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82 Cards in this Set
- Front
- Back
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***What is cell division?***
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The continuity of life is based on teh reproductions of cells. Cells come from other cells. Cell division is involved in: Reproductions, Growth, and Development
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What are the three types of cell division?
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Binary Fission (prokayotic), Mitosis and Meiosis (eukaryotic)
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***What is a very simple definintion of Mitosis?***
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Changes in the nucleus.
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***What is cytokinesis?***
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division of the cytoplasm
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***What is the result of binary fission?***
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produces genetically (same DNA) idnetical daughter cells.
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***What is the result of Mitosis?***
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produces genetically identical daugher cells.
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***What is the result of meiosis?***
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produces nonidentical daughter cells
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***What is a chromosome?***
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A long DNA molecule
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How is the DNA found in Eukaryotic and Prokaryotic cells?
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Prokaryotic: Most DNA is in one long, double stranded moelcule
Eukaryotic: Usually several long, double stranded DNA molecules (in the nucleus) |
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***What is ploidy?***
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sets of chromosomes
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***Haploid***
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One set of chromosome
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***Diploid***
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Two Sets of chromosomes (2 ploid)
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What is "n" used for?
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It is used to fill-in for the number of chromosomes in a single set, so n=3, a 2n(diploid) would have 6 chromosomes.
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How is ploidy affected between Mitosis and Meiosis?
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Mitois: maintains ploidy
Meiosis: reduces ploidy (in half) |
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***mutation***
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errors in copying DNA
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***sexual reproduction***
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alternation of meisois and fertilization
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***What are the haploid cells in humans?***
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sperm or eggs
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Describe the cells in three steps of meiosis. (See figure 13.7)
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1. Diploid cell with replcated chromosomes
2. Becomes Haploid cells with replicated chromosomes (2cells) 3. Becomes haploid cells with unreplicated chromosomes (4 cells) |
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***crossing over***
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chromosomes that match cme together and trade traits, which creates new combinations of DNA molecules on the chromosmes.
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What is the Linnaean System?
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Placing organisms into categories which are: Domain, Kingdom, Phylum, Class, Order, Family, Genus and Species
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When naming the genus and species of an organism what is the correct way to write it?
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Genus always capitalized, speicies not and either underlilned or italisized
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What was Jean-Baptiste de Lamarck's partially flawed hypothesis?
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He believed in change over time but was incorrect because he believed the mechanism of evolution by inheritance was aqured traits, like traits you aqure by nature will be passed on to offspring.
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What is artificial selection?
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choosing mates to get a specific offspring, ex. dog breeding.
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In the logic of natural selection what are three ovservations on population growth and resources?
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1. Potential Rapid Population Growth- populations have the potential to grow rapidly, ex. one prokaryote undergoes binary fission, and produces two, and then 4 etc...
2. Most populations are fairly stable- dont over populate 3. Resources are limited-controls population. |
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What are 2 observations on heritable variation?
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populations are variable, most of the variety is inherited by your parents. An example is that fitness to the environment is variable. Greater fitness leads to a higher number of offspring. This will change the composition of the population if the organisms with the fitest traits are surviving.
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***evolution***
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change in gene frequencies
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What is the difference in Natural selction and evolution
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Natural selection acts on individuals which leads to evolution which occurs in populations
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***Homology***
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organisms have traits in a particulat arangement because of their ansestors and may be similar to others of teh same ansestor. Ex. Humans, cats, whales, bats all have same arrangement of bones in their hands, paws, flippers and wings.
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Biogeography can produce what seems like homologous characteristics but are really what?
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They dont share common ansestors but live in a similar environment which over time they have developed similar characteristics.
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What are transition fossils?
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proof of animals with intermediate characteristics, ex: whales are mammals and fossils have been found with whales with intermediate stages of characteristics of a water vs land animal (like hip bones)
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What is a scientific theory?
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a conceptual framework in which hypotheses spring from.
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What does it mean to say evolution is not goal oriented?
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~populations dont strive for new evolutionary traits but develop them when environments allow them to be.
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What is a "species concept"?
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The way in which a speices can be classified, there is no one species concept because not all 1.8 million speices can be classified in the same way.
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***Biological Species Concept***
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a species is a group of actually or potentially interbreeding organisms. This emphasizzes reproductive isolation (Cant interbreed=reproductively isolated). This species concept does not include prokaryotes or organisms that reproduce asexually.
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***Morphological Species Concept**
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categorize species by how they look
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***Paleontological Species Concept***
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categorize with the use of fossils
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***Ecological Species Concept***
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categorize by evaluating habits.
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***Phylogenetic Species Concept***
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categorizing by attempting to establish traits to relate species
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What are the two main types of reproductive isolation?
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Prezygotic and Postzygotic
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What are the different types of Prezygotic reproductive isolation?
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1. Habitat- ex. one snake lives in water, another on dry land
2. Temporal- temporary (different) breeding seasons. 3. Behavioral Isolation- different ways of selecting parners. Such as looks. Ex. butterflies 4. Mechanical- genitalia of a species doesnt fit with another species 5. Gametic- fushion of gametes is blocked, ex. sperm and egg will not fuse |
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What are the different types of Postzygotic reproductive isolation?
