BIOLOGY 111 FINAL

What are the other forms of evidence that provide the strong support the theory of evolution? Explain the evidence, don't just list them. (note there are a number of them -- not a short answer!)

- The Medium Ground Finch case is evidence of evolution due to natural selection leading to a certain beak size being the one that takes over a population. - Artificial Selection is also evidence of evolution in how certain traits are selected for by breeding parents w/ desired traits over multiple generations (genetic variation). - Fossil records show us changes in species composition, how they adapted to environmental changes, and at what point in time it all occurred. - Homologies are aspects of an organism that are derived from a common ancestor. This occurs anatomically, w/ vestigial structures (structures w/o a function), and developmentally (presences of gills in vertebrates). - Biogeography (similarities based on geographical location) - Convergent Evolution (similarities between species that are NOT closely related) which occurs when organisms have adaptations to similar ecological conditions.

Explain the genetic structure of a population. How does gene pool, allele frequency and genotype frequency inter-relate?

-Gene pool:the stock of different genes in an interbreeding population -Allele freq.: relative frequency of an allele at a particular locus in a population, expressed as a fraction or percentage -Genotype freq.: the number of individuals with a given genotype divided by the total number of individuals in the population These all inter-relate because the allele freq. creates certain genes that are expressed that is calculated into the genotype frequency. Both of these frequencies then make up the gene pool found in any given population.

What are the main causes of microevolution? a. Explain genetic drift. Why is it more likely in a small population? b. How does gene flow lead (or potentially lead) to microevolutionary change? c. What are mutations? When are they likely to result in microevolutionary change? d. What is non-random mating?

-Natural selection -Mutation -Genetic drift -Bottleneck, founder effect -Gene flow -Nonrandom mating A. Genetic drift is the change in allele freq. due to chance events alone. It's more likely in small populations because in large populations, chance fluctuations are masked & in a small population the fluctuations can eliminate an allele from the population B. Gene flow leads to microevolutionary change by the movement of genes to varying locations, immigrants increasing frequency of an existing/new allele, and emigrants taking away alleles from the population. C.Mutations are direct changes in DNA sequence. They are likely to result in microevolutionary change when they interact w/ another microevolutionary force (natural selection) or reproductive rates are high. D. Non-random mating occurs when the probability that two individuals in a population will mate is not the same for all possible pairs of individuals.

What are the five conditions for Hardy-Weinberg Equilibrium? Why must those conditions be met in order to say that the population is NOT evolving?

-no natural selection -no mutations -very large population size - isolation from other populations (no gene flow) - random mating

Explain "the unity and diversity of life." What is the underlying reason for the suite unifying characters? Hod did/does diversity arise?

1. Diversity and Unity are the dual faces of life on Earth. Unity arises because genes of organisms are inherited in discrete units. Characteristics are then passed from generation to generation due to common ancestors having said characteristics. (Diversity below) 2. Evolution 3. Diversity arises through descent with modification or vertical evolution with mutation (evolutionary changes).

What are the four core themes that unite biology? Explain.

4 Themes: 1. New properties (emergent properties, structure/function, the cell) emerge at successive levels of biological organization 2. Life's processes involved the expression and transmission of genetic information (DNA) 3. Life requires the transfer and transformation of energy and matter 4. From molecules to ecosystems, interactions are important in biological systems (molecules: interactions w/in organisms & ecosystems: organism's interactions with other organisms and the physical environment)

Define allele, loci, diploid, & haploid

Allele: one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome Loci: the position of a gene or mutation on a chromosome Diploid: containing two complete sets of chromosomes, one from each parent Haploid: having a single set of unpaired chromosomes

Define & give example of an analogous character & a homologous character

Analogous: similar due to similar selective pressures; not closely related & have different underlying structures (Ex.) wings of bat & fin of penguin Homologous: share common ancestry & have same DNA/morphology; differences due to different selective pressures (Ex.) arms of human, bat, horse, & porpoise

What role to ancient bryophytes and ancient seedless vascular plants play in the changing atmospheric conditions?

Ancient bryophytes: - contributed organic substances to early soils enriching them -utilized CO2 removing it from atmosphere-- reducing the earth's temperature & precipitation Ancient seedless v. plants: - today's coal derives from remains of these ancient plants -caused dramatic change in CO2 levels which resulted in ( CO2 trapped in plant tissues, burial of this tissue removes it from atmosphere, cooler, drier conditions resulted)

Explain balance polymorphism. Why is it that deleterious alleles sometimes remain in a population?

Balanced polymorphism is a situation in which two different versions of a gene are maintained in a population of organisms because individuals carrying both versions are better able to survive than those who have two copies of either version alone. Deleterious genes are generally recessive alleles, yet the traits persist in populations despite natural selection. They remain because of linkage to beneficial alleles.

What are the unifying characteristics of life?

Cells Organization Homeostasis Energy Reproduction Adapt & Evolve

Compare and contrast meiosis and mitosis (Fig. 13.10)

Compare: forms of cellular reproduction, involve chromosomes from both parents Contrast: Mitosis- daughter cells identical, asexual, diploid and ends with diploid, 2 daughter cells, # of chromosomes stay the same, produces most cells in body Meiosis- don't make identical copies, sexual reproduction, diploid ends with haploid, 4 daughter cells, # chromosomes splits in half, produces gametes, daughter cells unique

There are three "modes" of natural selection that are used to describe the impact of natural selection on a population: directional, disruptive and stabilizing selection. Explain what happens to the distribution of alleles (variation) w/in a population in response to these types of selection. Make sure you can explain why, and not just say that the peak moves one direction or another. You need to be able to distinguish between the three types. For example: In a species of fly the female bores a hole into the stalk of a plant and lays her eggs. In response to the egg laying, the plants will form a "gall" which is a swelling that basically seals off the "infection" to prevent further damage to the plant. If left alone, the fly larvae will develop and emerge from the gall. The size of the gall is dependent on the degree of infection (how many eggs are laid) and it is a heritable trait in these flies (a female will lay x# of eggs -- a characteristic she has inherited from her parents). So, some flies cause the formation of small galls, some intermediate, and some large. Small galls tend to be thinned walled and can be easily parasitized by wasps. The wasps eat the fly larvae. The largest galls are a tempting target for woodpeckers, which break open the galls and eat the fly larvae. What would you predict would happen to the distribution of gall size formation in the flies in response to the predation pressures described above? (Remember the size of the gall is in response to what the flies are doing). What type of selection would likely result?

Directional Selection: Variation w/in a population responds to this selection by causing one extreme to be selected AGAINST (lower fitness) &/or one being selected FOR (higher fitness). Stabilizing Selection: This occurs when the population mean stabilizes on a particular non-extreme trait value. Variation w/in a population responds by the extremes being selected AGAINST and the intermediate being more successful. Disruptive Selection: Variation w/in a population responds by selecting FOR extremes & AGAINST intermediate values.

What is epistasis?

Epistasis: the phenotypic expression of a gene at one locus alters that of a gene at a second locus

What are the two major processes that influence the water cycle? What are the major reservoirs for water?

Evaporation & Precipitation. The reserves are oceans, glaciers & polar ice caps, & lakes & rivers.

Explain Darwin's Theory of Evolution by means of Natural Selection. Be sure you can explain not only what evolution is, but HOW it occurs and at what level. Using the example of evolution of beak size in the Medium Ground Finch, explain how natural selection act as a mechanism of evolutionary change (Be specific). Explain the relationship between variation and environmental conditions.

Evolution is "descent w/ modification" according to Darwin's theory. Structures are modified w/in a population by adapting to environmental change w/in or between environments. Populations evolve NOT individuals. In regards to the Medium Ground Finch, natural selection causes evolutionary change by how a specific beak size allowed finches to thrive in their environment. Due to those that survive having similar beak types, offspring gain the ideal beak size, and this transition continues until a population has evolved. Environmental conditions determine what's adaptive for populations. This relates to variation in how variation must exist w/in a population for natural selection to be occurring. So, variation is a result of environmental conditions.

