentage of the time had only anaerobic life?
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Oxygen first reached about 15 percent 750 million years ago and the most complex life were multicellular eukaryotes. The most dramatic increase of oxygen after the Cambrian explosion was around 250 million years ago during the Permian era. It took earth many millions of years to develop an oxygenated atmosphere. Oxygen concentration increased during the Carboniferous and Permian periods because of the evolution of large vascular plants.
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The oxygen concentration during the Cambrian period was about 18 to 19 percent and it did not change much in that period. Perhaps 3.5 billion years ago the earth had only anaerobic life until about 200 million years ago the Great Oxygenation Event occurred, which was the biologically induced appearance of dioxygen in Earth's atmosphere, began producing oxygen by photosynthesis. The Great Oxygenation Event, the excess free oxygen started to accumulate in the atmosphere. Free oxygen is toxic to obligate anaerobic organisms.
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What are common characteristics that are found in all domains of life (there should be at least 7)? What specific adaptations, found among these common characteristics resulted in the successful colonization of land plants, specifically among the angiosperms? Are there any interspecific interactions that are important for the survival of land plants?
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The five Kingdoms were generally grouped into two categories called Eukarya and Prokarya. Eukaryotes represent four of the five Kingdoms (animals, plants, fungi and protists). Eukaryotes are organisms whose cells have a nucleus. A sort of sack that holds the cell’s DNA.
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Animals, plants, protists and fungi are all eukaryotes because they all have a DNA-holding nuclear membrane within their cells. Characteristics of these are, they are all based on the cell and they use the same genetic code (DNA and RNA). Also they share similar or identical metabolic pathways and enzymes as well as similarities of cell structures.
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Using the tree above identify a set of shared synapomorphies between organisms within each group of protists covered in lecture. If possible, identify at least 1 derived trait among the taxa discussed.
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According to the figure, Amoebozoans was the single clade of eukaryotes which diverged from the other eukaryotes. Among the Stramenoplies, a morphological synapomorphy is the possession of rows of tubular hairs on the longer of their two flagella. Another example are Rhiozarians. The three primary groups of it are: cercozoans, foraminiferans and radiolarians, which are unicellar and mostly aquatic. These organisms typically have long, thin pseudopods that contrast with the broader, lobelike pseudopods of the more familiar amoebozoans.
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Continuing with amoebozoans, which use lobe-shaped pseudopods for locomotion. They differ in form and function from the slender pseudopods of rhizarians.
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Choose any particular disease causing protest discussed in class. This organism may effect the health of any organism or may interfere with the health of any given ecosystem. Indentify any traits (derived or synapomorphic) that allow the organism to infect a host, evade host defenses and cause disease. If the organism is heteroxenous, explain the role of different hosts in its lifecycle. You may use outside resources to answer this question so long as you use the proper citation and reference format.
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For this question I decided to choose Malaria, which is a mosquito-borne infectious disease of humans and other animals caused by parasitic protozoans, belonging to the genus Plasmodium. Malaria causes symptoms that typically include fever, vomiting and headaches and in severe cases it can cause yellow skin, coma, seizures or death. When an infected Anopheles mosquito bites a human, she may inject sporozoites, which are produced by sexual reproduction, along with saliva into small blood vessels.
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Sporozoites are thought to enter liver parenchymal cells within 30 minutes of inoculation. In the liver cell, the parasite develops into a spherical, multinucleate liver-stage schizont which contains 2,000 to 40,000 uninucleate merozoites. This process of enormous amplification is called exoerythrocytic schizogony. Depending on the species of plasmodium,tThis liver phase of the disease usually takes between 5 and 21 days. These quiescent liver-phase parasites are called hypnozoites.
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How have Koch’s postulates been adapted for this study? What challenges do researchers face in trying to apply Koch’s postulates when examining microbial communities verses a monoculture of a single organism? What sort of microbial interactions might have an effect during colonization on the host?
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First of all, the microorganism is found in abundance in all organisms suffering from the disease and also the cultured microorganism should cause disease when introduced into a healthy organism. Countless numbers and types of bacteria can still not be cultured with currently available techniques. Some of these non-culturable bacteria are considered dormant. These cells, called Somnicells include those bacteria that become dormant and cannot be cultured on available media, when stressed.
