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One of the interesting things about using the Linnaean taxonomic system for classification of organisms is how little it has changed over the years. It has expanded from 2 kingdoms to 6 and it has added the higher level of domain but very few organisms have had to be moved from one classification to another. That is because Linnaeus based his classification on physiology. Today most taxonomists classify organisms based on molecular biology. In other words, they use DNA to decide which group and organism should be put into. Since the physiology of an organism depends on its DNA, almost no organisms have been moved.
Can anyone find an example of an organism that was reclassified based on its DNA?

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Sixta Kovacek
Sixta KovacekLv2
28 Sep 2019
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Related questions

2.Conclusion:

What have you learned from your study?

Interpret your data/ results:

Do your results support of disprove your hypothesis?

Compare and contrast your result with those of previous research.

Significance of the results: “Big Picture”

What is the global impact of your results?

What questions remain unanswered?

What kinds of experiments can come out of your study?

i have lab for biology and i need help with the Lab Report

the lab name is Bacterial Transformation Lab

1. Introduction:

Introduce the background and the nature of the problem your experiment is investigating.

Summarize the current knowledge of your subject.

Use examples of other research that have examined the same or a similar topic as your experiments.

Ending your introduction:

State your hypothesis

State your predictions

Give a brief statement about how you tested your hypothesis.

please help me with it is important for my lab class tomorrow

that is the lab i put the info please help me for the intro and for number 2 please be clear please

i would be happy if you help me it is due tommorrow i realy need your help on the intro and number 2 please be clear and show clear work hope you do it because it is due tomorrow

Bacterial Transformation Lab

Genetic engineering is one of the newest applications of basic knowledge in biology. It involves the isolation of specific genes from one organism and the insertion of those genes into a second organism of the same, or even different, species. Remember that a gene is a piece of DNA which codes for a product, usually a protein, which gives an organism a particular trait. The development of these techniques has generated considerable excitement and answered many questions, but it has also raised questions. Many scientists and others see genetic engineering as offering opportunities to make life better, for example, by exploring how genes are regulated, by curing diseases of genetic origin, by adding desirable traits to agricultural crops such as the ability to fix nitrogen in corn and pest resistance in cotton, and by genetically altering bacteria with genes enabling them to digest oil spills.

For almost 100 years, it has been possible to isolate DNA from cells, but only in the last 40 years or so has its function been understood. Your textbook discusses the work of such investigators as Fred Griffith and Oswald Avery, who demonstrated that if DNA was isolated from a pneumonia-causing strain of bacteria and added to cultures of nonvirulent bacteria, the recipient cells were transformed into virulent types that caused pneumonia. These transformation experiments were the first to show that genes could be artificially transferred in the laboratory. Since the time of those experiments (Avery's work was done in the 1940s), our knowledge of gene structure, function and control has increased astronomically. The application of this knowledge has created the field of genetic engineering.

Modern genetic engineering techniques depend on three critical factors:

A suitable host organism in which to insert the foreign gene;

A vector to carry foreign genes into the host; and

A means of isolating the host cells that have taken up the foreign gene.

The host organism

The most commonly used host organism is the gut bacterium Escherichia coli (E. coli). Its chromosome is a single large circular DNA molecule, called the genomic DNA, containing about 4 x 106 base pairs. Not every cell will take up foreign DNA when exposed to it, but E. coli grows rapidly, dividing in less than 20 minutes, so that a single cell can give rise to a billion genetically identical descendants in a matter of 10 hours. Thus, a few transformed cells can provide a large number of offspring within a day. The strain we are using is K-12.

The vector

A vector is a DNA molecule used as a vehicle to carry genes from one organism to another. This DNA molecule can be modified by gene-splicing techniques using restriction enzymes and ligases so that it carries the genes of interest (essentially a cut-and-paste operation). Sometimes viruses are used as vectors, but for E. coli, plasmids are often used. A plasmid is a small circular DNA molecule containing 1000 to 200,000 base pairs. Plasmids exist naturally in many strains of E. coli and other bacteria. Plasmids replicate as the cell grows, independent of replication of the genomic DNA. These plasmids are transmitted to each of the product cells during cell division. Plasmids carrying genetic information that is beneficial to the host cell are maintained in a given population by natural selection. Plasmids frequently carry genes that confer antibiotic resistance, an obvious benefit.

When E. coli cells are exposed to plasmids or any other foreign DNA, some of the cells, called competent cells, will take up the DNA. We can induce cells to become competent by treating them with divalent cations, such as Ca++, followed by a brief exposure to high temperature, called a heat shock treatment. Exactly how this treatment causes cells to become competent is not understood, but it is described as making the membranes "leaky" so that large DNA molecules (like plasmids), which would not normally pass through the cell membrane, can enter the cell. This treatment does not make all cells competent, but it greatly increases the number of competent cells. Once in a cell, the plasmids replicate and are passed to the product cells during cell division.

