Biology Chapter One

illustrated with how research upended a commonly held beliefs about diet and health,

, -for example that chronic stomach issues and intestinal inflammation is caused by spicy food. -incorrect belief dominated medicine for decades. -ulcer patients were given drugs to reduce stomach acid levels and told to stop eating spicy acidic foods. -treatments weren't successful and ulcers were considered chronic problems.

Nucleic acids are composed of long strings of monomers called nucleotides.

- A nucleotide is made up of a sugar, a phosphate, and a nitrogen-containing base. - There are two classes of nucleic acids in living organisms. -riboNucleic acid plays an important role in helping cells synthesize proteins. -The nucleic acid that serves as a primary storage of genetic information in nearly all living organisms is deoxyribonucleic acid. F -figure 2.16 shows a three-dimensional structure of a DNA molecule and Zooms in word into the chemical structure. -You can see that DNA is composed of two curving strands wind around each other to form a double helix. -The sugar in DNA is a five carbon sugar deoxyribose. -Nitrogen-containing base, or night shift basis, one of four different chemical structures, each with a different name a denine, guanine, thymine, and cytosine. - nucleotides are joined to each other through the length of the Helix by covalent bonds.

So is there any is there any selective pressure on Lower organisms that led to the evolution of higher organisms like humans?

- Are humans currently evolving into superhumans? -his is not how scientists see the process of evolution because the real success, or failure, of an organism is measured by how well it is adapted to its environment. -Many respects, bacteria are more successful than humans. - Bacteria far outnumber humans and are found in Far More environments in humans. - They also have been near involving and diversifying for billions of years while humans in their ancestors have only been on Earth million years.

Another commonly used source for health information is the internet.

- As you may know anyone can post information on this great source. -Typing in common cold prevention, on a standardized web search will return thousands of pages, -from highly respected academic and government sources to small companies trying to sell their products to individuals who have strong, sometimes completely unsupported ideas about cures. - Often is difficult to determine the reliability of a well-designed website, and even sites such as Wikipedia may contain erroneous or misleading information.

Oh, you must consider the source and media reports.

- Certainly, news organizations will be more reliable reporters then will be entertainment tabloids, and news organizations with science writer should be better reporters of a substance study. '-Television talk show host, which need to fill air time, regularly have guests who promote a particular health claim. - Too often these guests may be presenting information that is based on anecdotes or an incomplete summary of the primary literature.

The tendency of like molecules to stick together is called cohesion.

- Cohesion is stronger in water than it is in most liquids because of the sheer number of oxygen bonds between water. -Cohesion is important property of many biological systems. -For instance, many plants depend on cohesion to help transport a continuous column of water from the roots to the leaves.

Researchers who use correlated studies can eliminate a number of their alternative hypothesis by carefully examining their subjects

- For example the study on stress and cold susceptibility collected data from subjects on age, weight, sex, education and their exposure to infected individuals. -None of these factors differenered consistently among low-stress and high-stress groups. -Well this analysis increases our confidence in the hypothesis that high stress levels increase susceptibility to colds, people with high stress levels still may have important differences for those with low stress levels. -Is possible that one of these differences the real cause of disparities in cold frequency.

Addition, even the most respected media sources may not be as thorough as readers would like.

- For example, a recent review published in the New England Journal of Medicine evaluated the news media's coverage of new medications. - Of 207 randomly selected news stories, only 40% that cited Financial ties to a drug told readers about this relationship. -This conflicts of interest calls into question the experts objectivity - Another 40% of the new stories did not provide basic to statistics about the drugs benefits. -Most of the new stories also failed to distinguish between absolute benefits and relative benefits. -The journals review is a vivid reminder that we need to be cautious when reading or topics on news reports on scientific topics.

The more participants there are in a study, the more likely it is that researchers will see a true effect of an experimental treatment, even if the effect is very small.

- For example, a study of over 21,000 men over 6 years in Finland demonstrated that those who took Vitamin D supplements had 5% fewer colds and than those who did not take those supplements. -In this case, the real sample size allowed researchers to see that vitamin A has a real, but relatively tiny effect on cold incidents. -Other words, this is historically significant result has little real-world practical significance. -The relationship between hypothesis experimental test, sample size and statistical and practical significance and summarized in figure 1.15 on the next page.

A scientific review of literature on cold prevention and treatment you may come across statements about the significance of the effects of different cold reducing measures.

- For instance one report factor a reduces cold severity, but that the results of the study were not significant. - Another study B state that factor be caused a significant reduction in illness - We might assume in this statement means that factor B will help us feel better, while Factor will a have little effect. -This is a correct and incorrect assumption because in scientific studies, significance is defined a little bit differently from its usual sense - to evaluate the scientific use of this term we need to undergo a basic understanding of statistics.

We often use a term statistics refer to a summary of accumulated information.

- For instance, a baseball player success hitting is summarized by statistics his batting average, the total number of hits he made divided by the number of opportunities he had to bat. -the science of statistics is a bit different, it is a specialized branch of mathematics used to evaluate and compare data

Imagine we had five Volunteers in each group and saw a difference, or that the difference is only one day instead of 3 days.

- How would we determine if the lozenges had an effect? - statistical tests allow researchers to look at their data and determine How likely it is that is the probability the result is due to a sampling error. - In this case, this is statistical test distinguished between two possibilities for why the group experimental had shorter colds. - Either the difference is due to the effect of zinc as a cold treatment or is due to a chance difference from the control group. -The results indicated there was a low probability, lesson 1 in 10,000 or 1% at the experimental and control groups were so statistically different simply by chance - in other words the result is statistically significant.

The advertisements are legitimate means of disseminating information.

- However, claims in advertising should be carefully evaluated. -Advertisements of over-the-counter and prescription drugs must conform to rigorous government standards regarding the truth of their claims. -Low standards apply to advertisements for herbal supplements, many health food products and diet plans. - Be sure to examine the fine print because advertisers are often required to clarify the statements made in their ads.

Popular news source provide a steady stream of scientific information.

- However, stories about research results often do not contain information about the adequacy of experimental designs or controls, the number of subjects, or the source of the scientists fundings. -How can anyone evaluate the quality of research that supports dramatic headlines such as those describing risk to human health and the environment.

Placebo treatments are practical and unethical in many cases.

- Imagine testing the effectiveness status of a birth control drug using a controlled experiment -this would require women to take a pill that Mary may not prevent pregnancy will not using any other form of birth control.

Have you ever heard a relative claim that there is something in turkey that puts them to sleep, as they make their way to the couch after Thanksgiving dinner?

- Is commonly believed that the presence of the amino acid tryptophan in the protein Rich meat of turkey causes drowsiness. -This myth may have gotten some traction when scientist showed that sleep and mood can be affected by tryptophan. - However when one looks at the data showing levels of tryptophan and other food rich protein-rich foods should put this myth to bed! - An alternative hypothesis that seems better supported is it eating a large amount of food, which certainly happens on Thanksgiving, leads to drowsiness.

