Biology 101 (chapter 26, 27, 28)

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

1930s

Looking at the character table and phylogenetic tree above, which of the following is a true statement?

A backbone is a shared ancestral character in mammals (leopard)

Why are phylogenetic trees considered hypotheses?

A phylogenetic tree can be used to make testable predicitions

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

Analogous structures

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

Analogous structures

Prokaryotic cells are found in the domain(s)________.

Bacteria and Archaea

While examining a rock surface, you have discovered an interesting new organism. Which of the following criteria will allow you to classify the organism as belonging to Bacteria but not Archaea or Eukarya?

Cell walls are made primarily of peptidoglycan

Which of the following taxonomic categories contains all the others listed here?

Class

Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gather at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. A P. bursaria cell that has lost its zoochlorellae is aposymbiotic. If aposymbiotic cells have population growth rates the same as those of healthy, zoochlorella-containing P. bursaria in well-lit environments with plenty of prey items, then such an observation would be consistent with which type of relationship?

Commensalistic

Some beetles and flies have antler-like structures on their heads, much like male deer. The existence of antlers in beetle, fly, and deer species with strong male-male competition is an example of

Convergent evolution

The prokaryotic cells that were the first to add significant quantities of oxygen to Earth's atmosphere are classified as ___________. a) proteobacteria b) chlamydias c) spirochetes d) gram-positive bacteria e) cyanobacteria

Cyanobacteria

If organisms A, B, and C belong to the same class but to different orders and if organisms D, E, and F belong to the same order but to different families, which of the following pairs of organisms would be expected to show the greatest degree of structural homology?

D and E

Which of the following best summarizes the neutral theory?

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

Which of the following statements is accurate with regard to a phylogeny, as represented by a phylogenetic tree? a) Shared ancestral characters are excellent traits to use in developing a phylogeny. b) Descendant groups (branches) from the same node likely share many derived characters. c) The ancestral group often has all the derived characters of the descendant species. d) A monophyletic group can be properly based on convergent features.

Descendant groups (brances) from the same node likely share many derived characters.

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

A rose bush is classified in domain _____ and kingdom _______.

Eukaraya Plantae

A human is classified in domain _______ and kingdom ________

Eukarya Animalia

The horizontal line indicating a branch on a phylogenetic tree represents ancestral forms of the named taxon, thereby illustrating the ____________ leading to that taxon.

Evolutionary Lineage

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

Evolutionary relationships among bird families

Which statement about the domain Archaea is accurate?

Genetic prospecting has recently revealed the existence of many unknown archaean species

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

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

Horizontal gene transfer is known to occur within both prokaryotes and eukaryotes

Nitrogenase, the enzyme that catalyzes nitrogen fixation, is inhibited whenever free oxygen (O2) reaches a critical concentration. Consequently, nitrogen fixation cannot occur in cells wherein photosynthesis produces free O2. Consider the colonial aquatic cyanobacterium, Anabaena, whose heterocysts are described as having "...a thickened cell wall that restricts entry of O2 produced by neighboring cells. Intercellular connections allow heterocysts to transport fixed nitrogen to neighboring cells in exchange for carbohydrates." Think about this description of the colonial aquatic cyanobacterium, Anabaena. Which of the following question below is important for understanding how nitrogen (N2) enters heterocysts, and how oxygen (O2) is kept out of heterocysts?

If carbohydrates can enter the heterocysts from neighboring cells via the "intercellular connections", how is it that O2 doesn't also enter via this route?

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.

The thermoacidophile Sulfolobus acidocaldarius lacks peptidoglycan, but still possesses a cell wall. Which of the following statements is likely to be an accurate description of this species?

It could inhabit hydrothermal springs.

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. Which of the following statements about the cell wall is most probable? a) After it has been subjected to Gram staining, the cell should remain purple. b) It has an outer membrane of lipopolysaccharide. c) It is mostly composed of a complex, cross-linked polysaccharide. d) Its innermost layer is composed of a phospholipid bilayer.

It has an outer membrane of lipopolysaccharide

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.

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

In the five-kingdom system, prokaryotes are placed in the kingdom ______.

Monera

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?

Most Useful: - Data about skull bones - Descriptions of various types of limbs (wings, legs, flippers, etc.) - DNA base sequences - The fact the teeth vary among types of mammals Least useful: - The fact the all mammals have hair

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

None of the listed assumptions should be made.

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.

Carolus Linnaeus believed that species remained fixed in the form in which they had been created. Linnaeus would have been uncomfortable with ____________.