Define fitness in an evolutionary sense. What does it mean when an organism is "selected against" or "selected for?"

Fitness: number of offspring an individual produces that survive to a reproductive age Traits that cause greater reproductive success of an organism are said to be selected for, while those that reduce success are selected against.

What is the selective advantage of flowers?

Flowers have their pollen transferred more directly due to animals transferring it from one sex organ to another which therefore increases the diversity compared to gymnosperms (wind-pollinated plants) Angiosperms attract pollinators w/ a pay-off of nectar & their pretty colors

Gene linkage? Which Mendelian laws of genetic does it violate?

Genetic linkage is the tendency of DNA sequences that are close together on a chromosome to be inherited together during the meiosis phase of sexual reproduction This violates law of independent assortment.

How is incomplete dominance DIFFERENT than co-dominance?

Inc. Dominance: one allele doesn't completely mask the expression of another allele. Heterozygotes will have an intermediate form between the 2 parents. For example, if red flower color is inc. dominant to white flower color. If you cross a red flower with a white flower, all offspring would be heterozygous and express pink. The red doesn't completely mask the white. Co-Dominance: Both alleles are expressed when both are found in heterozygotes. For example, if red flower color is co-dominant to white flower color. If you cross a red and a white flower, all offspring will be heterozygous and express BOTH red AND white flower -both parental phenotypes are expressed.

Understand Jean Baptiste Lamark's theory of evolution by means of acquired characteristics. Using this theory, explain how traits were thought to evolve and persist in a population? Why does Lamark not get any credit for the theory of evolution, after all he was the first person to propose a model of evolution?

Lamark's theory was that an organism can pass on characteristics that it has acquired through use or disuse during its lifetime to its offspring. He doesn't get credit because his theory was very wrong.

Explain law of independent assortment Why does this law predict a 9:3:3:1 ratio instead of a 3:1 ratio when crossing parents who are different on two characters (dihybrid)

Law of independent assortment: stating that when two or more characteristics are inherited, individual hereditary factors assort independently during gamete production, giving different traits an equal opportunity of occurring together The ratio changes because the variability increases. There are two characteristics being crossed instead of one now.

Explain law of segregation According to this law, if you did a monohybrid cross (cross heterozygotes), what is the predicted phenotypic ratio of the offspring for one character?

Law of segregation: states that allele pairs separate or segregate during gamete formation, and randomly unite at fertilization The predicted phenotypic ratio of offspring for one character is 3:1

Variation in a particular character within a population of sexually reproducing organisms is the result of both mutations and sexual reproduction. Explain how the two phenomena influence the frequency of the alleles in the population differently

Mutations: They influence allele frequencies by permanently and randomly changing nucleotide sequences. This causes variation because the changes are random and numerous and result in varying genotypes/phenotypes. Sexual Reproduction: Two organisms come together with two different genotypes and combine them into one. The zygote will have a combination of these genotypes that have also undergone mutations. It's different from mutations in how it has a choice in the matter.

Independent Assortment

One of Mendel's principles that state​s that genes for different traits can segregate independently during the formation of gametes; increases variation because it results in gametes that have unique combinations of chromosomes

Explain how epistasis differs from polygenic inheritance

Polygenic inheritance occurs when one characteristic is controlled by two or more genes. Multiple genes go into the creation of characteristics. In epistasis, one gene controls phenotypic outcome of another.

When does crossing over occur?

Prophase 1

sister chromatids

Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II

You should be able to recognize a sporophyte or a gametophyte generation of a fern. Where are the spores found (typically) on a fern? How are spores dispersed? How are gametes dispersed?

Spores are typically found in sporangiums on the underside of the fronds & are dispersed via air. Gametes are dispersed via water & are housed in the archegonium (female) and antheridium (male).

What types of questions can be addressed by science? Understand how a hypothesis is formed and how it relates to theory

Testable questions ask about objects, organisms, and events in the natural world. A hypothesis is a provable statement derived from a theory

The strength of selection influences the rate of evolutionary change. Be comfortable with how the Hardy-Weinberg formula can be modified to predict genotype frequencies in the next generation in the face of differential selection.

The H-W formula can be modified to predict genotype frequencies in the next generation in the face of differential selection by assigning values to the selection (degree of selection). The strength of the selection influences the prediction. Strong selection against (few/no offspring) = very low frequency. Weak selection (reduced # of offspring) = decrease frequency.

Why can you be certain a Calico cat is female? Explain what the source of the black and orange patches of fur coloration is in calico cats

The calico coat is a sex-linked trait given only when a cat has an X black fur gene and an X orange fur gene. One must have both to be calico. X inactivation involved: the gene that dictates fur color happens to be located on the X chromosome. ... If the X chromosome carrying the gene for orange fur is inactivated, that cell will create black fur. Because the Xs that are inactivated are chosen at random, the pattern on each calico cat is distinct from another

What is a theory? a hypothesis?

Theory: A tentative explanation that tries to integrate and account for the relationship of various findings and observations. Hypothesis: A tentative statement about the relationship between two or more variables; a testable prediction or question

Why are bryophytes restricted to moist habitats and short in stature?

They're restricted to moist habitats bc they reproduce through water & they're short in stature bc they lack vascular tissue (no vascular tissue=less support for it to grow tall)

If given a scenario describing an evolving population over generations, you should be able to pick out what the main driving force behind the change is (in other words, you need to be able to apply the main causes of microevolutions to "real life" situations). (Not a short answer). For example, what type of microevolutionary force is occurring, when there is a population where the largest individuals are not able to eat enough food to sustain themselves and as a result, they do not have the energy necessary to find a mate and reproduce, while the smaller individuals in the population are more successful (in terms of getting enough food and reproducing) and leave more offspring, resulting in fewer of the larger individuals in the next generation?

Understand causes of microevolution (most explained on other flashcard) -Natural selection: the process whereby organisms better adapted to their environment tend to survive and produce more offspring -Mutation -Genetic drift --Bottleneck effect: drastic reduction in population size that results in change in allele freq, lose of genetic diversity, and a smaller, less diverse population. --Founder effect: subpopulation breaks off & colonizes a new area; small # of individuals isolated fro parent population. Results in low genetic variations and increase in chance of fixation of alleles. -Gene flow -Nonrandom mating

Evolution by means of natural selection is dependent on variation in the population. Without variation, evolution by natural selection cannot happen. Why is variation necessary? What are the major sources of variation?

Variation is necessary because w/o natural selection wouldn't occur, organisms from the beginning of time would have never evolved into people today, genes would stay the same, and life wouldn't thrive as it does today. The major sources of variation are mutations (changes in DNA sequences) and gene recombination (gene exchanges/swaps due to meiosis).

Explain evolutionary change. What does that mean? What has driven evolutionary change?

a gradual change in the characteristics of a population of animals or plants over successive generations: accounts for the origin of existing species from ancestors unlike them Natural Selection, Genetic Drift, Mutations and Gene Flow drive evolutionary change.

When do homologous pairs split?

anaphase 1

Explain the relationship between chromosomes, DNA, genes, and alleles

chromosomes are long strands of DNA, which then code for genes on chromosomes, which produce an allele A chromosome contains 100's - 1000s of genes found on one long DNA molecule

Understand Hardy-Weinberg equation: p+q =1. What is meant by genetic equilibrium?

p+q=1 is the equation for allele frequencies, assuming two alles ( 1 dom./1 rec.). P is the frequency of the dominant allele (Q: the opposite). Genetic equilibrium describes the condition of an allele or genotype in a gene pool (such as a population) where the frequency does not change from generation to generation.

