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205: Midterm 1
How Populations Evolve, Origin of Species, Tracing Evolutionary History, Evolution of Vertebrate Diversity,
166
Biology
Undergraduate 3
09/22/2013

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Term
Science
Definition
Means "knowledge"
System of acquiring knowledge based on scientific method.
Term
Scientific Method
Definition
Gathering observable, empirical, and measurable evidence subject to specific principles of reasoning, the collection of data through observation and experimentation, and the formulation and testing of hypotheses
Term
Types of Science
Definition
Discovery (through observation and measurement)
Hypothesis- Driven (questions drawn from observations or previous knowledge)
Term
What are the four points of the Scientific Method (application of hypothesis- based science)?
Definition
Use observations from others or results of earlier tests
Ask questions about unclear aspects (How, Why, When)
Make predictions developed by the use of deductive reasoning (if..n then)
Test predictions to determine if they are supported or faslified
Term
Hypothesis
Definition
Proposed explanation for set of observations
Term
Theory
Definition
Supported by a large and usually growing body of evidence
Term
Evolution
Definition
Process of change that transforms life (resulting in adaptations)
Core theme of Biology
Term
Biosphere
Definition
All environments on Earth that support life
Term
Ecosystem
Definition
All organisms living in a particular area
Term
Community
Definition
Array of organisms living in a particular ecosystem
Term
Population
Definition
All individuals of a species within a specific area
Term
What must an ecosystem do to be successful?
Definition
Recycle chemicals necessary for life and move energy through the ecosystem (e.g. energy enters as light and exists as heat)
Term
What is a cell?
Definition
Smallest living organism (largest: Ostrich egg)
Term
What are the three domain (groups) of life (what are their characteristics)?
Definition
Bacteria (prokaryotic, and most are unicelllular and microscopic)
Archaea (prokaryotic, and most are unicellular and microscopic)
Eukarya (eukaryotic and contain a nucleus and organelles)
Term
What are Prokaryotic Cells?
Definition
Simple, unicellular and small
Blue-green algae and bacteria represent 80-90% of total biomass of planet
Term
What are Eukaryotic Cells?
Definition
Possess organelles separated by membranes
Plants, animals and fungi
Includes all the other living bacteria
Term
A gene is a discrete unit of DNA; What is DNA?
Definition
Deoxyribonucleic Acid
Nucleic acid that contains the genetic instructions used in development and functioning of all known living organisms
Term
What are the seven common properties that all living things share?
Definition

Order (complex organization of living things) Regulation (an ability to maintain an internal environment consistent with life) Growth and development (consistent growth and development controlled by DNA Energy processing (acquiring energy and transforming it to a form useful for the organism)

Respone to the Environment (an ability to respong to environmental stimuli)

Reproduction (ability to perpetuate the species)

Evolutionary adaptation (acquisition of traits that best suit the organism to its environment)

Term
What were Jean Baptiste Lamarck's theories on Evolution?
Definition
Use and Disuse
Inheritance of Acquired Characteristics
Term
Natural Selection
Definition
Differential survival and reproduction of individuals within a population
Term
Three Important Points on Natural Selection
Definition
Individuals do not evolve, populations do
N.S. can amplify or diminish only heritable traits; acquired traits cannot be passed to offspring
Evolution is not goal directed and does not lead to perfection; favorable traits vary as environments change
Term
How do fossils provide evidence for evolution?
Definition
Oldest known fossils are prokaryote cells
Show the historical sequence:
The oldest eukaryotic fossils are a billion years younger
Multicellular fossils are more recent
Term
Biogeography
Definition
Geographic distribution of species
Term
Comparative Anatomy
Definition

Comparison of body structures in different species

Homologies: similarity in characteristics resulting from common ancestry

Can result in some species having Vestigial Organs (structures that are marginal or no importance to the organism)