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1. Reduced Hybrid viability- zygotes may form but will not live very well or long
2. Reduced Hybrid fertility- zygoes make it to adulthood but cannot reproduce ex. mule=horse + donkey 3. Hydrid Breakdown- a couple of generations pass before problems are seen |
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***What is allopatric speciation?***
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forming new species from one because of differed locations. ex. geographically split one species and become two
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***What is sympatric Speciation?***
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One species diverge into two while staying in the same location
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***What is adaptive radiation?***
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new species emerging from a common ancestor because of different habitats and environments
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***Phylogenies***
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present hypotheses about evolutionary history of clades.
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***clades***
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groups of evolutionary related organisms.
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***systematists***
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work on formulating and testing phylogenies
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What are two characteristics or phylogenies?
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Traits can be mapped onto them and most of them treat time implicitly (in a relative sense)
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What is a valid clade?
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A clade that includes the ancestral species and all of its descendants (monophyletic)
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What are invalid clades?
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Clades that are either missing a common ancestor or all the descendants. (paraphyletic (2) and polyphletic(1))
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How old is the oldest known fossil?
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3.5 b.y.a
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What are the oldest fossils?
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Stromatolites fossils- Fossils or formally prokaryotic cells mixed with sediment.
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What are microbial mats?
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layers of prokaryotic cells- see powerpoint for pictures
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How did oxygen increase on earth about 2.7 b.y.a?
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Photosynthetic prokaryotes increased, which increased their release of oxygen. Because of this many anaerobic prokaryotes that lacked adaptation to O2 went extinct.
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What is multi-cellularity?
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made up of multiple cells.
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What was the Cambrian Explosion?
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An era with widespread variation in organisms- diversity
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What is continental drift?
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an ongoing process where continents are moving, at one point they were all connected, this was called Pangaea- it was about 251 m.y.a
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What is mass extinction?
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periods in which large proportions of organisms die off. The Cretaceous Mass extinction was the extinction of all dinosaurs except birds.
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What are the causes of Mass extinction?
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"Extraterrestrial triggers"- such as astroids, as well as volcanic activity
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What group do prokaryotes fit into?
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They are a paraphyletic group
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What are the two domains of prokaryotes?
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Archaea and Bacteria
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What is the metabolic diversity of prokaryotes?
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All types which Chemo-means they uses molecules for energy, Photo means they use light for energy, Hetero means they use catabolism as their source of carbon, and auto means they use Co2 as their form of carbon
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What is an example of Cooperation among prokaryotes?
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Photosynthetic Cells, and Heterocytes have different metabolic functions but work together to exchange different needed substances
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What are three classifying interactions between prokaryotes?
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Mutualism- +/+
Commensalism- +/0 Parasitism, or Predation - +/- |
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What are the three main cell morpholgies?
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cocci, bacilli and spirilla
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What are two differences between archaea and bacteria?
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Bacteria have Peptidoglycan in their cell walls, Archaea dont.
Bacteria have no hyperthemophiles and archaea have some. |
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How are archaea classified?
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In the text they are classified by habitat and metabolism
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What are "exremophiles"?
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archaea that are found in unusual environments, such as in high temperatures (Thermophiles) or high salt environments (Halophiles)
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What are methanogens?
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Archaea that produce methane
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Describe Bacterial Genetics
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DNA is in the Nucleoid- unmembrane bound.
Cell division by Binary Fission Additional DNA sometimes found in Plasmids Sex (genetic exchange) w/ reproduction ex. transferring plasmids |
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What is the qualities of a cell that is Gram Positive?
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It will be purple. It has a cell wall that is peptidoglycan, which is carbohydrate chains and polypeptides.
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What are the qualities of a cell that is Gram Negative?
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It will be pink. Has one layer of poptidoglycan that is inbetween an outer and inner membrane. No cell wall.
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What are endospores?
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They are cells in a durable resting stage, that become very tough to kill
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What are the 5 Bacterial Clades?
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1. Proteobacteria (5 subgroups)
2. Chlamydia 3. Spirochetes 4. Gram-positive bacteria 5. Byanobacteria |
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What is symbiont?
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lives in a host
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What are characteristics of Proteobacteria?
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They are very diverese in metabolism and nutrition, They can be free living or symbiont.
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What are the 5 subgroups of Proteobacteria?
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Alpha, Beta, Gamma, Delta and Epsilon
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What are characteristics of Chlamydias?
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They are all parasites and they don't have peptidoglycan
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What are characteristics of Spirochetes?
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They can be free living or parasitc, they are spirilla shaped
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What are characteristics of Gram-Positive bacteria?
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Diverse, include bacteria to make antibiotics as well as cause disease
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What are characteristics of Cyanobacteria?
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Oxygen photosynthesis (like chloroplast-common ancestor), Almost all free living
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Describe Endosymbiosis
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It is the process that occurred that made eukaryotes from prokaryotes. One prokaryote began to host another, which eventually evolved into cell organelles. examples are mitochondira and chloroplasts.
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