Crossing Over

produces recombinant chromosomes by combining two chromosomes from different parents; creates variation by combining DNA from two parents into single chromosome & crossing over occurs 1-3 times per chromosome

Ferns, horsetails, whisk ferns, club mosses and lycopods are all seedless vascular plants. You should be comfortable with ferns as a representative. Explain what feature(s) separate seedless vascular plants from mosses, and other vascular plants.

- Roots, leaves, & stems present -vascular tissue present -In ferns, the sporophyte is the dominant stage of the life cycle, while in mosses, the gametophyte is the dominant stage of the life cycle. -Xylem & Pholem - Has a waxy cuticle to protect plant from pathogen attack -Has a stomata

Fungi are quite diverse! What are some general characteristics of fungi?

- eukaryotic - mostly unicellular -NOT photosynthetic - yeast unicellular -cell walls contain chitin (chitin is found in exoskeleton of some arthropods) -more closely related to animals than plants - secrete digestive enzymes into their enzymes -- external digestion -network of hyphae: filament structure of fungus-- high surface area; assists fungi in feeding - morphologically adapted for this type of feeding: break down of cellulose in trees, digest lignin, obtain nutrients from dead organisms

What are the general characteristics of prokaryotes?

- unicellular - variety of shapes - many may form aggregates (a whole formed by many) & create 'functional units' - cell wall & capsule/biofilm (additional sticky layer for protection) - endospores - nucleiod region (lacks nucleus, simple genome, one ring of DNA & one chromosome, plasmids) - ribosomes (aid in protein production)

Understand the differences between Allopatric and Sympatric speciation (be able to provide example of each)

-Allopatric; geographically isolated, formation of new species (Ex.) a lake is divided into two separate bodies of water -Sympatric; small sub-population diverges from parent population without geographic isolation (Ex.) a lake has two separate parts but the organisms still interact with one another

What are the general characteristics of molds, yeasts, lichens and mycorrhizae?

-Molds: grow rapidly and produce many spores asexually, enabling the fungi to colonize new sources of food -Yeasts: eukaryotic single celled fungi; reproduce by budding or fission; utilized in food production; converts carbohydrates, starches, and sugars to alcohol and carbon dioxide gas (fermentation) -Lichens: grow on surfaces of rocks, rotting logs, trees and roofs in various forms & is mutualistic btwn fungi, algae or bacteria; usually green algae or cyanobacteria; tolerant of extreme cold & water fluctuation; can break down rock -Mycorrhizae: "fungus roots" (mutualisitc association of plant roots and fungi); provides food for fungi & is found in almost all vascular plants

What is meant by reproductive isolation? List and explain all the pre- & post- zygotic reproductive barriers (must be able to apply this information if given an example)

-R. isolation: a collection of evolutionary mechanisms, behaviors and physiological processes critical for speciation. They prevent members of different species from producing offspring, or ensure that any offspring are sterile -A prezygotic reproductive barrier is a mechanism that prevents fertilization from occurring. (Ex.) temporal isolation, behavioral isolation, mating rituals, mechanical isolation -A postzygotic reproductive barrier is a mechanism that reduces the viability or reproductive capacity of hybrid offspring. (Ex.) reduced hybrid viability

Taxonomic categories (most inclusive - most exclusive)

1. Domains (bacteria, archaea, and eukarya) 2. Kingdom 3. Phylum 4. Class 5. Order 6. Family 7. Genus 8. Species

How do you determine parsimony?

1. Find the possible trees for the species 2. Arrange the molecular data for the species 3. Mark base changes on all types of possible trees 4. Whichever tree has the least amount of markings is parsimony

What are the three major threats to biodiversity? Explain each threat and how the threat impacts biodiversity

1. Habitat degradation: (habitat loss/alteration) over 70% of threatened species are due to habitat threats. This includes loss of habitat, reduction in available habitat, pollution (biomagnification, acid rain, or eutrophication/nutrient enrichment), or habitat fragmentation. 2. Introduced species: (non-native) 40% of threatened species impacted; predators, competitors, and parasites are some that are introduced. (Ex. Cane toads) 3. Overexploitation: when removal exceeds rates of replacement larger/long-lived species are typically impacted more (Ex. excessive commercial harvesting, excessive sport hunting, or illegal trade in wildlife & wildlife productions; can have cascading effects at an ecosystem level

What is the 'molecular clock'? What role does it play in phylogenetic trees? What data is used to calibrate the molecular clock?

A molecular clock is an approach for measuring the absolute time of evolutionary change based on the observation that some genes and other regions of genomes appear to evolve at constant rates. Data used to calibrate the clock is graphing the number of genetic difference against the dates of evolutionary. branch points that are known from the fossil record Helps create phylogenetic trees by determining the ORDER of evolutionary events

What exactly is a seed? What will it mature into when it germinates? From what or where did it arise? What is/are the difference(s) you see between the seeds of gymnosperms and angiosperms?

A seed is an embryo & nutrients surrounded by a protein coat (sporophyte tissue). The seed of a plant is made up of tissues from three generations(blue/integument ----> parent sporophyte, light green/food supply ---> female gemetophyte, yellow/megasporocyte ---> new sporophyte generation) When it germinates, it will become a seedling, eventually maturing into either an angiosperm or gymnosperm. It arose from the soil after being filled with nutrients, sunlight, and water. Gymnosperm seeds are naked seeds, not produced in the ovary w/ one integument. Ovules become the seed. The seeds themselves rest on top of scales or w/in cones and they are exposed during fertilization. Angiosperm seeds have two integuments & produce both flowers and fruit. They're also enclosed by the ovary and contained in fruits.

Explain the impact of acid rain and eutrophication

Acid rain: chemical pollutants in the air that come down in precipitation. For example, low pH is acidic, so when lower pH levels become of lakes/streams it kills organisms, including mycorrhizae. Eutrophication: excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen. This creates algae blooms/plant growth that results in them both dying & consumed by aerobic bacteria. It also creates a depletion in oxygen, so other organisms die.

Explain the Biological Species Concept; What criteria are used to classify species?

BSC: defines a species as members of populations that actually or potentially interbreed in nature, not according to similarity of appearance. Although appearance is helpful in identifying species, it does not define species. Organisms may appear to be alike and be different species. The main criterion is: Reproductive Isolation - no gene flow occurs between populations that are reproductively isolated from each other; Can the two organisms interbreed and produce fertile offspring?

What are the two domains of prokaryotes?

Bacteria and Archaea

Understand the conservation strategies for the Bald Eagle re-introduction program. You should be comfortable with the conservation plan, and why the plan was devised the way it was.

Bald eagles lay three eggs, but they're only able to keep 2 alive into adulthood. The 3rd is mainly there just in case one doesn't survive hatching. The re-introduction program takes the third baby away and puts them into towers/platforms. They don't see humans (no imprinting) & they're released into areas where reintroduction needs to take place. Bald Eagles also return to breed in their natal areas, so it's important as to where they're raised. It was devised this way because the overall population was diminishing, and there are these babies that are being neglected that could be raised to adulthood with proper care.

Why do we talk about the flow of energy through an ecosystem, instead of a cycling within an ecosystem? Tie this into the concept of trophic levels.

Basically, energy is taken from the sun by producers. Each successive trophic level gains limited energy from the ones below it, all the way up to the top. While some energy may continue through the food web through decomposition and further consumption of those decomposers, all energy is eventually lost through heat, cellular respiration, and other functions. Each time energy is acquired some of it is loss in the form of heat but also utilized and not store in a biomass available to the next trophic level. The continual loss of energy means that there has to be a constant input of sunlight (energy) to the photosynthetic organisms to sustain the ecosystem. Chemicals, on the other hand, are continually recycled. Molecules are broken apart and rearranged into other inorganic or organic molecules.

Given that prokaryotes primarily reproduce via binary fission (explain what this is), where does the variation/diversity we see in prokaryotes come from? Make sure you can explain the processes, not just list them. Be sure to tie in the idea of horizontal gene transfer.