Term
Homology
Definition
Similarity in characteristics that result from common ancestry
Term
Comparative Embryology
Definition
Comparison of early stages of development among different organisms
Term
Molecular Biology
Definition
Comparisons of DNA and amino acid sequences between different organisms revealing evolutionary relationships
Term
Gene Pool
Definition
Total collection of genes in a population at any one time
Term
Microevolution
Definition
Change in the relative frequencies of alleles in a gene pool over time
Term
Population genetics
Definition
Studies how populations change genetically over time
Term
Mutation
Definition
Changes in the nucleotide sequence of DNA; the ultimate source of new alleles
Term
In which phase do homologous chromosomes sort independently as they separate?
Definition
Anaphase I of Meiosis
Term
During which phase to pairs of homologous chromosomes cross over and exchange genes?
Definition
Prophase I of Meiosis
Term
How many chromosomes to human have?
Definition
23 pairs
Term
How many possible combinations of chromosomes are possible in a human sperm or egg due to independent assortment during Meiosis?
Definition
46 Combinations
Term
Hardy-Weinberg Equilibrium
Definition

Amount of genetic variation in a population will remain constant from one generation to the next in the absence of distributing factors

Genotype Frequency: (total number of that genotype/ total number of all organisms) = 0._ _

Allele Frequency: (frequency of that allele/ total number in all organisms) = 0._ Allele

For Next Generation: p2 (frequency of homologous dominants) + 2pq (frequency of heterozygotes) + q2 (frequency of homologous recessives) = 1

Term
What seven conditions must be met for evolution to not occur, as stated by Hardy and Weinberg?
Definition
Mutation not occurring
Natural Selection not occurring
Population infinitely large
All members of the population breed
All mating is totally random
Everyone produces same number of offspring
No migration in or out of the population
Term
What are the three main causes of evolutionary change?
Definition
Natural Selection, Genetic Drift, and Gene Flow
Term
Genetic Drift
Definition
Change in the gene pool of a population due to chance
In a small population, chance events may lead to the loss of genetic diversity
Term
Bottleneck Effect
Definition
Leads to a loss of genetic diversity when a population is greatly reduced (such as in a natural disaster or near extinction)
Term
Founder Effect
Definition
Few individuals colonize a new habitat with a smaller group having a more different gene pool from that of the original
Term
Gene Flow
Definition
Movement of Individuals or Gametes/ Spores between populations and can alter allele frequencies in a population
Term
What is an individual's fitness?
Definition
The contribution it makes to the gene pool of the next and subsequent generations
Term
Stabilizing Selection
Definition
Favors Intermediate phenotypes, acting against extreme phenotypes
Very common, especially when environments are stable
Term
Directional Selection
Definition
Acts against individuals at one of the phenotypic extremes
Common during periods of environmental change, or when a population migrates to a new and different habitat
Term
Disruptive Selection
Definition
Favors individuals at both extremes of the phenotypic range
May occur in patchy habitats
Term
What is Balancing Selection and what are two types of it?
Definition

Occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population

Heterozygote Advantage (heterozygotes have a better reproductive advantage) and Frequency- dependent selection (maintains 2 different phenotypic forms in a population)

Term
Natural Selection cannot fashion perfect organisms because...
Definition

Selection can only act on existing variation

Evolution is limited by historical constraints

Adaptations are often compromises

Chance, natural selection and the environment interact

Term
Sexual Dimorphism
Definition
Distinct appearance differences in animals
Attributed to sexual selection
Term
Types of Sexual Selection (form of Natural Selection in which individuals with certain characteristics are more likely than other individuals to obtain mates)
Definition

Intrasexual Selection: secondary sex structures used to compete with members of the same sex for mates (mostly seen in males competing for females)

 

Intersexual Selection: meaning between sexes or mate choice; individuals of one sex (usually females) are choosy when selecting a mate of the opposite sex (usually males)

