Download David Milstid Section 0026 Study Guide for Exam 3 Linneaus had

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David Milstid
Section 0026
Study Guide for Exam 3
Linneaus had the idea of a Hierarchical system of taxonomy – system of increasing
inclusiveness (Kingdom, phylum, class, order, family, genus species); Cuvier discovered that
different forms of the same species are located in different layers of rock in the Earth’s crust,
the fossils are different ages and one species would disappear and another of similar form
would appear, there would be no gradual change; Hutton believed in Gradualism – geologic
processes occur gradually with the exception of major catastrophes; Lyell believed in
uniformatism – processes occur at the same rate since the beginning of the earth; Lamark
believed in inheritance of acquired characteristics – organisms change in response to the
environment
observations – organisms from similar climates had fewer similarities than organisms
geographically close to each other but from different climates - birds from temperate south
America were less similar than birds in England and birds from temperate south America were
more similar to birds in tropical south America
natural selection – darwin’s idea of the mechanism of evolution – frequency of characteristics
in a population changes due to selective pressures from the environment; artificial selection –
used historically for our domesticated animals - dog breeds – good example - human desired
characteristics and in natural selection, they are environmentally favored characteristics;
survival of the fittest – only the strong will survive
evidences of evolution
- biogeography – the study of the geographic distribution of living organisms
o organisms geographically closer are more similar (more closely related) than
organisms far apart
o plate tectonics – land masses shift around the earth due to movement of large plates
in the earth’s crust
 pangea - original land mass
o biogeography is not only the distribution today but historic land mass also reflect
biogeography
- fossil record – fossils formed when bodies of organisms become trapped in layers of
sediment and are either preserved or an imprint has been preserved
o layers of the earth contain different types of organisms
- comparative anatomy
o similar structures between different organisms
o homologous structures – very similar but not exactly the same
o vestigial structures – not currently used but still found
- comparative embryology – embryos of fishes, birds, and mammals all look alike
o ontogeny recapitulates phylogeny – ontogeny is embryonic development,
recapitulates means sums up, phylogeny means evolution
o mollusks (clams, snails, and octopods) annelids (earth worms and leeches)
 both of larval form that is exactly alike
- molecular biology – comparison of the DNA
o see what percentage of DNA is either alike or unlike each other
o sequence of DNA in humans and chimpanzees, 3% difference between the two
Gene pool – all the genes and the alleles of those genes in a population
If there is no evolution, you have a very large population with no immigration, no emigration,
random or non selective mating, and no environmental selective pressures
David Milstid
Section 0026
Study Guide for Exam 3
If there is no selection going on in a population, then the frequencies of alleles do not change
over time
Hardy-Weinburg principle – In a large, stable population with no immigration or emigration
and no selective pressures, the ratios of alleles will stay stable over time
6. Genetic drift – there is a change to the frequency of alleles in a population due to change in
population numbers, selective pressures, immigration or emigration, or non-random mating
Founder effect – a very small portion of a population becomes reproductively isolated Amish –
small population
7. Darwinian evolution (gradualism) – evolution occurs at a slow rate over thousands of millions
of years as a gradual process
Punctuated equilibrium – Steven J. Gould – evolution occurs in sudden bursts due to rapidly
changing environmental conditions
8. Biological species concept – the smallest distinct group of organisms which are actually or
potentially interbreeding – produce viable, fertile offspring
9. Two main types of reproductive isolation
- pre-zygotic barriers – barriers to reproduction before mating occurs
o temporal isolation – mating occurs at either different seasons or different times of
day
o mechanical isolation – parts don’t fit
o behavioral isolation – fireflies – patterns of light
- post-zygotic barriers – barriers to reproduction after mating occurs
o meiotic isolation – sperm cannot fertilize the egg
o spontaneous abortion – sperm fertilizes the egg but will not develop
o hybrid infertility – mule
o hybrid recessiveness – the hybrid is fertile, but will not be able to find proper mates
– dog/wolf
Speciation – change from one species to another or several species by the process of
evolution/natural sel.
