Bio Final Study Set

अब Quizwiz के साथ अपने होमवर्क और परीक्षाओं को एस करें!

Over time, the same bones in different vertebrates were put to different uses. An example of this is the forelimbs of vertebrates. This falls under the category of

homologous structure

carolus Linnaeus

invented current taxonomy using binomial nomenclature (genus then species)

What is true about genetic variation

it must be present in a population before natural selection can act upon the population

radiometric dating

measured absolute age of rocks based on the decay of radioactive isotopes and half life

How long does it take new species to form on Earth?

millions of years

Types of Sympatric Speciation: Hybridization

occurs when 2 forms of a species mate and produce progeny along a geographic boundary called a hybrid zone. Hybrids normally diverge from both parent populations

James Hutton's theory of gradualism

(1795) stated that the earth had been molded by slow and gradual change. natural wind and water and weather damage formed the geologic features on earth

when did earth form

4.6bya

Natural selection changes allele frequencies because some___ survive and reproduce more successfully than others

Individuals

What is true of natural selection?

Mutations occur at random; natural selection can preserve and distribute beneficial mutations

DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that A) humans and chimpanzees share a relatively recent common ancestor. B) humans evolved from chimpanzees. C) chimpanzees evolved from humans. D) convergent evolution led to the DNA similarities. E) humans and chimpanzees are not closely related.

During oxidative phosphorylation, H2O is formed. Where do the oxygen atoms in the H2O come from? a. molecular oxygen b. pyruvate c. glucose d. carbon dioxide e. lactate

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that A) island forms and mainland forms descended from common ancestors. B) common environments are inhabited by the same organisms. C) the islands were originally part of the continent. D) the island forms and mainland forms are converging. E) island forms and mainland forms have identical gene pools.

Molecules capable of interacting must first overcome a thermodynamic barrier known as the reaction's a. activation energy. b. free-energy content. c. heat content. d. entropy. e. endothermic level.

Which of the following pairs is mismatched? a. lysosomeπprotein synthesis b. nucleolus-ribosomal RNA c. nucleus-DNA replication d. cytoskeleton-microtubules e. cell membrane-lipid bilayer

Which of these conditions should completely prevent the occurrence of natural selection in a population over time? A) All variation between individuals is due only to environmental factors. B) The environment is changing at a relatively slow rate. C) The population size is large. D) The population lives in a habitat where there are no competing species present.

A high degree of endemism is most likely in environments that are A) easily reached and heterogeneous. B) isolated and heterogeneous. C) isolated and homogeneous. D) isolated and extremely cold. E) easily reached and homogeneous.

A new plant species formed from the hybridization between a plant with a diploid number of 16 and a plant with a diploid number of 12 would probably have a gamete chromosome number of A) 12. B) 14. C) 16. D) 22. E) 28.

About 13 different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the 13 species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). Which of the following is not an observation or inference on which natural selection is based? A) There is heritable variation among individuals. B) Poorly adapted individuals never produce offspring. C) Species produce more offspring than the environment can support. D) Individuals whose characteristics are best suited to the environment generally leave

About thirteen different species of finches inhabit the Galápagos Islands today, all descendants of a common ancestor from the South American mainland that arrived a few million years ago. Genetically, there are four distinct lineages, but the thirteen species are currently classified among three genera. The first lineage to diverge from the ancestral lineage was the warbler finch (genus Certhidea). Next to diverge was the vegetarian finch (genus Camarhynchus), followed by five tree finch species (also in genus Camarhynchus) and six ground finch species (genus Geospiza). If the six ground finch species have evolved most recently, then which of these is the most logical prediction? A) They should be limited to the six islands that most recently emerged from the sea. B) Their genomes should be more similar to each other than are the genomes of the five tree finch species. C) They should share fewer anatomical homologi

Catastrophism was Cuvier's attempt to explain the existence of _____. A) evolution B) the fossil record C) uniformitarianism D) the origin of new species

Currently, two extant elephant species (X and Y) are classified in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true? A) Species X and Y are not related to species Z. B) Species X and Y share a greater number of homologies with each other than either does with species Z. C) Species X and Y share a common ancestor that is alive today. D) Species X and Y are the result of artificial selection.

Currently, two extant elephant species (X and Y) are placed in the genus Loxodonta, and a third species (Z) is placed in the genus Elephas. Thus, which statement should be true? A) Species X and Y are not related to species Z. B) Species X and Y share a greater number of homologies with each other than either does with species Z. C) Species X and Y share a common ancestor that is still extant (in other words, not yet extinct). D) Species X and Y are the result of artificial selection from an ancestral species Z. E) Species X, Y, and Z share a common ancestor, but nothing more can be claimed than this.

Darwin was able to formulate his theory of evolution based on several facts. Which of the following facts was unavailable to Darwin in the mid-nineteenth century? a. Natural resources are limited. b. Characteristics are inherited as genes on chromosomes. c. Individual organisms in a population are not alike. d. Most populations are stable in size. e. All populations have the potential to increase.

Each element is unique and different from other elements because of its a. atomic weight. b. atomic number. c. mass number. d. Only A and B are correct. e. A, B, and C are correct.

For a science fair project, two students decided to repeat the Hershey and Chase experiment, with modifications. They decide that labeling the phosphates of the DNA wasn't good enough. Each nucleotide has only one phosphate, whereas each has two to five nitrogens. Thus, labeling the nitrogens would provide a stronger label than labeling the phosphates. This experiment will not work because a. radioactive nitrogen has a half-life of 100,000 years and the material would be too dangerous for too long. b. amino acids (and thus proteins) also have nitrogen atoms, thus the radioactivity would not distinguish between DNA and proteins. c. there is no radioactive isotope of nitrogen. d. Meselson and Stahl already did this experiment. e. although there are more nitrogens in a nucleotide, labeled phosphates actually have 16 extra neutrons, so they are more radioactive.

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, then what should happen in environments from which antibiotics are missing? A) These genes should continue to be maintained in case the antibiotics ever appear. B) These bacteria should be outcompeted and replaced by bacteria that have lost these genes. C) The bacteria should try to make the cost worthwhile by locating, and migrating to, microenvironments where traces of antibiotics are present. D) The bacteria should start making and secreting their own antibiotics.

If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics? A) These genes would be maintained in case the antibiotics appear. B) These bacteria would be outcompeted and replaced by bacteria that have lost these genes. C) These bacteria would try to make the cost worthwhile by locating and migrating to microenvironments where traces of antibiotics are present. D) The number of genes conveying antibiotic resistance would increase in these bacteria.

Races of humans are unlikely to evolve extensive differences in the future for which of the following reasons? I. The environment is unlikely to change. II. Human evolution is complete. III. The human races are incompletely isolated. A) I only B) III only C) I and II only D) II and III only E) I, II, and III

Scientific theories _____. A) are nearly the same things as hypotheses B) are supported by, and make sense of, many observations C) cannot be tested because the described events occurred only once D) are predictions of future events

The Hawaiian islands are a great showcase of evolution because of intense A) ecological isolation and sympatric speciation. B) adaptive radiation and allopatric speciation. C) allopolyploidy and sympatric speciation. D) cross-specific mating and reinforcement. E) hybrid vigor and allopatric speciation

The biological species concept is not useful for organisms known only from fossils because A) fossils are rarely preserved well enough to distinguish species based on morphology. B) it is not possible to test reproductive isolation in fossil forms. C) it is not possible to infer the types of habitats occupied by fossil forms before their extinction. D) in examining fossil organisms, it is not possible to distinguish males from females. E) the fossil record can only be used for studying anagenesis, but not cladogenesis.

The greatest number of endemic species is expected in environments that are _____. A) easily reached and ecologically diverse B) isolated and show little ecological diversity C) isolated and ecologically diverse D) easily reached and show little ecological diversity

The origin of a new plant species by hybridization coupled with nondisjunction is an example of A) allopatric speciation. B) sympatric speciation. C) autopolyploidy. D) heterochrony. E) habitat selection.

The two ring forms of glucose a. arise when different carbons of the linear structure join to form the rings. b. arise because the hydroxyl group at the point of ring closure can be trapped in either one of two possible positions. c. include an aldose and a ketose. d. arise from different linear (nonring) glucose molecules. e. are made from different structural isomers of glucose.

Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should a. eventually result in the formation of a single species from the two parental species. b. reinforce prezygotic isolating mechanisms between horses and donkeys. c. cause convergent evolution. d. weaken the intrinsic reproductive isolating mechanisms between horses and donkeys. e. result in the extinction of one of the two parental species.

There are __________ subgroups within the domain Archaea. a. one b. two c. three d. four e. five

Variations in allometric growth patterns demonstrate how A) relative large genetic change can have minor impact on phenotype. B) relative small genetic change can have a major impact on phenotype. C) chimpanzees and humans could not have a common ancestor. D) adult chimpanzees are basically juvenile humans that have gained the ability to reproduce. E) differences in the fetal skulls of chimpanzees and humans lead to very similar adult skulls.