Binary fission: asexual reproduction by a separation of the body into two new bodies The variation we see comes from the processes conjugation & transduction which occur via horizontal gene transfer. Conjugation: DNA is transferred between two prokaryotic cells that are temporarily joined. The DNA from one cell is enveloped by the receiving cell which, in turn, causes genetic variation Transduction: phages carry prokaryotic genes from one host cell to another. The genes can attach to another prokaryotic cell (the recipient) and inject DNA acquire by the donor. If the DNA is then incorporated into the recipient cell's chromosome by crossing over, a recombinant cell is formed

What is meant by biodiversity? Explain the three types of diversity.

Biodiversity is a crucial natural resource & is defined as the variety of life in the world or in a particular habitat or ecosystem. The types include: 1. Genetic diversity: genetic variation found within and between populations of the same species; adaptations to environmental conditions 2. Species diversity: variety of species in an ecosystem (endangered species or threatened species) 3. Ecological (ecosystem) diversity: diversity w/in an ecosystem impacts both abiotic and biotic interactions; loss of one species impacts the remaining species.

What is biomagnificaton? Give an example and explain why it is a problem.

Biomagnification is when toxin levels increase in tissues as you move up the trophic levels & has severe impact on carnivores. An example of this is DDT, a synthetic organic compound used as an insecticide. When the bottom of trophic levels is impacted the rest of the levels above it are impacted too.

Explain how bioremediation and biological augmentation go about reaching that goal?

Bioremediation uses organisms to detoxify ecosystems. In other words, the organisms (prokaryotes, fungi, or plants) take up/metabolize toxic molecules. Biological augmentation is the addition of archaea or bacterial cultures required to speed up the rate of degradation of a contaminant (the act of bioremediation).

What is the primary abiotic reserve for carbon, nitrogen and phosphorus. Explain how each of the chemicals cycle through ecosystems.

Carbon: co2 in atmosphere & dissolved in water. heterotrophs obtain carbon from photosynthetic organism, respiration & photosynthesis cycle carbon from abiotic to biotic reserves, burning of fossil fuels upsets the balance - increase abiotic reserves! Nitrogen: in atmosphere. prokaryotes "fix" atmospheric nitrogen - placing it in the biotic reserve! plants take up nitrogen compounds from soil (with help from nitrogen - fixing bacteria) animals obtain nitrogen from eating plants or other animals. death, excretion or feces cycles back to soil. prokaryotes cycle nitrogen back to N 2 in atmosphere. Phosphorus: in mineral form. weathering of rocks & minerals --> leeches into soil & water. taken up by plants & animals (biotic reserve) recycled back to abiotic reserves by decomposers.

What is carrying capacity? What happens to the growth rate as the population size approaches carrying capacity? What happens to the shape of the curve when carrying capacity is changed (or varies)?

Carrying capacity is the population size that is sustainable w/in the given environment. Growth rate slows as population size reaches capacity, and the shape of curve can become more or less steep based on if capacity increases/decreases (K isn't fixed & the types of limitations changes over time causing fluctuations).

Prokaryotes have tremendous ecological impact. What role(s) do prokaryotes play in chemical cycling, why is this important?

Chemical cycling: The cycling of chemical elements between the living and nonliving components of the ecosystem Prokaryotes are major decomposers that cycle chemicals back into the environment through the break down of organic matter. It's important bc decomposers obtain energy by breaking down their remains and, in the process, they return key nutrients like nitrogen to the soil so primary producers can use them Ex. A tree that's fallen down & is decaying is a result of decomposers breaking it down. W/o decomposition, the tree would remain there.

Does a cladogram tell you anything about the timing of evolutionary events? Does it tell you anything about the chronology of the events? Explain.

Cladorgrams tell us the ORDER of evolutionary branching events, not the timing; examines divergences in chronological sequence. Chronology does NOT mean all descendants of one ancestor came before ancestor of another group.

Global Climate Change is a major issue facing us today. Explain what it is and why it is a source of major concern? Be sure to understand the four examples I gave in class about the cascading impact it can have.

Climate change is an increase of greenhouse gases, such as carbon dioxide and methane, in Earth's atmosphere which increases global temperatures. An upward shift in temperatures is a major concern because it influences growing seasons in plants, migratory patterns in animals, alters habitats in which communities/species are adapted to, and it changes the composition of species in a community due to populations responding differently. Examples: --Effect on cells: pine trees have specialized cells that produce resin that kills pine beetles. Warmer temperatures/ drought causes the trees to produce less resin therefore allowing the beetles mature/reproduce faster. As a result, pine trees are dying. --Effects on Individual Organisms: American Pika live in higher elevation and are adapted to cool conditions. Warmer temperatures cause them to spend more time in their burrows which increases mortality. --Effects on Populations: Caribou migrate north in spring to give birth and eat sprouting plants. Due to temperatures rising, the plants sprout earlier, so because the caribou haven't adjusted to this change, they arrive too late. Now the offspring production has dropped immensely. --Effects on Communities: Climate change affects the distribution of species. Sea urchins require warm temperatures to reproduce, so as the oceans warm, sea urchins are invading and outcompeting kelp. Kelp colonies have high levels of biodiversity, so as they dwindle so does biodiversity.

While the degree of impact of abiotic vs. biotic factors on community structure varies with species composition, both factors influence to some degree all communities. Interspecific interactions are major biotic factors, acting as major selective pressures on the species involved in the interactions. Explain the different types of interactions and how they might affect community structure. (not a short answer)

Competition 1. Competitive exclusion: one species out-competes another for LIMITED resources; This could cause one species to become extinct, therefore altering the community's structure 2. Resource Partitioning: differentiation of niches that enables similar species to coexist in a community (using similar resources at different times of the day/year); (if there's intense competition) selection will favor those that engage in behaviors that reduce/avoid competition (Ex. shift in location w/in habitat); Reduced competition is due to shift in fundamental niche 3. Character Displacement: tendency for characteristics to diverge more in sympatric then allopatric populations of two species (Ex. Galapogos finches beak depths are similar in two different species in allopatric populations but have diverged considerable in sympatric populations) Exploitation 1. Predation: +/- interaction btwn species in which one species (predator) kills/eats other (prey); Impactful bc it causes a fluctuation in the amount of organisms in the predator/prey populations 2. Herbivory: +/- interaction in which an organism eats parts of a plant or alga; some plants being eaten are useful to the environment by absorbing CO2 or by being used to produce human-needed products 3. Parasitism: +/- interaction in which one organism (parasite) derives its nourishment from another organism (host): Endoparasites- live w/in host (Ex. tape worm) or Ectoparasites- feed on external surface (Ex. lice); impact community by significantly affecting the survival, reproduction, & density of host population (directly or indirectly) Positive Interactions 1. Mutualism: +/+ interaction that benefits both species (Ex. cellulose digestion by microorganisms) 2. Commensalism: +/0 interaction that benefits one but neither benefits or harms other (Ex. Trees providing shade for wildflowers that helps them grow) ***Symbiotic relationships: a special type of interaction between species. Sometimes beneficial, sometimes harmful, these relationships are essential to many organisms and ecosystems, and they provide a balance that can only be achieved by working together. (Ex. lichens, sea otters & sea urchins, flowers & hummingbirds)

You should know that conifers are the major representatives of gymnosperms, but there are other plants, while different they are still classified as gymnosperms (primarily due to life-cycle, and xylem tissues). What are the major characteristics of conifers?

Conifers: - largest phyla of gymnosperms - seeds primarily wind-dispersed -tend to be found in cold, drier regions - tallest vascular plants -source of timber, paper, resin, & turpentine -Pollen cones produce microspores & develop into the MALE gametophyte (dispersed via air) - ovulate cones produce megaspores & develop into FEMALE gametophyte (retained w/in cone)

Researchers found that the basic body types on one island are found on other islands as a result of convergent evolution, not common ancestry. Explain

Convergent evolution is the process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. While the anoles are related with others on their island, they individually adapted to survive in their specific environment. They look like other anoles since they evolved independently on the same island, but they each deal with different daily tasks which makes their adaptations create varying body types. In conclusion, it's a result of convergent evolution because each island has anoles that aren't closely related yet look alike.

