Biology 181 Final Exam
Species
A group of similar organisms that can breed and produce fertile offspring.
Describe what a 'hybrid' is according to the BSC.
A hybrid is an offspring produced by a cross of species. It complicates the BSC because a hybrid is not its own species; it shows that some species are not reproductively isolated.
binary fission
A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size
intersexual selection
A form of sexual selection involving interaction between males and females, as when females choose from among males.
intrasexual selection
A form of sexual selection involving interactions between individuals of one sex, as when members of one sex compete with one another for access to the other sex.
Explain in detail how all populations are not the same. Be sure to include the details and significance of each: o Size and abundance (minimum viable population & carrying capacity), distribution and density, ranges and age structures.
Some populations are large and others are small; some are barely surviving at minimum viable population and some at barely surviving at carrying capacity; some are distributed around the globe and others have a small range, some have dense populations and age structures vary from lots of young to lots of old.
Explain how we know that chloroplasts and mitochondria are the result of endosymbiosis.
mitochondria originated as endosymbiotic bacteria like chloroplasts
gene flow
movement of alleles from one population to another
balancing selection
natural selection that maintains two or more alleles of a given gene in a population
Explain all of the 'steps' of the scientific method including all pertinent vocabulary.
observation, hypothesis, test/experimentation, conclusion
Allele
one of a number of different forms of a gene
Explain the types of symmetry and the differences between deuterostomes and protostomes.
there is radial and bilateral symmetry. Radial can be divided evenly anywhere (think of jellyfish) and bilateral only has one plane of symmetry. In Deuterostomes, the anus develops first, whereas in Protostomes the mouth develops first.
Explain the anatomy of a vascular plant in general, and in detail: a leaf, a stem and a root
vascular plants have four main organs: leaves, reproductive organs, stems and roots. Roots absorbs water, stems carry it to leaves,
Explain why viruses are not considered living organisms.
viruses cannot reproduce on their own
morphospecies concept
members of the same species usually look like each other more than like other species
Explain the basic phylogeny of animals
-Choanoflagellates -Porifera -Cnidaria -Bilateria
Explain the four major evolutionary trends of land plants and apply them to each of the main plant groups.
1. alternation of generations 2. xylem and phloem 3. seeds and pollen 4. flowers
Explain the significance of meta-populations, habitat patches/fragmentation, and habitat corridors.
A metapopulation is a large population made up of smaller populations linked by occasional movements of individuals among them. It is a habitat patch, often fragmented from other habitats. However, there are corridors that allow for populations to travel in-between them, subsequently allowing for species diversity.
inbreeding depression
A reduction in fitness resulting from breeding among relatives causing homozygosity of deleterious recessive mutations.
Commensalism
A relationship between two organisms in which one organism benefits and the other is unaffected
Gene
A segment of DNA on a chromosome that codes for a specific trait
GD: Founder Effect
A type of genetic drift in which a small number of individuals leaves one population and establishes a new population; by chance, the newly established population may have lower genetic diversity than the original population.
Describe the four main tenants of natural selection and the 'raw material' of evolution. Be able to define both terms
All organisms are varied, most organisms produce more offspring than environment can support, favorable traits survive, over time, population becomes adapted to environment, raw material is DNA/genetics
Explain how Bishop Ussher, Charles Lyell, Jean Baptiste de Lamarck, Thomas Malthus, and Alfred Russell Wallace influenced Charles Darwin as he formed his theory of evolution.
Bishop Ussher believed Earth was thousands of years old; Charles Lyell believed Earth was millions of years old; Lamarck believed in an inheritance of acquired characteristics (He was wrong, Darwin did not agree with him); Malthus stated that if the population kept growing, we would run out of resources; Wallace was Darwin's colleague and came to the same conclusion as Darwin did about evolution.
Explain the main structures and functions of the various bryophytes, lycophytes, gymnosperms and angiosperms
Bryophytes: A moss, liverwort, or hornwort; a nonvascular plant that inhabits the land but lacks many of the terrestrial adaptations of vascular plants. Rely on surface water for hydration Lycophytes: A monophyletic major group of spore-dispersing vascular plants that are the sister group to all other vascular plants. Gymnosperms: seed plant that bears its seeds directly on the surfaces of cones Angiosperms: A flowering plant which forms seeds inside a protective chamber called an ovary
Explain the differences between and identify examples of allopatric and sympatric speciation, including adaptive radiation.