What are the maximum number of covalent bonds an element with atomic number 16 can make with hydrogen? a. 5 b. 2 c. 3 d. 1 e. 4

What are the two classifications of prokaryotes? a. Domain Bacteria and Domain Eukarya b. Domain Bacteria and Domain Archaea c. Domain Eukarya and Domain Archaea d. Domain Archaea and Kingdom Monera e. Domain Bacteria and Kingdom Monera

What must be true of any organ described as vestigial? A) It must be analogous to some feature in an ancestor. B) It must be homologous to some feature in an ancestor. C) It must be both homologous and analogous to some feature in an ancestor. D) It need be neither homologous nor analogous to some feature in an ancestor.

What must be true of any organ that is described as vestigial? A) It must be analogous to some feature in an ancestor. B) It must be homologous to some feature in an ancestor. C) It must be both homologous and analogous to some feature in an ancestor. D) It need be neither homologous nor analogous to some feature in an ancestor.

What was the species concept used by Linnaeus? A) biological B) morphological C) paleontological D) ecological E) phylogenetic

Which of the following characterizes the sodium-potassium pump? a. Potassium ions are pumped into a cell against their gradient. b. Sodium ions are pumped out of a cell against their gradient. c. A and B d. A carrier protein undergoes conformational change. e. A, B, and C

Which of the following evidence most strongly supports the common origin of all life on Earth? All organisms _____. A) require energy B) use essentially the same genetic code C) reproduce D) show heritable variation

Which of the following is a way that allopolyploidy can most directly cause speciation? A) It can improve success in island habitats. B) It can overcome hybrid sterility. C) It can change the mating behavior of animals. D) It can generate geographic barriers. E) It can produce heterochrony.

Which of the following may explain genomic imprinting? a. retrotransposons b. DNA methylation c. microsatellite DNA d. post-translational modification of proteins e. oncogenes

Which of the following pieces of evidence most strongly supports the common origin of all life on Earth? A) All organisms require energy. B) All organisms use essentially the same genetic code. C) All organisms reproduce. D) All organisms show heritable variation. E) All organisms have undergone evolution.

Which of the following represents an idea that Darwin learned from the writings of Thomas Malthus? A) Technological innovation in agricultural practices will permit exponential growth of the human population into the foreseeable future. B) Populations tend to increase at a faster rate than their food supply normally allows. C) Earth changed over the years through a series of catastrophic upheavals. D) The environment is responsible for natural selection.

two species of pine shed their pollen at different times A. gametic B. temporal C. behavioral D. habitat E. mechanical

two species of trout that breed in different seasons A. gametic B. temporal C. behavioral D. habitat E. mechanical

sexual selection

based on variation in secondary sexual characteristics related to competing for and attracting mates. determined by male competition for females to mate with and female choice in mates. male competition=evolution of antlers and horns or a larger size female choice creates traits and behaviors in males to attract females.

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These ritual involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?

behavioral isolation

A defining characteristic of allopatric speciation is A) the appearance of new species in the midst of old ones. B) asexually reproducing populations. C) geographic isolation. D) artificial selection. E) large populations.

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back made possible the evolution of the tetrapod limb. This type of change is illustrative of A) the influence of environment on an individual's development. B) paedomorphosis, or retention of ancestral juvenile structures in an adult organism. C) a change in a developmental gene or in its regulation that altered the spatial organization of body parts. D) punctuated equilibrium. E) the origin of a new species due to allopolyploidy.

A new organism is discovered in the deserts of New Mexico. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 68 amino acid differences from humans, 62 differences from a gibbon, 24 differences from a rat, and 6 differences from a frog. These data a. were collected to determine the type of blood in the new organism. b. show that the new organism is best adapted to an aquatic habitat. c. indicate that the new organism may be closely related to frogs. d. suggest that the new organism is closely related to humans. e. suggest that the new organism evolved from gibbons but not rats and mice.

Autopolyploidy is a speciation process that begins with an event during A) habitat selection. B) copulation. C) meiosis. D) embryonic development. E) hybridization.

Both ancestral birds and ancestral mammals shared a common ancestor that was terrestrial. Today, penguins (which are birds) and seals (which are mammals) have forelimbs adapted for swimming. What term best describes the relationship of the bones in the forelimbs of penguins and seals, and what term best describes the flippers of penguins and seals? A) homologous; homologous B) analogous; homologous C) homologous; analogous D) analogous; analogous

Cotton-topped tamarins are small primates with tufts of long white hair on their heads. While studying these creatures, you notice that males with longer hair get more opportunities to mate and father more offspring. To test the hypothesis that having longer hair is adaptive in these males, you should _____. A) test whether other traits in these males are also adaptive B) look for evidence of hair in ancestors of tamarins C) determine if hair length is heritable D) test whether males with shaved heads are still able to mate

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. Which of these would have prevented this evolution of DDT resistance in insect pests? A) All habitats should have received applications of DDT at about the same time. B) The frequency of DDT application should have been higher. C) None of the insect pests would have genetic variations that resulted in DDT resistance. D) DDT application should have been continual.

Darwin and Wallace's theory of evolution by natural selection was revolutionary because it _____. A) was the first theory to refute the ideas of special creation B) proved that individuals acclimated to their environment over time C) dismissed the idea that species are constant and emphasized the importance of variation and change in populations D) was the first time a biologist had proposed that species changed through time

Energy enters most ecosystems as a. chemical energy. b. heat and chemical energy. c. light. d. light and chemical energy. e. heat.

Fossils of Thrinaxodon, a species that lived during the Triassic period, have been found in both South Africa and Antarctica. Thrinaxodon had a reptile-like skeleton and laid eggs, but small depressions on the front of its skull suggest it had whiskers and, therefore, fur. Thrinaxodon may have been warm-blooded. The fossils of Thrinaxodon are consistent with the hypothesis that _____. A) fossils found in a given area look like the modern species in that same area B) the environment where it lived was very warm C) mammals evolved from a reptilian ancestor D) Antarctica and South Africa separated after Thrinaxodon went extinct

In a hypotonic solution an animal cell will a. experience turgor. b. shrivel. c. lyse. d. lose water. e. neither gain nor lose water.

Many species of snakes lay eggs, but in the forests of northern Minnesota where growing seasons are short, only live-bearing snake species are present. This trend toward species that perform live birth is an example of A) natural selection. B) sexual selection. C) species selection. D) goal direction in evolution. E) directed selection

Over evolutionary time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? A) Natural selection cannot account for losses, only for innovations. B) Natural selection accounts for these losses by the principle of use and disuse. C) Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. D) The ancestors of these organisms experienced harmful mutations that forced them to find new habitats that these species had not previously used.

Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses? A) Natural selection cannot account for losses, but accounts only for new structures and functions. B) Natural selection accounts for these losses by the principle of use and disuse. C) Under particular circumstances that persisted for long periods, each of these structures presented greater costs than benefits. D) The ancestors of these organisms experienced harmful mutations that forced them to lose these structures.

A rapid method of speciation that has been important in the history of flowering plants is A) genetic drift. B) paedomorphosis. C) a mutation in the gene controlling the timing of flowering. D) behavioral isolation. E) polyploidy.

Therapeutic cloning

has the potential to produce organs transplants

Adaptive radiation (process of speciation)

relatively rapid evolution of many species from a single ancestor; all become different due to diverse environmental factors -ex: marsupials adaptively radiated from one mammal species that came to australia -ex:14 species of Darwin's finches on the galapagos islands came from 1 ancestor from the mainland

studying undisturbed sedimentary rock layers...

reveals relative age of rocks and fossils

embryology

reveals similar stages in development(ontogeny) among related species. similarities help establish evolutionary relationships(phylogeny) (gill slits and post anal tails in humans and fish)

intRAsexual selection

selection within the same sex, individuals of one sex compete directly for mates of the opposite sex. in many species this only occurs between males

biogeography

uses geography to describe the distribution of species found that unrelated species look similar when found in similar habitats

paleomagnetic dating

uses the fact that earths magnetic poles shift and sometimes reverse(recorded in rock levels)

founder effect

when a few individuals become isolated from a larger population, this smaller group may establish a new population whose gene pool differs from the source population

O2 and the ozone layer formed and abiotic chemical evolution ended

(life can leave ocean) -as a by-product of the photosynthetic activity of autotrophs, O2 was released and accumulated in atmosphere -interaction b/w uv light and oxygen produced the ozone layer -ozone layer blocked uv light -major source of energy for abiotic synthesis of organic molecules and primitive cells was terminatef

Genetic flow

(movement of people that take or introduce alleles) -emigration-remove alleles from population when they leave -immigration-introduction of alleles when they enter

Comparative anatomy

- homologous structures have a common function and a common ancestry (bat wing and human arm) -analogous structures have same function but not a common ancestor. (bat wing and fly wing) -vestigial structures are evidence of structures that have evolved and are unnecessary (human appendix)

primitive heterotrophic prokaryotes formed (LIFE)

-3.9 bya -heterotrophs(obtain energy from eating other living things) formed +organic soup was a source of organic material for heterotrophic cells +as cells reproduce, competition for organic material increased (started natural selection) - RNA entered protobiotins +RNA can now mutate and evolve +now a life form -first fossils from 3.5bya

primitive autotrophic prokaryotes were formed

-by mutation, heterotrophs became able to produce their own food -3.6 bya autotrophs formed autotrophs make their food using light energy or energy from inorganic substances

how were organic molecules synthesized

1) energy catalyzed the formation of organic molecules from inorganic molecules (organic soup formed) 2) energy provided by uv light, lightening, radioactivity, and heat 3) complex molecules (s/a amino acids) formed. these would later serve as monomers to build polymers 4) simple molecules were only able to form when oxygen was absent. (oxygen is very reactive and wouldve prevented the formation)