Term
What are the genetic interests of Cichlids?
Definition
Diversified 100,000 years ago in Lake Victoria
Have specialized mouth-parts for their section of the lake
Lake Victoria dried out 3x over 400,000 years, refilling 15,000 years ago- the few remaining cichlid species that retreated to fluvial habitats diversified
Term
Species
Definition
Group of organisms whose members can breed and produce fertile offspring, but who do not produce fertile offspring with members of other groups
Term
Speciation
Definition
Emergence of new species, increasing diversity of life
Term
Taxonomy
Definition
Branch of biology that names and classifies species and groups them into broader categories
Carolus Linnaeus: developed binomial system of naming organisms using physical characteristics over 11,000 species
Term
Biological Species Concept
Definition
Defines species as a population or group of populations whose members have the potential to interbreed in nature and produce fertile offspring
Term
Morphological Species Concept
Definition
Classifies organisms based on observable phenotypic traits
Can be applied to asexual organisms, fossils, and in cases when we don't know about possible interbreeding
Term
Ecological Species Concept
Definition
Defines species by its ecological role or niche
Term
Phylogenetic Species Concept
Definition
Defines species as a set of organisms representing a specific evolutionary lineage
Term
Reproductive Barriers
Definition
Serve to isolate species gene pool and prevent interbreeding
Categorized as prezygotic (before-) or postzygotic (after- zygote formation)
Term
What are the Prezygotic Barriers that prevent mating or fertilization?
Definition
Temporal isolation
Habitat isolation
Behavioral isolation
Mechanical isolation
Gametic isolation
Term
What are the Postzygotic Barriers that prevent development of fertile adults?
Definition
Reduced hybrid viability (don't achieve sexual maturity)
Reduced hybrid fertility (fail to produce functional gametes)
Hybrid breakdown (offspring of hybrids weak/ infertile)
Term
Allopatric Speciation
Definition
Populations of the same species are geographically separated, separating their gene pools
Term
Sympatric Speciation
Definition
New species may arise within the same geographic area as a parent species
Term
How are new Polyploid species created?
Definition
Multiplication of chromosome number due to errors in cell division
Term
What occurs in Hybrid Zones?
Definition

Members of different species meet and mate to produce hybrid offspring

Results in...

Reinforcement (hybrids less fit, N.S. strengthens reproductive barriers)

Fusion (weak reproductive barriers between the species with considerable gene flow, reverse speciation and species become 1)

Stability (many hybrid zones are stable, producing hybrids; maintains gene flow and 2 separate species)

Term
Adaptive Radiation
Definition
Diverse species evolve from common ancestor
Occurring...
When a few organisms colonize new unexploited areas
After a mass extinction
Term
What is the total length of time between speciation events (formation of species and subsequent divergence)?
Definition
Time ranged (in survey of 84 plants and animals) 4,000 to 40 million years
Average: 6.5 million years, rarely taking less than 50,000 years
Term
How many living plant species are descendants of ancestors that formed by polyploid speciation?
Definition
80%
Term
What have been some advantages to hybridization?
Definition
Polyploid food plants (oats, potatoes, banana, barely, apples, coffee, wheat)
Polyploid products (cotton)
Term
What is the connection between wheat and polyploidy?
Definition
Wheat is the most widely cultivated plant in the world, after being domesticated 11,000 years ago
Bread wheat is a polyploid with 42 chromosomes
Term
What are the 4 different species concepts?
Definition