Phylogenies

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.

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

Phylum Chordata

In a bacterium that possesses antibiotic resistance and the potential to persist through very adverse conditions, such as freezing, drying, or high temperatures, DNA should be located within, or be part of, which structures? a) fimbriae, nucleoid, and endospore b) nucleoid, fimbriae, and plasmids c) endospore, fimbriae, and plasmids d) plasmids, nucleoid, and endospore

Plasmids, nucleoid, and endospore

In the five-kingdom system, which kingdom consists primarily of unicellular eukaryotes?

Protista

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

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

Share an immediate common ancestor and are each other's closest relatives

Which of the following statements best describes the rationale for applying the principle of maximum parsimony in constructing phylogenetic trees? a) Parsimony allows the researcher to "root" the tree b) the outgroup roots the tree, allowing the principle of parsimony to be applied c) the molecular clock validates the principle of parsimony d) Similarity due to common ancestry should be more common than similarity due to convergent evolution

Similarity due to common ancestry should be more common than similarity due to convergent evolution

The common ancestors of birds and mammals were very early (stem) reptiles, which almost certainly possessed three-chambered hearts (two atria, one ventricle). Birds and mammals, however, are alike in having four-chambered hearts (two atria, two ventricles). The four-chambered hearts of birds and mammals are best described as ________. a) structural homologies b) structural analogies c) vestiges d) the result of shared ancestry

Structural analogies

What is the relationship between systematics and taxonomy?

Systematics is a discipline within taxonomy.

Each branch tip on a phylogenetic tree represents a specific group of organisms known as a(n) _________.

Taxon

Leaf-cutter ants harvest plant leaves and bring them back to their nests. There, in the warm, moist environments of their underground nests, they grow fungi (Leucoagaricus) that they then eat. These ants also host bacteria on their exoskeleton. Another fungus, Escovopsis, kills Leucoagaricus when the ants are removed from the nest. Knowing that the bacteria on the ants are in the same phylogenetic group of other bacteria that produce antibiotics, which of the following research hypotheses is most likely correct?

The bacteria on the exoskeleton provide nutrition to the ants

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 observations about flagella is accurate and is consistent with the scientific conclusion that the flagella from eukaryotes and bacteria evolved independently? a) The mechanics of movement and protein structure are the same in these flagella, but there are significant genetic differences. b) The protein structure and the mechanism of movement in eukaryotes flagella are different from those of bacteria flagella. c) Although the mechanism of movement in both flagella is the same, the protein that accomplishes the movement is different. d) The flagella of both eukaryotes and bacteria are made of the same protein, but the configuration is different.

The protein structure and the mechanism of movement in eukaryotes flagella are different from those of bacteria flagella.

If all prokaryotes on Earth suddenly vanished, which of the following would be the most likely and most direct result?

The recycling of nutrients would be greatly reduced, at least initially

Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gather at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. Which of the following experimental results would suggest that the zoochlorellae and P. bursaria are mutualists?

The reproductive rate of P. bursaria is higher with zoochlorellae than without.

Imagine that a phylogeny was developed for a group of mammals based on bone structure. Which of the following statements would be a reasonable prediction about a phylogeny for the same group of species based on similarities and differences in the structure of a particular enzyme? a) The amino acid sequence would be identical in all species. b) No prediction could be made. c) The same phylogeny would be predicted. d) The same phylogeny would be unlikely.

The same phylogeny would be unlikely

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

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

In the two-kingdom system, why were fungi classified in the kingdom Plantae?

They are sedentary

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. Adherence to the intestinal lining by this bacterium is due to its possession of _____. a) fimbriae b) a flagellum c) a capsule d) pili

a capsule

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 paraphyletc group[

In a comparison of birds and mammals, having four limbs is _______. a) a shared ancestral character b) and example of analogy rather than homology c) a shared derived character d) a character useful for distinguishing birds from mammals

a shared ancestral character

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

For several decades now, amphibian species worldwide have been in decline. A significant proportion of the decline seems to be due to the spread of the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Chytrid sporangia reside within the epidermal cells of infected animals, animals that consequently show areas of sloughed skin. They can also be lethargic, which is expressed through failure to hide and failure to flee. The infection cycle typically takes four to five days, at the end of which zoospores are released from sporangia into the environment. In some amphibian species, mortality rates approach 100%; other species seem able to survive the infection. If infection primarily involves the outermost layers of adult amphibian skin, and if the chytrids use the skin as their sole source of nutrition, then which term best applies to the chytrids? a) anaerobic chemoautotroph b) aerobic chemoheterotroph c) aerobic chemoautotroph d) anaerobic chemoheterotroph

aerobic chemoheterotroph

Which of the following extremophiles might researchers most likely use as a model for the earliest organisms on Earth?