Maintaining reproductive isolation: Postzygotic isolating techniques (prevent formation of fertile offspring)

1) hybrid inviability: zygote fails to develop properly and is aborted or dies before sexual maturity 2) hybrid sterility: hybrids are functional adults but reproductively sterile 3) hybrid breakdown: hybrids produce offspring that have reduced viability or fertility

5 forces of evolution

1) natural selection (increase/decrease allele frequencies due to the impact of the enviro) 2)mutations( new alleles; either selective advantage or deleterious/harmful) 3) Gene flow(movement of people that take or introduce alleles) 4) Genetic drift (random increase or decrease of alleles) 5) nonrandom mating(when individuals choose mates based on their particular traits)

Patterns of macroevolution

1) phyletic gradualism: evolution by the gradual accumulation of small changes (near constant change) 2) punctuated equilibrium: long periods of little or no change (stasis) and then interrupted/punctuated by short periods of rapid evolution

arguments for natural selection

1) populations possess an enormous reproductive potential 2) population sizes remain stable 3) resources are limited 4) individuals compete to survive 5) there is variation among individuals in a polulation 6) much variation is heritable (loss of a limb is not heritable. traits are passed from parents to offspring) 7) only the most fit individuals survive 8) evolution occurs as favorable traits accumulate in the population

Maintaining reproductive isolation: prezygotic isolating mechanism(prevent fertilization)

1)habitat isolation: species don't encounter other species 2)Temporal isolation: species mate or flower during different seasons or times 3) behavioral isolation: species don't recognize each other as mating partners due to different courtship behaviors or pheromones 4)mechanical isolations: when male and female genitalia aren't compatible 5)gametic isolation: males gametes do not survive in the female's reproductive parts

Jean-baptiste Lamarck's theory of evolution

1)use and disuse:: body parts develops with usage and weaken when not used (CORRECT) 2) inheritance of acquires characteristics:: body features acquired during the adults life are passed on to offspring (like muscle mass or a stretched neck) (INCORRECT)

WHY NATURAL SELECTION CANNOT FASHION PERFECT ORGANISMS

1. selection can act only on existing variations. natural selection favors only the fittest phenotypes among those currently in the population, which may not be the ideal traits. new advantageous alleles do not arise on demand. 2. evolution is limited by historical constraints. each species has a legacy of descent with modification from ancestral forms. evolution does not scrap the ancestral anatomy and build each new complex structure from scratch; rather, evolution co-opts existing structures and adapts them to new situations. 3. adaptations are often compromises. each organism must do many different things. a seal spends part of its time on rocks, it could probably walk better if it had legs instead of flippers, but then it would not swim nearly as much. 4. chance, natural selection, and the environment interact. chance events can affect the subsequent evolutionary history of populations.

Divergent evolution

2 or more species that originate from a common ancestor and become increasingly different over time

Parallel Evolution

2 related species or 2 related lineages that made similar evolutionary changes after their divergence from a common ancestor

Convergent Evolution

2 unrelated species that have evolved to have similar(analogous) traits because they live in similar ecological conditions ex: shark, dolphin, and penguin body shape and fins

Approximately how far back in time does the eukaryote fossil record extend?

2.1 billion years

During a study session about evolution, one of your fellow students remarks, "The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception? A) Characteristics acquired during an organism's life are generally not passed on through genes. B) Spontaneous mutations can result in the appearance of new traits. C) Only favorable adaptations have survival value. D) Disuse of an organ may lead to its eventual disappearance. E) If the giraffes did not have to compete with each other, longer necks would not have been passed on to the next generation.

What was the prevailing belief prior to the time of Lyell and Darwin? A) Earth is a few thousand years old, and populations are unchanging. B) Earth is a few thousand years old, and populations gradually change. C) Earth is millions of years old, and populations rapidly change. D) Earth is millions of years old, and populations are unchanging. E) Earth is millions of years old, and populations gradually change.

Catastrophism, meaning the regular occurrence of geological or meteorological disturbances (catastrophes), was Cuvier's attempt to explain the existence of A) evolution. B) the fossil record. C) uniformitarianism. D) the origin of new species. E) natural selection.

Which of the following statements best describes theories? A) They are nearly the same things as hypotheses. B) They are supported by, and make sense of, many observations. C) They cannot be tested because the described events occurred only once. D) They are predictions of future events.

Who is credited with creating the theory of evolution?

Charles Darwin

Ichthyosaurs were aquatic dinosaurs. Fossils show us that they has dorsal fins and tails, as do fish, even though their closest relatives, terrestrial reptiles, had neither dorsal fins nor aquatic tails. The dorsal fins and tail of ichthyosaurs and fish are A) homologous. B) examples of convergent evolution. C) adaptations to a common environment. D) A and C only E) B and C only

Correct answer: E

Neutral variation(nonselective)

EX: variation in human fingerprints (doesn't give us an advantage or disadvantage) in many cases, the enviro to which the variation is exposed to determines whether it is neutral or selective. Humans impact the evolutionary potential of species by reducing the size of their population and decrease genetic variation. when genetic variation decreases, pop lacks the variation necessary to respond to selection pressures imposed by a changing enviro.

Which of the following is the correct sequence of event in the origin of life? I. formation of protobionts II. synthesis of small organic molecules III. synthesis of organc polymers IIII. formation of self-replicating molecules

II, III, I. IV

Why was it helpful to Darwin to learn Earth was very old?

It meant there was enough time for evolution to have occurred slowly

A population of lizards live on a farm. On the farm is a green field with a wooden fence surrounding it. The blue birds love to eat lizards. A mutation in the lizards occurs so that some of them lose their tails to escape a predator. Which of the following statements is correct?

Lizards that lose their tails when attacked will probably become more prominent in the population

_____ can have catalytic activity and was probably the first genetic material on earth

RNA

average heterozygosity

The percent, on average, of a population's loci that are heterozygous (two different alleles for a given loci) in members of the population.

Bird guides one listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of he following pieces of evidence, if true, would be cause for this reclassification?

The two forms interbreed often in nature, and their offspring have good survival and reproduction

A biologist discovers two populations of wolf spiders whose members appear identical. Members of one population are found in the leaf litter deep within a woods. Members of the other population are found in the grass at the edge of the woods. The biologist decides to designate the members of the two populations as two separate species. Which species concept is this biologist most closely utilizing? A) ecological B) biological C) morphological D) paleontological E) phylogenetic

A population of organisms will not evolve if _____. A) all individual variation is due only to environmental factors B) the environment is changing at a relatively slow rate C) the population size is large D) the population lives in a habitat without competing species present

After the drought of 1977, researchers on the island of Daphne Major hypothesized that medium ground finches that had large, deep beaks, survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. If this hypothesis is correct, what would you expect to observe if a population of these medium ground finches colonizes a nearby island where Tribulus cistoides is the most abundant food for the next 1000 years? Assume that (1) even the survivors of the 1977 drought sometimes had difficulty cracking the tough T. cistoides fruits and would eat other seeds when offered a choice; and (2) food availability is the primary limit on finch fitness on this new island. A) evolution of yet larger, deeper beaks over time B) evolution of smaller, pointier beaks over time C) random fluctuations in beak size and shape D) no change in beak size and shape

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species. Recently, these birds have been classified as eastern and western forms of a single species, the yellow-rumped warbler. Which of the following pieces of evidence, if true, would be cause for this reclassification? A) The two forms are observed to interbreed successfully where their habitats overlap. B) The two forms live in similar habitats. C) The two forms have many genes in common. D) The two forms have similar food requirements. E) The two forms are very similar in coloration.

Claytonia virginica is a woodland spring herb with flowers that vary from white to pale pink to bright pink. Slugs prefer to eat pink-flowering over white-flowering plants (due to chemical differences between the two), and plants experiencing severe herbivory are more likely to die. The bees that pollinate this plant also prefer pink to white flowers, so that Claytonia with pink flowers have greater relative fruit set than Claytonia with white flowers. A researcher observes that the percentage of different flower colors remains stable in the study population from year to year. Given no other information, if the researcher removes all slugs from the study population, what do you expect to happen to the distribution of flower colors in the population over time? A) The percentage of pink flowers should increase over time. B) The percentage of white flowers should increase over time. C) The distribution of flower colors

Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. A) 2 → 4 → 1 → 3 B) 4 → 2 → 1 → 3 C) 4 → 2 → 3 → 1 D) 2 → 4 → 3 → 1

Given a population that contains genetic variation, what is the correct sequence of the following events, under the influence of natural selection? 1. Well-adapted individuals leave more offspring than do poorly adapted individuals. 2. A change occurs in the environment. 3. Genetic frequencies within the population change. 4. Poorly adapted individuals have decreased survivorship. A) 2 → 4 → 1 → 3 B) 4 → 2 → 1 → 3 C) 4 → 1 → 2 → 3 D) 4 → 2 → 3 → 1 E) 2 → 4 → 3 → 1

Given what we know about evolutionary biology, we expect to find the largest number of endemic species in which of the following geological features, which have existed for at least a few million years? A) an isolated ocean island in the tropics B) an extensive mountain range C) a grassland in the center of a large continent, with extreme climatic conditions D) a shallow estuary on a warm-water coast

If Darwin had been aware of genes and their typical mode of transmission to subsequent generations, with which statement would he most likely have been in agreement? A) If natural selection can change gene frequency in a population over generations, given enough time and genetic diversity, then natural selection can cause sufficient genetic change to produce new species from old ones. B) If an organism's somatic cell genes change during its lifetime, making it more fit, then it will be able to pass these genes on to its offspring. C) If an organism acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will result. D) A single mutation in a single gene in a single gamete, if inherited by future generations, will produce a new species.