What are the main criticisms about the BSC?; Understand WHY the criticisms are leveled at the concept

Criticisms: - no way to evaluate the reproductive isolation of fossils - Doesn't apply to organisms that are asexual (prokaryotes) - Species are designated by the absence of gene flow, but there are many pairs of species that are morhpologically and ecologically distinct yet gene flow occurs between them Why?: The BSC is based on the ability to interbreed & produce fertile offspring, so if you're unable to (or unable to tell <fossils>) then its a criticism of the concept

What is the difference between "density-dependent" vs. "density-independent" limits on population growth. Again, using an example is a great way to explain it.

Density-dependent: death rate that increases/birth rate that falls w/ population density (Ex.) competition for resources/territories, parasite or disease/host, interactions btwn organisms Density-independent: birth/death rate doesn't change w/ population density (Ex.) temperature, precipitation, natural or human-caused disasters

Is a derived character a homologous or analogous character? Does an out-group of a cladogram share any homologous characters w/ the in-group? Why use an out-group?

Derived characters are homologous. Yes, it is possible an out-group shares homologous characters w/ in-group Out-groups are used to determine ancestral v. derived characters (shared w/ out-group= ancestrial; not shared= derived)

What is ecological niche? What is the difference between fundamental niche and realized niche (tie into the concept of competitive exclusion)?

Ecological niche: specific set of biotic & abiotic resources that an organism uses in its environment -Fundamental niche: habitat in which the organism is adapted -Realized niche: habitat in which the organism is adapted minus the habitat from which its excluded ***Competitive exclusion is when a species out-competes another for limited resources; makes it so 2 species cannot live in the presence of another so the realized niche is due to this exclusion

What are endospores and under what conditions would you predict they would be produced? Why are they adaptive? (think about what being adaptive means and explain it in evolutionary terms)

Endospores are (bacteria-produced) very resistant cells that increase bacteria's chance of survival/persistance. They're produced when bacteria lack water & essential nutrients. It's adaptive bc they remain dormant yet viable for centuries. The primary function of most endospores is to ensure the survival of a bacterium through periods of environmental stress.

Be comfortable with the generalized scheme of nutrient cycling & energy flow.

Energy: Flows from sun to producers through trophic levels, eventually released through heat, cellular respiration, etc. Nutrients: Come from various places, like rocks, atmosphere, or other places. Cycle through ecosystem. Can move between accessible and inaccessible biotic and abiotic reserves, but will always stay within ecosystem.

Understand the differences between exponential and logistic models of growth. Which type of growth is more likely to be seen in nature? Explain.

Exponential growth is when the average birth rate exceeds death rate in an idealized, "unlimited" environment, the growth is unchecked, J-shaped curve & the steepness of slope is influenced by the intrinsic growth rate (r). Logistic growth is constrained by carrying capacity, slow growth rate when approaching carrying capacity, S-shaped curve, slope of line changes relative to how close it is to carrying capacity, & the intrinsic growth rate is adjusted based on how close the population is to carrying capacity ([K-N]/K) Logistic growth is more likely to be seen in nature bc each environment has a certain amount of available resources so when the population reaches carrying capacity it can't handle more individuals than what the available resources cover.

How does the growth curve shift if there is a shift in growth rate? Be sure you can answer this for both logistic and exponential growth curves. Draw out a schematic of the curves and compare and contrast the shapes.

Exponential: -population growth slower = small # of individuals added to the population at one time -lower max growth rate per capita = less steep line initially Logistic: steepness of slope is influenced by how close the population is to carrying capacity [S-shaped curve:] - slow= low population size -faster= medium population size, little constrained by K - slow= constrained by K

Archaea is made up of a number of "extreme" organisms. Why are they considered extreme organisms? Under what conditions do they thrive? Why are Archaea called 'archaea' (hint: what does the name mean - but be careful)?

Extreme organisms: methanogens (poisoned by oxygen), extreme thermophiles & extreme halophiles They're considered extreme organisms bc their living conditions were so extreme that few other organisms could live there. Condtions they thrive in: Methanogens: under kilometers of ice, swamps & marshes, guts of cattle, termites, & other herbivores Extreme Thermophiles: very hot/cold environments Extreme Halophiles: highly saline environments 'Archaea' means "ancient," not bc it's ancient itself but bc it lives in conditions thought to be similar to ancient earth's environment

Explain figure 55.16 - what does the removal experiment tell us about the importance of chemical recycling and changes in habitat?

Figure 55.16 represents nitrate runoff from watersheds. The experiment took away producers (trees) of an area to see what would happen. The figure shows two lines -- one was a line of a deforested area & the other a control group with no trees cut down. The results were in the deforested areas the nitrate levels rose significantly while they stayed fairly steady in the control group. During the removal experiment, the trees that were cut down remained in place to be decomposed-- they just weren't alive. This tells us that chemical recycling and changes in habitat are very important due to the dramatic increase in nitrate levels in deforested areas. Nitrate is what plants use as building blocks of proteins.

Bryophytes are the first major group of plants to have evolved. If I gave you a picture of a moss, you should be able to recognize the gametophyte and the sporophyte. What are the general characteristics of bryophytes; what separates them from the other major groups of plants?

General characteristics: -20,000 species -dominant gametophyte generation (dominant stage in their life cycle) -sporophytes attached to gametophytes -require water for fertilization -gametangia prevents drying out of gametes & protects from microbes -lack vascular tissue -mircophylls: "leaves" -rhhizoids: "root-like" absorb water -play a vital role in regulating ecosystems because they provide an important buffer system for other plants, which live alongside and benefit from the water and nutrients that bryophytes collect They're different from other major groups bc they have no vascular tissue.

What is the difference between gradualism and punctuated equilibrium? Are they mutually exclusive ideas? Can both have operated on the evolution of a particular group of organisms?

Gradualism: slow, gradual changes accumulated over 1,00's - millions of years Punctuated equilibrium: long periods of no change & spurts of rapid change They aren't mutually exclusive, they both can play a role in evolution of particular groups of organisms

What are the two major groups of seed plants? Which group of seed plants evolved first? How do these plants differ from ferns? What do they have in common with ferns, but not mosses?

Gymnosperms & Angiosperms. Gymnosperms evolved first. They differ from ferns in how they aren't seedless and don't need water to reproduce. They're similar to ferns, but different to mosses in how they their sporophytes are dominant and gametophytes are reduced.

How do angiosperms differ from gymnosperms?

Gymnosperms bear naked seeds whereas angiosperms bear seeds within fruits or flowers. Angiosperms are flowering whereas the gymnosperms are non-flowering plants. In evolution, gymnosperms are more primitive than angiosperms. Gymnosperms were the first seed plants and they bear their ovules and seeds exposed. The male and female gametophyte structures are present on separate male and female cones in gymnosperms, whereas in angiosperms, they are a part of the flower. **They are alike in how the spores of both are retained on the parent sporophyte plant and develop into the gametophytes

Why is fragmentation of a landscape detrimental?

Habitat fragmentation is an umbrella term describing the complete process by which habitat loss results in the division of large, continuous habitats into a greater number of smaller patches of lower total area. It's detrimental because species w/ large home ranges are hurt, not enough resources to support higher trophic levels, higher predation/parasitism rates, lack of "buffer zone" (a neutral area serving to separate hostile forces or nations).

What role has horizontal gene transfer played in the history of life and how has it impacted scientists ability to determine evolutionary relationships?