Nitrogen bases form hydrogen bonds with each other across the width of the Helix.

- On a DNA molecule and a denine on one strand always pairs with thymine on the opposite strand. -Likewise, guanine is always pairs with the cytosine. -The term complementary is used to describe these pairings. -For example, a is complementary to T, and C is complementary to G therefore, the order of nucleotides on one strand of the DNA Helix predicts the order of nucleotides on the other strand. -That's, if one strand of the DNA molecule is composed of nucleotides capital aagatccg then we know the order of nucleotides on the other strand is ttgctatggc.

It is difficult to determine a cause and effect relationship between two factors simply by showing a correlation between them.

- Other words correlation does not equal causation. -For Example of community commonly understood correlation exists between exposure to cold air and epidemics of the common cold. - It is true that as outdoor temperatures drop, the incidence of colds increases. -But numerous controlled experiments have indicated the chilling of an individual does not increases susceptibility acceptability to cold's. -Instead, cool outdoor temperature mean increase cold contact with other people this contact increases the number of cold we get during cold weather Despite the correlation Cold Air does not cause cold exposure to viruses does.

Living organisms require proteins for a variety of processes.

- Proteins are important structural components of cells, there integrals to the makeup of cell membranes and make up half of a dry weight of most cells. - some Cells, such as animal muscle cells, are primarily composed of proteins. -Proteins called enzymes accelerate and help regulate all the chemical reactions that build up and break down tinside the cells. -catalytic power of enzymes, that is their ability to help start chemical reactions, allows metabolism to encourage under normal cellular conditions. - Protein can also serve as channels through which substances are brought into cells and they can function as hormones that send chemical messages into an organism's body.

Science:

- Refers to a body of knowledge -the science of biology is the study of living things -action in science isn't memorization, but to discover something new and unknown.

Of course not anyone get sick when exposed to a cold virus.

- The reason one person has more cool than the other might not be due to a difference in personal hygiene - The correlation that shows the relationships between stress and cold susceptibility appears to have some Merit -Research indicates among people exposed to viruses, the likelihood of ending up with infection increases with high levels of psychological stress, something that many students clearly experience.

An experimental test use a small subgroup or sample of a population.

- The statistical methods can summarize data from the sample for instance, we can describe the long length of cold by experimental and control groups. -In statistics, this average is known as the mean. -Tests can then be used to extend the results from a sample to the entire population

proteins are large molecules composed of monomer subunits called amino acids

- There are 20 amino acids -Like carbohydrates, amino acids are made of carbon, hydrogen and oxygen. -These form the amino acids carboxyl group. -In addition, amino acids have nitrogen is part of an amino group along with various side groups. -Side groups are chemical groups that give amino acid different chemical properties.

at first glance, zombies seem to Fit parts of this definition of life

- They can certainly move, even though their movements tend to be hindered by various injuries they have sustained. - It might even appear that zombies are reproducing, because they cause a production of more zombies when they attack living humans. - Likewise, they may even respond to a limited number of stimuli lurching towards humans for the next meal.

However, Closer inspection leads us to question just how much zombies resemble living organisms.

- They do not grow, A child zombie does not become as an adult zombie overtime. -And, while The Binding of humans by zombies does cause a production of more zombies, this is not the same as a kind of reproduction living organisms are capable of. -Living organisms pass genetic iinformation to their offspring when they reproduce. - Is also unlikely that zombies actually metabolize of Flesh they eat. -It seems they are driven to eat human flesh more to spread zombie-ism than to provide nourishment to themselves.

Once you satisfied that a media source is relatively reliable, you can examine the scientific claim that it presents

- Use your understanding of the process of Science and of experimental design to evaluate the story and the science - does a story about the claim present the results of a scientific study or is it built around an untested hypothesis? - Were the results obtained using the scientific method, which test designs to reject fake hypothesis? -is a story confusing correlation with causation? - Does it seem that the information is applicable to download for situations, or is it based on results from luminary or animal studies?

Does drinking water during an exam help students perform better?

- When this hypothesis was tested by researchers at the University of East London, they found that this might be the cause. - Before we Analyze This study, let's first learn about some of the properties of water and whether any of these properties can be used to help explain these results.

Conversely if the effect of a treatment is real but the sample size of the experiment is small,

- a single experiment may not allow researchers to determine convincingly that their hypothesis has support. - For example, one experiment performed at a Wisconsin clinic with 48 participants indicated that tea drinkers were 30% less likely to experience any cold symptoms after virus exposure as compared to individuals who received a placebo tea. - However, the sample size of the study meant this result was not successfully significant -based on this experiment we cannot say whether the tea has a protective effect.

Covalent bonds are shown .

- by a short line indicating a shared pair of electrons. -Double bonds involve two pairs of shared electrons. -A double bond is symbolized by two horizontal lines

Because it is such a powerful solvent, water

- can facilitate chemical reactions which are changes in the chemical composition of substances. -Solutes in a mixture, called reactants, can come in contact with one another, permitting the modification of chemical bonds that occur during the reaction. -The molecules formed as a result of a chemical reaction are known as products

here are many reasons why this hypothesis is about vitamin C is very appealing and what is a testable and falsifiable hypothesis we can make?

- fruits and vegetables contain a lot of vitamin C people diets rich in fruits and vegetables are healthier than those to skimp on those items -vitamin C is known to be an anti-inflammatory agent reducing throat and nose irritation Vitamin C decreases the rich of catching school this is a testable and possible hypothesis. is hypothesis makes sense given the statements just listed experiences of the next people who insist that vitamin C keep them healthy

Structure of a fat is that of a three-carbon glycerol molecule with three long Hydrocarbon chains attached to it.

- hydrocarbons are carbon and hydrogen rich. -Like The hydrocarbons present in gasoline, these can be burned to produce energy. - The long hydrocarbon chains are called fatty acid Tails. -fats are hydrophobic and function in living organisms. -Fatty acid tails are covalently bonded to glycerol through a type of chemical bond called an ester bond.

The line connecting the five points on the graph

- illustrates a correlation relationship between stress and susceptibility to cold virus infections -because the line Rises to the right illustrates a positive correlation. - The data tells us that people have higher stress levels are more likely to come down with Is this a good assumption? Not necessarily most correlations cannot control for alternative hypothesis. People who feel more stress me I'm poor diets because they feel time-limited and William fast food more often. In addition people who feels highly stressed. -dos this relationship mean that the high stress causes increase cold susceptibility?

Polymers of amino acids can be joined together

- in various sequences called polypeptides. a covalent bond joins adjacent amino acids to each other. -figure 2.14 shows three amino acid valine, a lineBy peptide bonds. -Precisely folded polypeptides produced different proteins in much the same manner that children can use differently shaped beads to produce a wide variety of structures. - Each amino acid side group has a unique kind of chemical properties including being polar or nonpolar. - Because each protein is composed of a specific sequence of amino acids, each protein has a unique shape and therefore specialized chemical properties.

the prediction

- is a result we expect from a hypothesis test - the prediction concerns the outcome of an action, test, or investigation.

the Bermuda Triangle

- is a roughly triangular area off the coast of Florida. -The fact that there is actually no evidence that ships and planes go missing from this area to higher rate than other areas has done little to damper the fears of Perspective Travelers.