Allopatric: populations that are geographically separated from each other Sympatric: geographically overlapping adaptive radiation: the diversification of a group of organisms into forms filling different ecological niches.
Explain 'alternation of generations' and apply it to bryophytes, lycophytes and gymnosperms
Alternation of generations is plants cycling through a haploid and diploid generation. Bryophytes rely heavily on the haploid generation, whereas gymnosperms rely heavily on the diploid generation.
GD (bottleneck effect)
An extreme, usually temporary, reduction in population size that may result in marked loss of genetic diversity and in the process, genetic drift
Explain the main differences between C3, C4 and CAM photosynthesis.
C3: plants that do not use 4-carbob organic acids to supply the Calvin cycle with carbon dioxide. C4: plants in which carbon dioxide is incorporated into 4-carbon organic acids in mesophyll cells that are then used to supply the Calvin cycle in bundle sheath cells, results in the suppression of photorespiration. CAM: plants use nocturnal CO2 storage to avoid water loss during the day.
Interpret a phylogeny of vertebrate animals
Can you accurately interpret a picture of a phylogenetic tree of vertebrate? (radial symmetry, bilaterians, etc.)
Explain in detail the biogeochemical cycles of carbon (short- and long-term), nitrogen and phosphorus. o Include the major reservoirs and fluxes.
Carbon has short term(days, months, years) and long term cycles (thousands of years). Carbon is high in spring because photosynthesis rate is low, and low in fall after a summer high is photosynthesis rates. Nitrogen go through living organisms, added to the food web, returns to soil (decomposers), and returns to air. Phosphorus is released by weathering, taken up by consumers, released as runoff, and back to rock. Never in atmosphere.
Aerobic & anaerobic, photo- and heterotrophs, auto- and chemotrophs, C/N/S metabolism
Chemotrophs-energy source is chemicals Phototrophs-energy source is light Autotrophs-self feeders heterotrophs-have to have an an external organic source to help produce energy (have to consume it to make energy)
Explain various similarities and differences between the different vertebrate groups.
Chordata
Explain and identify the various body forms/structures of Cnidarians, Ctenophores and placozoans
Cnidarians: A phylum characterized by radial symmetry, two germ tissues in the embryo, a closed internal gastric cavity, and well-developed tissues but not organs; includes jellyfish, sea anemones, and corals. Ctenophores: Comb-jellies; species in this phylum have a radial body plan but a flow-through gut; they propel themselves by cilia arranged like a comb along the long axis of the body. Placozoans: Possibly the simplest of all animals; each contains only a few thousand cells arranged into upper and lower epithelia that sandwich an interior fluid crisscrossed by a network of multinucleate fiber cells.
Explain which phyla of animals would be deuterostome vs protostome, bilateral vs radial symmetry, Ecdysozoans vs Lophotrochozoans, etc.
Cnidarians: protostomes, radial, Bilaterians: Deuterostome, bilateral, lophotrochozoan
Explain the main structures of the eukaryotic cell
Cytoskeleton supports the cell, nuclear membrane protects the nucleus, mitochondria creates energy, endoplasmic reticulum, Golgi apparatus and plasma membrane
Explain and be able to identify examples of dependent and independent pop. density factors
Density-dependent: Describes processes affecting populations that are influenced by the number of individual organisms, such as the use of resources or susceptibility to predation or parasitism. Density-independent: Describes factors such as severe drought that influence population size without regard for the density of the population
Explain why prokaryotic cells are so small.
Diffusion limits the size of prokaryotic cells. In order to molecules to benefit the cell, it has to be small enough to diffuse into the cell.
Explain the embryological development of animals from zygote to gastrula for both diplo- and triploblastic organisms.