1. allopatric speciation – formed by actual, physical separation (canyons and glaciers)
a. the two groups face different selected pressures
b. natural selection results in change in body form, food habits, behaviors; could
result in reproductive isolation even if the two groups are put back togeth
2. sympatric speciation – two species form from the same species while still physically in
the same area
a. plants often speciate by forming polyploids
i. diploid – 2N – chromosomes in pairs – meiosis
ii. gamets – haploid – N – chromosomes not in pairs
iii. non-disjunction – failure of homologous pairs to separate during meiosis
1; failure of sister chromatids to separate during meiosis 2; diploid
gametes fertilize diploid gamete
iv. tetraploids – chromosomes are still in pairs – reproduce sexually
3. parapatric speciation – two species that are marginally, reproductively isolated
there is a overlap of habitat that some of one species and some of another species are adapted
for; in that area, the species hybridize, forming a 3rd species
10. Adaptive radiation – ex. Darwin’s Finches
David Milstid
Section 0026
Study Guide for Exam 3
- Galapagos islands – found several species of finches that were similar to a species found on
the mainland
- Niche – complete description of habitat and habitat utilization by the organism
- Competitive exclusion principle – no two species can occupy exactly the same niche
because of intense competition
- In mature systems, most niches will be occupied but in new, developing systems
(ecosystem), many habitats are empty
- Galapagos islands compared to the south American mainland is very young
- Ancestral finch from the mainland was blown to the Galapagos islands
- Many available niches for the finches to stay in
- The species radiated out to fill all available niches
11. Kingdom
Phylum
Class
Order
Family
Genus
Species
12. binomial nomenclature – assigning two names to a specific organism
- micropertous salmoides – scientific name for large mouth bass
- the first name is the genus name and the second one is the species name, genus is set,
species is made up
- the names are always Latinized because it is a dead language, does not change
- the genus portion is always uppercase and the species portion is always lower case
- the entire name is always underlined or in italicized
- ameba spp.
13. Taxonomy - categorizes living organisms based on evolutionary relatedness
Phenetics – classify by similarities
Cladistics – classifies based on differences
- tries to identify ancestral vs. derived (more modern) characteristics
Evolutionary systematics – use a combination approach, look at both similarities and
differences
- use parts of both phenitics and cladistics
evolutionary taxonomy – modern forms evolve from ancestral forms, idea is to attempt to find a
common ancestor for a modern group
14. Kingdom Eubacteria (monera)
- prokaryotes (pro meaning before, karyote meaning nucleus, so they have no true nucleus)
- chromosome are found in a nucleoid region, not bound by membranes
- they have no membrane bound organelles
- but they do have ribosomes
generally smaller than eukaryotic cells
protists – eukaryotic cells – generally single celled organisms - colonial but not true
multicellular
- colonial – a group of the same species living together and being dependant on each other
- not specialization of cells into different functions
David Milstid
Section 0026
Study Guide for Exam 3
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15. many are heterotrophs (take in organic material to create energy)
many are also autotrophs (fewer) – cyanobacteria – photosynthetic dinoflagellets – chlorophyll A
– there are no chloroplasts
the cyanobacteria produces enormous amounts of oxygen
they are generally found in the open ocean and are the base of many food chains
16. bacterial taxonomy – ways to tell what bacterium you have
- shape of bacteria
o spirillum - spiral
o coccus - sphere
o bacillus – rod shaped
bacterial cell wall – the wall is made of something known as peptidoglycan (protein
carbohydrate combo)
- identify different bacteria according to the thickness of the cell wall
- gram staining will die the peptidoglycan in the cell wall and if the cell wall is thick, it will
stain very dark and we call that a positive (gram positive) and if the cell wall is thin, it has a
very light stain and it is called gram negative
differential media – exams the growth pattern and rates on nutrient agar containing different
chemicals – this is usually done in Petri dishes or test tubes
17. Nitrifying Bacteria
nitrogen is an essential and limiting nutrient for plants
