BIO1011 Exam 1 Chapter 13-14-15-16
homeotic genes
Genes that determine basic features of where a body part is.
How could a microscope help you distinguish the cocci that cause "staph" infections from those that cause "strep" throat?
It would show clusters of cells for staphylococcus and chains of cells for streptococcus.
kelp
Large brown seaweed
Refer to the evolutionary tree in Figure 13.5. Are crocodiles more closely related to lizards or birds?
Look for the most recent common ancestor of these groups. Crocodiles are more closely related to birds because they share a more recent common ancestor with birds (ancestor ➎) than with lizards (ancestor ❹).
Diploid
(genetics) an organism or cell having two sets of chromosomes or twice the haploid number
Arthropods
A group of organisms that have jointed appendages, an exoskeleton, bilateral symmetry, and reproduce sexually; insects, arachnids, millipedes and cenitpedes, and crustaceans
Scientific evidence indicates that Earth formed about
4.5 billion years ago from a vast swirling cloud of dust that surrounded the young sun.
Species
A group of similar organisms that can breed and produce fertile offspring.
Three key points about evolution by natural selection
1. although natural selection occurs through interactions between individual organisms and the environment, individuals do not evolve. Rather, it is the population—the group of organisms—that evolves over time as adaptive traits become more common in the group and other traits change or disappear. 2.natural selection can amplify or diminish only heritable traits. Certainly, an organism may become modified through its own interactions with the environment during its lifetime, and those acquired characteristics may help the organism survive. But unless coded for in the genes of an organism's gametes, such acquired characteristics cannot be passed on to offspring. Thus, a championship female bodybuilder will not give birth to a muscle-bound baby. 3. evolution is not goal directed; it does not lead to perfectly adapted organisms. Whereas artificial selection is a deliberate attempt by humans to produce individuals with specific traits, natural selection is the result of environmental factors that vary from place to place and over time. A trait that is favorable in one situation may be useless—or even detrimental—in different circumstances. And as you will see, adaptations are often compromises. Now let's look at some examples of natural selection.
Chlamydia
A bacterial infection that affects the reproductive organs of both males and females
pseudopodia
A cellular extension of amoeboid cells used in moving and feeding.
Mutation
A change in a gene or chromosome information encoded in the DNA
Research shows that many differences in body form are caused by changes in gene regulation and not changes in the nucleotide sequence of the developmental gene itself. Why might this be the case?
A change in sequence may affect a gene's function wherever that gene is expressed—with potentially harmful effects. Changes in the regulation of gene expression can be limited to specific areas in a developing embryo.
Genus
A classification grouping that consists of a number of similar, closely related species
Symbiosis
A close relationship between two species that benefits at least one of the species.
phylogenetic species concept
A definition of species as the smallest group of individuals that share a common ancestor, forming one branch on the tree of life.
ecological species concept
A definition of species in terms of ecological niche, the sum of how members of the species interact with the nonliving and living parts of their environment.
Proteobacteria
A diverse clade of gram-negative bacteria that encompasses enormous diversity, including all four modes of nutrtion
What is a general definition for "protist"?
A eukaryote that is not an animal, fungus, or plant
evo-devo (evolutionary developmental biology)
A field of biology that compares developmental processes of different multicellular organisms to understand how these processes have evolved and how changes can modify existing organismal features or lead to new ones.
Clade
A group of species that includes an ancestral species and all its descendants.
molecular clock
A molecular clock estimates the actual time of evolutionary events based on the number of DNA changes. It is based on the assumption that some regions of genomes evolve at constant rates.
Contrast the plasmodium of a plasmodial slime mold with the slug-like stage of a cellular slime mold.
A plasmodium is not multicellular, but is one cytoplasmic mass with many nuclei; the slug-like stage of a cellular slime mold consists of many cells.
Endotoxins
A poisonous component of the outer membrane of gram-negative bacteria that is released only when the bacteria die.