Part of the reason we find zombies entertaining

- is because they do show some evidence of scientific possibility. -They exist in state somewhere between the living and the dead - the transmission of zombism through a bite from infected zombie is the mode of transmission we know to be at work at other infectious diseases. - We will all see that this confusion of scientific plausible Notions With our willingness to accept things that seem like they could be true, can lead us to suspend our belief in cases where entertainment is not the only thing at stake.

Evaluating the hundreds of scientific papers that are published weekly

- is tast not one of us can perform alone. Even if we are focused only on a particular field of Interest, the technical jargon used in many scientific papers may be significant barrier to our understanding.

When heat energy is added to water,

- its initial effect is to disrupt the hydrogen bonding among water molecules. -Therefore, is heat energy cannot be absorbed without changing the temperature of the water. -Only after the hydrogen bonds have been broken can added heat increase the temperature -. In other words, the initial input of energy is absorbed.

Information about dietary supplements such as tea and zinc is often in the form of antecedal evidence,

- meaning that the advice is based on one person's individual experience. - A person's enthusiastic plug for vitamin C, because she felt it helped her, is an example of a testimonial a common form of antidote. -Advertisements that use a celebrity to pitch a product, because it works for them, are classic forms of testimonials.

Water is a good solvent because it is polar,

- meaning the different regions or poles of the molecules have different charges. -That is the polarity arises because oxygen is more attracted to electrons, that is, is more electronegative than most atoms including hydrogen. -As a result of oxygen electronegativity electrons in a water molecule spread more time near the nucleus of the oxygen atom than near the nuclei of the hydrogen atoms. -With more negatively charged electrons, the oxygen in the water carries a partial negative charge, symbolized by the Greek Delta. - The hydrogen atoms thus have a partial positive change, symbolized by the Greek Delta. -When atoms of a molecule carry no partial charge, they are said to be nonpolar. -the carbon hydrogen atoms for example share electrons equally are nonpolar.

Research also indicates

- of vitamin C intake, diet quality exposure to cold temperatures, and exercise frequently appear to have no effect on cold sectibility ability, - although along with tea and massages there is some evidence of vitamin C May reduce cold symptoms of a bit - Surprisingly,even if medical research has led to the elimination of killer viruses such as smallpox and polio, scientist are still a long way from curing the common cold.

All statistical test

- operate under the assumption that the experiment was designed and carried out correctly. I -n other words, statistical test values a chance of sampling error, not Observer area and a statistically significant result is not the last word on an experimentally tested hypothesis. -An examination of the experiment itself is required.

Atoms are composed of subatomic particles called protons, neutrons, and electrons

- protons have a positive electric charge, those particles and the uncharged neutrons make up the nucleus of an atom. -All atoms of a particular element have the same number of protons, giving the element its atomic number. - The negatively charged electrons are found outside the nucleus in an electron cloud. - Electrons are attracted to the positively charged nucleus -. A neutral atom has equal numbers of protons and electrons. -Actually charged ions do not have an equal number of protons and neutrons. - In this case the atom is not neutral but is instead charged.

placedo

- sham tea would be the equivalent to Sugar pills that are given to control groups during drug trials. - the tea is similar to other intentionally effected Medical Treatments. - employment Placido generates only one consistent difference between individuals into groups, in this case the type of TV 2.

Aoms with one, two, or three electrons in their valence shell

- tend to lose electrons and become positively charged ions, -while atoms with six or seven tend to gain electrons and become negatively charged ions. -Positively and negatively charged ions dissociate into a type of bond called the ionic bond.

It is important to note that statistical significance is also not equivalent to significance as we usually Define the term

- that is, as meaningful or important. - unfortunately, experimental results reporting the news often use the word significant without clarifying this important distinction. -Understanding that problem, as well as other misleading aspects of how science can be presented, will enable you to better use scientific information.

Despite all the research and emergence of some promising possibilities,

- the best prevention method for known for common colds is still the old standby Keep Your Hands Clean. -numerous studies have indicated that rates a common cold are 20 to 30% lower than those who employ effective hand-washing procedures. -Cold viruses can survive on surfaces for many hours. - If you take them up on your hand from a surface and transfer them to your mouth eyes, or noise you may get a 7-Day sniffle.

In a test of the effectiveness of zinc Lozenges

- the experimental design double-blind, randomized, and controlled minimize the likelihood that alternative hypothesis could explain the results. -Given such a well-designed experiment, this is statistically significant result allows researchers to infer strongly than consuming zinc massages reduces the duration of colds.

When the data from the experiment were summarized

- the stats indicated that the mean recovery time was over three days shorter in the zinc group than in the placebo group. -On the surface, this result appears to support the hypothesis. - However, recall the example of a snapshot of women's hair length. -A statistical test is necessary because of the chance of effect

Helicobacter Pylori conforms to a well-accepted scientific principle,

- the theory of germ disease. -the basic premise of germany there is that microorganisms are the cause of some or all of human disease

each strand of the Helix

- thus consists of a series of sugar and phosphates alternating along the length of the Helix, the sugar phosphate backbone -. The strand of the Helix align so that the nucleartides face up on one side of the Helix and face down on the other side of the Helix. -For this reason, the two strands of Helix are said to be antiparallel. - Overall structure of a DNA molecule can be likened to a rope ladder that is Twisted with the sides of the ladder composed of sugar and phosphates. -And the rungs of the ladder comprised of the new nitrogen base sequence has a, c, g,t

Double blind

- we call experience double blind when the research subjects and a technician is performing the measurements are unaware of the hypothesis or whether a subject is in the control or experimental group. -Double-blind experiments literally nearly and eliminate the effects of human bias on results. -when both the researcher and subject have few expectations about the outcome, the results obtained from an experiment are more credible.

The previous actions

- will help you see why definitive scientific answers to our questions are slow in coming. -However, well-designed experiment can certainly allow us to approach the truth

Even after falling all these guidelines,

- you will still find well-researched news reports on several scientific studies that seemed to give conflicting and confusing results. - As you now know such confusion is the nature of scientific process, - early in our search for understanding many hypothesiss are proposed and rejected and discussed, some are tested and rejected, immediately, - some are supported by one experiment by rejected only to be rejected by more thorough experience. - There's only by clearly understanding the process and pitfalls of scientific research they can distinguish between what we know from what we don't know

Atoms are the Smallest units that have the properties of Any Given element.

-92 natural element atoms have been described by chemists, and several more have been created in Laboratories. - Hydrogen, oxygen and calcium are example of elements commonly found in biological systems. -Each element has one or two letters or symbols H for hydrogen O for oxygen and C for calcium for example.

There is one caveat to this discussion.