Biological Species Concept

Morphological Species Concept

Ecological Species Concept

Phylogenetic Species Concept

Term
What are the Mechanisms of Speciation?
Definition

Allopatric Speciation

Sympatric Speciation

Hybrid Zones

Adaptive Radiation

Term
What is the "recipe for life"?
Definition
Raw materials + Suitable environment + Energy sources
Term
What is the composition of Earth's early atmosphere, which led to origin of life?
Definition
H2O vapor and compounds from volcanic erutptions (N2 and its oxides; CO2, CH4, NH3, H2, and H2S)
Term
What energy sources existed on early Earth, which made the origin of life possible?
Definition
Intense volcanic activity, lightening and UV radiation
Term
What was the early formation of the Earth and it's life forms?
Definition
Earth formed 4.6 billion years ago
Photosynthetic bacteria had formed sandy stromatolite mats by 3.5 billion years ago
Term
What is the Oparin-Haldane Hypothesis?
Definition
Proposition that organic molecules could have formed on an early Earth
The rich O2 atmosphere (which oxidizes and disrupts chemical bonds)
Term
What did the Miller-Urey experiments demonstrate?
Definition
Stage 1, abiotic synthesis of organic molecules was possible on early Earth
Term
What was an alternative hypothesis to organic molecule formation?
Definition
Submerged volcanoes and deep-sea hydrothermal vents may have produced chemical resources for first life
Term
What are the 3 eons?
Definition
Archaean and Proterozoic (which lasted 4 billion years) and Phanerozoic (which is the last 1/2 billion years; divivied into 3 eras)
Term
What are the names of the 3 eras the Phanerozoic eon is divided into?
Definition
Paleozoic, Mesozoic, and Cenozoic
Term
How long were Prokaryotes "alone" on Earth and what did they create?
Definition
1.5 billion years
Created atmosphere and transformed biosphere
Evolved all metabolic pathways including atmospheric oxygen (2.7 billion ya due to photosynthesis) and cellular respiration (oxygen harvested energy from organic molecules)
Term
What is the origin of Eukaryotic cells?
Definition
Community of small prokaryotes (capable of aerobic respiration or photosynthesis) began living in larger cells
Oldest fossils: 2.1 billion years old
Term
What is the origin of Multicellular Forms?
Definition
1.5 billion ya, descendants include algae, plants, fungi and animals
Oldest fossils: small algae, living 1.2 billion ya
Term
When was the sudden increase in animal diversity and what was this time called?
Definition
535-525 million years ago
Cambrian explosion
Term
What are the most widespread and diverse land animals?
Definition
Arthropods and tetrapods
Term
When did the human lineage diverge from apes and when did the species originate?
Definition
7-6 million ya
160,000 ya
Term
Radiometric Dating
Definition
Measures decay of radioactive isotopes
Use Carbon-14 (half-life 5,730 years) to date fossils up to 75,000 years old
Potassium-40 (half-life 1.3 billion years) can be used to date volcanic rock hundreds of millions of years old
Term
Geologic Record
Definition
Defined by major transitions in life on Earth
Term
Continental Drift
Definition
Slow, continuous movement of Earth's crustal plates (carrying continents and seafloors) on hot, liquid mantle
Term
What important geologic processes occur at plate boundaries?
Definition
Sliding plates cause earthquakes
Colliding plates create mountains
Separating plats create bodies of water
Term
What is the significance of the super-continent Pangaea?
Definition
Formed 250 million ya, altered habitats and triggered greatest mass extinction in Earth's history
Breakup led to modern arrangement of continents
Australia's marsupials became isolated and placental mammals arose on other continents
India's collision with Eurasia 55 million ya led to formation of Himalayas
