BIOLOGY Practice questions exam 1

The three domains of life __________

are bacteria, archaea, and eukarya

Homologies that appear to have marginal, if any, importance to an organism are called _______

vestigial structures

How does our understanding of genetics today refute Lamarck’s principle of the inheritance of acquired characteristics?

Experiments in genetics show that traits acquired during an individual’s lifetime are not inherited in the way proposed by Lamarck

Adaptations are defined as _____

nherited characteristics of organisms that enhance their survival and reproduction in specific environments

The bacteria Staphylococcus aureus has developed resistance to some antibiotic drugs. How did this resistance come about?

Some members of the bacteria populations possessed some sort of genetic variation for antibiotic resistance that was selected for when the bacteria was exposed to the drugs.

How did Hutton and Lyell’s ideas influence Charles Darwin’s thinking?

Darwin reasoned that the Earth must be very old and that slow, subtle processes could produce substantial biological changes.

Which of the following is not an observation or inference that Darwin made while developing his theory of evolution

Interactions between individuals and their environments cause individuals to evolve

All known organisms transcribe genetic information to protein molecules via the same genetic code. This finding strongly supports the hypothesis that

all organisms are descended from a single common ancestor

not an observation or inference on which natural selection is based?

poorly adapted organisms never reproduce

A(n) __________ is the smallest unit that can evolve.

population

Darwin originally defined evolution as __________

descent with modification

Even though rodents known as sugar gliders and flying squirrels are members of distinctly different groups of organisms and live on different continents, they possess similar characteristics.

convergent evolution

What insight did Darwin gain from reading Thomas Malthus’s essay on human suffering?

organisms have capacity to overproduce

Animals that possess homologous structures probably __________.

evolved from the same ancestor

An important challenge to traditional (pre-1860) ideas about species was the observation that seemingly dissimilar organisms such as hummingbirds, humans, and whales have similar skeletal structures.

This most directly suggested to biologists that ___

dissimilar organisms might have evolved from a distant, common ancestor

During periods of rapid environmental change, what may happen to a species that was well-suited to the former environment?

the species may go extinct, individuals with particular traits that provide an advantage in the new environment will have higher reproductive success, the population may change so much in adapting to the new environment that it is considered a new species, and traits that were favorable in the original environment may be detrimental in the new environment. When environments change, species will either adapt, possibly giving rise to new species, or go extinct.

A population of zooplankton is exposed to a small number of predatory fish that feed on the larger-sized (adult) zooplankton. Which of the following predictions would most likely occur based on the principles of natural selection?

Adult zooplankton will start to reach sexual maturity when they are still relatively small.

In Darwin’s view of descent with modification, _________

natural selection can improve the match between an organism and its environment

At the time Darwin voyaged on the HMS Beagle, the popularly accepted theory in Western culture that explained the origin of Earth’s plants and animals held that the various species __________.

had been created by divine intervention a few thousand years before

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time

Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy

Darwin’s explanation of how adaptations arise centered on __________.

natural selection

Organisms found only in specific places in the world are referred to as

endemic

Carolus Linnaeus is considered to be the founder of __________, and he

the binomial classification system; thought that resemblances among different species reflected the pattern of their creation

Which of the following people developed the idea known as the scala naturae, or scale of nature?

aristotle

What does each branch point on an evolutionary tree represent?

The common ancestor of the lineages beginning there and to the right of it

The modern idea of extinction as a common occurrence in Earth’s history was first proposed in the early 19th century writings of _________

Cuvier

On an evolutionary tree, __________.

homologous characteristics form a nested pattern

Inductive Reasoning

…

Regulation of molecules within an organism in response to a changing level of chemicals and the ability to self-regulate is called __________.

feedback regulation

attribute of all living things

…

The energy used by most organisms for metabolism and growth ultimately comes from

the sun

Which observations and inferences led Charles Darwin to his theory of natural selection as a mechanism for evolution?