The selective medium

The last requirement for genetic engineering is a means of isolating host cells that have taken up the gene of interest. The techniques used depend on the growth requirements of the host organism. For example, each species of bacteria has particular nutrient requirements. The composition of the growth medium (agar or broth) can be modified to allow growth of only certain bacteria -- for example, by adding or removing nutrients or other chemicals from the medium mixture. This modified medium is called a selective medium, because it selects for the growth of only some species. By introducing an antibiotic such as ampicillin into the medium in which the bacteria are grown, you will select for growth of only those bacteria carrying the antibiotic-resistance gene on newly acquired plasmids. In a matter of days, billions of antibiotic-resistant cells, all with the plasmid, can be grown.

Genetic engineers use a modification of this technique to insert a foreign gene into E. coli. In simplified terms, the plasmid (already carrying an ampicillin resistance gene) is modified by inserting the gene of interest. The gene of interest has been isolated from another source; for example, the gene for human insulin has been isolated from the human genome. The modified plasmid, carrying the inserted gene, is then mixed with competent E. coli and the bacteria are placed in a medium containing ampicillin. Only those cells that have the plasmid will grow in the medium, and they are also the cells carrying the insulin gene (in their plasmids). These selected cells can now be used to manufacture insulin, which can be used for insulin therapy by diabetics.

The genes

In the following experiment, you will insert a plasmid into E. coli. The plasmid you will use carries the gene bla, which codes for a protein (beta-lactamase) that is secreted by the bacteria, inactivating the ampicillin in the agar and allowing for bacterial growth. The plasmid also carries an indicator gene. The indicator gene we are using was isolated from a bioluminescent jellyfish, Aequorea victoria. It codes for Green Fluorescent Protein (GFP).

The GFP gene has been modified to include a regulator system that can be used to control the expression of the gene. Gene expression in all organisms is carefully regulated to allow for adaptation to differing conditions and to prevent wasteful overproduction of unneeded proteins. The genes involved in the breakdown of different food sources are good examples of highly regulated genes. For example, the sugar arabinose is both an energy source and a carbon source for bacteria. The bacterial genes that make digestive enzymes to break down arabinose for food are not expressed when arabinose is not in the environment. But, when arabinose is present, these genes are turned on. When the arabinose runs out, the genes are turned off.

Arabinose initiates transcription of these genes by promoting the binding of RNA polymerase. In the genetically engineered pGLO DNA, some of the genes involved in the breakdown of arabinose have been replaced by the jellyfish gene GFP. When bacteria with this plasmid are grown in the presence of arabinose, the GFP gene is turned on and the bacteria glow green in UV light. When arabinose is absent form the growth medium, the GFP gene remains turned off and the colonies appear white. This is an example of the central molecular framework of biology in action: DNA ? RNA ? protein ? trait.

In summary, you will render E. coli cells competent to take up plasmid DNA. The plasmid carries two identifiable phenotypic markers:

The beta-lactamase or bla gene codes for resistance to the antibiotic ampicillin. We will use this to select for bacteria that have taken up the plasmid.

The pGLO gene codes for Green Fluorescent Protein (GFP), which is switched “ON” if arabinose is present.

Safety Procedure

For your own safety and the safety of others, it is essential that you follow all instructions about handling bacteria and disposal of materials. When you finish work for the day, swab your table with disinfectant. WASH YOUR HANDS thoroughly with soap before leaving the lab for any reason, and at the end of the day after you have cleaned your table. Report any spills to your instructor.

List of Materials

Prepared agar plates (2 LB, 2 LB/amp, 1 LB/amp/ara)

Transformation solution (50 mM CaCl2, pH 7.4)

LB broth

1 pack of inoculation loops

Sterile transfer pipets

1 foam microtube holder w/ tubes

E. coli starter plate

1 red biohazard bag for loop disposal (common use – Loops/pipets only - NO PAPER!!!)

Random, chance events that change allele frequencies are knownas:

A. Gene flow
B. Genetic drift
C. Natural selection
D. Balancing selection

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Question 21 pts

What type of selection acts to maintain the two extremephenotypic variants in a population?

A. Disruptive selection
B. Directional selection
C. Positive selection
D. Artificial selection

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Question 31 pts

Approximately, how much of our DNA is shared with our closestrelatives, chimpanzees?

A. 100%
B. 98.9%
C. 88.3%
D. 75.8%

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Question 41 pts

The large canines of male baboons are likely the result of________, while the fact that some male baboons are very colorfulis probably the result of _______.

A. Mutation; balancing selection
B. Gene flow; sexual dimorphism
C. Male competition; female choice
D. Mate choice; genetic drift

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Question 51 pts

Negative assortative mating results in an increased frequency ofhomozygous genotypes within a population.

True
False

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Question 61 pts

Genetic evidence suggests that humans and Neandertals neverinterbred.

True
False

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Question 71 pts

The specific variant of the FOXP2 gene associated with languageacquisition in humans is found in both humans and Neandertals.