If Darwin had been aware of genes, and of their typical mode of transmission to subsequent generations, with which statement would he most likely have been in agreement? A) If natural selection can change one gene's frequency in a population over the course of generations then, given enough time and enough genes, natural selection can cause sufficient genetic change to produce new species from old ones. B) If an individual's somatic cell genes change during its lifetime, making it more fit, then it will be able to pass these genes on to its offspring. C) If an individual acquires new genes by engulfing, or being infected by, another organism, then a new genetic species will be the result. D) A single mutation in a single gene in a single gamete will, if perpetuated, produce a new species within just two generations.

If one wanted to find the largest number of endemic species, one should visit which of the following geological features (assuming each has existed for several millions of years)? A) an isolated ocean island in the tropics B) an extensive mountain range C) a midcontinental grassland with extreme climatic conditions D) a shallow estuary on a warm-water coast

In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP? a. energy released from movement of protons through ATP synthase b. energy released as electrons flow through the electron transport system c. No external source of energy is required because the reaction is exergonic. d. energy released from substrate-level phosphorylation e. energy released from ATP synthase pumping hydrogen ions against their concentration gradient

In the 5-6 million years that the hominid lineage has been diverging from its common ancestor with the great apes, dozens of hominid species have arisen, often with several species coexisting in time and space. As recently as 30,000 years ago, Homo sapiens coexisted with Homo neanderthalensis. Both species had large brains and advanced intellects. That these traits were common to both species is most easily explained by which of the following? A) species selection B) uniformitarianism C) sexual selection D) A and B only E) A, B, and C

It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that ____. A) island forms are descended from mainland forms B) common environments are inhabited by the same organisms C) island forms and mainland forms have identical gene pools D) the island forms and mainland forms are converging

Mimulus lewisii and M. cardinalis are plants that do not hybridize in nature but can be readily crossed in the laboratory to produce fertile offspring. Which of the following is least likely to keep the gene pools of these two plants separate in nature? A) gametic incompatibility B) different attractiveness to pollinators C) different ecological niches D) different geographic ranges E) seasonal differences in flowering

Prior to the work of Lyell and Darwin, the prevailing belief was that Earth is _____. A) a few thousand years old, and populations are unchanging B) a few thousand years old, and populations gradually change C) millions of years old, and populations rapidly change D) millions of years old, and populations are unchanging

Some species of Anopheles mosquito live in brackish water, some in running fresh water, and others in stagnant water. What type of reproductive barrier is most obviously separating these different species? A) habitat isolation B) temporal isolation C) behavioral isolation D) gametic isolation E) postzygotic isolation

Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale, and cabbage. Therefore, which of the following statements is correct? A) In this wild mustard, there is enough heritable variation to permit these different varieties. B) Heritable variation is low in wild mustard—otherwise this wild strain would have different characteristics. C) Natural selection is rare in wild populations of wild mustard. D) In wild mustard, most of the variation is due to differences in soil or other aspects of the environment.

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of _____. A) homology B) convergent evolution C) the evolution of common structure as a result of common function D) the evolution of similar appearance as a result of common function

Two species of frogs belonging to the same genus occasionally mate, but the offspring do not complete development. What is the mechanism for keeping the two frog species separate? A) the postzygotic barrier called hybrid inviability B) the postzygotic barrier called hybrid breakdown C) the prezygotic barrier called hybrid sterility D) gametic isolation E) adaptation

What is generally true of two sibling species? A) They shared a common ancestor recently in evolutionary time. B) Genes are unable to pass from one sibling species' gene pool to the other's. C) They are unable to produce hybrid offspring upon interbreeding. D) Their reproductive isolation from each other is complete. E) They are the result of anagenesis

What is macroevolution? A) evolution as it occurs on a large scale B) it is a synonym for "stabilizing selection" C) population-level changes in gene frequencies D) a uniform change in the rate and pattern of evolution E) change on the subspecies level

When Cuvier considered the fossils found in the vicinity of Paris, he concluded that the extinction of species _____. A) occurs, but that there is no evolution B) and the evolution of species both occur C) and the evolution of species do not occur D) does not occur, but evolution does occur

Which of the following can best be explained by continental drift? a. The scarcity of eutherian (placental) mammals in Australia. b. The relative age of fossils. c. The Chicxulub crater. d. The Cretaceous extinctions of 65 million years ago. e. The evolution of aquatic reptiles, such as ichthyosaurs.

Which of the following must exist in a population before natural selection can act upon that population? A) genetic variation among individuals B) variation among individuals caused by environmental factors C) sexual reproduction D) the population has predators

Which of the following statements about the domains of prokaryotes is not true? a. Of the two groups, bacteria are more closely related to eukaryotes. b. Bacteria include the cyanobacteria. c. The lipid composition of the plasma membrane found in archaea is different from that of bacteria. d. Both archaea and bacteria have cell walls, but the walls of archaea lack peptidoglycan. e. Archaea and bacteria probably diverged very early in evolutionary history.

Which of the following would be a position held by an adherent of the punctuated equilibrium theory? A) A new species forms most of its unique features as it comes into existence and then changes little for the duration of its existence. B) One should expect to find many transitional fossils left by organisms in the process of forming new species. C) Given enough time, most existing species will gradually evolve into new species. D) Natural selection is unimportant as a mechanism of evolution. E) Most speciation is anagenetic.

Which of these is not one of the procedures used in Southern blotting? a. DNA microarray assay b. hybridization c. restriction fragment preparation d. electrophoresis e. autoradiography

sexual dimorphism

a difference between the two sexes in secondary sexual characteristics. this includes distinctions in size, color, ornamentation, behavior

cline

a graded change in character along a geographic axis produced by a gradation in an environmental variable, ex temperature result from natural selection

species

a group of individuals cam able of interbreeding

population

a group of individuals of the same species that line in the same area and interbreed, producing fertile offspring

bottleneck effect

a sudden change in the environment, such as a fire or a flood, may drastically reduce the size of a population. a severe drop in population size can cause the bottleneck effect, so named because the population has passed through a 'bottle-neck' that reduces its size and by chance alone, certain alleles may be overrepresented among the survivors, other underrepresented, others gone altogether humans actions can cause bottlenecks in other populations

The easiest way to describe genetic engineering is

a way to move genes from one organism to another

stabilizing selection

acts against both extreme phenotypes and favors intermediate variants. this mode of selection reduces variation and tends to maintain the status quo for a particular phenotypic character

A zebra's ability of change in response to a "problem" is an example of an organism's ability to ___ to it's environment.

adapt

In its most basic form, evolution is defined as change in ____ in a population over time

allele frequency

intERsexual selection

also called mate choice, individuals of one sex (usually the females) are choosy in selecting their mates from the other sex. in many cases, the female's choice depends on the showiness of the male's appearance or behavior.

Types of Sympatric Speciation: Balanced polymorphism

among subpopulations may lead to speciation; EX: if a pop of insects possesses a polymorphism for color(each one provides different camouflage) and if not camouflaged, it will be eaten. only insects w/ same color can associate (to live) and mate, so they are reproductively isolated. gene pool then diverges in allopatric speciation

The polymerase chain reaction (PCR) is a technique used to

amplify a region of DNA

An example of vestigial organ in humans is

appendix

fossil evidence indicates living organisms arose

approximately 3.5 billion years ago

RNA world hypothesis

argues that RNA was formed before DNA. Based on:: RNA molecules can act as enzymes and as vehicles for storing genetic info.

In order for speciation to occur, what is true?

at least one gene, affecting at least one phenotypic trait, must change

All of the following statements are true except: a. Mitosis and cytokinesis are required for asexual reproduction. b. The mitotic spindles in prokaryotic cells are composed of microtubules. c. Mitosis may occur without cytokinesis. d. Mitosis produces new nuclei with exactly the same chromosomal endowment as the parent nucleus. e. All cells come from a preexisting cell.

Antibody diversity is due to a. alternative splicing. b. genetic recombination and combining of polypeptides. c. the attachment of acetyl groups to histone proteins. d. the presence of thousands of enhancers. e. the cell's ability to make rRNA.

If two modern organisms are distantly related in an evolutionary sense, then one should expect that A) they live in very different habitats. B) they should share fewer homologous structures than two more closely related organisms. C) their chromosomes should be very similar. D) they shared a common ancestor relatively recently. E) they should be members of the same genus.

In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to increasingly colder temperatures, would eventually give rise to more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of _____. A) Cuvier B) Lamarck C) Darwin D) Lyell

Members of two different species possess a similar-looking structure that they use in a similar fashion to perform the same function. Which information would best help distinguish between an explanation based on homology versus one based on convergent evolution? A) The two species live at great distance from each other. B) The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical. C) The sizes of the structures in adult members of both species are similar in size. D) Both species are well adapted to their particular environments.