-A statistically significant result is typically defined as one that has a probability of 5% or less of being due to chance alone. - If all scientific research uses the same standard as many as one in every 20 statistically significant results that is 5% of the total is actually reporting an effect that is not real -In other words, some statistically significant results are false positives representing a surprisingly large sampling error. - This potential explains why one supportive experiment is not enough to convince all scientists that a particular hypothesis is correct.

Water has the ability to dissolve a wide variety of substances.

-A substance that dissolves when mixed with another substance is called a solute. - When a solute is dissolved in liquid, such as water the liquid is called the solvent. -Once dissolved, components of a particular solute can pass freely throughout the water, making a chemical mixture or solution.

Observer bias:

-Another sources of bias arises when a researcher makes consistent errors in the measurements and evaluation of results -.in the tea experiment Observer bias can take various forms. -Expecting a particular outcome may lead scientists to give slightly different instructions about which symptoms constitute which subjects will receive the tea. -If the researcher expected people who drank tea to experience fewer colds, She may make small errors in the measurement of cold severity that could influence the final result.

Hypothesis

-Are ideas about how things work -is a proposed explanations for one of more observations

Finally, the news media generally highlight only those scientific stories that news editors find newsworthy.

-As we have seen, scientific understanding accumulates rather slowly, -with many test of the same hypothesis finally leading to an accurate understanding of a natural phenomenon. -News organizations are also more likely to report a study that supports the hypothesis rather than one that generates less supportive results, even if both types of those studies exist.

To investigate this let's see what happens to the earlier organisms to inhabit Earth, the tiny single-celled bacteria.

-Bacteria are classified as prokaryotic because they do not have a nucleus, a separate membrane component to hold the gene material -. They also do not contain any membrane-bound internal compartments. - Ihey do, however have a cell wall that helps to maintain their shape.

It might be the case that the more prepared students bring water to exams.

-Being more prepared for the exam could certainly increase test scores whether someone or not drinks the water. - The fact the alternative hypothesis may explain the data does not mean that the original is hypothesis is incorrect, only that it requires more testing. -in fact, the researchers that presented the study pointed out the students bring water to the exam and tend to the upperclassmen, a variable that will need to be controlled for in subsequent studies. - It is Possible upperclassmen, having proved gone to experience taking more exams, are more relaxed and perform better than other students, regardless as much knowledge of the subject they have.

How a hypothesis that follows inductive reasoning and sometimes not be true

-Consider the ancient hypothesis that the Earth revolves around the Earth hypothesis was induced based on observations the sun rose in the East every morning, traveled across the sky and set in the west every night in the early seventeenth Century Galileo observe venus Galileo's observation proof false hypothesis that the sun revolves around the Earth

Data

-Data collected on variables of a test that is any factor that can change in value under different conditions. -Experimental test scientist manipulate an independent variable to measure its effects on a defendant

Ability of water to dissolve substances such as sodium chloride is a direct result of its polarity.

-Each molecule of sodium chloride is composed of one sodium ion and one chloride ion. - In the case of sodium chloride, the negative pole of water molecules will be attracted to a positively charged sodium ion and separate it from a negatively charged chlorine Ion. - Water can also dissolve other polar molecules such as alcohol, in a similar manner. -Polar molecules are called hydrophilic because of their ability to dissolve in water. -Nonpolar molecules such as oil do not contain charged atoms and are referred to as hydrophobic because they cannot usually mix with water.

water is made up of two elements hydrogen and oxygen.

-Elements are the fundamental forms of matter - are composed of atoms that cannot be broken down by normal physical means such as boiling.

hypothesis testing is based on deductive reasoning

-Even a sensible hypothesis like vitamin C causes colds needs to be tested to see if I can you prove false -Can involve using a general principle to predict unexpected observation -Deduction uses a general principle to predict an expected outcome

Ionic bonds form between charged atoms attracted to each other by similar opposite charges.

-For example, a sodium atom forms an ionic bond with a chlorine atom to produce table salt when the sodium atom gives up an electron and a chlorine atom gains one - more than two atoms can be evolved in an ionic bond, calcium will react with two chlorine atoms to produce calcium chloride, because calcium has two electrons in its valence shell.

Popular news source provide a steady stream of scientific information.

-However, stories about scientific about research results often do not contain information about the adequacy of environmental controls or design.

Reasoning takes the the form of if/then statements

-If our idea is correct then we should expect to observe a specific outcome from a hypothesis test

How ulcers were successfully treated.

-In 1982 australian scientist robin warren and barry marshall changes the view of how to treat ulcers. -they discovered the bacteria Helicobacter Pylori in almost all of the ulcer tissue. -they thought H. pylori was the cause of most ulcers. -Barry marshall tested by consuming the bacteria -he got acute stomach pain.

The potential problem of bias is avoided by a blind experiment

-In a blind experiment individuals are not aware if they receive the placebo drug or not. - this individual problem is avoided by designing a blind experiment in which individual subjects are not aware of exactly what they are predicted to experience. This means not telling the participants whether they are receiving a drug or a Placebo

While their difference between prokaryotic and eukaryotic cells, there are also similarities.

-In fact all living organisms are made of cells would contain exactly the same kind of macromolecules and other structural features, most likely because they share a common ancestor.

Chemical bonds between atoms and molecules involved attractions that help stabilize structures.

-In general, this involves the sharing or transfer of electrons -. Carbon is often involved in chemical bonding because of its ability to make up bonds with up to four other elements. -Like a tinkertoy connector, carbon has multiple sites for connections that allow carbon-containing molecules to take an almost infinite variety of shapes.

Not all hypothesis are proved false

-In science incorrect ideas must be discarded, and this can only happen if one can prove ideas are false.

One potential source of bias is subject expectation

-Individual experiment subjects make consciously or unconsciously Model Behavior they feel the researcher expects from them. -an individual who was receiving the tea may feel more confident that she would recover more quickly.

the second step to designing a well controlled experiment

-Is to treat all subjects identically during the course of an experiment. - In this study all participants weather in the control and experimental group, information about the benefits. - During the course of the study all participants were given tea to drink five or six times.Until their system subside. - However individuals in the control group received sham tea which does not contain the hahaha extract - treating all participants the same ensures that no factor related to the interaction between the subject and the researcher influences results.

we can now come back to your original question about whether drinking water can help students perform better on exams.

-It is not too hard to imagine how some of the properties of water outlined earlier might lend it to the ability to help regulate blood pressure, deliver dissolved nutrients to the body, and maintain body pressure. - It is also not hard to imagine that keeping blood pressure and temperature stable during a stressful exam and delivering nutrients to a hard-working brain may mean increased performance on exam. Tempting as it is to stop there, a good scientist must not simply accept results because they are believable. - A good scientist must also evaluate alternative hypothesis.