Exotoxins
A poisonous proteins secreted by certain bacteria and other organisms
natural selection
A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
Amoebozoans
A protist in a clade that includes many species with lobe- or tube-shaped pseudopodia.
molecular systematics
A scientific discipline that uses nucleic acids or other molecules in different species to infer evolutionary relationships.
plate tectonics
A theory stating that the earth's surface is broken into plates that move.
Endospore
A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions.
geological record
A time scale established by geologists that divides Earth's history into time periods, grouped into three eons— Archaean, Proterozoic, and Phanerozoic— and further subdivided into eras, periods, and epochs.
Adaptation
A trait that helps an organism survive and reproduce
Ameobas
A type of protist characterized by great flexibility and the presence of pseudopodia.
plasmodial slime molds
A type of protist that has amoeboid cells, flagellated cells, and an amoeboid plasmodial feeding stage in its life cycle.
cellular slime molds
A type of protist that has unicellular amoeboid cells and a multicellular reproductive body in its life cycle
Diatoms
A unicellular photosynthetic alga with a unique glassy cell wall containing silica
Theory
A widely accepted explanatory idea that is broader in scope than a hypothesis, generates new hypotheses, and is supported by a large body of evidence.
Explain why the concept of exaptation does not imply that a structure evolves in anticipation of some future environmental change.
Although a structure is co-opted for new or additional functions in a new environment, the structure existed because it worked as an adaptation in the old environment.
Allele
An alternative form of a gene.
shared derived character
An evolutionary novelty that is unique to a particular clade.
Haploid
An organism or cell having only one complete set of chromosomes.
mixotroph
An organism that is capable of both photosynthesis and heterotrophy.
Chemoheterotrophs
An organism that must consume organic molecules for both energy and carbon.
Photoheterotrophs energy
An organism that uses light to generate ATP but that must obtain carbon in organic form.
What types of animals do you think would be most represented in the fossil record? Explain your answer.
Animals with hard parts, such as shells or bones that readily fossilize, and those that lived in areas where sedimentary rock may form
Cyanobacteria
Bacteria that can carry out photosynthesis. The only group of prokaryotes with plantlike, oxygen-generating photosynthesis
Three domains of life
Bacteria, Archaea, Eukarya
Some archaea are referred to as "extremophiles." Why?
Because they can thrive in extreme environments that are too hot, too salty, or too acidic for other organisms
Females of the Galápagos finch Geospiza difficilis respond to the songs of males from their island but ignore songs of males from other islands. How would you interpret these findings?
Behavioral barriers to reproduction have begun to develop in these allopatric (geographically separated) finch populations.
phylogenic trees
Branching diagrams used to illustrate evolutionary relationships.
Volcanoes usually destroy life. How might undersea volcanoes create new opportunities for life?
By creating new landmasses on which life can evolve, such as the Galápagos and Hawaiian Islands
Why might hybrid zones be called "natural laboratories" in which to study speciation?
By studying the fate of hybrids over time, scientists can directly observe factors that cause (or fail to cause) reproductive isolation.
Autotrophs, including plants and some prokaryotes and protists, obtain their carbon atoms from:
CO2
Chance, natural selection, and the environment interact.
Chance, natural selection, and the environment interact. Chance events often affect the genetic makeup of populations. When a storm blows insects over an ocean to an island, the wind does not necessarily transport the individuals that are best suited to the new environment. In small populations, genetic drift can result in the loss of beneficial alleles. In addition, the environment may change unpredictably from year to year, again limiting the extent to which adaptive evolution results in a close match between organisms and the environment.
morphological species concept
Defines a species by structural features; applies to sexual and asexual species but relies on subjective criteria
Biofilms
Colonies of bacteria that adhere together and adhere to environmental surfaces.
gene pool
Combined genetic information of all the members of a particular population
What was Darwin's phrase for evolution? What does it mean?