atmospheric nitrogen which is the primary nitrogen source, is not biologically available to plants
(N2 molecular nitrogen)
rhizobium – bacteria which can “fix” nitrogen (fix means to make biologically available, plants
can use
plants who have developed symiotic relationships with rizobyium
o mutualistic – symbiotic relationship where both organisms benefit
o root nodule – houses for rhizobium bacteria (legumes – peas, beans, soybeans)
18. asexual
binary fission
o simple due to only having one major chromosome (circular in shape)
o chromosome attaches to the cell membrane
o chromosome replicates
o cell elongates between the chromosomes
o cytokinesis (division of the cell with one chromosome in each cell)
sexual reproduction
o exchange of plasmids (non-chromosomal DNA) which contains some important genes
o cells form a mating bridge or pilus between the cells
o then the cell with the plasmid copies it and donates a copy to the other cell
o bacteria can also use this method to transfer antibiotic resistance to another cell – genes of
antibiotic resistance is found on the plasmids, they donate it to other bacteria of the same
species and can quickly transform colonies to antibiotic resistant ones
19. inside there is a nucleoid region with ribosomes that are surrounded by cytoplasm, that is
surrounded by a cytoplasmic membrane and a cell wall and a capsule, there are pili and maybe
a flagella to help move it around
David Milstid
Section 0026
Study Guide for Exam 3
20. sarcodinids (amoebas) – move with a pseudopod; euglenophyta (euglena) move with flagella;
zooflagellates move with flagella; sporozoans (all parasites) do not move; ciliates move with
cilia
21. fungi are made of filamentous tubes called hyphae; walls are septa can divide the hyphae into
cells containing one or two nuclei
22. they digest food outside of their body, fungi don’t need a place to grow, fungi reproduce by
making spores which are smaller fragments of the parent cell,
23. mycelium or yeast
24. the reproductive portion
25. and 26. Ascomycota
Yeast – unicellular fungi
Asexual spore production – uia. Conidia = haploid spore producing structures
Two mating strain
- one produces an antheridium – gives up a nuclei (haploid)
- other produces an ascogonium – receives nuclei, nuclei don’t immediately fuse to form a
diploid
- dikaryotic cell – cell with 2 haploid nuclei
- dikaryotic hyphae grow by mitosis
- mass of hyphae forms the reproductive structure
- sac or cup fungi
- cells that actually go through meiosis, line in the interior portion of the cup, the cells are
called asci
- asci are dikaryotic with two haploid nuclei, form diploid cell, forms four haploid nuclei,
forms eight haploid nuclei – the eight haploid nuclei become surrounded by membranes
which are environmentally resistant – you get eight ascopores
- ascospores (if in good, moist soil) will germinate and begin growing and form haploid
hyphae
basidiomycota
- mushrooms, puffballs, shelf fungi, (plant diseases) called rusts and smuts
- common field mushroom (agaricus) – kind you eat
- angel of death (amanita)
- cap, stipe, gills (produce spores by meiosis (basidiospores))
- haploid hyphae – mucelial mass, under substrate
- fairy ring – ring of mushrooms at the outer edge of mycelium
- two mating strains will meet and fuse the cells but not the nuclei, forms dikaryotic cells
which will grow by mitosis and form dikaryotic hyphae and then forms reproductive
structure
- cells will line the gills and go through meiosis (basidia)
- dikaryotic cell forms diploid cells which forms 4 haploid nuclei and forms the basdiospores
- the cap will not open and reveal the gills until sexual reproduction is finisheda and the
spores are ready to be released
deuteromycota
- no known form of sexual reproduction
David Milstid
Section 0026
Study Guide for Exam 3
aspergillus (fungus which produces sever respiratory infections) – high moisture, high nutrient
environment to grow – found often in the poultry production industry
27. lichen – symbiotic relationship between ascomycete and algae
mild form of parasitism - not mutualistic
fewer algae is eaten than grown
crusose – crusty – found on rocks
foliose – leafy – found on trees
fruticose – spongy, shrubby – found on ground or on other vegetation
pioneering organism – can grow on bare rock, which is important for soil formation – the
fungus produces an enzyme to break down the rock, and provides an anchor hold for it
base of the food chain in artic regions for animals such as reindeer or caribou
lichens are an indicator of air pollution - they require clean air