How Germ theory was supported

-Louis Pasteur observed that bacteria caused milk to become sour -he reasoned that bacteria could harm humans, from observations -Robert Koch demonstrated a link between anthrax bacteria and a specific set of fatal symptoms in mice providing additional evidence for the theory -Antibiotic treatment That Target specific particular microorganisms can cure certain certain illnesses

Convergence and differences among groups of organisms arose as a result of natural selection, a process of gradual changes in the characteristics of populations over time.

-Natural selection was a major process in the diversification life from a single ancestor because organisms vary from one to another and because some of those variations increase the chance of survival and reproduction. -A genetic trait that Increases survival and reproduction should become more prevalent overtime. -In contrast, less successful variants should be eventually lost from the population.

Correlation sutudes are the main tool of epidemiology the study of distribution and causes of disease.

-One commonly used epidemiological technique is cross-sectional survey. -This type of survey, many individuals are tested for the presence of a particular condition and asked about their exposure to various factors. -Limitations of cross-sectional surveys include the effect of subject bias and poor recall by set your survey participant, addition to all the problems associated with interpreting correlations. -Table 1.1 provides an overview of the variety of correlations tragedies employee to study the links between environment and health.

The effect of chance on experimental results is known as sampling error.

-One more specifically sampling error is the difference between a sample and the population from which it was drawn. - In any experiment, individuals and experimental group will differ from individuals in the control group and random ways. -Even if there is no true effect of an experimental treatment, the data from the experimental group will never be identical to the data from the control group.

Joining many individual together produces polymers.

-Polymers of sugar monomers are called polysaccharides -. Plants use tough polysaccharides in their cell wall as sort of a structural skeleton. -The external skeletons of insects, spiders and lobsters are composed of the same polysaccharide charide chitin, and a cell walls that surrounds bacterial cells are rich in structural polysaccharides.

How are control and experimental groups illustrated in the tea experiment/?

-Researcher might put all the volunteers names in a hat draw hash out and designate the people drawn out as the experimental group -the remaining people will be designated as a control group -the volunteers were randomly assigned to either the experimental or control group is it came into the clinic

Correlations

-Scientist can also test hypothesis using correlations when controlled experiments on humans are difficult or impossible to perform. - A correlation is a relationship between two variables

o avoid the problem of observer bias.The data collectors themselves should be blind.

-Scientist doctor or technician applying the treatment does not know which group any given subject is a part of until after all the data has been collected and analyzed. - Blinding the data collector ensures that the data are objective in other words about bias.

Look for clues about how well the reporters did their homework.

-Scientist usually discuss the limitations of their research in the paper. -Are these cautions noted in an article or television piece? -If not, the reporter maybe overemphasizing applicability of results.

Then, note it's a scientific discovery itself is controversial.

-That is, does it reject a hypothesis that has long been supported? - Does it concern a subject that is controversial? - Might it lead to a change in social policy? -And these cases, be strongly cautious. - New and unexpected research results may be evaluated in light of other scientific evidence and understanding, - reports that lack comments from other experts may miss problem with the study or fail to place it in the context of other research. -The Savvy reader feature in this chapter provide a checklist of questions to ask an answer as you evaluate news reports.

The chemistry of biological systems is based on the element carbon.

-The Branch of chemistry that is concerned with carbon-containing molecules is called organic chemistry. -Carbon interacts with other elements to produce a more complex molecules that comprise all living things. -These interactions, or chemical bonds, follow a few simple patterns.

Making chemical bonds depends on an atom's electron configuration.

-The electrons in the cloud that surrounds the atoms nuclei have different energy levels based on their distance from the nucleus. -The first level or electron shell, is closest to the nucleus, and the electrons located there have the lowest energy. -The second energy level is far away and these electrons have more energy, and so on.

Each energy level can only hold a specific number of electrons.

-The first shell holds two electrons, the second shell holds up to eight. -Electrons fill the lowest shell before filling the highest shell. -For example, hydrogen with only one electron needs only one more to fill its first shell.

Anytime a small number of water molecules in a pure solution will be dissociated into H+ and oh 0H negative ions.

-The pH scale measures the relative amounts of these ions in a solution. - Acid is a substance that donates H+ ions to a solution -a base is a substance that accepts H+ ions. -the more acidic a solution is the higher the H+ concentration is relative to the OH minus ions. -the higher the H+ concentration, the lower the ph. -BasicaSolutions had fewer OH+ ions and thus a higher pH -. There are equal numbers of both in pure water, so it is neutral, or 7. -PH of most cells is very close to 7.

sugars, or carbohydrates, are the major source of energy for cellular processes and play important structural rules in cells.

-The simplest carbohydrates are composed of carbon, hydrogen, and oxygen in the ratio CH2O. -for example glucose is a simple sugar or a monosaccharide metabolized at 6 (ch2o) or C6H12O6 -glucose is a simple sugar, or monosaccharide, that consist of a single ring shape. -Disaccharides are two rings joined together -. Table sugar is a disaccharide composed of glucose and fructose and sugar found in fruits.

Mechanic analogy

-There are many reasons why a car engine might not start if a mechanic Begins by tinkering with numerous parts to play at all possible fixes for restoring the car she will not know what exactly caused the problem. instead of mechanic Begins by testing the battery for powe r if a battery is charged she didn't check starter motor if the car doesn't shut she looks over the fuel pump she continues in this manner until identifying the problem Similar to a scientist systemically attempting to eliminate hypothesis that don't explain a phenomenon

Bias

-These opinions may cause participants to influence or bias the results of an experiment. -Scientists and researchers may have strong opinions about the truth of a particular hypothesis even before it is tested.

Let;s examined the results presented in figure 1.10 The horizontal axis of the graph or x-axis illustrates the independent variable.

-This variable is stress - the graph rank subjects along a scale of stress from low stress on the left edge of the scale to high stress on the right - The vertical axis of the graph is a dependent variable the percentage of participants study participants develop cold as reported by their doctors. - Each point on the graph represents a group of individuals and tells us what percentage of people in each Stress category had clinical colds.

Molecules are large organic molecules made of subunits.

-Those present in living organisms include carbohydrates, proteins, lipids, and nucleic acids, -. Some are synthesized by the body and others are obtained in diet. - Dietary macromolecules tend to be the focus of many myths about how what we eat affects us

The chemical formula for water H2O shows that it contains two hydrogen atoms for every one oxygen.

-Water, like other molecules consist of two or more atoms joined by chemical bonds. -a molecule could be composed of the same or different atoms -. For example, a molecule of oxygen consists of two oxygen atoms joined to each other, - while a molecule of carbon dioxide consists of one carbon into oxygen atoms.

Double-blind placebo-controlled randomized experiments Sent the gold standard for medical research.

-Well controlled experiments can be difficult to perform when the subjects are human. - In the case of hell is the volunteers with colds, the placebo treatment of shamte did not hurt those received it.

What is the Scientific Method?

-allows answers and problems to be solved efficiently and effectively -the process of making observations about the world, proposing ideas about how something works, testing those ideas and discarding our ideas to the test results.