Members of two different species possess a similar-looking structure that they use in a similar way to perform about the same function. Which of the following would suggest that the relationship more likely represents homology instead of convergent evolution? A) The two species live at great distance from each other. B) The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical. C) The structures in adult members of both species are similar in size. D) Both species are well adapted to their particular environments.

The largest unit in which gene flow can readily occur is a A) population. B) species. C) genus. D) hybrid. E) phylum.

After the drought of 1977, researchers hypothesized that on the Galápagos island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island? A) evolution of yet larger, deeper beaks over time, until all birds have relatively large, deep beaks B) evolution of smaller, pointier beaks over time, until all birds have relatively small, pointy beaks C) increased variation in beak size and shape over time D) no change in beak size and shape over time

In a hypothetical environment, fishes called pike-cichlids are visual predators of algae-eating fish (in other words, they locate their prey by sight). If a population of algae-eaters experiences predation pressure from pike-cichlids, which of the following is least likely to be observed in the algae-eater population over the course of many generations? A) selection for drab coloration of the algae-eaters B) selection for nocturnal algae-eaters (active only at night) C) selection for larger female algae-eaters, bearing broods composed of more, and larger, young D) selection for algae-eaters that become sexually mature at smaller overall body sizes E) selection for algae-eaters that are faster swimmers

In a hypothetical environment, fishes called pike-cichlids are visual predators of large, adult algae-eating fish (in other words, they locate their prey by sight). The population of algae-eaters experiences predatory pressure from pike-cichlids. Which of the following is least likely to result in the algae-eater population in future generations? A) selection for drab coloration of the algae-eaters B) selection for nocturnal algae-eaters (active only at night) C) selection for larger female algae-eaters, bearing broods composed of more, and larger, young D) selection for algae-eaters that become sexually mature at smaller overall body sizes

In the mid-1900s, the Soviet geneticist Lysenko believed that his winter wheat plants, exposed to ever-colder temperatures, would eventually give rise to ever more cold-tolerant winter wheat. Lysenko's attempts in this regard were most in agreement with the ideas of A) Cuvier. B) Hutton. C) Lamarck. D) Darwin. E) Lyell.

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian islands have different elaborate courtship rituals that involve fighting other males and stylized movements that attract females. What type of reproductive isolation does this represent? A) habitat isolation B) temporal isolation C) behavioral isolation D) gametic isolation E) postzygotic barriers

Parasitic species tend to have simple morphologies. Which of the following statements best explains this observation? A) Parasites are lower organisms, and this is why they have simple morphologies. B) Parasites do not live long enough to inherit acquired characteristics. C) Simple morphologies convey some advantage in most parasites. D) Parasites have not yet had time to progress, because they are young evolutionarily.

The biological species concept is inadequate for grouping A) plants. B) parasites. C) asexual organisms. D) animals that migrate. E) sympatric populations.

The cow Bos primigenius (which is bred for meat and milk) has a smaller brain and larger eyes than closely related wild species of ungulates. These traits most likely arose by _____. A) natural selection, because these traits evolved in the population over time B) natural selection, because these traits were not consciously selected by humans C) artificial selection, because changes in these traits co-occurred with human selection for high milk output and high muscle content D) artificial selection, because these animals differ from their close relatives and common ancestor

The fetal skulls of chimpanzees and humans both have A) massive jaws. B) heavy brow ridges. C) small jaws. D) sharp angular skulls. E) three eyes.

The rise of methicillin-resistant Staphylococcus aureus (MRSA) can be considered to be an example of artificial selection because A) humans purposefully raise MRSA in large fermenters in an attempt to make the bacteria ever-more resistant. B) S. aureus is cultivated by humans to replenish the soil with nutrients. C) humans synthesize methicillin and create environments in which bacteria frequently come into contact with methicillin. D) Humans are becoming resistant to bacteria by taking methicillin.

The role that humans play in artificial selection is to A) determine who lives and who dies. B) create the genetic variants, which nature then selects. C) choose which organisms breed, and which do not. D) train organisms to breed more successfully. E) perform artificial insemination.

The role that humans play in artificial selection is to _____. A) determine who lives and who dies B) create genetic diversity C) choose which organisms reproduce D) perform artificial insemination

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. Which of the following is the most likely explanation for these data? A) Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms. B) Forelimb evolution was adaptive in people and bats, but not in whales. C) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. D) Genes mutate faster in whales than in humans or bats. E) Whales are not properly classified as mammals.

Theoretically, the production of sterile mules by interbreeding between female horses and male donkeys should A) result in the extinction of one of the two parental species. B) cause convergent evolution. C) reinforce postzygotic barriers between horses and donkeys. D) weaken the intrinsic reproductive barriers between horses and donkeys. E) eventually result in the formation of a single species from the two parental species.

Water's high specific heat is mainly a consequence of the a. inability of water to dissipate heat into dry air. b. small size of the water molecules. c. absorption and release of heat when hydrogen bonds break and form. d. high specific heat of oxygen and hydrogen atoms. e. fact that water is a poor heat conductor.

What are the basic "building blocks" of DNA? a. 20 amino acids b. protein c. four nucleotides d. carbohydrates and lipids e. 26 nucleotides

Which is one way that the skulls of adult chimpanzees and humans differ? A) Adult chimpanzees have a less angled skull. B) Adult chimpanzees have less massive jaws. C) Adult chimpanzees have heavier brow ridges. D) Adult chimpanzees have flatter faces. E) Adult chimpanzees have rounded faces.

Which of Darwin's ideas had the strongest connection to Darwin having read Malthus's essay on human population growth? A) descent with modification B) variation among individuals in a population C) struggle for existence D) the ability of related species to be conceptualized in "tree thinking" E) that the ancestors of the Galápagos finches had come from the South American mainland

Which of Darwin's ideas had the strongest connection to his reading of Malthus's essay on human population growth? A) descent with modification B) variation among individuals in a population C) struggle for existence D) that the ancestors of the Galápagos finches had come from the South American mainland

Which of the following applies to both anagenesis and cladogenesis? A) branching B) increased diversity C) speciation D) more species E) adaptive radiation

Which of the following is the most accurate summary of Cuvier's consideration of fossils found in the vicinity of Paris? A) extinction of species yes; evolution of new species yes B) extinction of species no; evolution of new species yes C) extinction of species yes; evolution of new species no D) extinction of species no; evolution of new species yes

Which of the following responses would be expected in myxobacteria when nutrients are scarce? a. Cells secrete an a-factor and an a-factor signal that releases new nutrients. b. Cells would cannibalize each other unless they secrete a chemical signal telling the other myxobacteria they are alike. c. Starving cells secrete a chemical signal that simulates other cells to aggregate in the soil and form spores. d. The starved cells secrete a signal to other cells that it is time to move to another environment. e. Both C and D are expected responses.

Which of the following statements about species, as defined by the biological species concept, is (are) correct? I. Biological species are defined by reproductive isolation. II. Biological species are the model used for grouping extinct forms of life. III. The biological species is the largest unit of population in which successful reproduction is possible. A) I only B) II only C) I and III D) II and III E) I, II, and III

Which of the following statements most detracts from the claim that the human appendix is a completely vestigial organ? A) The appendix can be surgically removed with no immediate ill effects. B) The appendix might have been larger in fossil hominids. C) The appendix has a substantial amount of defensive lymphatic tissue. D) Individuals with a larger-than-average appendix leave fewer offspring than those with a below-average-sized appendix. E) In a million years, the human species might completely lack an appendix.

Which of the following would be an example of macroevolution? A) evolution of antibiotic resistance in a strain of E. coli B) evolution of polymorphism in Papilio dardanus, with each morph mimicking a different protected butterfly C) evolution of modern humans, Homo sapiens, from australopithecine ancestors D) evolution of insecticide resistance in populations of insect pests treated through the years with DDT E) replacement of a melanin-poor morph by a melanin-rich morph over many generations under conditions of increased UV exposure

Which of the various species concepts identifies species based on the degree of genetic exchange between their gene pools? A) phylogenetic B) ecological C) biological D) morphological E) paleontological

Which of these conditions are always true of populations evolving due to natural selection? Condition 1: The population must vary in traits that are heritable. Condition 2: Some heritable traits must increase reproductive success. Condition 3: Individuals pass on most traits that they acquire during their lifetime. A) Condition 1 only B) Condition 2 only C) Conditions 1 and 2 D) Conditions 2 and 3

mating fruit flies recognize the appearance, odor, tapping motions, and sounds of members of their own species, but not of other species A. gametic B. temporal C. behavioral D. habitat E. mechanical

two species of meadowlarks with different mating songs A. gametic B. temporal C. behavioral D. habitat E. mechanical

quantitative characters

cary along a continuum within a population, usually results from the influence of two or more genes on a single phenotypic character

discrete characters

characteristics that are either/or. Purple or white, for ex, in Mendel's flower experiment

gene pool

characterizes a population's genetic makeup and consists of all copies of every type of allele at every locus in all members of the population

proof of how organic molecules were synthesized

chemist Stanley miller simulated primordial conditions. he applied electric sparks to simple gases (no O2) connected to a flask of heated water. after one week, water contained various organic molecules including amino acids

Sexual reproduction

creates individuals with unique combinations of alleles genetic recombinations originate from: 1) Crossing over (Prophase 1) 2) Independent assortment of homologues (metaphase 1) 3)Random joining of gametes (any 1 egg and any 1 sperm of many)

Why might the cricket genome have 11 times as many base pairs as that of the fruit fly, Drosophilia melanogaster

crickets must have more noncoding DNA

"Allometric" growth refers to A) the retention of juvenile characteristics in the adult. B) growth in height. C) large genetic changes. D) the variation in growth rate of various parts of the body. E) growth in girth.