Descent with modification. An ancestral species could diversify into many descendant species by the accumulation of adaptations to various environments.
Taxonomy order
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Adaptations are often compromises
Each organism must do many different things. A blue-footed booby uses its webbed feet to swim after prey in the ocean, but these same feet make for clumsy travel on land.
Evolution is limited by historical constraints
Each species has a legacy of descent with modification from ancestral forms. Evolution does not scrap ancestral anatomy and build each new complex structure from scratch. Rather, it co-opts existing structures and adapts them to new situations. Thus, as birds and bats evolved from four-legged ancestors, their existing forelimbs took on new functions for flight and each lineage was left with only two limbs for walking.
Why does rapid reproduction produce high genetic variation in populations of prokaryotes?
Each time DNA replicates, spontaneous mutations may occur.
How do the nutritional modes of Euglena and Trichomonas differ?
Euglena is mixotrophic; Trichomonas is strictly heterotrophic.
Why can't an individual evolve?
Evolution involves changes in the genetic makeup of a population over time. An individual's genetic makeup rarely changes during its lifetime.
What Island did Darwin visited?
Galapagos
Macroevolution
Evolutionary change above the species level.
Phylogeny
Evolutionary history of a species
Exotoxins VS Endotoxins.
Exotoxins are proteins secreted by pathogenic bacteria; endotoxins are components of the outer membranes of pathogenic bacteria.
Kingdom
First and largest category used to classify organisms
Who wrote a groundbreaking paper on inheritance in pea plants?
Gregor Mendel
Phylum
Group of closely related classes
Dinoflagellates
Group of protists that form "blooms", can be toxic. make up phytoplankton and can be bioluminescent. They generally have two flagella, half are heterotrophic and the other half are photosynthetic, many species are luminescent
To distinguish a particular clade of mammals within the larger clade that corresponds to class Mammalia, why is hair not a useful character?
Hair is a shared ancestral character common to all mammals and thus is not helpful in distinguishing different mammalian subgroups.
Galapagos Islands
Home to many unique species, such as the marine iguanas
What is homology? How does the concept of homology relate to molecular biology?
Homology is similarity in different species due to evolution from a common ancestor. Similarities in DNA sequences or proteins reflect the evolutionary relationship that is the basis of homology.
How does the punctuated equilibrium model account for the relative rarity of transitional fossils linking newer species to older ones?
If speciation takes place in a relatively short time or in a small isolated population, the transition of one species to another may be difficult to find in the fossil record.
How might an influx of toxic chemicals affect the ability of a wastewater treatment plant to treat sewage?
If the toxic chemicals kill the prokaryotic decomposers, the organic matter in sewage will not be decomposed.
Compare artificial selection and natural selection.
In artificial selection, humans choose the desirable traits and breed only organisms with those traits. In natural selection, the environment does the choosing: Individuals with traits best suited to the environment survive and reproduce most successfully, passing those adaptive traits to offspring.
In what way do multicellular organisms differ fundamentally from unicellular ones?
In unicellular organisms, all the functions of life are carried out within a single cell. Multicellular organisms have specialized cells that perform different functions.
What lines of evidence support the conclusion that sexual selection led to reproductive isolation between P. nyererei and P. pundamilia?
Mate-choice experiments performed in the laboratory; difference in color vision of females of the two species; difference in breeding location
How does microevolution differ from speciation?
Microevolution involves evolutionary changes within a population; speciation occurs when a population changes enough that it diverges from its parent species and becomes a new species.
For how long did life on Earth consist solely of single-celled organisms?
More than 2 billion years: From the first fossils of prokaryotes (3.5 billion years old) until the oldest known fossils of multicellular eukaryotes (1.2 billion years old)
What is the ultimate (original) source of genetic variation? What is the source of most genetic variation in a population that reproduces sexually?
Mutation; unique combinations of alleles resulting from sexual reproduction
Systematics
The science of naming and grouping organisms into groups that have biological meaning
In what sense is natural selection more an editing process than a creative process?