The Use the model systems especially an animal's,

-allows experimental testing on potential drugs and other therapies before those therapies are employed on humans research. - Research on model organisms such as lab rats have contribute to a better understanding of nearly every serious human thread thread including cancer, heart disease, Alzheimer's disease, and AIDS, acquired immunodeficiency syndrome, - however in research studies in addition the results of animal studies are not always directly applied to humans despite a shared evolutionary history -animals can have important differences from humans - testing hypothesis about human health and human being still provides the clearest answer to these questions

Experimentation science is anagoules to what a mechanic does when diagnosing a problem

-an experiment allow the scientists to control the conditions that may affect subject of a study

A scientific hypothesis must be falsifiable

-an observation or a set of observations that could potentially be proven false

Some people find chemistry intimidating

-and shy away from trying to understand chemical principles. -Even the most basic understanding of chemistry can help one sort out fact from fiction. - A basic understanding of chemistry will be used to help consider What are the claims made about the rate of disappearance of ships and planes over the so-called Bermuda Triangle are based on science or pseudoscience.

Suggestions about using meditation to reduce acceptability to colds

-are based on a correlation between psychological stress and susceptibility to colds virus infections. -This correlation was generated by researchers who collected data on subjects psychological stress levels before giving them nasal drops that contain a cold virus. -Doctors later reported on the incident and severity of called the monk dissidents in the study. -Note that while the cold virus was applied to each participant in a study, the researchers had no influence on the stress levels of the study participants -in other words this was not a controlled experiment because people are not randomly assigned to different treatments of high or low stress.

The vast majority of animals used in biomedical research

-are rodents such as rats, mice, and guinea pigs, -although some areas of research requires animals more similar to humans in size such as dogs or pigs -or share a closer evolutionary relationship such as chimpanzees.

A hypothesis it seems to be true

-because it has not been rejected by initial tests may be rejected later because of a different test - this is what happened to their hypothesis is Vitamin C consumption reduces the susceptibility to cold

We can explore the role that statistical test play in more detail

-by evaluating another city on cold treatments. -This study examines efficiency of zinc lozenges on reducing cold severity..

Carbon with it's 4 unpaired outer electrons can form up to 4 bonds.

-carbon can form four single bonds , two double bonds, one double bond and two single bonds and so on, depending on the number of electrons needed by the item that is its partner. -Methane is formed when carbon makes 4 single bonds to hydrogen.

Hypothesis in biology

-come from knowledge on how the body and other biological systems work -experiences in similar situations -also shaped by our creative mind

Living organisms

-contain a common, set of biological molecules and are composed of cells. -Other attributes found in most living organisms include growth, movement, reproduction, responds to external environmental stimuli and metabolism. -metabolism includes all of the chemical process that occur in cells, including the breakdown of substances to produce energy, the synthesis of substances necessary for life, and the extraction of waste generated by those processes.

The ancestor of the bacteria also gave rise to a more structural the complex group of organisms called eukaryotic cells.

-eukaryotic cells have a nuclear membrane. -eukaryotic cells contain membrane-bound subcellular organisms called organelles. - Organelles will be covered indeed for now it is enough to understand the organelles work together to perform specific jobs inside cells that allow the cells to function properly. -Eukaryotic organisms include single-celled amoeba and yeast as well as multicellular plants, fungi and animals.

hypothesis that hp hyori is accepted today as fact

-even if warren and marshel's colleagues were unconvinced that ulcers could have a simple cause -No other reasonable alternative explanation for has been supported by hypothesis tests -the hypothesis has not been rejected, no carefully designed experiments that prove the Helicobacter Pylori removal doesn't cure ulcers.

Statements that are value judgements

-example "it is wrong to cheat on an exam are not scientific. -people have different ideas of right and wrong. -it is impossible to falsify these types of statements. -to answer questions of morality, ethic of justice we turn to philosophy or religion.

Most hypothesis

-fit into a larger picture of scientific understanding.

Statistical test calculates the likelihood,

-given the number of individual sample and their variations within samples, that the difference between two samples or reflects a real, underlying difference between the populations from which these samples were drawn. - A statistically significant result is one that is very unlikely to be due to chance differences between experimental and control groups, so it likely represents a true difference between the groups.

A statistical measure of the amount of variability in a sample is the number called the statistical error of the mean.

-greater variability generates a larger standard error -Put Simply put the true population mean is very likely to lie somewhere in the range Between the mean of the sample minus the standard error and the mean of the sample plus the standard error. - You have likely heard the term standard error used before, when public opinion polls are released, this range is often referred to the margin of error. -Results with a small standard are more likely to be statistically significant if a hypothesis is true

A search of medical publication databases

-indicates that every year nearly hundred scholarly articles regarding biology, treatment and consequences of common colds are public -This research has led to several important discoveries about the structures and biochemistry is a common cold virus is, how they enter cells, and how the body reacts to those infection

Rigorous testing of alternative hypothesis

-is one major difference between, bad science, pseudoscience and good science. - Good scientist don't perform only experiments that will confirm their hypothesis. - They actively seek out ways to falsify their hypothesis, by developing and testing alternative hypothesis.

Testable

-it should be possible to evaluate hypothesis thought observation of the measurable universe -The hallmark of science is that hypothesis are subject to rigorous testing -Can't be a ridiculous statement like colds are caused by psychics because there are no proof of psychics.

If we survive a viral infection we are unlikely to experience a recurrence of the disease virus causes

-it's unusual to suffer from chickenpox twice because one's exposure to the chickenpox virus provides lifelong immunity to infection. Variety of cold viruses make immunity to the common cold and the development of vaccines prevent it very improbable.

Is the supernatural scientific

-lack of falsifiability is the reason the supernatural can't be scientific. -a supernatural force can cause any possible result, hypothesis that rely on supernatural ofreces cannot be falsified.

Our question about effective cold treatment

-lends itself to a variety of controlled experiments on possible drug therapy. -for example the extract of common North American Prairie plant has been promoted as a treatment to reduce the reduce the likelihood as well as a severity and duration of colds. People who drink the tea reported that it was 33% effective. 33% effective is in comparison to the effect that did not contain the abstract, that is a result from the control group.

Instead of reading the primary literature,

-most of us receive scientific information from secondary sources such as books, news reports and advertisements. -How can we evaluate information in this contexts?

the argument for the power of vitamin c was popularized by 1970 prize-winning chemist Linus Pauling

-pauling based his assertion that large doses of Vitamin C reduce the incidence of cold by much as 45% - still be careful test of this hypothesis have sense fail to support it - in many of the studies calling cited appear as an alternative hypothesis explain the difference between vitamin C supplements and non supplementers Now scientists agree that the hypothesis that vitamin C prevents colds has been convincingly -false

Model systems

-scientists use model systems to When testing hypotheses that would raise ethical or practical problems when tested on people -Four basic research that helps us to understand how cells and genes function, the model systems are easily grown and manipulated organisms such as certain species of bacteria nematodes and fruit flies - even isolated cells from larger organisms that reproduce and dishes in the lavatory. -Chase of research on human health and disease model systems are typically other mammals and human cells. Non-human animals are especially useful as model organisms in medical research because they are closely related to us. Like us mammals have hair and produce milk for their young and thus they share similarities in anatomy and physiology.

