text stringlengths 1.02k 3.02k |
|---|
can vary widely in length and diameter, which prevents the plant from being cross-pollinated with a different species (Figure 18.22). Figure 18.22 Some flowers have evolved to attract certain pollinators. The (a) wide foxglove flower is adapted for pollination by bees, while the (b) long, tube-shaped trumpet creeper f... |
of sympatric speciation. Lake Apoyeque, a crater lake, is 1800 years old, but genetic evidence indicates that the lake was populated only 100 years ago by a single population of cichlid fish. Nevertheless, two populations with distinct morphologies and diets now exist in the lake, and scientists believe these populati... |
the hybrids are less fit than the parents, reinforcement of speciation occurs, and the species continue to diverge until they can no longer mate and produce viable offspring. If reproductive barriers weaken, fusion occurs and the two species become one. Barriers remain the same if hybrids are fit and reproductive: sta... |
x.org/content/col12078/1.6 Chapter 18 | Evolution and Origin of Species 745 Figure 18.25 In (a) gradual speciation, species diverge at a slow, steady pace as traits change incrementally. In (b) punctuated equilibrium, species diverge quickly and then remain unchanged for long periods of time. Describe a situation in wh... |
formed within a single species behavioral isolation type of reproductive isolation that occurs when a specific behavior or lack of one prevents reproduction from taking place convergent evolution process by which groups of organisms independently evolve to similar forms dispersal allopatric speciation that occurs when... |
the process of adaptation through mutation which allows more desirable characteristics to be passed to the next generation. Over time, organisms evolve more characteristics that are beneficial to their survival. For living organisms to adapt and change to environmental pressures, genetic variation must be present. Wit... |
are inherited. b. Offspring vary among each other in regard to their characteristics. c. Some generations of offspring do not need to compete for resources. d. Certain traits will be better represented in the next generation. 3. Which is the best definition of adaptation? This OpenStax book is available for free at ht... |
likely an example of convergent evolution? d. a group of individual organisms that interbreed and produce viable, fertile offspring a. Some fish that live in total darkness have eyes. b. Hawks and other birds have feathers. c. Worms and snakes both move without legs. d. Flowers that look very different have the same r... |
18. What is the main difference between an autopolyploid individual and a allopolyploid individual? a. number of extra chromosomes b. c. functionality of extra chromosomes source of extra chromosomes d. number of mutations in the extra chromosomes a. b. c. It leads to multiple species forming from one parent species. ... |
those that are accepted easily b. The theory of evolution has its foundation in both biological and geological observations, making it a more credible theory because it can explain more about the world c. The theory of evolution relies on the heritability of traits, but the mechanism of this inheritance was not unders... |
the process of natural selection can produce similar adaptations in two very different types of organisms who share a similar environment 28. Why do scientists consider vestigial structures evidence for evolution? a. Vestigial structures are the result of convergent evolution, so they are good evidence that natural se... |
the human genome, you find a gene that is not homologous to any other organisms known to man. You conclude that this gene must be unique to the human species and could not have evolved from another organism. Would this discovery suggest that humans do not share a common ancestor with all other organisms on Earth? Expl... |
breed, so hybrid reproduction does not occur in nature prevents gene flow between the species. b. b. Allopatric speciation is more common because it involves stronger prezygotic barriers. c. Sympatric speciation is more common because it prevents gene flow between the species. d. Sympatric speciation is more common bec... |
continue divergence. a. b. c. d. f two closely related species continue to produce hybrids, the hybrids will compete with both species, causing them to find new niches which will further their divergence If two closely related species continue to produce hybrids, they will develop reproductive barriers to prevent prod... |
is favored and the light form is eradicated in the population due to predatio<|endoftext|>n. Conditions change again, the dark form is vulnerable. It develops an adaptation that shields it from predation. 45. Given your understanding of evolutionary theory and the relationship between evolution and the genetic makeup ... |
ia (peppered moth) had a light pattern. Dark colored moths were rare. By the late 19th century, the light-colored moths were rare, and the moths with dark patterns were abundant. The cause of this change was hypothesized to be selective predation by birds (J.W. Tutt, 1896). During the industrial revolution, soot and ot... |
of natural selection? Does artificial selection provide evidence for evolution by natural selection? Explain. a. Geologists provide evidence that earthquakes reshape life by causing mass extinctions. b. Botanists provide evidence that South American temperate plants have more in common with South American tropical pla... |