A biologist studied a population of squirrels for fifteen years. During that time, the population was never fewer than thirty squirrels and never more than forty-five. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to eighty. Which inference(s) about this most recent surge in the population size might be true? A) The amount of available food may have increased. B) The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight. C) The number of predators that prey upon squirrels may have decreased. D) The amount of available food may have increased and/or the predators that prey upon squirrels may have decreased.

A farmer uses triazine herbicide to control pigweed in his field. For the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. Which of these explanations best explains what happened? A) The herbicide company lost its triazine formula and started selling poor-quality triazine. B) Natural selection caused the pigweed to mutate, creating a new triazine-resistant species. C) Triazine-resistant pigweed has less-efficient photosynthesis metabolism. D) Triazine-resistant weeds were more likely to survive and reproduce.

According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that A) the species is now extinct. B) speciation occurred instantaneously. C) speciation occurred in one generation. D) speciation occurred rapidly in geologic time. E) the species will consequently have a relatively short existence, compared with other species.

All of the following have contributed to the diversity of organisms on the Hawaiian archipelago except that A) the islands are distant from the mainland. B) multiple invasions have occurred. C) adaptive radiation has occurred. D) the islands are very young in geologic time. E) environmental conditions differ from one island to the next.

Changes to the nucleotide sequence within a gene can occur through which process(es)? a. crossing over b. mutation c. independent assortment d. Only A and B are correct. e. A, B, and C are correct.

Charles Darwin was the first person to propose A) that evolution occurs. B) a mechanism for how evolution occurs. C) that Earth is older than a few thousand years. D) a mechanism for evolution that was supported by evidence. E) that population growth can outpace the growth of food resources.

DDT was once considered a "silver bullet" that would permanently eradicate insect pests. Today, instead, DDT is largely useless against many insects. Which of these would have been required for this pest eradication effort to be successful in the long run? A) Larger doses of DDT should have been applied. B) All habitats should have received applications of DDT at about the same time. C) The frequency of DDT application should have been higher. D) None of the individual insects should have possessed genomes that made them resistant to DDT. E) DDT application should have been continual.

Darwin and Wallace were the first to propose _____. A) that evolution occurs B) a mechanism for how evolution occurs C) that Earth is older than a few thousand years D) natural selection as the mechanism of evolution

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are in season. This kind of isolation is most similar to which of the following reproductive isolating mechanisms? a. reduced hybrid fertility b. mechanical isolation c. hybrid breakdown d. habitat isolation e. gametic isolationd

For which two species concepts are anatomical features the primary criterion for determining species identities? 1. biological 2. ecological 3. morphological 4. phylogenetic 5. paleontological A) 1 and 2 B) 1 and 3 C) 2 and 3 D) 3 and 5 E) 4 and 5

In terms of the hierarchical organization of life, an amoeba is __________ level of organization, whereas a dog is at the __________ level of organization. a. only at the tissue ... multicellular organism b. only at the organelle ... cell and multicellular organism c. only at the organelle ... unicellular organism d. at the cell and organism ... multicellular organism e. only at the cell ... organism

Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of _____. A) convergent evolution B) a homologous structure C) natural selection D) a vestigial trait

Of the following anatomical structures, which is homologous to the bones in the wing of a bird? A) bones in the hind limb of a kangaroo B) chitinous struts in the wing of a butterfly C) bony rays in the tail fin of a flying fish D) bones in the flipper of a whale

Plant species A has a diploid number of 12. Plant species B has a diploid number of 16. A new species, C, arises as an allopolyploid from A and B. The likely diploid number for species C would probably be A) 12. B) 14. C) 16. D) 28. E) 56.

Plant species A has a diploid number of 28. Plant species B has a diploid number of 14. A new, sexually reproducing species C arises as an allopolyploid from hybridization of A and B. The diploid number of C would probably be A) 14. B) 21. C) 28. D) 42. E) 63.

Pseudogenes are _____. A) composed of RNA, rather than DNA B) the same things as introns C) unrelated genes that code for the same gene product D) nonfunctional vestigial genes

The DNA content of a diploid cell in the G1 phase of the cell cycle is measured (see Chapter 12 in the textbook). If the DNA content is x, then the DNA content of the same cell at metaphase of meiosis I would be a. 0.25x b. 0.5x c. x. d. 2x. e. 4x.

The Galapagos archipelago appeared about 2 million years ago, when submerged volcanoes (seamounts) rose above the ocean's surface. A single hypothetical colonization event introduced a species of finch to one island in the distant past. Today, several islands in the archipelago contain unique species of finches. What must have happened following the initial colonization event to account for the current situation? 1. cladogenesis 2. anagenesis 3. allopatric speciation 4. adaptive radiation A) 1 and 3 B) 1 and 4 C) 2 and 3 D) 1, 3, and 4 E) 2, 3, and 4

The general name for an enzyme that transfers phosphate groups from ATP to a protein is a. ATPase. b. phosphorylase. c. phosphatase. d. protein kinase. e. protease.

What is true of pseudogenes? A) They are composed of RNA, rather than DNA. B) They are the same things as introns. C) They are unrelated genes that code for the same gene product. D) They are vestigial genes.

Which of the following does not occur during mitosis? a. separation of the centrosomes b. separation of sister chromatids c. spindle formation d. replication of the DNA e. packaging of the chromosomes

Which of the following is an example of a hydrogen bond? a. the bond between two hydrogen atoms b. the bond between C and H in methane c. the bond between Na and Cl in salt d. the bond between the H of one water molecule and the O of another water molecule e. the bond between Mg and Cl in MgCl2

Which of the following is an example of polymorphism in humans? a. variation in intelligence b. variation in fingerprints c. variation in the number of fingers d. the presence or absence of a widow's peak e. variation in height

Which of the following must occur during a period of geographic isolation in order for two sibling species to remain genetically distinct following their geographic reunion in the same home range? A) prezygotic barriers B) postzygotic barriers C) ecological isolation D) reproductive isolation E) temporal isolation

Which of the following observations helped Darwin shape his concept of descent with modification? A) Species diversity declines farther from the equator. B) Fewer species live on islands than on the nearest continents. C) Birds can be found on islands located farther from the mainland than the birds' maximum nonstop flight distance. D) South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe. E) Earthquakes reshape life by causing mass extinctions.

Which of the following scientists argued that variation among individuals allows evolution to occur? A) Aristotle B) Lamarck C) Linnaeus D) Wallace

Which of the following, if discovered, could refute our current understanding of the pattern of evolution? A) no fossils of soft-bodied animals B) a modern bird having reptile-like scales on its legs C) radioactive dating of rocks showing that rocks closer to the Earth's surface are younger than lower rock strata D) diverse fossils of mammals in Precambrian rock

With what other idea of his time was Cuvier's theory of catastrophism most in conflict? A) the scala naturae B) the fixity of species C) island biogeography D) uniformitarianism

With what other idea of his time was Cuvier's theory of catastrophism most in conflict? A) gradualism B) the fixity of species C) island biogeography D) uniformitarianism E) the scala naturae

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new infections were caused by MRSA. How can this result best be explained? A) S. aureus can resist vaccines. B) A patient must have become infected with MRSA from another community. C) In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug. D) Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency. E) The drug caused the S. aureus DNA to change.

the scarlet oak is adapted to moist bottomland, whereas the black oak is adapted to dry upland soils A. gametic B. temporal C. behavioral D. habitat E. mechanical

two species of garter snakes live in the same region, but one lives in water and the other lives on land A. gametic B. temporal C. behavioral D. habitat E. mechanical

genetic variation

differences among individuals in the composition of their genes or other DNA segments without genetic variation, evolution would not occur can measure gene variability (whole-gene level) or nucleotide variability (molecular level of DNA)

Darwin's theory of natural selection

differences in survival and reproduction among individuals in a population as a result of their interaction with the environment. some alleles are better for survival. having those superior inherited traits are adaptations to the enviro. it increases ones fitness(ability to survive and reproduce) we overpopulated with limited resources so we compete for life

neutral variation

differences in the DNA sequence that do not confer a selective advantage or disadvantage. but variation is also found at loci affected by selection. what prevents natural selection from reducing genetic variation at those loci by culling all unfavorable alleles? the tendency for directional and stabilizing selection to reduce variation is countered by mechanisms that preserve or restore it.

geographic variation

differences in the genetic composition of separate populations within the same species

In seedcracker finches from Cameroon, small- and large-billed birds specialize in cracking soft and hard seeds, respectively. If long-term climatic change resulted in all seeds becoming hard, what type of selection would then operate on the finch population?

directional selection

A 0.1% frequency of recombination is observed a. on unlinked chromosomes. b. for any two genes on different chromosomes. c. on genetic maps of viral chromosomes. d. only in sex chromosomes. e. in genes located very close to one another on the same chromosome.