Phospholipids are

-similar to fat in the each glycerol molecule is attached is too fatty acid tails. The third bond in a phospholipid is to a phosphate head group. -The phosphate head group consists of a phosphate atom attached to four hydrogen atoms and is hydrophilic. -Thus, a phospholipid has a hydrophilic head and two hydrophobic Tails. -Phospholipids often have additional head group attached to the phosphate, which also confers unique chemical properties on the individual phospholipid. - Phospholipids are important of the membranes that surround cells and that designate compartments within cells.

Water molecules tend to orientate themselves

-so that the hydrogen atom with its partial positive charge of one molecule is near the oxygen atom with its partial negative charge of another molecule. -The weak attraction between hydrogen atoms and oxygen atoms in adjacent molecules forms a hydrogen bond. -Hydrogen bonding is a type of weak chemical bond that forms when a partially positive hydrogen atom is attracted to a partially negative atom. -Hydrogen bombs can be intermolecular, involving different regions within the same molecule, -but they can be intermolecular with a different molecules, as is the case in hydrogen bonding between two different water molecules.

During the days of sea exploration,

-speculation about the cause of these disappearances focused on sea monsters, and was later replaced by Notions about disruptions in gravitational or methadone fields. -As understanding of gravity and magnetic fields increased, the Allure of these explanations decrease. -one explanation circulating around now involves methane. - This idea persists that methane deposits under the ocean produce Giant gas bubbles that rises in the ocean floor and sinks ships. -If these gas bubbles escape the ocean, rise to the atmosphere and are struck by lightning, they can cause fires that bring down airplane. -Well there's no scientific evidence to support this hypothesis, its possibility is enhanced, like all those of all pseudo-science, by the inclusion of scientific principles, in this case chemistry.

Atoms with five or four electrons in the outer shell

-tend to share electrons to complete their valence shells. - When atoms share electrons, a covalent bond is formed.

Hand surgeon medical databases indicates

-that every year nearly a hundred articles regarding biology, treatment and consequences of the common cold are published. T -his research has led to several important discoveries about the structure and biochemistry of common cold virus is, how they entering cells and how the body reacts to those infections.

In experiment with the Tea, statistical tests indicated

-the 33% reduction and cold severity observed by the researchers was significantly statistically -in other words, there's a low probability that the difference in cold susceptibility between the two samples in the experiment is due to chance. - if The experiment is properly designed, and a significant result allows researchers to infer that the research had an effect

An additional quality of living organisms is ability to achieve homeostasis.

-the maintenance of an internal constant environment despite a consistently changing external environment. -Zombies are surprisingly good at maintaining their body temperature and blood pressure even with multiple slash wounds and severed limbs. - Unfortunately, their limited homeostatic abilities do not prevent them from being in a progressive state of decline with each assault bringing new injuries, piled on top of previously obtained unfilled injuries.

One characteristic of experiments that influence influences sampling error is sample size,

-the number of individuals in the experimental and control groups. - If a treatment has no effect, a small sample size could return results that appear differently simply because of a large sampling error. - This is a case of the vitamin C hypothesis described at the beginning of the chapter. -Subsequent tests with larger sample sizes allowed scientists reject the hypothesis that vitamin C prevents colds.

A supernatural hypothesis can't be tested with science

-the supernatural isn't constrained by the laws of nature -those behavior cannot be predicted with our current understanding of the natural world.

When scientists conduct an experiment, .

-they hypothesize that there is a true, underlying effect of their experimental treatment on the entire population. -An experiment on a sample of a population can only estimate this to affect because their samples all was an imperfect snapshot of an entire population

To conclude that stress causes illness,

-we need the same assurances that are given by a controlled experiment. -In other words we assume that the individuals measured for the correlation are similar in every way except for their stress levels. - Is this a good assumption? Not necessarily most correlations cannot control for alternative hypothesis. People who feel more stressed eat Poor diets because they feel time-limited and Will fast food more often. -In addition people who feel Highly stressed may be in situations where they are exposed to more cold viruses. - These differences among people who differ in stress levels may also influence their colds acceptability - even with a strong correlation relationship between the two factors we cannot strongly infer that stress causes decreased resistance to cold.

Even with the statistical tests indicating that the results had a probability of less than 0.01% of occurring by chance

-we should begin to feel assured that taking zinc lozenges reduce the duration of the cold only after additional hypothesis test give similar results. -In fact, scientists continue to test this hypothesis, and there's still no consensus about the effectiveness of zinc as a cold treatment.

so where does that discussion leave us

-when we ever find the best way to prevent a cold or reduce its effects? -In the United States alone over 1 billion cases of the common cold atr reported every year, costing many more billions of dollars in medical visits, treatment and lost work days. -Consequently, there is a significant cause to search for Effective protection in the different viruses that cause colds.

Atoms

-with the same amount of number of electrons in their outer shell called the valence shell, exhibit similar chemical behavior. -When the valence shell is full, the atom won't normally found form bonds with other atoms - Atoms whose valence shells are not full often combined via chemical bonds.

What is a scientific theory?

A scientific theory is an explanation for a set of related observations that is based on well-supported hypothesis

steroids are composed of four fused carbon containing Rings. -

Cholesterol is one steroid that is probably familiar, its primary function in animal cells is to help maintain the fluidity of membranes. -Other steroids into the sex hormones testosterone, estrogen and progesterone which are produced by the sex organs that have effects throughout the body Body.

An Effective way to test many hypothesis is by rigorous scientific experiments

Experimentation has enabled scientists to prove Beyond A Reasonable Doubt the common cold is caused by a virus.

You should be cautious about basing decisions on antecedal evidence which is not at all equivalent to a well-designed scientific research.

For example, many of us hear anecdotes along the lines of the grandpa was pack a day smoker and live to the age of 94. - However, hundreds of students have demonstrated the clear link between cigarette smoking and premature death. Although anecdotes May indicate that a product or treatment has Merit, only well-designed test of a hypothesis can determine its safety and efficiency.

For example, we know that people differ in their ability to recover from a cold infection. -

If we give zinc massages to volunteer and Placebo massages to the other volunteer, it is likely the two volunteers will have colds of different lengths. -Even if the zinc taker had a shorter cold than the placebo take/r, you would probably say that the test did not tell us much about our/ hypothesis, -the zinc taker might just have had a less severe cold for other reasons.

Does science require us to remember specific sets of facts about the world?

It's impossible and unnecessary due to reference books

In the teas study

The data indicated that the cold severity was lower than experimental group compared to those who receive Sido. Because their study utilize controls reaches can be confident that the groups only different because of the effects of the tea. By reducing the likelihood that alternate hypothesis could explain the results, the researchers could strongly Infer that they were measuring a real positive effects of tea and colds.