that cause organisms to be better adapted over time. In artificial selection, humans have trained animals to be more successful in completing tasks that the humans want completed. In natural selection, organisms train the functions that they will need to survive and reproduce d. Both artificial selection and natural s... |
of Pangaea b. broad because some dinosaurs could fly between continents c. narrow because they went extinct too quickly to disperse very far d. narrow because they lived so long ago that the fossils have mostly broken down or disappeared 54. The term microevolution describes evolution on its smallest scale: the change... |
Darwin’s theory of evolutionary change? a. The idea that the same processes that operate in the present also operated in the past, and at the same rate, supported Darwin’s hypothesis of natural selection because humans could select for desirable traits and produce change very rapidly, so natural selection would also b... |
disciplines can you offer to support your agreement or your disagreement? a. The statement is true. If an organism is not strong and fast, it will not survive long enough to reproduce and pass on its genes, and if it is not large and fitter than the other individuals around it then it will not be able to compete for a... |
the number of germinated seeds in dish A on days 7 and 14 the death of all the yellow-leaved seedings the existence of yellow-leaved seedlings as well as green-leaved ones on day 14 in dish B 59. Use the data from Figure 18.27 to answer the question. Which best describes the usefulness of the yellow-leaved phenotype a... |
are populations of a toad that appear similar. Which of the following data would provide compelling evidence that the two populations represent different species? a. The populations of toads on the other side of the banded territory are not completely nocturnal. b. Fertile hybrid populations of toads are found between... |
reproductively isolated and remain one species. If hybrid forms are found, the two populations are not reproductively isolated and hybrids are both viable and successful. If the genetic codes of the two plants are identical, then they must belong to the same species. Also, if genes transplanted between the plants func... |
s environment. 66. A biologist studies a population of voles for 20 years. During almost the entire research period, the population stays between 50 and 75 individuals. Additionally, fewer than half of the voles born do not survive to reproduce, due to predation and competition for food. Then, in one generation, 80% of... |
will be neither phenotypic nor genotypic changes in the population. 68. At one time, avian researchers in the Sulawesi region of Indonesia described the Flowerpecker populations on the mainland and the Wakatobi archipelago as one species. A recent reassessment of the Wakatobi populations resulted in the suggested recl... |
71. Consider two species of birds that diverged while separated geographically but resumed their contact before reproductive isolation was complete. Which describes the first step in what would happen over time if the two 762 Chapter 18 | Evolution and Origin of Species species mated extensively and their hybrid offsp... |
protons and 50 neutrons decays when a proton is converted into a neutron to produce an atom, 87Sr, with 36 protons and 51 neutrons. As time passed, the number of each isotope changed from its initial value. When a crystal containing 87Rb atoms formed from the molten surface of the hot, early Earth during the Hadean eo... |
b, where a is the term in parenthesis containing the half-life of 87Rb. If Y = N87Sr/ N86Sr is graphed versus N87Rb/ N86Sr, the slope can be used to determine the time, t, that has passed since the rock formed from melting: 0.683t/ T1 / a = e t = ln(a + 1) • T1 / 2 − 1, so 2 / 0.693 D. Data on the rubidium and stronti... |
leftand right-hand symmetries. • No peptide bonds between amino acids were observed. • Early Earth’s atmospheric oxygen concentration is known to have been very low, implying the absence of an ozone layer to filter high-energy ultraviolet (uv) radiation. • Ammonia decomposes when it absorbs high-energy uv radiation, b... |
for the directed panspermia revision of this hypothesis. To avoid the conflicting chicken-and-egg claims that “protein catalyst was first” and “DNA information storage was first,” two alternatives have emerged regarding the origin of life on Earth. Consider two simple ideas: 1) water blocks uv radiation, and cracks in... |
traveled furthest towards the bottom of the column were removed and placed in a new column. After 60 generations of repeated selection, yeast became multicellular. In this experiment, selection was acting on the collection of cells and not on the individual. To test the claim that selection was acting on the multicell... |
avement, migration, or another similar event. Invaders have traditionally been male. Predict the effect of invasion on the differential inheritance of genes in X- and autosomal chromosomes. 766 Chapter 18 | Evolution and Origin of Species This OpenStax book is available for free at http://cnx.org/content/col12078/1.6 C... |