Diploblastic: when goes through gastrulation, the gastrula develops two layers of embryonic cells, the ectoderm and endoderm, there is also a blastopore Triploblastic: Gastrulation results in 3 layers in the gastrula: ectoderm, mesoderm, and endoderm, also has a blastopore
Explain what ecosystem ecologists study and what ecosystem services are.
Ecosystem ecologists study all living and non-living things that interact in an environment. Ecosystem services are services provided by the environment. (planet cleans water for us, etc.)
Explain in detail the process of eutrophication and what 'dead zones' are.
Eutrophication is phosphorus fertilizer runoff in waterways. It causes algae to bloom and bacteria to bloom too, which in turn absorb all the sunlight and oxygen that fish and plants underneath the water surface need. Dead zones are areas with no oxygen, caused by eutrophication
Explain how prokaryotes coevolved with eukaryotes and identify examples.
Even after the rise of eukaryotic cells and, later, plants and animals, Bacteria and Archaea have remained essential to the functioning of biogeochemical cycles and hence to the maintenance of habitable environments on Earth. Prokaryotic organisms have also radiated into the many novel environments made possible by eukaryotes. We noted earlier that bacteria fix nitrogen in nodules formed on soybean roots. Soybeans and nitrogen-fixing bacteria have evolved together, in a process called coevolution.
Explain the 'niche' concept, differentiating between the fundamental and realized niche.
Fundamental: The fundamental niche of a species includes the full range of climate conditions and food resources that permit the individuals in a species to live. Realized: The actual range of habitats occupied by a species is its realized niche.
heterozygote advantage
Greater reproductive success of heterozygous individuals compared to homozygotes; tends to preserve variation in gene pools
Horizonal Gene Transfer (conjugation, transformation and transduction)
HGT is the transfer of genetic material between organisms that are not parent and offspring. Conjugation: In bacteria, the direct transfer of DNA between two cells that are temporarily joined, usually by plasmid Transformation: DNA released into the environment by dead cells is taken up by a recipient cell Transduction: horizontal gene transfer by means of viruses
Explain how humans are impacting the carbon cycle, what the greenhouse effect is, what is currently happening and what is predicted to happen with continued climate change.
Humans are adding to the carbon cycle with fossil fuels, causing it to steadily increase over time. The greenhouse effect allows incoming solar radiation to reach Earth's surface, but traps heat that is re-emitted from land and sea. Currently, climate change is already bleaching our coral reefs and killing other animals species who cannot tolerate it, like frogs.
Competition (inter- and intraspecific, competitive exclusion, resource partitioning),
Interspecific: Competition among individuals of different species, called interspecific competition, is also common. Intraspecific: competition among the same species Competitive exclusion: Competitive exclusion is what keeps species that depend on the same resource from living at the same place at the same time Resource partitioning: Resource partitioning, the division of resources by different species living in the same habitat, can minimize competition, allowing two or more species to coexist.
Explain the limitations of the BSC
It does not apply to fossils or to bacteria.
Explain the difference between K- and R-selected species, as well as Type I, II and III survivorship curves.
K-selected species: In contrast, other species produce relatively few young but invest considerable resources in their support. These are termed K-strategists. R-selected species: Some species produce large numbers of offspring but provide few resources for their support. Such species are described as r-strategists. Type 1: survive early years, steep decline later in life (humans) Type 2: lose numbers steadily throughout life span (small animals) Type 3: many do not survive early life, but after that stage there is a slow decline of population (frogs)
Explain who Charles Keeling was and what he contributed to the field of science.
Keeling created the "Keeling Curve" which measured and explained how Co2 in the air rises and falls with the seasons.
**Describe the four main tenants of natural selection and the 'raw material' of evolution. Be able to define both terms.
Living organisms are variable, favorable traits survive, genetic variability, and reproductive success.
identify examples of animals from each of the phyla discussed.
Metazoans: sponges Cnidarians: jellyfish Bilaterians: humans
Explain ways that we can respond to climate change (hint: a 2-part approach)
Mitigate and adapt
Explain why the following statement is incorrect: "NS creates new traits and is goal-oriented." Be able to re-phrase the statement correctly.
NS is not goal oriented.
mutualism (symbiosis, obligate, facultative and facilitation), and commensalism.