Individuals in a population of any species vary in many heritable traits. Individuals with heritable traits best suited to the local environment will generally produce a disproportionate number of healthy, fertile offspring. A population of any species has the potential to produce far more offspring than will survive to produce offspring of their own. Individuals of a population are unequal in the likelihood of surviving and reproducing.

The fundamental organizing principle of biology and core theme is __________.

evolution

Reductionism

is a strategy for studying life which reduces complex systems to simpler components that are more manageable. It is not a property or process associated with life itself.

With evolution as the core theme of biology, we can explain traits shared by organisms as evidence of __________ and traits that differ among organisms as evidence of __________.

descent from a common ancestor; adaptation through natural selection

The units of inheritance are called __________.

genes

The use of energy by living organisms __________.

involves chemical cycling from light energy from the sun for the production of chemical energy in food to the decomposition and the returning of chemicals to the cycle

What is the appropriate term for an interacting group of individuals of a single type occupying a defined area?

Population

A nonlinear, realistic model of the scientific process is called the process of science. The core activity of this process is __________.

forming and testing hypotheses

Which of the following statements best describes what is meant by "emergence"?

The whole is greater than the sum of the parts.

In the theme of biological organization, the approach called reductionism ________

allows us to reduce complex systems to simpler components that are more manageable to study

Hierarchy of Organization from least to most complex.

…

Using models that represented camouflaged and non-camouflaged mice, Hoekstra and her students tested the hypothesis that coloration of beach and inland mice provides camouflage that protects them from predation.

Regardless of whether the models were placed in the beach or the inland habitat, the camouflaged model always acted as the __________ group

control

Which of the following is the smallest unit of organization that can perform all activities required for life?

cell

The genetic material within cells is called __________ and is organized into structures called __________.

DNA; chromosome

A hypothesis must be testable and falsifiable to be scientifically valid. Being testable and falsifiable means that __________

some conceivable observation or experiment could reveal whether a given hypothesis is incorrect

What is the molecule that can account for both the unity and the diversity of life?

DNA

The process that directs the manufacture of a cell product from a gene is called __________

gene expression

Natural selection tends to act at which of the following levels?

population

The concept of "descent with modification" was proposed by __________he concept of "descent with modification" was proposed by __________

charles darwin

The information in a gene that directs the production of a cellular product is gene expression. The correct sequence for the transfer of information from a gene to a function protein is _________

transcription, translation and protein folding

A scientific theory is __________.

a well-supported concept that has broad explanatory power

How is the information encoded in DNA actually used by organisms?

he information in DNA is transcribed to RNA and then translated into protein.

Feedback regulation includes __________.

both negative feedback where the pathway shuts down and positive feedback where the pathway speeds up

Paleontology, the study of fossils, was developed by __________.

Georges Cuvier

The fossil record is __________.

biased in favor of species that existed for a long time

What evidence most strongly suggests that an impact by an asteroid or meteorite may have caused the extinction of the dinosaurs?

Sedimentary rocks contain a layer of iridium, a mineral uncommon on Earth

Which of the following is a true statement about the current status of Earth’s biodiversity?

The current rate of extinctions is as high as 1,000 times the typical rate seen in the fossil record.

Single-celled prokaryotes had the Earth to themselves for approximately

1.5 billion years

The original atmosphere of Earth had little oxygen. What was the likely first source of oxygen that led to an oxygen atmosphere?

Cyanobacteria

What was one ecological change that occurred following the Permian mass extinction?

The percentage of marine predators increased.

Adaptive radiations can be a direct consequence of

…

Which of the following is the correct ordering of divisions of the geologic record from largest to smallest?

eon, era, period, epoch

unique anatomical features of mammals that can be recognized in the fossil record?

…

What were the two major "problems" that had to be solved before plants, animals, and fungi could move into terrestrial habitats?

Reproduction and prevention of dehydration

Why is RNA, rather than DNA, thought to have been the first genetic material?

RNA can also function as a catalyst

Prior to the Cambrian explosion, all large animals had what characteristic in common?