ulations 19.1 | Population Evolution In this section, you will explore the following questions: • What is population genetics and how is population genetics a synthesis of Mendelian inheritance and Darwinian evolution? • What is the Hardy–Weinberg principle, and how can it be applied to microevolution? The mechanisms o... |
equilibrium—a stable, non-evolving state. However, if a phenotype is favored by natural selection, allele frequencies can change. If this is the case, the population is evolving. Sometimes allele frequencies within a population change randomly with no advantage to the population over existing allele frequencies. This ... |
. The American Journal of Tropical Medicine and Hygiene, 88(5), 897–907. doi:10.4269/ajtmh.12-0467 This OpenStax book is available for free at http://cnx.org/content/col12078/1.6 Chapter 19 | The Evolution of Populations 769 Big Idea 1 The process of evolution drives the diversity and unity of life. Enduring Understand... |
an important health protection, or just a briefly uncomfortable prick in your arm. But do you think of it in terms of evolution? The media hype of annual flu shots is scientifically grounded in our understanding of evolution. Each year, scientists across the globe strive to predict the flu strains that they anticipate... |
alleles, IA, is the number of copies of that allele divided by all the copies of the ABO gene in the found a frequency of IA to be 26.1 percent. The IB and I0 alleles made up 13.4 population. For example, a study in Jordan percent and 60.5 percent of the alleles respectively, and all of the frequencies added up to 100... |
Principle of Equilibrium In the early twentieth century, English mathematician Godfrey Hardy and German physician Wilhelm Weinberg stated the principle of equilibrium to describe the genetic makeup of a population. The theory, which later became known as the Hardy–Weinberg principle of equilibrium, states that a popul... |
only two possible alleles for a given trait in the population, these genotypes frequencies will sum to one: p2 + 2pq + q2 = 1. 772 Chapter 19 | The Evolution of Populations Figure 19.2 When populations are in the Hardy–Weinberg equilibrium, the allelic frequency is stable from generation to generation and the distribu... |
Hardy–Weinberg equation, then the population is evolving. Use this online calculator (http://openstaxcollege.org/l/hardy-weinberg) to determine the genetic structure of a population. What would violate the conditions of Hardy-Weinberg equilibrium? a. random mating b. mutations c. large population d. no natural selecti... |
of kittens illustrates population variation. (credit: Pieter Lanser) As you learn in the chapter that discusses the evolution and origin of species, natural selection works by selecting for phenotypes—and the alleles that determine them—that confer beneficial traits or behaviors. Deleterious qualities are selected aga... |
the genetic makeup of a population over time is evolution. Essential Knowledge Science Practice Learning Objective Essential Knowledge Science Practice Learning Objective Essential Knowledge Science Practice Learning Objective Essential Knowledge Science Practice Learning Objective Essential Knowledge Science Practice... |
1][APLO 1.3][APLO 1.4][APLO 1.8][APLO 1.23][APLO 1.24][APLO 1.25][APLO 1.6][APLO 1.7][APLO 1.22] Genetic Variance Natural selection and some of the other evolutionary forces can only act on heritable traits, namely an organism’s genetic code. Because alleles are passed from parent to offspring, those that confer benefi... |
phenotypic diversity as they can. This also helps reduce the risks associated with inbreeding, the mating of closely related individuals, which can have the undesirable effect of bringing together deleterious recessive mutations that can cause abnormalities and susceptibility to disease. For example, a disease that is... |
s allele and genotype frequencies can change is genetic drift (Figure 19.4), which is simply the effect of chance. By chance, some individuals will have more offspring than others—not due to an advantage conferred by some genetically-encoded trait, but just because one male happened to be in the right place at the righ... |
all of its genes—1/10 of the population’s gene pool—will be suddenly lost. In a population of 100, that’s only 1 percent of the overall gene pool; therefore, it is much less impactful on the population’s genetic structure. Go to this site (http://openstaxcollege.org/l/genetic_drift) to watch an animation of random sam... |
the Afrikaner population of Dutch settlers in South Africa, as evidenced by mutations that are common in Afrikaners but rare in most other populations. This is likely due to the fact that a higher-than-normal proportion of the founding colonists carried these mutations. As a result, the population expresses unusually ... |
will only allow a few beads out at a time. Then, pour 1/3 of the bottle’s contents into a bowl. This represents the surviving individuals after a natural disaster kills a majority of the population. Count the number of the different colored beads in the bowl, and record it. Then, place all of the beads back in the bot... |
the genome. Some can have a dramatic effect on a gene and the resulting phenotype. Nonrandom Mating If individuals nonrandomly mate with their peers, the result can be a changing population. There are many reasons nonrandom mating occurs. One reason is simple mate choice; for example, female peahens may prefer peacock... |