Term
What is the significance of mass extinctions?
Definition
It's the fate of all species and most lineages
History of life on Earth reflects a steady background extinction rate with episodes of mass extinction
Over last 600 million years, 5 mass extinctions have occurred (50% or more of Earth's species went extinct)
Term
What occurred during the Permian extinction?
Definition
96% of shallow water marine species died
Extreme volcanism in Siberia released CO2, warmed global climate, slowed mixing of ocean water, and reduced O2 availability in the ocean
Took 100 million years to recover
Term
What occurred during the Cretaceous extinction?
Definition
65 million ya, 50% of marine species and many terrestrial lineages went extinct (all dinosaurs, except birds)
Likely caused by a large asteroid that struck Earth, blocking light and disrupting global climate
Term
Is there a 6th extinction under way?
Definition
Current extinction rate is 100- 1,000 x the normal background rate
Term
How is adaptive radiation connected to mass extinction and mammals?
Definition
Rebound in diversity following mass extinction as survivors become adapted to vacant ecological niches
Mammals underwent dramatic adaptive radiation after extinction of non-avian dinosaurs 65 million ya
Term
How are humans threatening animal diversity with non-native species?
Definition
Australia:
Cat-like quoll is a marsupial predator, endemic to Australia
Dying because they feed on introduced poisonous cane toads
Australia has moved some threatened species to uninhabited offshore islands that lack invasive species
Term
Exaptation
Definition
Gradual adaptation of existing structures to new functions (e.g. the eye)
N.S. doesn't anticipate novel use; each intermediate stage must be adaptive and functional (ex. modification of vertebrate forelimb into wing in pterosaurs, bats, and birds)
Term
Species Selection
Definition
Unequal speciation or unequal survival of species on a branching evolutionary tree (species generating many new species may drive major evolutionary change)
Term
What are the differences in Hagfishes and Lampreys (which are craniates but lack hinged jaws and paired fins)?
Definition
Hagfishes: notochord is the body's main support in adults (no vertebrae), deep- sea scavenger that produce slime as anti-predator defense
Lampreys: supportive notochord and rudimentary vertebral structure (vertebrates), parasites that penetrate sides of fishes with rasping tongues
Term
What are some jawed vertebrates with gills and paired fins?
Definition
Sharks, ray-finned fishes, lobe-finned fishes
Term
When did novel vertebrate features arise and what are they?
Definition
470 million ya
Paired fins and tail, hinged jaws
Term
What are the three lineages of jawed fishes (Class Chondrichthyes)?
Definition
Sharks and rays
Ray-finned fishes
Lobe-fins (have lungs, or derivatives)
Term
What are some characteristics of Chondrichthyans?
Definition
Sharks and rays have flexible skeleton made of cartilage
Most sharks are fast-swimming predators with sharp vision and keen sense of smell
Electrosensors on their heads and a lateral line system aid them in locating prey
Most rays are adapted for life on the bottom with dorsoventrally flattened bodies and eyes on top of their heads
Term
What are some characteristics of ray-finned fishes?
Definition
Internal skeleton (bony) reinforced with a hard matrix of cartilage
27,000 species (50% of all vertebrates)
Term
Reptilian Amniotes
Definition
Tetrapods with terrestrially adapted egg
Major derived character is the amniotic egg (with an amnion or private pond in which embryo develops)
Reptiles incl. lizards, snakes, turtles, crocodilians, and birds
Term
What is involved in the Evolution of Birds?
Definition