A biologist studied a population of squirrels for 15 years. During that time, the population was never fewer than 30 squirrels and never more than 45. Her data showed that over half of the squirrels born did not survive to reproduce, because of both competition for food and predation. In a single generation, 90% of the squirrels that were born lived to reproduce, and the population increased to 80. Which inference(s) about this population might be true? A) The amount of available food may have increased. B) The parental generation of squirrels developed better eyesight due to improved diet; the subsequent squirrel generation inherited better eyesight. C) The squirrels of subsequent generations should show greater levels of genetic variation than previous generations, because squirrels that would not have survived in the past will now survive. D) Three of the statements above are correct. E) Two of the statements

All of the structures listed below are associated with movement in cells or by cells except a. flagella. b. cilia. c. dynein. d. myosin. e. peroxisomes.

CAM plants can keep stomates closed in daytime, thus reducing loss of water. They can do this because they a. fix CO2 into sugars in the bundle-sheath cells. b. use photosystems I and II at night. c. use the enzyme phosphofructokinase, which outcompetes rubisco for CO2. d. fix CO2 into pyruvic acid in the mesophyll cells. e. fix CO2 into organic acids during the night

Ichthyosaurs were aquatic dinosaurs. Fossils show us that they had dorsal fins and tails, as do fish, even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails. The dorsal fins and tails of ichthyosaurs and fish are A) homologous. B) examples of convergent evolution. C) adaptations to a common environment. D) Three of the responses above are correct. E) Two of the responses above are correct.

In animals, meiosis results in gametes, and fertilization results in a. sporophytes. b. clones. c. spores. d. somatic cells. e. zygotes.

Logically, which of these should cast the most doubt on the relationships depicted by an evolutionary tree? A) None of the organisms depicted by the tree ate the same foods. B) Some of the organisms depicted by the tree had lived in different habitats. C) The skeletal remains of the organisms depicted by the tree were incomplete (in other words, some bones were missing). D) Transitional fossils had not been found. E) Relationships between DNA sequences among the species did not match relationships between skeletal patterns.

Natural selection is based on all of the following except A) genetic variation exists within populations. B) the best-adapted individuals tend to leave the most offspring. C) individuals who survive longer tend to leave more offspring than those who die young. D) populations tend to produce more individuals than the environment can support. E) individuals adapt to their environments and, thereby, evolve.

Of the following anatomical structures, which is homologous to the bones in the wing of a bird? A) cartilage in the dorsal fin of a shark B) bones in the hind limb of a kangaroo C) chitinous struts in the wing of a butterfly D) bony rays in the tail fin of a flying fish E) bones in the flipper of a whale

Speciation A) occurs at such a slow pace that no one has ever observed the emergence of new species. B) occurs only by the accumulation of genetic change over vast expanses of time. C) must begin with the geographic isolation of a small, frontier population. D) proceeds at a uniform tempo across all taxa. E) occurs via anagenesis and cladogenesis, but only the latter increases biodiversity.

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities? A) by identifying the bones as being homologous structures B) by the principle of convergent evolution C) by proposing that humans, bats, and dolphins share a common ancestor D) Three of the statements above are correct. E) Two of the statements above are correct

The polymerase chain reaction (PCR) could be used to amplify DNA from which of the following? a. a fossil b. a fetal cell c. a virus d. B and C e. A, B, and C

What are ribosomes composed of? a. two subunits, each consisting of rRNA only b. mRNA, rRNA, and protein c. two subunits, each consisting of several proteins only d. mRNA, tRNA, rRNA, and protein e. both rRNA and protein

What kind of chemical bonds are found between paired bases of the DNA double helix? a. ionic b. covalent c. phosphate d. sulfhydryl e. hydrogen

Which example below will most likely guarantee that two closely related species will remain distinct biological species? A) colonization of new habitats B) convergent evolution C) hybridization D) geographic isolation from one another E) reproductive isolation from one another

Which of the following factors would not contribute to allopatric speciation? A) A population becomes geographically isolated from the parent population. B) The separated population is small, and genetic drift occurs. C) The isolated population is exposed to different selection pressures than the ancestral population. D) Different mutations begin to distinguish the gene pools of the separated populations. E) Gene flow between the two populations is extensive.

Which statement is most consistent with the natural theology that was prevalent in Europe and America during Darwin's life? a. God is nature. b. To love God is to love nature. c. God can be discerned only through the study of nature. d. God is all-natural. e. Nature reflects God's intelligent design.

You are confronted with a box of preserved grasshoppers of various species that are new to science and have not been described. Your assignment is to separate them into species. There is no accompanying information as to where or when they were collected. Which species concept will you have to use? A) biological B) phylogenetic C) ecological D) paleontological E) morphological

__________ first appeared during the Precambrian era. a. Amphibians b. Dinosaurs c. Reptiles d. Mammals e. Cyanobacteria

two species of orchids with different floral anatomy A. gametic B. temporal C. behavioral D. habitat E. mechanical

eukaryotes formed (endosymbiotic theory)

eukaryotic cells formed from a mutually beneficial association (symbiosis) among various kinds of prokaryotes think chloroplasts and mitochondria

microevolution

evolution on its smallest scale, looking at evolutionary change within populations, as change in allele frequencies in a population over generations (the change in the genetic makeup of a population from one generation to the next) three things that cause change: 1. natural selection 2. genetic drift 3. gene flow

adaptive evolution

evolution that results in a better match between organisms and their environment

phylogeny

evolutionary relationships among species or groups of species

molecular bio

examines Amino acid and nucleotide sequences in DNA and proteins of different species to look for similarities

Which of the following is NOT a type of evidence used for evolution

fitness

artificial selection

form of directional selection carried out by humans when they sow seeds or breed animals for certain traits

Sympatric Speciation

formation of a new species w/o presence of a geographic barrier

A population of of lady bugs is decimated by the onset of an early frost. The few survivors breed successfully the following year but the genetic variation within the available ____ was drastically reduced. This is an example of a _____.

gene pool; bottleneck effect

Macroevolution

general patterns of change in groups of related species that have occurred over broad periods of time

Microevolution

how populations of organisms change from generation to generation and how new species originate

heterozygote advantage

if individuals who are heterozygous at a particular locus have greater fitness than do both kinds of homozygotes, they exhibit heterozygote advantage. natural selection tends to maintain two or more alleles at that locus. defined in terms of genotype, not phenotype Greater reproductive success of heterozygous individuals compared to homozygotes; tends to preserve variation in gene pools. WHY IS IT ADVANTAGEOUS?

Balanced Polymorphism

maintenance of different phenotypes in a population: 1) Heterozygote advantage: when the heterozygous condition bears a greater selective advantage than either homozygous condition. -BOTH alleles and ALL 3 phenotypes are maintained in the population -ex: sickle cell (being a carrier is best) 2) Hybrid vigor or heterosis: the superior quality of offspring resulting from crosses btw 2 inbred strains of plants -results from a reduction of loci with deleterious homozygous recessive conditions and an increase opt loci w/ heterozygous advantage -ex: a hybrid of corn is more resistant to disease and produces larger corn ears than its parents 3) Frequency-dependent selection or minority advantage: when the least common phenotypes have a selective advantage. -common phenotypes selected against -the rare phenotypes are selected for, and eventually occur more commonly and loose their rarity(now selected against). Then more extreme traits are selected for -ex: a predator will make an image of its prey, s/a a rat with a long tail. they won't eat the rat with a short tail, so they survive and reproduce. eventually the predator will catch on and only eat rats with short tails and the long tailed rats are rare and reproduce

Outbreeding

mating w/ unrelated partners (increases the possibility of mixing alleles and making new allele combos)

evidence for endosymbiotic theory

mitochondria and chloroplasts have their own circular DNA (like prokaryotes/ no histones) ribosomes in chloroplasts and mitochondria resemble those in bacteria they reproduce independently from the cell using a way similar to binary fission they have 2 phospholipid bilayers (1 of its own and 1 of the host cell) thylakoids membranes in chloroplasts resembles the photosynthetic membranes of Cyanobacteria

morphological

Which of the following organisms is most likely to contain a significantly large portion of noncoding DNA sequences that has been described as "junk" DNA?

multicellular eukaryotess

the original source of all genetic variation is ___?

mutation

sources of genetic variation

mutation, gene duplication, sexual reproduction rearrangement, or other processes produce new alleles and new genes the faster the reproduction cycles, the more variation

disruptive selection

occurs when conditions favor individuals at both extremes of a phenotypic range over individuals with intermediate phenotypes. one example is a population of black-bellied seedcracker finches in Cameroon whose members display two distinctly different beak sizes. small-billed birds feed mainly on soft seeds, whereas large-billed birds specialize in cracking hard seeds. it appears that birds with intermediate-sized bills are relatively inefficient at cracking both types of seeds and thus have lower relative fitness.

directional selection

occurs when conditions favor individuals exhibiting one extreme of a phenotypic range, thereby shifting a population's frequency curve for the phenotypic character in one direction or the other. common when a population's environment changes or when members of a population migrate to a new (and different) habitat.