Obligate: cannot survive without the mutualism Facultative: can survive without it Facilitation: Facilitation benefits one species, and harms neither involved.
Explain the 5 historic mass extinctions, and general patterns that they share.
Ordovician, Devonian, Permian, Triassic, and K-T. In mass extinctions, most organisms on the world died. The three-way insult of lack of oxygen, ocean acidification, and global warming doomed many species on land and in the seas
Explain the keystone species and trophic cascade concepts. Include how ecosystem engineers are sometimes considered keystone species
Pivotal populations are called keystone species because they support a community in much the same way that an architectural keystone supports an arch. When a keystone species is removed, other populations skyrocket, ruining an ecosystem.
Calculate changes in population size, population growth rate, per capita population growth rate and per capita pop. Growth rate with carrying capacity. (equations will be provided)
Population growth rate= ∆n-∆t Per capita population growth rate: growth rate/population
Positive/negative selection
Positive: natural selection that increases the frequency of a favorable allele Negative: Natural selection that reduces the frequency of a deleterious allele.
Explain and be able to identify examples of each of the pre- and post-zygotic reproductive isolating mechanisms
Pre-Zygotic: reproductive isolation factors that prevent fertilization from taking place; behavioral isolation, gametic isolation, mechanical incompatibility, temporal isolation, geographic/ecological isolation. Post Zygotic: reproductive isolation factors that result in the failure of the fertilized egg to develop into a fertile individual. genetic incompatibility
exploitative (predation, parasitism, herbivory),
Predation: one animals eats another Parasitism: doesn't kill, but does harm an animal's fitness herbivory: eating of plants
Coevolution
Process by which two species evolve in response to changes in each other
Explain the trophic levels in an ecosystem and be able to identify organisms in the various levels. o Explain a trophic pyramid.
Producers (at bottom), then primary consumers, secondary, etc. that go up the pyramid.
Explain the evolution of the gametophyte and sporophyte generations over evolutionary time.
Starting off, generations were reliant on the gametophyte. Now, plants rely on the sporophyte generation.
Explain what stomata are and how they open/close.
Stomata are pores in the leaves that open and close to regulate water loss and carbon gain. Light stimulates stomata to open and high levels of CO2 inside the leaf cause them to close.
Explain the Keeling Curve
The Keeling Curve shows two patterns: seasonal oscillation and a steady CO2 increase over time
Explain in detail what a scientific theory is versus what is meant by the common use of the term 'theory.'
The common use of the word theory means a "hunch or guess" whereas the scientific meaning of the word theory is a testable explanation, based on huge amounts of data, and involves expert review.
Explain the concept of the 'ecological footprint.'
The ecological footprint concept represents an attempt to quantify our individual claims on global resources by adding up all the energy, food, materials, and services we use and estimating how much land is required to provide those resources.
Explain the basic body structure of lophotrochozoans.
United largely by their molecular synapomorphies, the Lophotrochozoa include several very different types of animals. On the one hand, there are the brachiopods, bryozoans, and related phyla that have a tentacle-lined organ for filter feeding called a lophophore. On the other hand, there are the mollusks, annelid worms, and their close relatives, which develop from a type of larva called a trochophore. The odd name "lophotrochozoan" is a contraction of the terms "lophophore" and "trochophore," with "zoan" added to indicate that these organisms are animals (zoon is Greek for "animal"). The majority of lophotrochozoan species also have a distinctive form of spiral cleavage early in development.
Explain the structures and functions of xylem and phloem. Be sure to include how they both transport materials
Xylem is dead, but water moves through it via diffusion. Water goes where it is less concentrated. Phloem transports sugar. It can move whereever.
Define 'population,' and explain why ecologists study them.
a population is defined as an interbreeding groups of species living in the same area; ecologists study them. One reason why it is important to study population ranges is to help prevent human and animal conflict Another reason it is important to study population ranges is due to economic reasons.