Horizontal gene transfer is the process in which genes are transferred from one genome to another through mechanisms such as exchange of transposable elements & plasmids, viral infection, and fusion of organisms Plays a role in history of life bc it was common in early stages of organismal evolution & diversifies genomes of all forms of life Impacts scientists ability to determine evol. relationships by complicating things. Instead of genes being ancestral/derived, they can be transferred from one organism to another

Explain the differences between "reinforcement", "fusion", and "stability" as outcomes which can occur when two divergent populations come back in contact after an extended time of allopatry where divergences accumulated

Hybrid Zone (area where two different species meet&mate) outcomes Reinforcement: strengthening reproductive barriers-- hybrids gradually cease to be formed Fusion: weakening repr. barriers--causes speciation to reverse, fusing 2 hybridizing species into 1 Stability: hybrids continue to be produced

What is meant by independent evolution? What is an evolutionary. reversal?

Independent evolution when two groups evolve similar characters as a result of the same selective pressures and do not share it because of recent common ancestry. Evolutionary reversal is when characters may evolve then disappear

What emphasis does the Phylogenetic Species Concept place on the formation of species? (what are the defining criteria used to determine species status?)

It places an emphasis on the unity of a species and sustainable differences between species

Explain primary production.

It's the amount of solar energy converted to chemical energy by producers of an ecosystem. It's what determines the number of trophic levels in an ecosystem & is used to compare ecosystems. In addition, it's constrained by nutrients (nitrogen & phosphorus) and available sunlight (greatests in areas w/ abundant warmth and moisture).

What are the Key Events in the history of life? Understand the sequence, & the data that supports the sequence

Key events (sequenced in order): -first single-celled organisms (stromatolites: layered rocks) orignated 3.5 billion yrs ago; data from fossilized stromatolies -oxygen revolution through photosynthesis: oxygen from prokaryotes dissolved into surrounding water until it reached high enough concentration to fill the lakes/seas. Oxygen began to "gas out" into the atmosphere 2.7-2.4 billion yrs ago; data from sediments banded into iron formations (red layers of rock containing iron oxide that are a source of iron ore today) -First eukaryotes originate through endosymbiosis (prokaryotic cell engulfs a small cell that evolved into an organelle found in all eukaryotes---mitochondria) 1.8 billion yrs ago. Over time, the host and edosymbionts would have become a single organism. Mitochondria & plastids descended from bacteria cells. The orignal host is through to have been an archaean (rocks); data from inner membranes of organelles have enzymes & transport systems that are homologous to those found in the plasma membranes of living bacteria - Small multi-cellular eukaryotes originated 1.8-1.2 billion yrs ago (algae, fungi, plants, animals). Larger multi-cellular eukaryotes don't appear until 600 million years ago; data from Endiacaran biota that lived 635-541 million yrs ago. The rise of Endiacaran biota set the stage for another burst of evolutionary change... -The Cambrian Explosion (670 million yrs ago) was where many present-day animal phyla appeared. Large animals developed claws, spines, and heavy body armor; data from fossils formed. -The colonization of land (500 million yrs ago) associated with adaptations pf aquatic life (adaptations began 420 million yrs ago) Arthropods (450 mill. yrs ago) & tetrapods (365 mill yrs ago) were among the first organisms to colonize land. ;data from fossil evidence of photosynthetic prokaryotes coating damp terrestrial surfaces well over a billion yrs ago even though large animals didn't colonize until 500 million yrs ago

What is a keystone species? Explain why its removal from a community has a greater impact than the removal of another species.

Keystone species are species w/ strong impact on composition of community They have pivotal ecological roles & if the species were to disappear from the ecosystem, no other species would be able to fill its ecological niche.

How do large morphological changes occur? Over evolutionary time how have some of the major changes occurred in physiology? Explain the role of developmental genes

Large morphological changes can result from genes that alter the rate, timing and spatial pattern of change in an organism's form from zygote to adult. New morphological changes occur through new developmental genes that arise after gene duplication events. They also occur through changes in gene sequence (changes in nucleotide sequence altering a developmental gene) & changes in gene regulation (can alter the form of individual organisms which leads to evolutionary change) Developmental genes' role includes determining how an organism's body will form, how they will adapt to their environment(s), and how they will develop over all as an organism.

What are meant by the costs of reproduction? How does this influence reproductive strategies?

Limited amount of resources, so increased investment in current young impacts amount of resources available for future young; longer lived species tend to produce fewer young per year which impacts reproductive strategies by causing organisms to produce less offspring in order to survive.

What are the consequences of mass extinctions? Tie this into the concept of adaptive radiation. What is adaptive radiation & why is it likely to occur after mass extinctions?

Mass extinctions reduce a thriving, complex ecological community to a pale shadow of its former self. It takes 5-10 million years for diversity of life to recover to previous levels. By eliminating so many species mass extinctions can pave the way for adaptive radiation Adaptive radiation is a period of evolutionary change in which groups of organisms form many new species whose adaptations allow them to fill different ecological roles in their communities. It's likely to occur after mass extinctions because survivors had to become adapted to the many vacant ecological roles (niches) in their communities.

What are mass extinctions? In reference to Permian & Cretaceous extinctions, what are the likely contributing factors?

Mass extinctions: large numbers of species become extinct worldwide through disruptive changes to the global environment Contributing factors: The Permian extinction occurred during a time when volcanic eruptions took over. The eruptions produced enough CO2 to raise global temperature. The Cretaceous extinction occurred via meteorite/comet hitting Earth. Researchers proposed the comet came from a huge cloud of debris the billowed into the atmosphere. The cloud would have blocked sunlight & disturbed global climate for several months. Therefore, mass extinctions occur through global changes that impact the overall homeostasis of organisms as small as bacteria which in turn disrupts the life on Earth and their ability to survive

Prokaryotes as a group exhibit all four means of nutrition. Explain the four modes of nutrition. Which modes are "self-sufficient" and which are directly dependent on other living organisms? Explain.

Mode of Nutrition: Energy source; Carbon source; type of organism 1. photoautotrophs: sunlight; CO2, HCO3; cyanobacteria: plants & algae Ex. sunlight + CO2= glucose (photosynthesis) 2. chemoautotrophs: inorganic substances (H2S, NH3, Fe2+); CO2; prokaryotes Ex. ammonia(NH3) + CO2= org. compunds 3.photoheterotrophs: sunlight; org. compounds; prokaryotes: aquatic/self-loving Ex. sunlight= break up org. compunds to make new org. compounds 4.chemoheterotrophs: org. compounds; org. compounds; animals, fungi, protists, porkaryotes Ex. glucose= ATP; breakdown foods for carbon= new organic compounds & more ATP The 'autotrophs' are self-sufficient bc they use sunlight to feed themselves. The heterotrophs depend on other organisms to survive.

Be comfortable with the generalized biogeochemical cycle within an ecosystem. What are the biotic reserves? ....abiotic reserves? What do the arrows mean in the figure? (You need to know the processes the arrows represent).

Nutrients can exist in four categories, defined by combinations of accessible and inaccessible biotic and abiotic reserves. Biotic reserves refer to any living being in which a particular nutrient exists. For example, Carbon can exist in the accessible biotic reserve of a tree or animal. It can also exist in an inaccessible biotic reserve of coal or peat. Conversely, Carbon could also exist in an abiotic reserve; it is accessible when stored in the atmosphere and inaccessible if stored in carbonate rocks. Nutrients freely move between all four possible states through processes like decomposition, fossilization, respiration, weathering, and other processes. Rocks can weather and release phosphorus, which moves that phosphorus into an accessible abiotic reserve. It then can be picked up through the soil by plants, where it transfers to the accessible biotic reserve. Eventually, it will either return to the ground as an accessible abiotic nutrient in the soil through decomposition or as an inaccessible biotic nutrient captured through fossilization. All nutrients follow this continuous cycle.

Describe the basic differences between the anoles: how do they differ in body type? How do the differences relate to habitat? How are the differences between anoles thought to have arisen?

