BIO 100 Exam 1

biotechnologist

Biotechnologists apply the knowledge of biology to create useful products

carbohydrates

Carbohydrates make up a large portion of our diet, whether they be consumed in their complex form in whole foods, such as wheat breads, cereals, potatoes, and pasta, or as simple sugars, such as table sugar (sucrose), fruit sugar (fructose), or milk sugar (lactose).

carbon dating

Carbon-14 (14C) is a naturally occurring radioisotope that is created in the atmosphere by cosmic rays. This is a continuous process, so more 14C is always being created. As a living organism develops, the relative level of 14C in its body is equal to the concentration of 14C in the atmosphere. When an organism dies, it is no longer ingesting 14C, so the ratio will decline. 14C decays to 14N by a process called beta decay; it gives off energy in this slow process. After approximately 5,730 years, only one-half of the starting concentration of 14C will have been converted to 14N. The time it takes for half of the original concentration of an isotope to decay to its more stable form is called its half-life. Because the half-life of 14C is long, it is used to age formerly living objects, such as fossils. Using the ratio of the 14C concentration found in an object to the amount of 14C detected in the atmosphere, the amount of the isotope that has not yet decayed can be determined. Based on this amount, the age of the fossil can be calculated as long as it is less than 50,000 years old. Isotopes with longer half-lives, such as potassium-40, are used to calculate the ages of much older fossils (a million to a billion years old). Through the use of carbon dating, scientists can reconstruct the ecology and biogeography of organisms living within the past 50,000 years.

polar vs nonpolar

Covalent bonds can be polar or nonpolar, depending on whether or not the electrons are shared equally. For example, within a water molecule the bonds are all polar (unequal sharing of electrons between the oxygen and the two hydrogens), whereas in methane the bonds are all nonpolar (electrons shared equally among the carbons and hydrogens). For this class, unless you see an oxygen or a nitrogen (another highly electronegative atom) involved in a covalent bond, consider the bond nonpolar.

ecologists

Ecologists study all types of interactions among organisms and their environments, including populations, ecosystems, and the biosphere.

compounds

Elements usually combine to form compounds, which contain 2 or more elements in a fixed ratio. Most compounds in living systems contain at least 3 or 4 elements, usually combinations of Hydrogen (H), Oxygen (O), Nitrogen (N), and Carbon (C).

electron arrangement

Figure 2B-1 shows the electron arrangement of an atom of neon, which is part of a group of elements called the noble gases. According to the Periodic Table of Elements, neon is atomic number 10. That means that neon has 10 protons. We also know that it has 10 electrons, because in a neutral state the positively (+) charged protons have to exactly equal the negatively (-) charged electrons. Notice that there are two orbits, or electron shells, around the neon. The innermost electron shell is the one closest to the nucleus. It is only able to hold 2 electrons. Each consecutive shell after that can hold up to 8 electrons, and in this case the outermost shell has all 8. Thus, if we add together the electrons in the two shells of neon we get 10, which is the total number that we determined by using the periodic table. The outermost shell is called the valence shell. You can think of the "goal" in chemical bonding as the need to fill the valence shell of each atom involved. This can be done by creating bonds with other atoms. The noble gases, which include elements such as neon, helium, and argon, already have full valence shells. Atoms with full valence shells do not bond with other atoms, and thus the reason for neon's reference as "noble."