Explain what co-speciation is.
a process in which two groups of organisms speciate in response to each other and at the same time
Adaptive vs. non-adaptive
adaptive allows organisms to adapt to the environment, anything within natural selection. non adaptive are external impacts, but don't necessarily make the organisms more fit (drought, flood)
Explain the process of ecological succession (primary, secondary, pioneer species, etc.)
after an event that causes succession, a pioneer species begins to grow on the land. then primary and secondary species after that (i.e. grasses, then shrubs)
gene pool
all the alleles present in all individuals in a population or species
non-random mating
alters genotypes frequencies without affecting allele frequencies
Mutations
any heritable change in genetic material, usually a change in the nucleotide sequence of a gene
Explain why prokaryotic phylogeny is particularly tricky to decipher.
because of horizontal gene transfer, it's hard to identify where origins come from.
Describe which phyla of organisms exhibit segmentation.
bilaterians
genetic drift
change in allele frequency due to chance
Explain what parsimony is and be able to identify the most parsimonious phylogenetic tree.
choosing the simplest hypothesis to account for a given set of observations; choosing the simplest phylogenetic tree
Explain the main characteristics that describe all living things
complexity, ability to change in response to the environment, the ability to metabolize and reproduce, and the capacity to evolve
ecological species concept
concept that there is a one-to-one correspondence between a species and its niche
Explain what the 'Modern Synthesis' is.
emphasizes importance of populations as the units of evolution; natural selection as the most important mechanism of evolution; idea of gradualism to explain how large changes can evolve as an accumulation of small changes over long periods of time
phylogenetic species concept
emphasizes that members of a specie all share a common ancestry and a common fate
Microevolution
evolutionary change within a species or small group of organisms, especially over a short period. looking at how alleles in genes in a population change over time
directional selection
leads to change in a trait over time
Explain exponential growth versus logistic growth and what influences each to occur.
exponential: Exponential growth occurs when the growth rate is constant, meaning the population grows in proportion to the number of individuals. When resources are unlimited, growth in exponential logistic: Growth is exponential at first, but then slows as the population size approaches its maximum sustainable size, K. The resulting pattern of population growth, with its characteristic S-shaped curve, is termed logistic growth.
disruptive selection
form of selection in favor of extremes and against intermediate forms, selecting against the means
Be able to interpret a phylogenetic tree, identifying grades, clades (para- and polyphyletic), and sister groups
grades: group of organisms not in a clade; either paraphyletic or polyphyletic clades: monophyletic group; includes all descendants with their common ancestor. paraphyletic: Describes groupings that include some, but not all, the descendants of a common ancestor. polyphyletic: groupings that do not include the last common ancestor of all members sister groups: groups that are more closely related to each other than either of them is to any other group
Explain the basic timeline of the evolution of land plants.
green algae first, then bryophytes, then vascular plants
Explain the factors that cause populations to grow or decline.
grow: immigration and birth decline: emigration and death
Explain in detail the 3 main threats to biodiversity.
habitat loss, overharvesting of species, and invasive species
Explain the concepts and be able to identify examples of homology, analogy and convergent evolution.
homology: characters that are similar in different species because of descent from a common ancestor analogy: describes similar characteristics that evolved independently in different groups as a result of similar selection pressures convergent evolution:
allele frequency
how often a form of a gene appears in a gene pool
Population
interbreeding group of organisms of the same species living in the same area
Characteristics of Proteobacteria, Gram-positive bacteria, photosynthetic bacteria, extremophile archaea
proteobacteria: defined largely by similarities in rRNA gene sequences; it includes many of the organisms that populate the expanded carbon cycle and other biogeochemical cycles gram-positive bacteria: Bacteria that have a thick peptidoglycan cell wall, and no outer membrane. They stain very darkly (purple) in Gram stain. photosynthetic bacteria: does not use oxygen; uses photosynthesis to create energy extremophile archaea: archaea that thrive in extreme environments, like heat, acid or salt
stabilizing selection
selects against the extremes and therefore maintains the status quo
Biological Species Concept (BSC)
species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups; most widely accepted definition of a species; more useful in theory than in practice, proposed by Ernst Mayr.
Explain the cyclical pattern of predator/prey relationships.
when prey is overhunted and they populations decrease, you will see predators decrease right afterwards because there is little prey. When prey rebounds due to lack of predators, predators will rebound shortly afterwards