One anole had was slender with a long tail, one was long-legged & stocky, another was slender w/ very short legs, and the last one was large w/ big toe pads. The varying body types are adapted by each organism to help them thrive in their habitat. (Ex.) Canopy anoles have large toe pads to keep them attached to canopy leaves so they don't fall The differences in body types arise through adaptations that arose rapidly because natural selection was strong when they were put on the island.

homologous chromosomes

Pair of chromosomes that are the same size, same appearance and same genes

What can you do to help preserve the environment and biodiversity?

People can recycle, use energy efficient lights, walk/carpool/take bus, plant native plants, and eat less meat in order to preserve the environment & biodiversity

Understand the distinctions between the the different Species Concepts

Phylogenetic: concept of a species as an irreducible group whose members are descended from a common ancestor and who all possess a combination of certain defining, or derived, traits Morphological: distinguishes a species by body, shape, and other structural features; can be applied to asexual/sexual beings & can be useful even w/o information on the extent of gene flow Ecological: defines a species in terms of its ecological niche (how members of the species interact w/ the nonliving/living parts of their environment); accomodates sexual/asexual beings Biological: defines a species as members of populations that actually or potentially interbreed in nature producing viable offspring. Thus, the members of a biological species are united by being reproductively compatible (lack of gene flow)

What is phylogeny? Explain why phylogenies are considered hypotheses

Phylogeny: evolutionary history of a species/group of species Because we can't actually witness the evolution of species over time, we only have a certain body of evidence for the interrelatedness, they're considered hypotheses

What is plasmogamy & karyogamy and how are they related? A fungus can be in a state where it is neither haploid nor diploid, instead it is dikaryotic (or heterokaryotic). Explain what these words mean.

Plasmogamy: fusion of 2 cytoplasm when 2 hyphae (gametes) come together Karyogamy: fusion of 2 haploid nuclei ***They are related bc in order for karyogamy to occur, the cell membrane and cytoplasm of each cell must fuse with the other in a process known as plasmogamy -Dikaryotic: the haploid nuceli pair off two to a cell, one from each parent (nuclei don't merge); dikaryotic mycellium produce fruiting body -Heterokaryotic: when parts of the fused mycellium contain coexisting, genetically different nuclei

How does pollination in gymnosperms and angiosperms differ?

Pollination differs between angiosperms and gymnosperms in that most angiosperms entice animals to carry their pollen from plant to plant, while most gymnosperms solely rely on the wind carrying their pollen to other plants.

In addition to their natural role within an ecosystem, understand the roles prokaryotes now play in the medical field and commercial industry

Prokaryotes help create milk, acetone & butanol, vitamins & antibiotics, insulin & therapeutic proteins

How often & why do the DNA replicate?

Replicates once; The DNA replicate because each chromosome has two copies -maternal and paternal

What is serial endosymbiosis? What key role is it thought to have played in the history of life? Give supporting evidence

S. endosymbiosis: A theory stating that the eukaryotes evolved through a process whereby different types of free-living prokaryotes became incorporated inside larger prokaryotic cells and eventually developed into mitochondria, chloroplasts, and possibly other organelles through a sequence of endosymbiotic events The key role it played was producing organelles which created the first eukaryotes. The creation of single-celled eukaryotes led to multi-cellular eukaryotes which eventually led to the vast variety of organisms today

Explain the major differences and similarities between the alternation of generations seen in mosses, as compared to ferns.

Similarities: - Spores are dispersed by air -Fertilization occurs via water - Both produce spores instead of seeds -Share similar habitats (moist) - Sporophyte is located near the tip of the plant, while the gametophyte is lower Differences: -Mosses: The sporophyte is dependent on the gametophyte. Ferns: The gametophyte is dependent on the sporophyte - Ferns have roots, stems, leaves while mosses don't

What are the pros and cons of these two approaches (we did not directly discuss this in lecture - think about it!)? Under what circumstances might you predict conservation biologists would concentrate on a single species, as compared to a habitat-oriented approach?

Species level: The pros of this approach is potentially saving a keystone species. The cons would be if the species being saved is more detrimental than for their environment, or it'd be better to focus on saving an ecosystem versus focusing on one species. Habitat/Ecosystem level: The pros of this approach is that habitat loss is a major threat to biodiversity, so this conservation keeps the ecosystem in check. The cons are that it has strict, extreme land constrictions, the costs are very high, it could save species that do more harm than good and the recovery rate is very slow. I believe that conservationists would concentrate on a single species approach if the species at risk is a keystone species. The species would then be important to balancing the ecosystem, so their survival is vital.

There are two general approaches to conservation of species and their natural habitat, at the species level and at the habitat/ecosystem level. Explain how the two approaches go about protecting/conservation populations. Provide an example of both (overlaps with questions below). Be specific in how the approaches work - what are their goals, how are the plans initiated, where are they initiated, etc.

Species level: This type of conservation begins by determining the threat(s)/what caused the decline in population. In order to conserve the environment you must understand the biology of the species. For example, the Bald Eagle re-introduction program. Habitat/Ecosystem level: This conservation type protects biological hotspots (areas of high productivity/high biodiversity). The focus is to maintain the quality of the area and work towards sustainable solutions. Mimicking natural cycles is a critical conservation tool. Other strategies include: minimizing distances between preserves, increase species diversity & ecosystem stability, create buffer zones/limit human encroachment, actively manage habitats, create multiple preserves when possible in order to reduce the impact of catastrophic events, and make smaller preserves more like larger preserves. For example, the Goose Pond Fish/Wildlife Area restoration.

What are spores and how are they dispersed? What is their adaptive significance?

Spores: a minute, typically one-celled, reproductive unit capable of giving rise to a new individual without sexual fusion They are dispersed by wind or water Their adaptive significance is that it doesn't take much energy to produce spores & they reproduce so quickly in large amounts that they are able to spread rapidly across hundreds of thousands of miles.

Using Goose Pond Fish & Wildlife Area, or wetlands in general as a model, explain how the preservation and maintenance of a habitat is critical for biodiversity. (Hint, tie back into ecosystem services).

The Goose Pond Fish Area was originally a glacier basin area that was drained and farmed with ponds, dikes, and land. The land was a created ecosystem dependent on active management to control water-levels & continue mimicking what would occur if humans weren't interfering. In addition to this, humans removed/controlled invasive plants to keep the ecosystem balanced and flourishing. This preservation is critical for biodiversity because it maintains every aspect of the ecosystem (plants, animals, etc.) while keeping it natural for the organisms at the same time. This in itself helps keep animals alive and thriving when in other situations they would die.

What is the difference between the direct impact vs. indirect impact of habitat loss?

The direct impact includes deforestation, clearing of prairie for crops, and urbanization. The indirect impact is the reduction in available habitat either through overcrowding (competition increase) or direct mortality.

Explain the adaptive significance of vascular tissue.

The evolution of vascular tissue is the 2nd major period of plant evolution. Its adaptive significance: -have ancient relatives w/ branched sporophytes that were not dependent on gametophytes for nutrition; their branching enabled their bodies to become more complex and to have multiple sporangia - Main traits that characterize living vascular plants TODAY: life cycles w/ dominant sporophytes, xylem & pholem, & well-developed roots and leaves

What is the goal of restoration ecology?

The goal is to initiate/speed up the recovery of degraded ecosystems to a more natural state because, with time, biological communities can recover from disturbances. The way they do this is through bioremediation and biological augmentation.

While it isn't always feasible, there are various goals that conservation biologist strive for when setting aside habitat for conservation. What are these goals, or habitat characteristics which are strived for?

The goals of setting land aside is to take it away from human interference or sudden environmental changes that are detrimental to the habitat and the species living within it. The point of it all is to save certain species of certain Kingdoms so they don't become further endangered or extinct.

Why is the loss of biodiversity problematic? How is a biodiversity of economic benefit to us?

The loss of biodiversity is problematic because it disrupts the functioning of ecosystems, making them more vulnerable to perturbations and less able to supply humans with needed services. It's an economic benefit because it creates food, medicine, paper products etc. It's also vital for a healthy ecosystem.