True
False

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Question 81 pts

Industrial melanism describes the change in moth color from paleto dark after pollution from factories resulted in coating treetrunks with a layer of dark soot. Which statement is trueconcerning industrial melanism?

A. After pollution levels increased, all moths became darkercolored because soot got on their wings
B. The dark moths survived better after pollution levelsincreased because they were not poisoned by the pollutants
C. Individual moths changed their color in response to thepollution
D. Dark moths were present in the population before pollutionlevels increased

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Question 91 pts

Patterns of evolution can be seen above the species level

True
False

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Question 101 pts

Inbreeding is problematic because it increases the probabilitythat offspring inherit two copies of a recessive mutation thatcauses disease.

True
False

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Question 111 pts

As a species, cheetahs seem to have a high risk of extinctionbecause:

A. Gene flow has caused a proliferation of unnecessarygenes.
B. The species' genetic diversity is very low due to a previouspopulation bottleneck event.
C. The species has undergone extreme sexual selection in orderfor males to achieve faster running speeds.
D. Gene flow has been stifled due to an increase in demand forcaptive cheetahs.

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Question 121 pts

A strand of DNA undergoes mutation. Which mutation occurred?

Original DNA- GGA CTC TTA CCC CAC GGA

Mutated DNA- GGG CTC TTA CCC CAC GGA

A. point mutation
B. insertion mutation
C. deletion mutation
D. inversion mutation

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Question 131 pts

A change from one nucleotide to another nucleotide is known as awhat?

A. Point mutation
B. Insertion mutation
C. Deletion mutation
D. Inversion mutation

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Question 141 pts

A change from one nucleotide to another nucleotide is known as awhat?

A. point mutation
B. insertion mutation
C. deletion mutation
D. inversion mutation

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Question 151 pts

According to the Typological Species Concept, species are:

A. An interbreeding group of organisms
B. Static entities endowed with fixed properties
C. A local population of organisms that have similargenes, interbreed, and produce offspring
D. An exclusive community of gene exchange

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Question 161 pts

Recognizing reproductive isolation is key to defining speciesunder the Biological Species Concept.

True
False

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Question 171 pts

The binomial system of classification was developed by:

A. Darwin
B. Wallace
C. Linnaeus
D. Malthus
E. None of the above

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Question 181 pts

A derived trait, unique to a particular taxon within a givencladogram is called:

A. Synapomorphy
B. Apomorphy
C. Analogy
D. Autapomorphy
E. Symplesiomorphy

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Question 191 pts

Analogy, and not homology, is useful for reconstructingevolutionary history.

True
False

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Question 201 pts

A phylogeny is which of the following:

A. A depiction of an organism's complete genome
B. A depiction of evolutionary relationships betweenorganisms
C. The gradual evolution of one species intoanother
D. The Latin name of an organism including its genus andspecies designation

Last week you studied fertility and the Reproductive System. There was a very interesting reading on page 376 on freezing embryos.

Read the case study below and respond to the questions for this week's post.

Acorn Fertility Clinic has a space problem. Its director, Franklin Pearce, just presented Acorn's Board of Directions with the problem, and now a vigorous discussion was going on. Pearce left the room to think.

The problem is partly a result of the clinic's success. Since its inception ten years earlier, the clinic has almost tripled its number of patients, and its success in achieving pregnancies in infertile couples is equal to the national average.

The clinic's greatest success has been in the use of in vitro fertilization. This procedure involves fertilizing the egg outside the body and then placing the zygote in the uterus of the patient. Usually up to 15 zygotes are produced, but only a few are placed back in the woman. The rest are frozen and held in liquid nitrogen.

Infertility specialists have been freezing embryos since 1984, with much success. The length of time an embryo can be held in a frozen state and "thawed out" succcessfully is not known. With better and better freezing techniques, the time is increasing. Recently a baby was born from an embryo that had been frozen for eight years.

Acorn Fertility has been freezing embryos since its inception. It has a large number of such embryos-thousands, in fact-some frozen for ten years. The parents of many of these embryos are present or past patients who have no need for them. With its patient base increasing, Acorn needs the space for new embryos.

The problem is not Acorn's alone. Ten thousand embryos are frozen each year in the United States, and the numbers are increasing. Many of these are sitting in liquid nitrogen in fertility clinics like Acorn.

Now sitting in his office, Dr. Pearce wondered what the Board of Directions would decide to do with the embryos that aren't being used.

Questions

1. What should the board decide? List five things that might be done.

2. In a number of legal cases, frozen embryos have created questions. Who owns them? Are they property? Are they children? In general, courts have decided that they are neither, and that they should be left frozen because no person can be made a parent if he or she does not want to be. Is this the right decision? Why or why not?

3. In the future, we will be able to successfully thaw and implant embryos that have been frozen for 25 to 30 years. What problems do you foresee with this? What benefits? List three of each.

4. Do you think that anyone should be denied fertility treatment? If so, what do you think a doctor should take into consideration when deciding whether to provide someone fertility treatment?

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