Natural selection cannot create beneficial traits on demand but instead "edits" variation in a population by selecting for individuals with those traits that are best suited to the current environment.
Stromatolites
Oldest known fossils formed from many layers of bacteria and sediment. (photosynthetic prokaryotes)
brown algae
One of a group of marine, multicellular, autotrophic protists, the most common type of seaweed. Brown algae include the kelps.
Unikonta
One of five supergroups of eukaryotes proposed in a current hypothesis of the evolutionary history of eukaryotes. This clade, which is supported by studies of myosin proteins and DNA, consists of amoebozoans and opisthokonts.
SAR
One of four supergroups of eukaryotes proposed in a current hypothesis of the evolutionary history of eukaryotes. This supergroup contains a large, extremely diverse collection of protists from three major subgroups: stramenopiles, alveolates, and rhizarians.
Archaeplastida
One of the five supergroups of eukaryotes. It includes red algae, green algae, and land plants, descended from an ancient protist ancestor that engulfed a cyanobacterium. (autotrophic)
Photoautotrophs energy
Organisms that use light as a source of energy to synthesize organic substances.
monophyletic
Pertaining to a group of taxa that consists of a common ancestor and all of its descendants. A monophyletic taxon is equivalent to a clade.
Taxonomy
The scientific study of how living things are classified
crossing over
Process in which homologous chromosomes exchange portions of their chromatids during metaphase 1 of meiosis.
What characteristic is shared by bacteria and archaea, but not by eukaryotes?
Prokaryotic cells, which lack nuclei and other membrane-enclosed organelles
Rybozymes
RNA molecules that function as enzymes
What characteristics of unicellular algae make them attractive candidates for the production of biofuels?
Rapid reproduction; would not occupy farmland needed to grow food crops
What anatomical feature did scientists predict in fossils of species transitional between terrestrial and aquatic mammals?
Reduced hind limb and pelvic bones
peptidoglycan cell wall
Repeating framework of long glycan (sugar) chains cross-linked by short peptide (protein) fragments Present in most bacteria Provides strength to resist rupturing due to osmotic pressure
Bacilli
Rod shaped bacteria
Why would the formation of protocells represent a key step in the evolution of life?
Segregating mixtures of molecules within compartments could concentrate organic molecules and facilitate chemical reactions. Natural selection could act on protocells once self-replicating "genes" evolved.
reproductive isolation
Separation of species or populations so that they cannot interbreed and produce fertile offspring
Analogy
Similarity between two species that is due to convergent evolution rather than to descent from a common ancestor with the same trait.
Which groups of Stramenopila, Alveolata, and Rhizaria include autotrophs?
Stramenopila: diatoms, brown algae; Alveolata: dinoflagellates; Rhizaria: none
homologous structures
Structures in different species that are similar because of common ancestry.
Why is the DNA that specifies rRNA useful for determining whether fungi are more closely related to plants or to animals?
The DNA that specifies rRNA changes very slowly, which makes it useful for studying the relationships of organisms that diverged long ago.
Earth's history can be divided into four eons of geologic time. What are they?
The Hadean, Archaean, and Proterozoic eons together lasted about 4 billion years. The Phanerozoic eon includes the last half billion years.
Why are biofilms difficult to eradicate?
The biofilm sticks to the surface it resides on, and the cells that make up the biofilm stick to each other; the outer layer of cells may prevent antimicrobial substances from penetrating into the interior of the biofilm.
Explain why isolated island chains provide opportunities for adaptive radiations.