an anaerobic archaean species

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. This bacterium derives nutrition by digesting human intestinal contents. Thus, this bacterium is an ________.

anaerobic chemoheterotroph

sister taxa

are groups of organisms that share a unique common ancestor not shared by any other group

The pathogenic prokaryotes that cause cholera are _____.

bacteria that release an exotoxin

The point at which two or more lineages diverge from their common ancestor is called a(n) ___________ or node.

branch point

The predatory bacterium Bdellovibrio bacteriophorus drills into a prey bacterium and, once inside, digests it. In an attack upon a gram-negative bacterium that has a slimy cell covering, what is the correct sequence of structures penetrated by B. bacteriophorus on its way to the prey's cytoplasm? a) lipopolysaccharide membrane, peptidoglycan, capsule, phospholipid membrane b) capsule, lipopolysaccharide membrane, peptidoglycan, phospholipid membrane c) lipopolysaccharide membrane, capsule, peptidoglycan, phospholipid membrane d) phospholipid membrane, capsule, peptidoglycan, lipopolysaccharide membrane

capsule, lipopolysaccharide membrane, peptidoglycan, capsule, phospholipid membrane

Organisms that can cause nongonococcal urethritis are classified with ___________. a) proteobacteria b) chlamydias c) spirochetes d) gram-positive bacteria e) cyanobacteria

chlamydias

To apply the principle of maximum parsimony to construction of a phylogenetic tree, __________. a) choose the tree with the fewest branch points b) choose the tree that assumes all evolutionary changes are equally probable c) choose the tree in which the branch points are based on as many shared derived characters as possible d) choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

choose the tree that represents the fewest evolutionary changes, either in DNA sequences or morphology

Foods can be preserved in many ways by slowing or preventing bacterial growth. Which of these methods should be least effective at inhibiting bacterial growth?

closing previously opened containers: prevents more bacteria from entering, and excludes oxygen

The prokaryotic cells that built stromatolites are classified as _______. a) proteobacteria b) chlamydias c) spirochetes d) gram-positive bacteria e) cyanobacteria

cyanobacteria

Which of the following pairs are the best examples of homologous structures? a) eyelessness in the Australian mole and eyelessness in the North American mole b) bat wing and bird wing c) owl wing and hornet wing d) in the bat wing and bones in the human forelimb

d) in the bat wing and bones in the human forelimb

Bacteria perform each of the following ecological roles. Which role typically does not involve symbiosis?

decomposer

Broad-spectrum antibiotics inhibit the growth of most intestinal bacteria. Consequently, assuming that nothing is done to counter the reduction of intestinal bacteria, a hospital patient who is receiving broad-spectrum antibiotics is most likely to become _____.

deficient in certain vitamins and nutrients

There is some evidence that reptiles called cynodonts may have had whisker-like hairs around their mouths. If true, then hair is a shared ________. a) ancestral character of the all vertebrates, but only if cynodonts are reclassified as mammals b) derived character of mammals, but only if cynodonts are reclassified as mammals c) derived character of all vertebrates and not of the mammal clade d) derived character of mammals, even if cynodonts continue to be classified as reptiles

derived character of mammals, but only if cynodonts are reclassified as mammals

Animals that possess homologous structures probably _____.

evolved from the same ancestor

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

genus and species

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. This bacterium's ability to survive in a human who is taking penicillin pills may be due to the presence of ________. a) gram-negative cell wall b) long polypeptides in the cell wall c) lipopolysaccharides in the cytoplasm d) peptidoglycan in the cell wall

gram-negative cell wall

Streptococcus pyogenes is classified with __________. a)proteobacteria b) chlamydias c) spirochetes d) gram-positive bacteria e) cyanobacteria

gram-positive bacteria

Use of synthetic fertilizers often leads to the contamination of groundwater with nitrates. Nitrate pollution is also a suspected cause of anoxic "dead zones" in the ocean. Which of the following might help reduce nitrate pollution? a) adding nitrifying bacteria to the soil b) using ammonia instead of nitrate as a fertilizer c) adding denitrifying bacteria to the soil d) growing improved crop plants that have nitrogen-fixing enzymes

growing improbed crop plants that have nitrogen-fixing enzymes

Mitochondria are thought to be the descendants of certain alpha proteobacteria. They are, however, no longer able to lead independent lives because most genes originally present on their chromosomes have moved to the nuclear genome. Which phenomenon accounts for the movement of these genes?