Developed from small, two-legged dinosaurs called theropods
Archaeopteryx is the oldest bird (150 million years old) with feathered wings
Living birds evolved form a lineage of birds that survived Cretaceous extinctions
Birds are reptiles with feathered wings, endothermic metabolism, and a number of adaptions for flight (loss of teeth, tail supported by few small vertebrae, feathers with hollow shafts, strong but light honeycomb bones)
Term
Mammalian Amniotes
Definition
Endothermic, have hair (to insulate body), and mammary glands (produce milk)
First true mammals: 200 million ya as small, nocturnal insectivores Marsupials diverged from eutherians (placental mammals) 180 million ya
Underwent adaptive radiation following Cretaceous extinction; gave rise to large terrestrial carnivores and herbivores, bats, and aquatic whales and porpoises
Term
Monotremes
Definition
Egg-laying mammals
Include duck-billed platypus
Term
Placenta-bearing Mammal Characteristics
Definition
Embryos of marsupials and eutherians
Placenta found within the uterus (allowing nutrients from mother's blood to diffuse into embryo's blood)
Term
Marsupial Characteristics
Definition
Brief Gestation (give birth to tiny, embryonic offspring which complete development attached to mother's nipples, usually inside a pouch or marsupium)
Term
Eutherian Characteristics
Definition
Also called Placental Mammals (placentas more complex than marsupials)
Bear fully developed live young
Term
Origin of order Primate and characteristics
Definition
Includes lemurs, tarsiers, monkeys, and apes
Arose as small arboreal mammals 65 million ya
Characteristics incl arboreal adaptations:
Shoulder and hip joints allow climbing and brachiation
Grasping hands and feet are highly mobile and flexible
Sensitive hands and feet aid in manipulation
Short snout and forward-pointing eyes enhance depth perception
Term
What are the three groups of the order Primate?
Definition
Lorises, Lemurs and Pottos
Tarsiers
Anthropoids
Term
What are the Anthropoid characteristics?
Definition
Large relative brain size
Rely more on eyesight and less on olfaction than other mammals
Fully opposable thumbs
Term
What are the characteristics of Hominoids (apes)?
Definition
Gibbons, orangutans, gorillas, chimpanzees/ bonobos, and humans
Nonhuman apes have smaller geographic range than monkeys
Nonhuman apes live only in Africa and SE Asia, in tropical rain-forests
Apes have relatively large brain size and flexible behavior
Gorillas, chimps, and humans have a high degree of social organization
Term
Characteristics of Gibbons
Definition
Only fully arboreal apes
Monogamous
Term
Characteristics of Orangutans
Definition
Shy and solitary
Live in rain-forest trees and forest floor
Term
Characteristics of Gorillas
Definition
Largest of the apes
Fully terrestrial
Term
Origin of Hominids
Definition
Divergence between chimpanzees and humans 5-7 million ya (share 99% of genes)
Term
What is the oldest possible hominid and when did is live?
Definition
Sakelanthropus tchadensis
7-6 million ya
Term
Origin of Bipedalism
Definition
Arose 4 million ya with first australopithecines
Larger brain evolved later
Evidence from fossil trackways and hominid fossils
Term
Evolution of Larger Brains
Definition
Homo sapiens: brain size 1350 cc, 3x size of australopiths
Homo ergaster: 1.9-1.6 million ya: brain size 850-1100 cc
Homo habilis: 2.4 million ya, brain size 500-800 cc
Homo erectus: brian size abut 1000 cc (first hominid to leave Africa)
Term
Characteristics of Neaderthals
Definition
Lived in Europe 30,000-40,000 ya
Sympatric with our Cro-magnon ancestors
Muscular and robust, brain similar in size but distinct in shape to "human" brain
Large noses, heavy brows and cheekbones, hunting tools made of stone and wood
Term
Did Neanderthals interbreed with Cro-Magnons?
Definition