a mountain, known as an altitudinal cline. If there is gene flow between the populations, the individuals will likely show gradual differences in phenotype along the cline. Restricted gene flow, on the other hand, can lead to abrupt differences, even speciation. This OpenStax book is available for free at http://cnx.o... |
different selective pressures, which often lead to distinct phenotypic differences, or sexual dimorphisms, between the two. For example, male birds often exhibit more colorful plumage than female birds of the same species. What is most important to recognize is that there is no perfect organism. Natural selection acts... |
same individual also carries an allele that results in a fatal childhood disease, that fecundity phenotype will not be passed on to the next generation because the individual will not live to reach reproductive age. Natural selection acts at the level of the individual; it selects for individuals with greater contribu... |
moth increased because they had a higher survival rate in habitats affected by air pollution because their darker coloration blended with the sooty trees. This OpenStax book is available for free at http://cnx.org/content/col12078/1.6 Chapter 19 | The Evolution of Populations 785 Scientist can observe directional sele... |
either the grass or the sand, and would thus be more likely to be eaten by predators. The result of this type of selection is increased genetic variance as the population becomes more diverse. This OpenStax book is available for free at http://cnx.org/content/col12078/1.6 Chapter 19 | The Evolution of Populations 787 ... |
otched lizard is smaller than either the blue-throated or orange-throated males and appears a bit like the females of the species, allowing it to sneak copulations. (credit: “tinyfroglet”/Flickr) In this scenario, orange males will be favored by natural selection when the population is dominated by blue males, blue mal... |
OpenStax book is available for free at http://cnx.org/content/col12078/1.6 Chapter 19 | The Evolution of Populations 789 Figure 19.11 Sexual dimorphism is observed in (a) peacocks and peahens, (b) Argiope appensa spiders (the female spider is the large one), and in (c) wood ducks. (credit “spiders”: modification of wo... |
, beautiful tail discourages predation, helping in survival. This means that those individuals are most likely to survive and produce offspring. b. The peacock’s tail is an example of the handicap principle. It appears that the tail makes the males more visible to predators and less able to escape, making it a disadvan... |
they are carried by individuals that also have several overwhelmingly bad alleles; likewise, bad alleles can be kept if they are carried by individuals that have enough good alleles to result in an overall fitness benefit. Furthermore, natural selection can be constrained by the relationships between different polymor... |
otypically similar to themselves bottleneck effect magnification of genetic drift as a result of natural events or catastrophes cline gradual geographic variation across an ecological gradient directional selection selection that favors phenotypes at one end of the spectrum of existing variation diversifying selection ... |
allele frequencies in a population over time population variation distribution of phenotypes in a population relative fitness individual’s ability to survive and reproduce relative to the rest of the population selective pressure environmental factor that causes one phenotype to be better than another sexual dimorphis... |
distinct phenotypes. Other types of selection include frequency-dependent selection, in which individuals with either common (positive frequency-dependent selection) or rare (negative frequency-dependent selection) are selected for. Finally, sexual selection results from the fact that one sex has more variance in the ... |
a. genetic structure b. environment c. diet composition d. All of the above 7. What is genetic variance? a. b. c. d. the change in a population’s genetic structure the effect of chance on a population’s gene pool the diversity of alleles and genotypes within a population the magnification of genetic drift as a result ... |
by natural selection c. why some deleterious mutations are maintained in the population d. why individuals of one sex develop impressive ornament traits 16. Which of the following describes when males and females of a population look or act differently/ a. sexual selection b. diversifying selection c. sexual dimorphis... |
to mate because inbreeding prevents gene flow which can bring new, successful genes into the population. c. A breeder would not allow close relatives to mate because inbreeding causes diversifying selection, which dilutes the breeder’s desired genes in the population. d. A breeder would not allow close relatives to ma... |
seal due to the loss of some alleles. c. The founder effect is when only a few males within a population are selected by females to reproduce, generating an allele frequency which is different from the original population. An example of the founder effect is the reproductive pattern of mountain gorillas. Mountain goril... |
. What is this an example of? Explain. 798 Chapter 19 | The Evolution of Populations a. This is an example of sexual selection. The females are selecting the small males over the large male. b. This is an example of genetic drift. Because there are so many medium-sized males to compete with the large alpha male, the sm... |