The formation of sodium chloride

Figure 2B-3: Electron arrangement of sodium (Na) and chlorine (Cl). Let's first look at the electron arrangements of sodium (Na) and chlorine (Cl). Notice in figure 2B-3 that sodium has 3 electron shells. Remember that the innermost shell contains only 2 electrons, and each addition shell contains up to 8 electrons. According to the periodic table, sodium is atomic number 11, and thus has 11 protons and 11 electrons. The electrons on the atom are placed as follows: 2 electrons in the innermost shell, 8 electrons in the next shell, and 1 electron in the outermost, or valence shell. That adds up to 11. The chlorine atom also has 3 electron shells. According to the periodic table of elements, chlorine is atomic number 17, and thus has 17 protons and 17 electrons. The electrons on the atom are placed as follows: 2 electrons in the innermost shell, 8 electrons in the next shell, and 7 electrons in the outermost, or valence shell. That adds up to 17. Figure 2B-4: Animation showing an electron being transferred from Sodium (Na) to Chlorine (Cl). When sodium and chlorine come in contact with one another they form what is called an ionic bond, which involves one or more electrons being transferred between two atoms (Figure 2B-4). In this case, one electron is transferred from sodium to chlorine. Figure 2B-5: The new electron arrangements of sodium (Na) and chlorine (Cl). They are now referred to as ions. You can now think of the two atoms as being both "happy." That is, each of them now has a full valence shell (Figure 2B-5). Sodium has 8 in its outermost shell and chlorine has 8 in its outermost shell. Remember, the "goal" of ionic bonding is to fill the outermost shell of each atom. Count the total number of electrons that now occur on each atom. Notice that sodium now has only 10 of its original 11 electrons, but chlorine now has an additional electron, such that it now has 18 electrons instead of the original 17. Because sodium has one less negatively-charged electron it now has a charge of +1. Chlorine has one extra negatively-charged electron, so its charge is now -1. The two atoms are now what we refer to as ions, or charged atoms. One final thing to note is that we can drop the number 1 from ions with a charge of 1. Thus, we can write them as Na+ and Cl- to indicate charges of +1 and -1, respectively.

Which criteria for defining a living organism are satisfied by fire? Which are not satisfied by fire? Thus, is fire a living organism?

Fire satisfied metabolizes, grows, responds to the environment and reproduces, not satisfied: composed of cells and pass down genes to the next generation. Thus fire is not living

Forensic science

Forensic science is the application of science to answer questions related to the law. Biologists as well as chemists and biochemists can be forensic scientists. Forensic scientists provide scientific evidence for use in courts, and their job involves examining trace material associated with crimes. Interest in forensic science has increased in the last few years, possibly because of popular television shows that feature forensic scientists on the job. Also, the development of molecular techniques and the establishment of DNA databases have updated the types of work that forensic scientists can do. Their job activities are primarily related to crimes against people such as murder, rape, and assault. Their work involves analyzing samples such as hair, blood, and other body fluids and also processing DNA (Figure 1C-2) found in many different environments and materials. Forensic scientists also analyze other biological evidence left at crime scenes, such as insect parts or pollen grains. Students who want to pursue careers in forensic science will most likely be required to take chemistry and biology courses as well as some intensive math courses

Approximately 99% of the human body is made up of what four elements?

Hydrogen (symbol H), Oxygen (symbol O), Nitrogen (symbol N), and Carbon (symbol C).

primary source

If research passes peer review, it may be published in a primary source, such as a reputable scientific journal. Some of the most prestigious primary sources include journals such as Nature, Science, and the Journal of the American Medical Association.

Phosphorus is atomic number 15. How many electrons are in its innermost shell? How many electrons are in its valence shell? How many more electrons does it need to fill its valence shell?

If we know that phosphorus is atomic number 15, then we also know that it has 15 protons and 15 electrons. Two of the electrons are placed into the innermost shell, which can only hold two. That leaves 13 more electrons to place on the next shells. 8 electrons would go into the next shell. If we sum that shell (with 8 electrons) with the innermost shell (with 2 electrons) we have a total of 10 electrons so far. That leaves 5 more electrons for the last, valence shell. Thus, phosphorus would need 3 more electrons to fill its valence shell with 8 electrons.

covalent bonds

In covalent bonds, 2 or more atoms share electrons. This is often shown by a single line between the two atoms. For example, methane has a carbon with 4 lines linking 4 different hydrogen atoms (Figure 2B-7). A single line indicates a single bond. Methane has four single bonds, each between the central carbon atom and the hydrogens. Atoms can also form double covalent bonds and triple covalent bonds. Two lines between two atoms indicates a double bond and three lines between two atoms indicates a triple bond. In the middle of ethylene there are 2 carbons linked by two lines, thus indicating a double bond. In the middle of acetylene there are 2 carbons linked by three lines, thus indicating a triple bond (Figure 2B-8). We will now look at how the covalent bonds are formed in methane (CH4).