Neanderthals are a distinct species from modern humans while Cro-Magnons are the earliest Homo sapiens specific to Europe

Last common ancestor between humans and Neanderthals lived 500,000 ya

However, 2-4% of DNA of living humans came from Neanderthals

European and Asian heritage most likely carry Neanderthal genes

Term
Origin of Homo Sapiens
Definition
mtDNA and Y Chromosome analysis suggests all living humans inherited mtDNA from a woman who lived 160,000-200,000 ya; diverging from a common ancestor in Africa
Term
What is the world's oldest and most complete skeleton of a potential human ancestor?
Definition
4.4 million ya
Ardipithecus ramidus from Ethiopia
Term
What was the emigration out of Africa like for early humans?
Definition
Migrated to Asia 50,000-60,000 ya
Then to Europe, SE Asia, and Australia
Term
What are the genetics behind language?
Definition
Uniquely human trait permitting creation of human culture
Linguistic ability linked to human version of FOXP2 gene (found in many vocalizing animals, controls expression of many genes; human form arose within last 100,000 years)
Term
What are the genetics behind skin color?
Definition
Varies geographically and likely a result of natural selection
Needed to balance skin's ability to block UV radiation (from degrading folate; vital for fetal development and spermatogenesis) and ability to absorb UV radiation (to synthesize vitamin D; esssential for proper bone development)
Term
Fossils
Definition
Imprints of remains of organisms that lived in the past
Term
Which of the following did not influence Darwin as he synthesized the theory of evolution by natural selection?
A) Examples of artificial selection that produce large and relatively rapid changes in domesticated species
B) Lyell's Principles of Geology on gradual geologic changes
C) Comparisons of fossils with living organisms
D) The biogeographic distribution of organisms such as the unique species on the Galapagos Islands
E) Mendel's paper describing "laws of inheritance"
Definition
E
Term
Natural selection is sometimes described as "survival of the fittest". Which of the following best measures an organism's fitness?
A) How many fertile offspring it produces
B) It's mutation rate
C) How strong it is when pitted against others of its species
D) Its ability to withstand environmental extremes
E) How much food it is able to make or obtain
Definition
A
Term
Mutations are rarely the cause of evolution in populations of plants and animals because
A) They are often harmful and do not get passed on
B) They do not directly produce most of the genetic variation present in a diploid population
C) They occur very rarely
D) They are only passed on when they occur in cells that lead to gametes
E) All of the above
Definition
E
Term
In an area of erratic rainfall, a biologist found that grass plants with alleles for curled leaves reproduced better in dry years, and plants with alleles for flat leaves reproduced better in wet years. This situation would tend to...
A) cause genetic drift in the grass population
B) preserve genetic variation in the grass population
C) lead to stabilizing selection in the grass population
D) lead to uniformity in the grass population
E) cause gene flow in the grass population
Definition
B
Term
Which of the following pairs of structures is least likely to represent homology?
A) Hemoglobin of human and babboon
B) Mitochondria of plant and animal
C) Wings of bird and insect
D) Tail of cat and alligator
E) Foreleg of pig and flipper of whale
Definition
C
Term
If an allele is recessive and lethal in homozygotes before they reproduce,
A) the allele is 0.001 present in the population frequency
B) allele will be removed from population by natural selection in 1,000 years
C) allele will remain in population at a low frequency because it cannot be selected against in heterozygotes
D) fitness of homozygous recessive genotype is 0
E) both C and D are correct
Definition
E
Term
Darwin's claim that all life is descended from a common ancestor is best supported with evidence from...
A) Fossil record
B) Molecular biology
C) Evolutionary trees
D) Comparatve anatomy
E) Comparative embryology
Definition
B
Term
In a population with two alleles, B and b, the allele frequency of b is 0.4. B is dominant to b. What is the frequency of individuals with dominant phenotype if the population is in Hardy-Weinberg equilibrium?
A) 0.16
B) 0.36
C) 0.48
D) 0.84
E) You cannot tell from this information
Definition
D
Term
Within a few weeks of treatment with the drug 3TC, a patient's HIV population consists entirely of 3TC-resistant viruses. How can this result best be explained?
A) HIV can change its surface proteins and resist vaccines
B) The patient must have become reinfected with a resistant virus
C) A few drug-resistant viruses were present at the start of treatment, and natural selection increased their frequency
D) The drug caused the HIV genes to change
E) HIV began making drug-resistant versions of its enzymes in response to drug
Definition
C
Term
Which concept of species would be most useful to a field biologist identifying new species in a tropical forest?
A) Biological
B) Ecological
C) Morphological
D) Phylogentic
E) A and B
Definition
C
Term
The largest unit within which gene flow can readily occur is a...
A) Population
B) Species
C) Genus
D) Hybrid
E) Taxon
Definition
B
Term
Bird guides once listed the myrtile warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Most likely, it has been found that the two kinds of warblers...
A) live in similar habitats and eat similar foods
b) interbreed often in nature, and the offspring are viable and fertile
C) are almost identical in appearance
D) have many genes in common
E) sing similar songs
Definition
B
Term