What is a falsifiable hypothesis?.

The hypothesis that exposure to cold temperature reduces your susceptibility to colds is falsifiable. We can think of an observation that rejects this hypothesis

Are humans evolving into higher beings? -

Theory of evolution explains how a single common ancestor present on Earth 4 billion years ago Could give rise to the over 10 million different kinds of organisms found on Earth today. -For now, you will try to understand whether the organisms on Earth today represent a series of steps in the Ladder toward humanness -Does that this ladder have a few more rugs that humans can climb, maybe gaining an extra gene or two that will provide superpowers similar to those found in the X-Men?

Some form of Zinc can block cold viruses from invading cells in the nasal cavity.

This observation led to the hypothesis that consuming Zinc at the start of a cold could decrease cold severity. Research at the Cleveland Clinic tested this hypothesis using a sample of 100 of their employees who volunteered for double-blind study within 24 hour of developing cold symptoms The researchers randomly assign subjects to the experimental group who receives zinc lozenges, or the control group. See if Placedo lozengos. Members of both groups receive the same as structures from using the massages ever asked to raise their symptoms until they had recovered.

Consider a hypothesis that at the average hair length of women in college in a college class in 1965 was shorter than the average hair length at the same College today. -

To test this hypothesis we could compare a sample of snapshots from college yearbooks. -If hairstyles were similar among women in the snapshot, you can reasonably assume that the average hair length in the college class is closed the average length in the snapshot. - However, what if you see that women in a snapshot have a variety of hairstyles, from short bobs to long braids? - In this case, it is difficult to determine whether the average hair length in the Snapchat is it all close to the average for the class. -With so much variation, the Snapchat could by chance contain a surprisingly High number of women with long average hair -causing the average length in the sample to be much longer than the average length for the entire class.

deductive reasoning

Wizards resulting predictions is a powerful message for testing hypothesis the structure of the statement means a hypothesis can be clearly rejected if untrue but impossible to prove if true

Looking critically at experience can help us make well-informed decisions about actions to take. -Most of the research on cold prevention and treatment is published first as primary sources

Written by the researchers themselves and reviewed within the scientific community. -The process of peer review, in which other scientists could critique results and conclusions of an experiment before it is published, helps increase confidence in scientific information. -Peer-reviewed research articles and journals such as science, nature, and the Journal of medical American Medical Association, and hundreds of others represents the first and most reliable resources of current scientific knowledge.

Control has a specific meaning in science

a control for an experiment is a project similar to a experimental subject except that the control is not supposed to experimental treatment. Controlled experiments are designed to eliminate as many hype alternative hypothesis impossible.

Pyramids

a set of actions or observations designed to test specific hypothesis an experiment allows a scientist to control the condition that may affect the subject of the study Manipulating the environment allows scientists to eliminate any alternative hypothesis that may explain the result.

Most people accept the hyper activity in children can be reduced by ingestion of sugary drinks or snacks,

and there is not much scientific evidence to support this notion. There is, in fact, more scientific evidence to support the notion that parents expect their children to become hyperactive from and dusting sugar.

Zombies

are definitely human corpses that have been brought back to life -often called the undead or Walking Dead -zombies are thought to survive by eating the flesh or drinking the blood of living humans. - While we know zombies are not actually alive, they share many characteristics seen in other living organisms.

Example of vitamin C hypothesis also highlights a change of challenge of communicating scientific information

even today the beliefs that vitamin C prevents colds as widespread it took many years of careful research to show this last word was in fact wrong

the previous discussion may seem discouraging

how can scientists determine the truth of any hypothesis when there is always a chance that hypothesis can be falsified even if a hypothesis is supported does the difficulty of eliminating alternative hypothesis mean that we will never truly know which approach is the best.

Not All scientific hypothesis can be tested through experimentation

hypothesis about how life on Earth originated where the cause of dinosaur instructions are usually not testable ' this hypothesis are instead tested using careful observation of the natural world Examination of fossils and other geological evidence allows scientists to test hypothesis regarding the extinction of dinosaurs

Theory

in everyday speech the word theory is synonymous with untested ideas based off little information little information -Scientists utilize the term when referring to well-supported ideas about how the natural world works. -The support Foundation of all scientific theories is a multiple hypothesis test.

A virus

is a microscopic and with a simple structure, it typically contains a short strand of genetic material sometimes a virus is surrounded by a membrane

Hypothesis cannot be proven absolutely true

it is always possible that the true cause of the phenomenon may be found in a hypothesis that has appear to inviten't been tested. When one hypothesis has not been disproven through repeated testing and all alternate hypothesis have been eliminated, scientists have accepted that the well-supported hypothesis is in a practical sense true.

The study here supports the hypothesis that tea reduces the severity of colds

it is extremely rare that a single experiment will cause the scientific Community to accept a hypothesis Beyond A Reasonable Doubt. Dozens of studies each with different experimental designs and Using =extracts from different parts of the plant from different parts of the plant have investigated the effects of tea on common cold And other illnesses. Some of these Studies have shown a positive effect, but many have shown none The medical community there's a lot of skepticism and disagreement in the effectiveness of this popular herb as a cold treatment. - Only through continued controlled test of the hypothesis will we discern an accurate answer to the question

Control groups and experimental groups

must be as similar as possible to each other to eliminate alternative hypothesis. That could explain the results. - the group should not do for systematically and eggs diet stress or other factors that might affect cold susceptibility Random assignment: one Effective way to minimize the differences between the groups of individuals.

A common hypothesis about cold prevention

s it taking vitamin C supplements keeps you healthy

Change from well-designed experiment

should allow researchers to convincingly reject a hypothesis or support it this is more likely to occur if experiment is controlled.

the dependent variable

the dependent may or may not be influenced by changes in the independent variable chill the dependent variable cannot be systematic

inductive reasoning

the process used to conduct this hypothesis is called inductive reasoning inductive reasoning combines a series of specific observations to discern a general principle inductive reasoning is it essential to a for understanding the world even if inductive reasoning leads hypothesis that makes sense, does not mean the hypothesis is true

how would researchers measure the effect of vitamin C on cold prevention

the scientist can vary the individuals vitamin C intake scientists who measure their susceptibility to illness on exposure to cold virus (dependent variable)

A virus must effective cell to reproduce

there are over 200 viruses that are known to cause a common cold, most affect the cells in our nose and throats sneezing coughing congestion and sore throat of a cold appear to result from the body's protective response to immune system established by a viral invasion.

alternate hypothesis

these alternative hypothesis explain why people with different vitamins taking it's very cold accessibility Stating the truth other than portion of a deductive statement does not prove that the portion is true.

Once subjects are listed in experiment

they are assigned to a control or experimental group Is members a controlled and experimental group differ at the end of a well designed test test, than difference may be due to the experimental treatment

There's three different type of lipids,

which are grouped together because they are partially or entirely hydrophobic organic molecules made primarily of hydrocarbons, - the three types of lipids include fat, steroids and phospholipids.