They were all soft-bodied

In the species selection model, __________ is to macroevolution as __________ is to microevolution.

differential speciation success; differential reproductive success

The correct order of the geologic eras, from most ancient to most recent, is __________.

Paleozoic, Mesozoic, and Cenozoic

Which of the following is not an internal structure that appears in eukaryotic cells and was also not present in more ancient prokaryotic cells?

Vesicles

Although they originated around 180 million years ago, mammals underwent an adaptive radiation starting approximately 65 million years ago. Why?

Between 180 and 65 million years ago, mammals were outcompeted by the well-established dinosaurs.

Which of the following would not have been a consequence of tectonic plate movements bringing previously separated landmasses together in the formation of the supercontinent of Pangaea about 250 million years ago?

Allopatric speciation increased

You are watching a movie in which one of the characters excitedly claims to have found human remains in Asia dated at 10 million years old. The date was obtained by carbon-14 dating.

This can’t possibly be true because carbon-14 dating can only be used back to about 75,000 years.

The amphibians, reptiles, and mammals comprise which group?

tetrapods

The Miller and Urey abiotic synthesis experiment (and subsequent, similar experiments) showed that __________.

simple organic molecules can form spontaneously under conditions like those thought to prevail early in Earth’s history

Fossilized stromatolites __________.

resemble structures formed by bacterial communities that are found today in some warm, shallow, salty bays

Which of the following is a true statement concerning the history of Earth’s biological diversity?

The majority of species that ever lived are now extinct.

If the wings of extant flying birds originally arose as thermoregulatory devices in ancestral reptiles, then the bird wings could be accurately described as __________.

exaptations

The ratio of carbon-14 to carbon-12 in a fossil can be used to determine the age of the fossil because __________.

carbon-14, unlike carbon-12, decays at a continuous rate after the death of an organism

Retention of juvenile body features into sexual maturity is referred to as the presence of __________.

paedomorphosis

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb
This type of change is illustrative of

a change in a developmental gene or in its regulation that altered the spatial organization of body parts

The early atmosphere may not have been as reducing as originally postulated by Haldane, Oparin, Miller, and Urey. In light of current thinking about the composition of the early atmosphere, what is regarded as a likely place for the abiotic synthesis of organic molecules to have occurred?

Near volcanoes

Why is the four-stage hypothesis for the abiotic origin of life useful?

It leads to predictions that can be tested.

Macroevolution differs from microevolution in that macroevolution __________.

includes broad evolutionary changes above the species level

What evidence supports the hypothesis that mitochondria and plastids evolved from prokaryotic endosymbionts?

They have a single circular chromosome similar to bacterial chromosomes; their ribosomes are more like prokaryotic ribosomes than eukaryotic ribosomes

Rabbits and guinea pigs both belong to class Mammalia. This means they must also both belong to __________.

phylum Chordata

The binomial system assigns to each organism a unique name that describes its __________.

genus and species

Which of the following is an assumption that should be made when reading a phylogenetic tree?

None of the listed assumptions should be made.

By applying a molecular clock, researchers have proposed that the first HIV-1 M invasion into humans occurred in the __________.

1930s

What is a primary reason why a three-domain taxonomic scheme has been adopted over the previous five-kingdom taxonomic scheme

Phylogenies based on genetic data revealed that some prokaryotes (kingdom Monera) differ as much from each other as they differ from eukaryotes.

Which of the following is a true statement concerning horizontal gene transfer?

Which of the following is a true statement concerning horizontal gene transfer?

Birds and mammals have a four-chambered heart, but most reptiles have a three-chambered heart. How does this fact affect the construction of phylogenetic trees for these groups?

The most likely tree is not always the most parsimonious.

Which of the following best summarizes the neutral theory?

Darwinian selection does not influence a lot of evolutionary change in genes and proteins because many of these changes do not affect fitness.

To which domain is the domain Eukarya (the domain to which humans belong) most closely related?