Which of the following is an example of postzygotic reproductive barrier?
A) One Ceanothus shrub lives on acid soil, another on basic sol
B) Mallard and pintail ducks mate at different times of year
C) Two species of leopard frogs have different mating calls
D) Hybrid offspring of two two spieces of jimsonweeds always die before reproducing
E) Pollen of one kind of tobacco cannot fertilize another kind
Definition
D
Term
Biologists have found more than 500 species of fruit flies on the various Hawaiian islands, all apparently descended from a single ancestor species. This example illustrates...
A) Polyploidy
B) Temporal isolation
C) Adaptive radiation
D) Sympatric speciation
E) Postzygotic barriers
Definition
C
Term
A new plant species C, which formed from hybridization of species A (2n =16) with species B (2n = 12), would probably produce gametes with a chromosome number of...
A) 12
B) 14
C) 16
D) 28
E) 56
Definition
B
Term
A horse (2n= 64) and a donkey (2n= 62) can mate and produce a mule. How many chromosomes would there be in a mule's cells?
A) 31
B) 62
C) 63
D) 126
E) 252
Definition
C
Term
What prevents horses and donkeys from hybridizing to form a new species?
A) Limited hybrid fertility
B) Limited hybrid viability
C) Hybrid breakdown
D) Gametic isolation
E) Prezygotic barrier
Definition
A
Term
Which of the following most likely contributed to the rapid speciation of the hundreds of cichlid species in Lake Victoria?
A) Introduction of Nile perch
B) Increasingly murky waters resulting from pollution
C) Female mate choice based on male coloration
D) Unique mouth and jaw structure that was adaptable to diverse food resources
E) C and D
Definition
E
Term
Which of the following factors could not contribute to allopatric speciation?
A) Population becomes geographically isolated from the parent population
B) Separated population is small, and genetic drift occurs
C) Isolated population is exposed to different selection pressures than parent population
D) Different mutations begin to distinguish the gene pools of the separated populations
E) Gene flow between the two populations continues to occur
Definition
E
Term
Phylogeny
Definition
Evolutionary history of a species or group of species
Term
Convergent Evolution
Definition
Species from different evolutionary branches may come to resemble one another if they live in similar environments and natural selection favors similar adaptations
Term
Analogy
Definition
Similarity due to convergent evolution
Term
Systematics
Definition
Discipline of biology that focuses on classifying organisms and determining their evolutionary relationships
Term
What is the hierarchical classification system?
Definition
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Term
Clade
Definition
Group of species that includes ancestral species and descendants
Cladistics is the most widely used method in systematics
Term
Parismony
Definition
Quest for the simplest explanation for observed phenomena
Term
You set your time machine for 3 billion ya and push the start button. When the dust clears, you look out the window. Which of the following describes what you would probably see?
A) Plants and animals very different from those alive today
B) A cloud of gas and dust in space
C) Green scum in the water
D) Land and water sterile and devoid of life
E) An endless expanse of red-hot molten rock
Definition
C
Term
Ancient photosynthetic prokaryotes, found in fossil stromatolites, were very important in the history of life because they...
A) Were probably the first living things to exist on Earth
B) Produced the oxygen in the atmosphere
C) Are the oldest known archaea
D) Were the first multicellular organisms
E) Showed that life could evolve around deep-sea vents
Definition
B
Term
The animals and plants of India are very different from the species in nearby SE Asia. Why might this be true?
A) They have become separated by convergent evolution
B) The climates of the two regions are different
C) India is in the process of separating from the rest of Asia
D) Life in India was wiped out by ancient volcanic eruptions
E) India was a separate continent until about 55 mya
Definition
E
Term
Adaptive radiations may be promoted as a direct consequence of all the following except one. Which one?
A) Mass extinctions that result in vacant ecological niches
B) Colonization of an isolated region with few competitors
C) Formation of a land bridge between two previously isolated and already inhabited continents
D) A novel adaptation
E) Adaptive radiation that produces new food sources
Definition
C
Term
A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from lugs of an ancestral fish is an example of...
A) an evolutionary trend
B) paedomorphosis
C) changes in homeotic gene expression
D) gradual refinement of a structure with the same function
E) exaptation
Definition
E
Term
If you were using cladistics to build a phylogenetic tree of cats, which would be the best choice for an outgroup?
A) Wolf
B) Leopard
C) Domestic cat
D) Turtle
E) Lion
Definition
A
Term
Which of the following could provide the best data for determining the phylogeny of very closely related species?
A) Fossil record
B) Comparison of embryological development
C) Analysis of the morphological differences and similarities
D) Comparison of nucleotide sequences in homologous genes and mtDNA
E) Comparison of their ribosomal DNA sequences
Definition
D
Term
Major divisions in the geologic record are marked by...
A) Radioactive dating
B) Distinct changes in the types of fossilized life
C) Continental drift
D) Regular time intervals measured in millions of years
E) Appearance, in order, of prokaryotes, eukaryotes, protists, plants, fungi, and animals
Definition
B
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