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