exerted on the malaria population? Figure 19.12 a. No, because the genotype frequencies, not allele frequencies, have to change for evolution to occur. b. No, because the allele frequencies are changing randomly, suggesting that genetic drift is occurring, not natural selection. c. Yes, because it shows that the previ... |
by selection in population B. In population A, gene flow apparently occurred, allowing allele B to become established in population A. Allele A also appears to be favored by selection in population A. In population B genetic drift is likely occurring, causing allele A to become more prevalent than allele B. In populat... |
the original population. c. Evolution has not occurred, because the frequency of the heterozygotes is the same 5 years later as in the original population. d. Evolution has occurred, because the frequency of the heterozygotes is different 5 years later compared with the original population. 34. Heterozygote advantage ... |
d. inbreeding will reduce the frequency of allele B in population 2 and 3 39. The diagram below shows two populations of organisms that have been long-separated by a river which prevents interbreeding. The two populations differ in coloration, as shown in the diagram. Recent human 802 Chapter 19 | The Evolution of Pop... |
C1 C2 C2 C3 C3 C1 C2 C1 C3 C2 C3 Total Observed 120 230 112 175 198 165 1,000 Table 19.3 C. The calculated number of individuals in this population that are heterozygotes is closest to ___. Chapter 19 | The Evolution of Populations 803 a. 240 b. 230 c. 430 d. 476 Mountain pine beetles (Dendroctonus ponderosae) were co... |
the gene is not in Hardy-Weinberg equilibrium, and temperature is exerting a selection pressure. return each year for several years and repeat this examination of the enzyme, calculating frequencies of each allele each year. If the allele frequencies are changing, the gene is not in Hardy-Weinberg equilibrium. Analysi... |
5.99 7.82 9.49 11.07 12.59 14.07 15.51 0.01 6.64 9.32 11.34 13.28 15.09 16.81 18.48 20.09 Table 19.6 C. Based on these data, predict, with justification, changes over time in the aminopeptidase enzyme for these populations. D. The B form of this aminopeptidase is slightly more efficient at extracting nutritional leuci... |
size, N. In the results of the simulation study shown above, there is no selection, and the mutation rate is fixed. Although both population size and mutation rate are fixed, randomness results in the five different outcomes shown in each graph above. A. Select the graph displaying the results that are closer to Hardy... |
, and DNA determined that it was in fact a separate species. For more information, read the research article (http://openstaxcollege.org/l/32dolphin) yourself. 808 Chapter 20 | Phylogenies and the History of Life 20.1 | Organizing Life on Earth In this section, you will explore the following questions: • Why do scienti... |
of the seven science practices. Big Idea 1 The process of evolution drives the diversity and unity of life. Enduring Understanding 1.B Organisms are linked by lines of descent from common ancestry. Essential Knowledge 1.B.1 Organisms share many conserved core processes and features that evolved and are widely distribu... |
be a hypothesis of the evolutionary past since one cannot go back to confirm the proposed relationships. In other words, a “tree of life” can be constructed to illustrate when different organisms evolved and to show the relationships among different organisms (Figure 20.2). Unlike a taxonomic classification diagram, a... |
a basal taxon. When two lineages stem from the same branch point, they are sister taxa. A branch with more than two lineages is a polytomy. The diagrams above can serve as a pathway to understanding evolutionary history. The pathway can be traced from the origin of life to any individual species by navigating through ... |
1.6 Chapter 20 | Phylogenies and the History of Life 811 Another aspect of phylogenetic trees is that, unless otherwise indicated, the branches do not account for length of time, only the evolutionary order. In other words, the length of a branch does not typically mean more time passed, nor does a short branch mean le... |
aisles, then each aisle into categories and brands, and then finally a single product. This organization from larger to smaller, more specific categories is called a hierarchical system. The taxonomic classification system (also called the Linnaean system after its inventor, Carl Linnaeus, a Swedish botanist, zoologis... |
that people typically use, in this case, dog. Note that the dog is additionally a subspecies: the “familiaris” in Canis lupus familiaris. Subspecies are members of the same species that are capable of mating and reproducing viable offspring, but they are considered separate subspecies due to geographic or behavioral i... |
History of Life 815 Visit this website (http://openstaxcollege.org/l/classify_life) to classify three organisms—bear, orchid, and sea cucumber—from kingdom to species. To launch the game, under Classifying Life, click the picture of the bear or the Launch Interactive button. Using the taxonomic classification system, ... |