balancing selection

occurs when natural selection maintains two or more forms of selection in a population. maintains variation. this type of selection includes heterozygote advantage and frequency-dependent selection

allele

one of several varieties of a gene

natural selection

only mechanism that consistently causes adaptive evolution

Math behind Hardy-Weinberg Equilibrium

p=dominant allele q=recessive allele p,q= allele frequencies for each allele p^2, q^2= frequency of homozygotes pq+qp=2pq or frequency of heterozygotes p+q=1 (all alleles sum to 100%) p^2 +2pq+ q^2=1 (all individuals sum to 100%)

A paleontologist has recovered a bit of tissue from the 400 yr old preserved skin of an extinct dodo (A bird). To compare a specific region of the DNA from the sample with DNA from living birds, which of the following would be most useful for increasing the amount of dodo DNA available for testing?

polymerase chain reaction (PCR)

Types of Sympatric Speciation: Polyploidy

possession of more than the normal 2 sets of chromosomes in diploid cells (2n). Occurs in plants and sometimes animals. Triploid(3n), Tetraploid(4n)(when a diploid sperm attaches w a diploid egg), and higher. occurs as a result of nondisjunction of all chromosomes during meiosis, producing 2 sterile gametes and 2 diploid ones. Causes the polyploid to become reproductively isolated from others in the population and speciation occurs after 1 generation

Diploidy

presence of 2 copies of each chromosome in each cell: in the heterozygous condition (2 alleles for 1 gene), the dominant hides the recessive trait. Recessive trait is hidden from natural selection and saved for future generations (prevents elimination of the recessive gene)

Three species of frogs- Rana pipens, Pana clamaitans, and Rana sylvatica- all mate in the same ponds, but they pair off correctly because they have different cells. This is an example of a ___ barrier, called ____

prezygotic.... behavioral isolation

mutations

provide the raw info material for new variations. creates new phenotypes and alleles from mutations in DNA and RNA

Genetic drift

random increase or decrease of alleles 1) Bottleneck effect: natural disasters decrease size of pop unselectively, causing loss in genetic variation. resulting population is small and not representative of the original one. certain alleles are over and underrepresented 2) Founder effect: a small population breaks away from a larger one; that pop reproduces and is probably not representative of the other pop's allele frequencies. Now rare alleles could be common and common ones rare

diploidy

recessive alleles that are less favorable or harmful can persist by propagation in heterozygous individuals. this latent variation is exposed to natural selection only when both parents carry the same recessive allele and two copies end up in the same zygote. low frequency. heterozygote protection maintains a huge pool of alleles that might not be favored under present conditions, but which could bring new benefits if the environment changes.

Monocultures in agriculture

reduce genetic variation bc only a few varieties or only 1 variety of many wild varieties of a plant are used. Meanwhile, wild varieties die out due to habitat destruction or other human impacts. monocultures have no genetic variation and are v susceptible to enviro change (EX potato famine)

Overuse of antibiotics

reduces variation in bacteria pops by getting rid of those that are susceptible to the antibiotic; those who are resistant to antibiotics increase in numbers and cause outbreaks of diseases

Which of the following can be duplicated in a genome

sequences, chromosomes, or sets of chromosomes

Survival of the fittest requires that genetic information be passed on to the next generation. Therefore a change must be located in the ______ cells to have a chance to make it to the next generation

sex

season creep

shortening of winter and lengthening of spring. plants have to germinate earlier. directional selection

paleontology

show extinct species and how species have changed over time. allows archeologists to accurately date the evolution of species

Gel electrophoresis separates DNA based on

size and charge

According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record mean that

speciation occurred rapidly in geologic time

Women often have complications during labor while giving births to very large babies, whereas very small babes tend to be underdeveloped. Which kind of selection is most likely at work regarding the birth weight of babies?

stabilizing selection

beetle pollinators of a particular plant are attracted to its flowers' bright orange color. The beetles not only pollinate the flowers, but they mate while inside of the flowers. A mutant version of the plant with red flowers becomes more common with the passage of time. A particular variant of the beetle prefers the red flowers to the orange flowers. Over time, these two beetle variants diverge from each other to such an extent that interbreeding is no longer possible. What kind of specialization has occur in this example, and what has driven it?

sympatric speciation; habitat differentiation

Two species of water lilies in the same pond do not interbreed because one blooms at night and the other during the day. The reproductive barrier between them is an example of

temporal isolation

What benefit does natural selection have for the next generation

the best characteristics and traits are passed to the next generation

relative fitness

the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals the potential for individuals of a given phenotype to survive and reproduce in the face of natural selection.

frequency-dependency selection

the fitness of a phenotype depends on how common it is in the population. if its less common, perhaps this makes it more secretive and better able to hide/its predator techniques less known? but then it will grow in population and it will lower this advantage.

speciation

the formation of new species

the hardy-weinberg principle

the frequencies of alleles and genotypes in a population will remain constant from generation to generation, provided that only Mendelian segregation and recombination of alleles are at work. such a gene pool is a hardy-weinberg equilibrium. p^2 + 2pq + q^2 = 1 ^^^^at a locus with two alleles, the three genotypes will appear in those proportions it's like a deck of cards!!!! no matter how many times the deck is reshuffled to deal out new hands, the deck itself remains the same. aces do not grow more numerous than jacks, even if they are the trump card, the dominant trait. conditions for the Hardy-Weinberg Equilibrium: 1) no mutations- the gene pool is modified if mutations alter alleles or if entire genes are deleted or duplicated 2) Random mating- if individuals mate preferentially within a subset of the population, such as their close relatives (inbreeding), random mixing of gametes does not occur, and genotype frequencies change 3) no natural selection- differences in the survival and reproductive success of individuals carrying different genotypes can alter allele frequencies 4) extremely large population size- the smaller the population, the more likely it is that allele frequencies will fluctuate by chance form one generation to the next (a process called genetic drift) 5) no gene flow- by moving alleles into or out of populations, gene flow can alter allele frequencies used as an initial test of whether evolution is occurring in a population can be used in order to find the number of alleles, dominant or recessive/carriers in a population

genetic drift

the process where chance events can also cause allele frequencies to fluctuate unpredictably from one generation to the next, especially in small populations. Effects: 1) genetic drift is significant in small populations. chance events can cause an allele to be disproportionately over or under represented in the next generation. although chance events occur in populations of all sizes, they tend to alter allele frequencies substantially only in small populations 2) genetic drift can cause allele frequencies to change at random. an allele may increase one year, decrease in frequency the next. thus, unlike natural selection, which in a given environment consistently favors some alleles over other, genetic drift causes allele frequencies to change at random over time 3) genetic drift can lead to a loss of genetic variation within populations. by causing allele frequencies to fluctuate randomly over time, genetic drift can eliminate alleles form a population. b/c evolution depends on genetic variation, such losses can influence how effectively a population can adapt to a change in the environment. 4) genetic drift can cause harmful alleles to become fixed. alleles that are neither harmful nor beneficial can be lost or become fixed entirely by chance through genetic drift. in very small populations, genetic drift can also cause alleles that are slightly harmful to become fixed. when this occurs, the population's survival can be threatened (as for the greater prairie chicken).

gene flow

the transfer of alleles into or out of a population due to the movement of fertile individuals of their gametes. alleles are exchanged between populations, which reduces the differences between the populations increased human migration today has decreased variation amongst humans

Genetic/Hardy-Weinberg Equilibrium

there is NO evolution at genetic equilibrium (allele frequencies remain constant from gen to gen in a pop) Occurs when: -all traits are selectively neutral (no natural selection) -Mutations do not occur -The population must be isolated from other populations (no gene flow) -Population is large(no genetic drift) -Mating is random

allopatric speciation

when a population is split due to a geographic barrier(mountains, oceans, areas covered in lava/volvanic rock) differential evolution (2 groups evolve separately and differently) occurs and the 2 are no longer similar enough to call a species. geographic barrier>reproductive isolation>differential evolution> reproductive barriers> new species

Nonrandom mating

when individuals choose mates based on their traits( either similar to themselves or much different from themselves) -also occurs when mates choose partners that are nearby individuals. Types:: -inbreeding:when individuals mate with relatives (limited gene pool, causes mutations) -Sexual selection: when females choose males based on their appearance or behavior or ability to win fights or whatever

a "fixed" allele

when only one allele exists for a particular locus

Coevolution

when the prey evolves to avoid the predator and then the predator evolves to catch the prey (or vice versa) also occurs with plants/plant-eating insects, pollinators/flowering plants, and pathogens/immune systems of animals

Bio Final Study Set

संबंधित स्टडी सेट्स

Chapter 16: Acute Kidney Injury

COM 231: Orientation Quiz

Disorders of Cardiac Conduction and Rhythm

MIS - Final Exam Review

chapter 9

Pediatric content exam 5 (ch. 44 & 49) cancer and neuromuscular

422 final

Exam 3

Neuroscience Week 1 - Cytology of Neurons

MId-Term Computer Concepts

Excel Chapter 2

Dinastiyang Politikal

Chemistry

THRS 106 Final Exam Part 2

DMV Practice 5

C718 - MicroEconomics -1

NURS 1240 Pharmacology Medical Surgical Drugs Case Study EAQ

ELA 11A Honors Unit Tests

Microeconomics Final: Practice Questions

Islam test