It is not clear whether eukaryotes are more closely related to bacteria or archaea.

Researchers can use molecular homologies to __________.

reveal the number of mutations in a particular sequence that has occurred in each species since they diverged from a common ancestor

If you wanted to determine the lineage of plants that have evolved on a relatively young archipelago—approximately 15,000 years old—what type of nucleic acid should you compare?

mtDNA

What is the relationship between systematics and taxonomy?

Systematics is a discipline within taxonomy.

The idea of using molecules as clocks to time evolutionary events is very attractive, but there are many problems in actually applying the technique. What seems to be the best way to get reliable results?

It is important to use as many genes as possible. With this approach, fluctuations in evolutionary rate will tend to average out

A phylogenetic tree of bird families constructed by cladistic analysis would be a hypothesis about which of the following?

Evolutionary relationships among bird families

Three living species X, Y, and Z share a common ancestor T, as do extinct species U and V. A grouping that consists of species T, X, Y, and Z (but not U or V) makes up __________.

a paraphyletic group

In a cladistic approach to systematics, an outgroup is __________.

a species or group of species from an evolutionary lineage that is known to have diverged before the lineage that includes all the species under study

What is the basis for the use of a molecular clock to determine the absolute time of evolutionary change

Nucleotide substitutions in a gene occur at a relatively constant rate.

A taxon __________

is a formal grouping at any given level

In cladistics, biologists attempt to place species into groups that each include an ancestral species and all of its descendants. A group that is paraphyletic fails to accomplish this goal in what way?

It consists of an ancestral species and some, but not all, of its descendants

Why are phylogenetic trees considered hypotheses

they can be used to make testable predictions

Which of the following would be the least useful in determining the relationships among various species?

Analogous structures

A bald eagle and a black bear both have four limbs with digits because they are both tetrapods, descendants of a four-limbed ancestor. In this comparison, the limbs of the eagle and the bear are what type of structure

Homologous

Sister taxa on a phylogenetic tree are defined as groups that ____

share an immediate common ancestor and are each other’s closest relatives

The term polytomy refers to a situation in which __________

there is a branch point on a phylogeny from which more than two descendent groups emerg

principle of maximum parsimony is applied to the process of constructing a phylogenetic tree in what way?

tree that requires the fewest evolutionary events, as measured by the origin of shared derived characters, is selected.

Using cladistic analysis, a taxonomist wishes to construct a phylogenetic tree showing the relationships among various species of mammals. Which of the following would be the least useful for this purpose?

The fact that all mammals have hair

two genes are recognized as orthologous if __________.

they are homologous genes found in different species, and their divergence traces back to speciation events that produced the specie

The separate lineages leading to dolphins and sharks both evolved streamlined bodies, dorsal fins, and broad tail fins as adaptations to efficient locomotion in a marine environment. In this comparison, the bodies and fins of dolphins and sharks are what type of structures

Analogous

Which of the following is the correct order of taxonomic levels in the Linnean system of classification, from most to least inclusive

Domain, kingdom, phylum, class, order, family, genus, species

Which subgroup of proteobacteria contains many species that are predators of other bacteria?

Delta

Which group of bacteria is unusual in that they lack peptidoglycan in their cell walls?

Chlamydias

Which of the following statements about cyanobacteria is true

Cyanobacteria are photoautotrophs that conduct plantlike photosynthesis, during which they split water, liberating oxygen. Some cyanobacteria are able to use atmospheric nitrogen directly as a source of nitrogen. These photoautotrophs are the only prokaryotes with plantlike, oxygen-generating photosynthesis. Both solitary and filamentous cyanobacteria are abundant components of freshwater and marine phytoplankton, the collection of photosynthetic organisms that drift near the water’s surface.

Which of the following mechanisms is/are (a) means of genetic recombination in prokaryotes?

transformation, transduction, conjucation,

Some prokaryotes stick to their substrate or to one another by means of hairlike appendages, each called a __________.

fimbria

Which of the following does not contribute to bacteria’s ability to evolve rapidly?