The chance colonization of an island often presents a species with new resources and an absence of predators. Through natural selection acting on existing variation, the colonizing population becomes adapted to its new habitat and may evolve into a new species. Subsequent colonizations of nearby islands would provide additional opportunities for adaptation and genetic drift, which could lead to further speciations.
allopatric speciation
The formation of new species in populations that are geographically isolated from one another.
sympatric speciation
The formation of new species in populations that live in the same geographic area
example of heterozygote advantage
The frequency of the sickle-cell allele is generally highest in areas where malaria is a major cause of death, such as West Africa
How does chromosome number differ in the gametophyte and sporophyte in the alternation of generations life cycle?
The gametophyte is haploid (n); the sporophyte is diploid (2n).
Evolution
The gradual change in a species over time
What would a scientist change in Miller's apparatus to incorporate new evidence about Earth's early atmosphere?
The mixture of gases in the second flask (labeled 2 in Figure 15.2)
Which species concepts could you apply to both asexual and sexual species? Explain.
The morphological, ecological, and phylogenetic species concepts could all be used because they do not rely on the criterion of reproductive isolation.
Hybrids
The offspring of two different varieties
gametophyte
The stage in the life cycle of a plant in which the plant produces gametes, or sex cells.
sporophyte
The stage in the life cycle of a plant in which the plant produces spores.
horizontal gene transfer
The transfer of genes from one genome to another through mechanisms such as transposable elements, plasmid exchange, viral activity, and perhaps fusions of different organisms.
Explain why the following statement is incorrect: "Antibiotics have created resistant bacteria."
The use of antibiotics did not cause bacteria to make new alleles. Rather, antibiotic use has increased the frequency of alleles for resistance that were already naturally present in bacterial populations.
Bioremediation
The use of living organisms to detoxify and restore polluted and degraded ecosystems
How are Thiomargarita namibiensis similar to the cyanobacteria?
They are both photoautotrophic.
T/F Endospores can survive all sorts of trauma, and some can remain dormant for decades, even centuries.
True!
T/F The evolutionary impact of natural selection is only apparent in the changes in a population of organisms over time.
True!
T/F Evolution is not goal directed.
True!
The number of bacterial cells that live in and on our body is greater than the number of eukaryotic cells that make up the body. Why aren't we aware of these trillions of cells?
We can't sense our own eukaryotic cells individually, and bacterial cells are much smaller than that. Also, our microbiota are adapted for coexisting with us.
Pathogen
a bacterium, virus, or other microorganism that can cause disease.
Microevolution
a change in a population's gene pool over generations
Endosymbiosis
a mutually beneficial relationship in which one organism lives within another
paleonthologist
a person who studies fossils or dinosaurs
Ciliates
a type of protozoa that moves using hairlike cilia
Heritability
ability of a trait to be passed from one generation to the next
The evolution of many diverse species from a common ancestor is known as:
adaptative radiation
French scientist Louis Pasteur in 1862, confirmed that
all life arises only by the reproduction of preexisting life.
Foraminiferans
amoeba like protist that has a shell and looks like a snail.
Plasmodium
amoeboid feeding stage in the life cycle of a plasmodial slime mold
Methanogens
an archaean that produces methane as a metabolic waste product
Tetrapods
animals with four limbs, including humans
Protozoans
are heterotrophs, eating bacteria and other protists.
Chemoautotrophs energy
arvest energy from inorganic chemicals and use carbon from Co2 to make organic molecules
Organisms that make their own organic compounds from inorganic sources are:
autotrophic
Dental plaque is an example of
biofilm
Prokaryotes called chemotrophs gets energy from?
chemicals, either organic molecules or inorganic chemicals.