Review pine's life-cycle (in lecture notes especially) The pine tree represents what stage of the plant's life-cycle? What are cones? What are the differences, if any, that we see between cones? Where does fertilization occur? How are pollen and seeds dispersed? Is the pine tree haploid or diploid? What about the seeds? When does meiosis vs. mitosis occur?

The pine tree is the mature sporophyte, diploid stage. Cones are masses of scales that hold male (Pollen) and female (ovule) cones. Male cones only live a few weeks and are smaller than female cones. Fertilization occurs in the ovule. Pollen & seeds disperse via wind or animal. The tree itself is diploid as are the seeds. Meiosis occurs twice: when pollen grains are dispersed & while the pollen grain develops. The rest of the cycle mitosis is occurring.

Explain secondary production.

The rate at which consumers convert chemical energy in food into own biomass

Explain the relationship between the rate of decomposition and nutrients present (and available) in the soil.

The rate of decomposition is controlled by temperature, moisture and nutrient availability. Rapid decomposition results in relatively low levels of nutrients in the soil. Cold & wet ecosystems store large amounts of undecomposed organic matter as decomposition rates are low. Decomposition is also very slow in anaerobic muds/conditions. For instance, in a tropical rain forest, material decomposes rapidly, and most nutrients are tied up in trees and other living organisms.

What is the ultimate source of energy for all organisms on earth? In other words, where did the energy come from originally?

The sun

Explain how different species interactions can interact. How might one factor influence the impact of another factor? (not really a short answer, make sure you think it through).

Think of the sea urchins, kelp, and otters. Sea urchins prey on kelp which impacts our environment greatly since kelp is one of the world's most efficient absorbers of CO2. Thankfully, otters prey on sea urchins and can eat up to 25% of their body weight, so vasts amount of sea urchins are eaten daily which helps kelp thrive. The predatory/prey interactions of three separate species interact in this example. If otters were no longer present then kelp would suffer greatly as urchins eat them. If sea urchins weren't around then the otters would have to find a new area where they do exist or else they'll suffer. If kelp were in low supply, then the environment would suffer along with sea urchins not having anything to eat.

Preserving land, in terms of setting aside an area that will not be developed, isn't good enough for conservation and preservation of species and ecosystems. Why? What else must be done in order to conserve habitats? Explain

This strategy isn't enough because habitats have to be protected & MANAGED in order to be properly conserved. In addition to setting land aside, conservationists also must mimic natural ecosystem cycles, even to the point of disturbing the habitat periodically. It's key because species are adapted to natural fluctuations (dependent on them). Other things that can be done include: minimizing distances between preserves, increase species diversity & ecosystem stability, create buffer zones/limit human encroachment, actively manage habitats, create multiple preserves when possible in order to reduce the impact of catastrophic events, and make smaller preserves more like larger preserves.

What is trophic efficiency and WHY is it so inefficient? Explain the significance of figure 55.11

Trophic efficiency is the percent of energy transferred from one trophic level to the next; varies from 5-40%. Also limits number of top carnivores — have to have the producer base to support it It's inefficient because some energy is lost at each trophic level as it flows through an ecosystem. Figure 55.11 depicts trophic levels, like the picture attached, but it also includes an inverted pyramid where the primary producers were a lot less than the primary consumers. An inverted pyramid is when the energy gained by the trophic level above was larger than the energy gained by its immediate predecessor

What is meant by the trophic structure of a community? Understand the different trophic levels of the "energy pyramid" and explain how they interrelate.

Trophic levels of a community are what determine the pathway of energy flow & nutrients cycling through an ecosystem. The levels are: Detritivores, Producer, Primary consumer (herbivore), Secondary consumer (carnivore), and Tertiary consumer (top carnivore). Detritivores include bacteria/fungi and keeps chemical cycling going. Next, producers are the source of nutrients for the other trophic levels. From then on, primary-tertiary consumers are organisms that provide energy for the organisms above them.

Be familiar with mosses as the example for a bryophyte. You should understand the life cycle of mosses. a. Where does fertilization take place? Why is water necessary? b. The sporophyte is dependent on the gametophyte - explain. c. How are spores dispersed? How are gametes dispersed? d. Is any states in the life cycle resistant to harsh conditions?

a. Fertilization takes place w/in the archegonium (female gametangia; pear-shaped organ that porduces a single nonmotile egg retained w/in the bulbous part of the organ) & water is necessary bc sperm must swim through a film of moisture to reach the egg b. The sporophyte generation is dependent on the photosynthetic gametophyte for nutrition. Cells within the sporangium of the sporophyte undergo meiosis to produce male and female spores, respectively. These spores divide mitotically to produce multicellular male and female gametophytes. Differentiation of the growing tip of the gametophyte produces antheridia in males and archegonia in females. The sperm and eggs are produced mitotically in the antheridia and archegonia, respectively. Sperm are carried to the archegonia in water droplets. After fertilization, the sporophyte generation develops in the archegonium and remains attached to the gametophyte. c. Meiosis occurs and haploid spores develop in the Capsule. When the Capsule is mature, its lid pops off, & the spores are released via air. Eggs aren't released; Sperm is released via water d. Yes; spores are the resistant state.

What is the 6th mass extinction?

an extinction that is potentially occurring today with humans destroying earth through habitat destruction and littering etc.; More than 1,000 species have become extinct in the past 400 years, so unless dramatic actions are taken, a sixth (human-caused) mass extinction is likely to occur

When do sister chromatids separate?

anaphase II

What is a cladogram?

branching diagram that examines divergences in chronological sequence; indicates ORDER of evolutionary branching events, not the timing (clade: ancestral species & all its descendants)

Explain the terms macroevolution & microevolution Tie them into adaptive radiation

macroevolution: formation of new species; this ties into adaptive radiation in how the formation of new species is how adaptive radiation occurs. The new species fill in ecological roles left by those who became extinct microevolution: changes w/in a population; ties into adaptive radiation bc after species adapt to the ecological niches, small changes need to be made for those populations to continue thriving

Define: out-group, in-group, monophyletic, paraphyletic, character state, ancestral & derived character, branch point, and parsimony

out-group: species/group of species from an evolutionary lineage that is closely related but not part of group of species that's being studied (determines ancestral v. derived) in-group: group of species being studied in a cladogram monophyletic: consists of an ancestral species and all its descendants (monophyletic group =clade) paraphyletic: consists of ancestral species and some of its descendants character state: version of a character (Ex.) character= horn; character state= curly or straight ancestral character: character that originated in an ancestor of the taxon (Ex.) backbone derived character: an evolutionary novelty unique to a clade (Ex.) hair branch point: represents the common ancestry of the evolutionary lineages diverging from it parsimony: all other things being equal, the best hypothesis is the one that requires the fewest evolutionary changes.

Why is speciation more likely to occur in isolated populations? Explain adaptive radiation & how it relates to speciation

small population size allows genetic drift to have a larger impact on the population's gene pool Adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms. It relates to speciation bc it creates multiple new groups/species.

Know the differences between: spores, sporophyte, gametes, gametophytes, sporangia, and gametangia. Understand when the organism is haploid vs. diploid and how these states relate to mitosis and meiosis. See the generalized life cycle of a plant in your text (pg. 618)

spores: reproductive cells that can develop into a new haploid organism w/o fusing w/ another cell (haploid; produced by meiosis in sporophytes) sporophyte: "spore-producing plant"; multicellular, diploid; produced by mitotic division of the zygote gametes: sperm & eggs gametophytes: "gamete-producing plant"; multicellular, haploid; production by mitosis of gametes sporangia: multicellular organs of a sporophyte that produce spores gametangia: multicellular organs that produce gametes (female gametangia: archegonia ; male gametangia: antheridia) ****Figure attached is the same as our book; plus the one in our lecture notes