horizontal gene transfer

A taxon _________.

is a formal grouping at any given level

You have found a new prokaryote. What line of evidence would support your hypothesis that the organism is a cyanobacterium? a. it lacks a cell wall b. it is able to form colonies and produce oxygen c. it is an endosymbiont d. it forms chains called mycelia

it is able to form colonie and produce oxygen

Which of the following traits do archaeans and bacteria share?

lack of nuclear envelope and presence of plasma membrane

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

If plaque on teeth is actually a biofilm, which of the following characteristics would you expect to find in plaque?

multiple species of bacteria, production of chemicals that attract other bacteria, and production of chemicals that allow the bacteria to adhere to enamel

Phylogenetic tree constructed from evidence from molecular systematics are based on similarities in __________. a) that pattern of embryological development b) morphology c) mutations to homologous genes d) biochemical pathways

mutations to homologous genes

In a hypothetical situation, a bacterium lives on the surface of a leaf, where it obtains nutrition from the leaf's nonliving, waxy covering while inhibiting the growth of other microbes that are plant pathogens. If this bacterium gains access to the inside of a leaf, however, it causes a fatal disease in the plant. Once the plant dies, the bacterium and its offspring decompose the plant. What is the correct sequence of ecological roles played by the bacterium in the situation described here?

mutualist, commensal, pathogen

A hypothetical bacterium swims among human intestinal contents until it finds a suitable location on the intestinal lining. It adheres to the intestinal lining using a feature that also protects it from phagocytes, bacteriophages, and dehydration. Fecal matter from a human in whose intestine this bacterium lives can spread the bacterium, even after being mixed with water and boiled. The bacterium is not susceptible to the penicillin family of antibiotics. It contains no plasmids and relatively little peptidoglycan. In which feature should one be able to locate a complete chromosome of this bacterium? a) nucleoid b) plasmid c) mitochondrion d) nucleus

nucleoid

This is (are) _____ eukaryotic domain(s).

one

Which of the following is (are) problematic when the goal is to construct phylogenies that accurately reflect evolutionary history? a) monophyletic taxa b) polyphyletic taxa and paraphyletic taxa c) paraphyletic taxa d) polyphyletic taxa

polyphyletic taxa and paraphyletic taxa

Some molecular data place the giant panda in the bear family (Ursidae) but place the lesser panda in the raccoon family (Procyonidae). If the molecular data best reflect the evolutionary history of these two groups, then the morphological similarities of these two species is most likely due to _________.

posession of analogous (convergent traits

Which of the following traits do archaeans and eukaryotes share?

presence of introns

The chemoheterotroph Proteus vulgaris is a rod-shaped bacterium classified with _______. a) proteobacteria b) chlamydias c) spirochetes d) gram-positive bacteria c) cyanobacteria

proteobacteria

The best classification system is that which most closely

reflects evolutionary history

The legless condition that is observed in several groups of extant reptiles is the result of

several instances of the legless condition arising independently of each other

Spiral-shaped bacteria are likely to be placed with __________. a) proteobacteria b) chlamydias c) spirochetes d) gram-positive bacteria e) cyanobacteria

spirochetes

The term convergent evolution is most applicable to which of the following features?

the legless condition found in various lineages of extant lizards

Biologists sometimes divide living organisms into two groups: autotrophs and heterotrophs. These two groups differ in ________. a) their electron acceptors b) their sources of carbon c) the way that they generate ATP d) their mode of inheritance

their sources of carbon

The term polytomy refers to a situation in which ____________.

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

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 species

Which of the following describe all existing bacteria? a. tiny, ubiquitous, metabolically diverse b. pathogenic, omnipresent, morphologically diverse c. extremophiles, tiny, abundant d. morphologically diverse, metabolically diverse, extremophiles

tiny, ubiquitious, metabolically diverse

What is the goal of bioremediation?

to clean up areas polluted with toxic compounds using bacteria

Your professor wants you to construct a phylogenetic tree of orchids. She gives you tissue from seven orchid species and one lily. What is the most likely reason she gave you the lily? a) to serve as an outgroup b) to see if the lily and the orchids show all the same shared derived characters c) to see if the lily is a cryptic orchid species d) to demonstrate likely homoplasies

to serve as an outgroup

If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup? a) domestic cat b) lion c) leopard d) wolf

wolf