Polyploidy
condition in which an organism has extra sets of chromosomes
organic compounds
contain carbon
punctuated equilibrium
describe these long periods of little apparent morphological change (equilibria) interrupted (punctuated) by relatively brief periods of sudden change
Both freshwater and marine environments are rich in
diatoms
Stramenopila
diatoms, brown algae, water molds
Alveolata
dinoflagellates, apicomplexans, ciliates
inorganic compounds
do not contain carbon
Rhizaria
foraminiferans and radiolarians
Parasite nutrition
from a living host
Speciation occurs only when the _____ ______ undergoes changes that establish reproductive barriers.
gene pool
Population
group of individuals of the same species that live in the same area
Two closely related fish live in the same lake, but one feeds along the shoreline and the other is a bottom feeder in deep water. This is an example of ________ isolation, which is a ________ reproductive barrier.
habitat prezygotic
fimbriea
hairlike extensions of bacteria that allow them to attach to surfaces and cause disease
Natural selection can only modify _______ traits
heritable
Most prokaryotes, as well as animals, fungi, and some protists, are:
heterostrophs
water molds
heterotrophic unicellular stramenopiles that typically decompose dead plants and animals in freshwater habitats.
homologous vs analogous
homo- structures share a common ancestry ana- structures are nor inherited from a common ancestor, but perform similar functions
Human forearms and a bat's wings are __________. A bat's wings and a bee's wings are __________.
homologous analogous
order
in classification, a group of closely related families
Each time speciation occurs, the diversity of life_____.
increases
Protists
is a unicellular eukaryotic organism that cannot be classified as an animal, plant, or fungus.
Pangaea
large, ancient landmass that was composed of all the continents joined together
In The Origin of Species, Darwin provided evidence that
life on Earth has evolved over time, and he proposed that natural selection, in favoring some heritable traits over others, was the primary mechanism for that change
radiometric dating
method used to determine the age of rocks using the rate of decay of radioactive isotopes
Selection can act only on existing variations
natural selection favors only the fittest phenotypes among those currently in the population, which may not be the ideal traits. New advantageous alleles do not arise on demand
The first atmosphere was probably thick with water vapor, along with various compounds released by volcanic eruptions, including:
nitrogen and its oxides, carbon dioxide, methane, ammonia, hydrogen, and hydrogen sulfide.
balancing selection
occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population
Eukaryote
organism whose cells contain a nucleus
Algae nutrition
photosynthesis
prezygotic barriers
prevent mating or fertilization between species
postzygotic barriers
prevent the hybrid zygote from developing into a viable, fertile adult
Barry Marshall and Robin Warren
proved that peptic ulcers were caused by bacteria
hybrid zone
regions in which members of different species meet and mate, producing at least some hybrid offspring.
vestigial structures
remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.
extreme halophiles (archaea)
salt loving
analogous
similar
Homology
similarity resulting from common ancestry
The process of speciation is generally extremely ______
slow (we can see speciation occurring)
Plasmids
small circular DNA molecules that replicate separately from the bacterial chromosome
Cocci
spherical bacteria
Spirochetes
spiral-shaped bacteria that have flexible walls and are capable of movement
exaptations
structures that evolve in one context but become co-opted for another function
Prokaryotic phototrophs energy source?
sunlight
Microbiota
the community of microorganisms that live in and on our bodies
Excavata
the eukaryotic supergroup that contains flagellated single-celled organisms with a feeding groove. (diplomonads, parabasalids, euglenozoans)
convergent evolution
the evolution of similar features in different evolutionary lineages, which can result from living in very similar environments.
Microbiome
the microorganisms in a particular environment
Speciation
the process by which one species splits into two or more species
Paedomorphosis
the retention in the adult body of structures that were juvenile features in an ancestral species.
parsimony
the search for the least complex explanation for an observed phenomenon
Metagenomics
the study of genetic material recovered directly from environmental samples
molecular biology
the study of heredity (gene, DNA) at the molecular level
biogeography
the study of the past and present distribution of organisms
Where does heterotrophs get their energy from?
they obtain their carbon atoms from the organic compounds of other organisms.
extreme thermophiles
thrive in very hot environments
Binomial
two-part format of the scientific name
heterozygote advantage
type of balancing selection in which heterozygous individuals have greater reproductive success than either type of homozygote, with the result that two or more alleles for a gene are maintained in the population.
Prokaryote
unicellular organism that lacks a nucleus