or groups are located to each on a phylogenetic tree or cladogram, they more recently they shared a common ancestor. With the influx of new information, scientists can revise phylogenetic trees; for example, computer programs, such as one called BLAST, which helps determine relatedness using DNA sequencing. Typically,... |
many disciplines, including mathematics. Science Practice Learning Objective 7.1 The student can connect phenomena and models across spatial and temporal scales. 1.12 The student is able to connect scientific evidence from many scientific disciplines to support the modern concept of evolution. Essential Knowledge 1.A.... |
Practice Learning Objective 3.1 The student can pose scientific questions. 1.17 The student is able to pose scientific questions about a group of organisms whose relatedness is described by a phylogenetic tree or cladogram. Essential Knowledge 1.B.2 Phylogenetic trees and cladograms are graphical representations (mode... |
car with all the same parts and in exactly the same arrangement without any previous or shared knowledge. That outcome would be highly improbable. However, if two people both invented a hammer, it would be reasonable to conclude that both could have the original idea without the help of the other. The same relationshi... |
) has several examples to show how appearances can be misleading in understanding the phylogenetic relationships of organisms. James Lake of the UCLA/NASA Astrobiology Institute presented new evidence regarding the evolution of eukaryotic cells. He hypothesized that eukaryotes developed from an endosymbiotic gene fusio... |
in China identified a segment of DNA thought to be common to some medicinal plants in the family Fabaceae (the legume family) and worked to identify which species had this segment (Figure 20.9). After testing plant species in this family, the team found a DNA marker (a known location on a chromosome that enabled them ... |
called a monophyletic group. Clades must include all of the descendants from a branch point. This OpenStax book is available for free at http://cnx.org/content/col12078/1.6 Chapter 20 | Phylogenies and the History of Life 823 Figure 20.10 Lizards, rabbits, and humans all descend from a common ancestor that had an amni... |
all groups in a single branch point, are not considered clades. Glycolysis, or the breakdown of glucose, is a process used by almost all organisms as a way to release energy stored within glucose molecules. This energy can then be stored in cells as ATP, which powers cell processes when needed. What does this show, in... |
derived character for some organisms in this group. These terms help scientists distinguish between clades in the building of phylogenetic trees. Choosing the Right Relationships Imagine being the person responsible for organizing all of the items in a department store properly—an overwhelming task. Organizing the evo... |
construct a phylogenetic tree or cladogram to reflect the evolutionary history among a group of organisms based on shared characteristics. Then share the phylogenetic tree or cladogram with peers for review and revision. Lab Investigation AP® Biology Investigative Labs: Inquiry-Based Approach, Investigation 3: Compari... |
://cnx.org/content/col12078/1.6 Chapter 20 | Phylogenies and the History of Life 827 Enduring Understanding 1.B Organisms are linked by lines of descent from common ancestry. Essential Knowledge 1.B.1 Organisms share many conserved core processes and features that evolved and are widely distributed among organisms toda... |
DNA sequence analysis and newly developed computer algorithms has caused skepticism about the validity of the standard tree model in the scientific community. 828 Chapter 20 | Phylogenies and the History of Life Figure 20.12 The (a) concept of the “tree of life” goes back to an 1837 sketch by Charles Darwin. Like an (... |
transferred by this process. Some researchers believe such estimates are premature: the actual importance of HGT to evolutionary processes must be viewed as a work in progress. As the phenomenon is investigated more thoroughly, it may be revealed to be more common. Many scientists believe that HGT and mutation appear ... |
karyote to another. GTAs have been shown to be responsible for genetic changes, sometimes at a very high frequency compared to other evolutionary processes. The first GTA was characterized in 1974 using purple, non-sulfur bacteria. These GTAs, which are thought to be bacteriophages that lost the ability to reproduce on... |
derived from the bark, have acquired the ability to make paclitaxel themselves, a clear example of gene transfer. In animals, a particularly interesting example of HGT occurs within the aphid species (Figure 20.13). Aphids are insects that vary in color based on carotenoid content. Carotenoids are pigments made by a v... |
acquired a nucleus to become the first eukaryotic cell that the nucleus evolved in prokaryotes first followed by fusion of the new eukaryote with bacteria that became mitochondria that prokaryotes actually evolved from eukaryotes by losing genes and complexity that eukaryotes developed Golgi before mitochondria Genome... |
Chapter 20 | Phylogenies and the History of Life in that they contain two lipid bilayer membranes, indeed resulted from an endosymbiotic fusion of archaeal and bacterial species. The double membrane would be a direct result of the endosymbiosis, with the endosymbiont picking up the second membrane from the host as it ... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.