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28 Cards in this Set
- Front
- Back
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Three domains of life
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Bacteria, Archaea, and Eukarya.
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Bacteria
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Bacteria or Archaeas members are all single-celled and microscopic.
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Eukarya
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Eukaryas diversity is so broad it is further divided into four kingdoms: plants, animals, fungi, and protists.
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Archaea
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Bacteria or Archaeas members are all single-celled and microscopic.
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Microbes
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Living things.
So small they cannot be seen with the naked eye. Indispensable to all life on Earth. Produce more than half of Earth’s atmospheric oxygen. The bacteria among them are responsible for putting nitrogen into a form plants can use. |
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Who are the most important “decomposers” of the natural world, and how do they do it?
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Bacteria and fungi— they break down dead organic matter, such as tree branches, and recycle the resulting elements back into the Earth.
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20.2 What are Viruses?
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Non-cellular replicating entities that invade living cells to carry out their replication.
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20.2 True or False: Scientists believe that Viruses are alive.
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False. Viruses cannot carry out replication by themselves, so therefore, they are not seen as living things.
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20.2 What are two structures common to almost all viruses?
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genetic material and a protein coat, called a capsid, surrounding this material.
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20.2 HIV has what structures that are similar to other viruses?
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genetic material, capsid (protein coat), envelope (fatty membrane. surrounds the capsid.)
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20.2 What are the four steps in a viruses life cycle?
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1. Insert genetic material into a “host” cell.
2. Turn out viral component parts. 3. Make virus clones or “particles” from them. 4. Move the new particles out of the cell. The particle then infect other cells |
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20.2 True or False: New viruses harmful to human beings periodically come along by means of viruses that infect other animals mutating and then “jumping” to human hosts
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True
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20.2 True or False: All forms of life are vulnerable to viral infections.
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True
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20.3 What are prokaryotes?
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Organisms whose genetic material is not contained within a nucleus. AKA: No nucleus.
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20.3 What are Bacteria?
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Microscopic. Single-celled organisms. Prokaryotes. Only have a single organelle (ribosome). Reproduce asexually (binary fission).
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20.3 What is binary fission?
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Asexual reproduction through a simple cell-splitting.
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20.3 True or False: Bacteria are metabolically far less diverse than plants or animals.
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False. They are more diverse.
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20.4 What is mutualism?
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A relationship between two organisms that benefits both of them.
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20.4 What is an example of mutualism?
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The digestive tract in humans. Bacteria get food and habitat from this relationship; human beings get an efficiently functioning digestive system.
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20.5 Define pathogenic
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Bacteria that are disease-causing.
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20.5 How do bacteria generally do their damage?
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By releasing or leaving behind harmful substances called toxins.
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20.5 What is the primary human defense against pathogenic bacteria?
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Antibiotics.
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20.5 What are Antibiotics?
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Substances produced by one microorganism that are toxic to another.
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20.5 What and when was the first antibiotic made?
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Penicillin, was developed in the 1940s.
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20.5 How are antibiotics being threatened?
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The emergence of antibiotic-resistant strains of bacteria. These bacteria are evolving in greater numbers because of an overuse of antibiotics in medicine and agriculture.
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20.5 How do Antibiotics work?
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By exploiting the differences between bacterial and human cells, such that they kill bacteria while leaving human cells relatively unharmed.
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20.6 Archaea
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Single-celled, microscopic, and are prokaryotes. Among the earliest evolving organisms on Earth. Found in large numbers both in extreme environments, such as hot springs, and in the world’s oceans.
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20.6 True or false: The extreme environments that so many archaea live in have prompted biotechnology firms to “prospect” for novel archaeans in their home environments, with the intent of developing commercial products from the enzymes these “extremophiles” produce.
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True.
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