BIOL 130: Lab Final
42 Cards in this Set
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Which is actually more ancient, the Bacteria or the Archaea?
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Bacteria: Archaea is actually more similar to Eukarya/ "younger" evolutionarily.
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What makes bacteria so important to the planet?
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- Major decomposers of organic matter
- Nitrogen-fixing bacteria increase the efficiency of plant growth
- Cyanobacteria are major producers of atmospheric oxygen
Bacteria can break down environmental toxins, create life-saving drugs, and manufacture vitamins
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Why is the diversity of bacteria so high in the soil?
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It has plenty of niches for organisms to live.
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What factors in the soil make biodiversity differ from location to location?
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- Moisture level
- pH
- Nutrients
- Soil texture
- Presence or absence of plants
- Oxygen level
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How is soil biodiversity sampled? Why has this not led to an accurate picture of what bacteria live in the soil?
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- Soil is collected and cultured in a lab by growing it in media in a petri plate
- Different types of media or growth conditions will favor the growth of some species and not others.
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Before DNA technology, how were bacteria identified?
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Through cellular and colony morphology and through gram stains.
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Even with DNA technology, what makes identification of bacteria difficult?
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The high rate of mutation of bacteria.
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How are community diversities compared?
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By the species composition and distribution of individuals.
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species richness
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Total number of species in a region.
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Simpson's Reciprocal Index of Diversity
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measures probability that two individuals randomly selected from a sample will belong to the same species
--high value= greater diversity
-- Actually takes into account both richness and abundance of a species
--D=1/(n(E)i=1 * p2i
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Keystone Species
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A species with a large effect on its ecosystem.
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Explain the Theory of Evolution by Natural Selection. How does it result in adaptations?
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- Heritable variation in phenotypes. Produce more offspring than can be supported. Some traits are better for survival.
- Over time, the population has more individuals with the favorable traits.
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How does sexual selection differ from natural selection?
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- Sexual selection is an organism's ability to obtain a mate
- While, natural selection is about an organism's survival traits.
- One trait could help an organism's mating (sexual selection), but hurt its fitness (natural selection).
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What are examples of adaptations?
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- Are inherited characteristics (traits) that help an organism survive and reproduce.
- Examples: A peacock's feathers, polar bear's white, thick fur, or a lizard's chameleon.
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Can an Adaptation Lose its Fit?
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Yes; environments are constantly changing. Therefore, what is beneficial at one time could become needless as an organism's niche evolves.
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How can an adaptation also be a trade-off?
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One trait may be great for survival, but it may be less beneficial for reproduction and vise-versa.
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How is dentition important to a mammal?
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It is what determines the type of food an organism can obtain and consume.
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What are the four types of mammal teeth?
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- Incisors: biting or cutting
- Canines: piercing or tearing
- Premolars: grinding and crushing
- Molars: grinding and crushing
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What are the four different feeding groups of animals?
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1. Carnivores
2. Herbivores
3. Insectivores
4. Omnivores
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What skull traits might be different among different groups of animals?
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- Dentition
- Jaw size
- Eye placement
- Hearing abilities
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Two limitations scientists face when studying soil biodiversity?
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1. Only 1% of bacteria can be sustained in the lab
2. We do not have the technology to study smaller bacteria
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What is the feeding strategy of fungi?
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They absorb nutrients from living and dead organisms on which they usually live (soil, leaf litter, leaf tissue, or even between human toes).
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What are the implications of this feeding strategy on a fungus's morphology?
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Their cells are long and filamentous and often form chains called hyphae.
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How are fungi different from plants?
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- They have chitin in their cell wall and not cellulose.
- No chlorophyll or other photosynthetic pigments
- Do not make their own food like plants
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How do fungi reproduce?
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Fruiting body: Produces millions of spores
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In what ways are fungi critical to life on the planet?
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- Important decomposers
- Antibiotics
- Can be used to make bread and brew beer
- Mutualistic with plants
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How do mycorrhizae help plants grow?
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Mycorrhizae live with plant roots and in exchange for protection and sugars help the plant absorb water and nutrients.
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What is a secondary compound?
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Are a diverse array of chemicals that plants have evolved to help their defense.
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In what ways are fungi detrimental to organisms on the planet?
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They cause diseases on both living crop plants or forest species, harvested grains, and humans.
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Why are fungal infections difficult to treat?
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-because fungal cells are eukaryotic like human cells and medications targeting fungal cells can damage our own cells
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How do plants defend themselves from attack by other organisms?
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"Stand and Deliver" defense: By using secondary compounds, they can kill bacteria, inhibit fungal growth, and make their tissue taste noxious to insects.
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Why don't plant defenses against organisms always work?
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- Altering the environment changes the utility of adaptations.
- New fungi can show up that they don't have defenses for
- Monocultures make the dispersal of fungi extremely fast and intense
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What is capsaicin?
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Capsaicin is a great product of evolution, allowing peppers to appear hotter and therefore, be less of a victim to fungi or other predators.
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What is behavior, and what types of organisms exhibit behavior?
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Behavior is any action that is a response to stimuli; all organisms exhibit behavior.
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How is innate behavior different from learned behavior?
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- Innate behavior is genetically-based, inherited, and often involuntary.
- Learned behavior is a change in behavior due to a specific experience in the organism's life.
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How are ultimate causes of behavior different from proximate causes?
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- Ultimate causes are the factors that have caused the behavior to evolve over time.
- Proximate causes are the immediate environmental stimuli causing the reaction.
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What are five questions that may drive behavior?
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1. What should I eat
2. Who should I mate with
3. Where should I live
4. How should I communicate
5. When should I cooperate
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What type of animal is a flour beetle?
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Group of Arthropods known as insects.
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How long is the life cycle of a flour beetle?
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5 weeks
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What environmental factors may affect the behavior of flour beetles?
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- Temperature
- Food source
- Stress
- Genetics
- Life history
- Density
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What are some examples of behavior that flour beetles demonstrate?
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- "play dead"
- Canabilistic behaviors
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What are some examples of behavior that flour beetles demonstrate?
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- "play dead"
- Canabilistic behaviors
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