Sexual reproduction

In an experiment, a microbiologist put equal numbers of each of the following organisms into a flask of sterile broth, consisting mostly of sugar and a few amino acids. She then placed the flask in the dark.
Which of the following organisms would be most likely to survive?

Chemoheterotrophic bacteria

Bacterial flagellum are_____ to eukaryotic flagellum

analogous

What is the structural feature of gram-positive bacteria that results in their retaining a crystal violet dye stain and thereby being distinguished from gram-negative bacteria in a Gram-stain technique?

Gram-positive bacteria have thicker cell walls

Bacteria that __________ tend to have abundant internal membranes.

are photosynthetic

Choose the list below that contains the substances required by typical nitrogen-fixing cyanobacteria

Carbon dioxide, nitrogen, water, light, and some minerals

Which subgroup of proteobacteria contains many species that are closely associated with eukaryotic hosts in mutualistic or parasitic relationships?

Alpha

What are biofilms?

Biofilms are cooperative colonies of bacteria

An F+ bacterial cell __________.

acts as a donor during conjugation

The Desulfovibrio bacterium breaks down organic matter (which it must have) and uses sulfate (not oxygen) as an electron acceptor. As a result, it produces hydrogen sulfide (H2S), accounting for the "rotten egg" smell of swamp muck. Oxygen is a deadly poison to Desulfovibrio.
We would call Desulfovibrio a(n) __________.

obligately anaerobic chemoheterotroph

Antibiotics administered in human medicine work against bacterial infections by __________.

interfering with an aspect of bacterial metabolism or structure that differs from that of eukaryotic cells

What is a difference between the cell walls of prokaryotes and the cell walls of eukaryotes?

The cell walls of prokaryotes are made of molecules different from those comprising the cell walls of eukaryotes

Portions of the genomes of certain prokaryotic species are very similar to portions of the genomes of distantly related prokaryotes. The process that most likely accounts for this genetic similarity is _

horizontal gene transfer

Plasmids __________

The cells of prokaryotes are simpler than those of eukaryotes in both their internal structure and the physical arrangement of their DNA. The genome of a prokaryote is structurally different from a eukaryotic genome and in most cases has considerably less DNA. In the majority of prokaryotes, the genome consists of a circular chromosome with many fewer proteins than found in the linear chromosomes of eukaryotes. In addition to its single chromosome, a typical prokaryotic cell may also have much smaller rings of independently replicating DNA molecules called plasmids, most carrying only a few genes. Plasmids have a number of different characteristics. They replicate independently of the main chromosome and often contain antibiotic resistance genes. Plasmids are transferred from one bacterium to another by conjugation. They also allow bacteria to survive adverse conditions and may also direct the metabolism of rarely encountered nutrients.

Bacterial flagella have a very complex structure composed of 42 distinct proteins. What is the most likely explanation for the evolution of these complex structures?

Exaptation

disease caused by bacteria

Tuberculosis

Which of the following characteristics is a reason why a Gram-stain to distinguish gram-positive from gram-negative bacteria is an important tool in a medical diagnosis of a bacterial infection?

All of the listed characteristics are reasons why a Gram-stain is important in medicine.

Bacteria that use light for their energy source and CO2 for their carbon source are called __________.

photoautotrophs

Acquiring an R plasmid would allow a bacterium to do what?

Resist antibiotics

Bacteria function primarily in which ecological role?

Bacteria are common in all of the listed ecological roles

Which of the following is a structure that bacteria, archaea, and eukaryotes have?

Plasma membrane

Why is salt a good preservative to use for foods such as pork and fish?

Prokaryotic cells living in the food will shrink from their cell walls, impacting their ability to reproduce.

Prokaryotes found inhabiting the Great Salt Lake would be ____

extreme halophiles

What is the function of a bacterial endospore?

To facilitate persistence in temporarily harsh environments

How do prions propagate and replicate themselves?

Prions convert normal proteins into the misfolded prion version.