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Characteristics between algae and seed plants? |
Common characteristics between algae and seed plants are that they have chloroplasts and they both are photosynthetic. Both are also considered eukaryotes, consisting of cells with specialized components. They both also have the same life cycle called alternation of generations.
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fungi and algae?
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Common characteristics between algae and fungi are that these two terms encompass a wide variety of species. For example, fungi, includes not only the mushrooms and larger fungi many people are familiar with, but also microscopic varieties, such as yeast. They both prefer to live in moist environments. In fact, one of the benefits algae derive from their symbiotic lichen relationship with fungi is their ability to survive on land in a moist environment. Both fungi and algae are, in general, examples of organisms possessing a haploid nuclei.
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seed plants & fungi? |
One common characteristic between fungi and seed plants is that all plants on the cellular level have a cell wall. The cell wall protects the cell membrane and prevents the cell from over-expanding. Although plants and fungi are different kingdoms, they evolved from the same parent kingdom, the Kingdom Protista, or the protists. These organisms are mostly unicellular and are considered to be the origin of plants, fungi and animals. An observable trait that plants and fungi share is their immobility.
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What are some characteristics that are unique to each group? Which of these are important adaptations that allowed plants, specifically seed plants, to successfully colonize land?
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Algae are eukaryotic organisms that have no roots, stems, or leaves but do have chlorophyll and other pigments for carrying out photosynthesis. Algae can be multicellular or unicellular.
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Most of the fungi are multicellar with a major haploid life stage. Unicellar fungi are called yeast. In nutrition, fungi feed by absorption. All fungi also produce spores and only one phylum has flagella. In terms of ecology the majority of fungi are saprobes. Other fungi are parasites, including mutual symbionts-especially mycorrhizae and lichens, while others are pathogens. Some are active predators. The cell walls of fungi contain chitin is another aspect.
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All seed plants hsare two characteristics. They have vascular tissue and use seeds to reproduce. In addition, they all have body plans that include leaves, stems, and roots. Most seed plants live on land. Seed plants face many challenges, including standing upright and supplying all their cells with water and food. They meet these two challenges with vascular tissue.
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The thick walls of the cells in the vascular tissue help support the plants. Also, water, food, and nutrients are transported throughout the plants in vascular tissue. Another important aspect is desiccation. This means cuticle and stomata to protect against dehydration.
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Using specific examplespresent in lecture or in the booth,identify interspecific interactions that occur betweeneach group,what class they belong to(mutualism, competition, parasitism, etc)and how do they work? Between which groups are these interactions the most important and why?
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Typically there are two types of competition: interference and exploitative competition. During interference competition, organisms interact directly by fighting for scarce resources. For example, large aphids defend feeding sites on cottonwood leaves by kicking and shoving smaller aphids from better sites.
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In contrast, during exploitative competition, organisms interact indirectly by consuming scarce resources. For example, plants consume nitrogen by absorbing it into their roots, making nitrogen unavailable to nearby plants. Plants that produce many roots typically reduce soil nitrogen to very low levels, eventually killing neighboring plants.
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Another aspect is the competition for resources. Organisms compete for resources features of the environment that are required for growth, survival, or reproduction, and which can be consumed to the point of depletion. Examples of resources that can be consumed to depletion: Food, water in terrestrial habitats, light for plants and space, especially for sessile organisms. For mobile animals, space for refuge, nesting, etc.
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What plant group do you think this plant most likely belong to? What are the leaf-like structures formally called? What other characteristics would you look for to confirm this hypothesis?
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It most likely belongs to the group of mosses and ferns, because of the flagellated sperm. Other characteristics are either that their gametophytes grow close together, or that they be hermaphroditic and that they have lignified vascular tissues, microphylls, strobili, true leaves and roots.
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Compare and contrast the reproductive life cyclesof these two groups of organisms. What are the names of the characteristic sexual reproductive structures?What is unique about the each of the fungal life cycles in comparison to each other?
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