Which of the following is not a class I virus?

parvovirus

Class IV viruses are characterized by which of the following types of genomes

single-stranded RNA that serves as mRNA

Restriction enzymes help defend bacteria against viral infections by _______

cutting viral DNA once it has entered the cell

The avian flu virus H5N1 is considered a greater long-term threat than the swine flu virus H1N1 because __________

it has a significantly higher mortality rate

Why are viruses often considered to be ?

Viruses do not carry out metabolic processes, a primary characteristic of living organisms

How does a retrovirus like HIV enter a host cell

Glycoproteins on the viral envelope bind to receptors on the host cell. The viral envelope fuses with the host cell’s plasma membrane, facilitating uptake of the virus by the host cell

HIV, the virus that causes AIDS, only infects certain cells within the immune system. This is because __________

the virus binds to specific receptors that are only present on certain immune cells

Viruses can vary with respect to all of the following characteristics except __________

the presence or absence of metabolic machinery

The phage reproductive cycle that kills the bacterial host cell is a __________ cycle, and a phage that always reproduces this way is a __________ phage

lytic; virulent

When a virus infects an E. coli cell, what part of the virus enters the bacterial cytoplasm?

Only the nucleic acid

When comparing DNA and RNA viruses, which mutate more quickly, and why?

RNA viruses, because no proofreading is done on RNA molecules

Which of the following events occurs during the lytic life cycle of phages?

The host cell usually dies, releasing many new copies of the virus.

Animals that harbor and can transmit a particular virus but are generally unaffected by it are said to act as a __________ for that virus.

natural reservoir

Viral DNA incorporated into a bacterial chromosome is known as a(n) __________

prophage

Which of the following statements correctly describes one difference between virulent phages and temperate phages?

Virulent phages replicate through the lytic cycle only, and temperate phages replicate using both the lytic and the lysogenic cycles.

Candidates for the original source of viral genomes include _________

plasmids and transposon

A widespread outbreak of a viral disease is called a(n) __________, and a global outbreak is called a(n) __________

epidemic; pandemic

Which of the following is an example of vertical transmission of a virus in plants?

An infected plant produces seeds that contain the virus, giving rise to infected progeny.

Vaccines for viral diseases are __________ and help prevent infection by __________.

harmless derivatives of pathogenic viruses; stimulating the immune system to mount a defense against the actual pathogen

Some viruses have membranous envelopes. Where do viral envelopes typically originate from?

Membranes from the host cell

Viruses that infect bacteria are called _________

bacteriophages

Why can flare-ups of herpes virus infection recur throughout a person’s life?

Herpes virus can leave its DNA behind as minichromosomes in nerve cell nuclei. Stress can trigger another round of virus production, producing characteristic blisters and sores.

Reverse transcription, carried out by retroviruses, is the process by which __________.

RNA information is copied into DNA

Circular RNA molecules that function like a virus in plants are termed __________

viroids

Prions are __________ that are thought to cause disease by __________.

abnormally shaped proteins; inducing similar but normally shaped proteins in the brain to adopt the abnormal form

A phage that inserts itself into the host DNA is called __________

lysogenic

Genomes of viruses may consist of which of the following types of nucleic acids?

We usually think of genes as being made of double-stranded DNA, but many viruses defy this convention. Their genomes may consist of double-stranded DNA, single-stranded DNA, double-stranded RNA, or single-stranded RNA, depending on the type of virus. A virus is called a DNA virus or an RNA virus based on the kind of nucleic acid that makes up its genome. In either case, the genome is usually organized as a single linear or circular molecule of nucleic acid, although the genomes of some viruses consist of multiple molecules of nucleic acid. The smallest viruses known have only three genes in their genome, while the largest have several hundred to a thousand. For comparison, bacterial genomes contain about 200 to a few thousand genes.

How are retroviruses different from other types of viruses?

Retroviruses use the enzyme reverse transcriptase to transcribe a copy of DNA from their own RNA