ionic bonds

In ionic bonds, one atom donates 1 or more electrons, and the other atom receives 1 or more electrons. Thus, the electrons are not shared. This results in the formation of ions, or charged atoms, held together by their opposite charges. Ions are either positively charged (+) or negatively charged (-). We will now consider the formation of sodium chloride (NaCl), also known as "table salt," as an example of ionic bonding.

tissues

In most multicellular organisms, cells combine to make tissues, which are groups of similar cells carrying out the same function

If an element in the periodic table of elements is atomic number 12, how many protons does it have? How many electrons does it have?

It has 12 protons and it has 12 electrons because it is on the periodic table so it is neutral

deductive reasoning

Making predictions and testing our hypotheses use deductive reasoning, such that our results are objective and unbiased -- important requirements of scientific testing! Deductive reasoning uses what is known as "if...then" logic.

macromolecules

Many molecules that are biologically important are macromolecules, large molecules that are typically formed by combining smaller units called monomers. An example of a macromolecule is deoxyribonucleic acid (DNA), which contains the instructions for the functioning of the organism that contains it.

matter

Matter occupies space and has mass.

microbiology

Microbiology is the study of the structure and function of microorganisms. It is quite a broad branch itself, and depending on the subject of study, there are also microbial physiologists, ecologists, and geneticists, among others.

atomic mass

Most of the weight of an atom is in its nucleus. Protons and neutrons weigh approximately the same amount and contribute significantly to an atom's weight, whereas electrons weigh very little. Thus, an element's atomic mass is approximately equal to the sum of its protons and neutrons.

secondary source

Most people get their scientific information from secondary sources of information, like what you would find in magazines, books, news reports, and advertisements. Much of our information is accessed on our phones, computers, TVs, and radios. Because we are not getting our information from the original, primary source, it important that we look at this secondary information critically.

homeostasis

One final thing to note is that living organisms maintain what is called homeostasis, which means that as their external environment changes, they maintain a roughly constant internal environment. For example, through a series of mechanisms in your body you maintain a roughly constant internal body temperature of 98.6 degrees Fahrenheit (37 degrees Celsius), even if put in an extreme cold or hot environment.

Suppose two atoms form an ionic bond by having one participant donate two electrons to the other participant. What will the charges end up being on the two ions?

One participant would lose two electrons, and thus become more positive. It would have a charge of +2. The other participant would gain two electrons, and thus become more negative. It would have a charge of -2.

Organism

Organisms are individual living entities. For example, each tree in a forest is an organism. Single-celled prokaryotes and single-celled eukaryotes are also considered organisms and are typically referred to as microorganisms.

organs

Organs are collections of tissues grouped together based on a common function. Organs are present not only in animals but also in plants

What are organs composed of? What are cells composed of? What are tissues composed of?

Organs are composed of tissues, Cells are composed of organelles, Tissues are composed of cells

Name two highly electronegative atoms that often create polar covalent bonds. Are the bonds in methane polar covalent or nonpolar covalent? What about the bonds within water molecules?

Oxygen and nitrogen are highly electronegative. The bonds within methane are nonpolar covalent, whereas the bonds in water are polar covalent

electronegative

Oxygen is a highly electronegative atom. This means that it tends to be a "bully" when sharing electrons with other atoms, such as hydrogen (Figure 2B-12). In effect, it "hogs" the electrons such that they tend to spend more time on the oxygen than on the hydrogen. This gives oxygen a slight negative charge and the hydrogen a slight positive charge. The d+ and d- are symbols using the Greek letter "delta"." They indicate partial positive charge on the hydrogen and partial negative charge on the oxygen.Note that these charges are much smaller than the charges created during ionic bonding.

paleontology

Paleontology, another branch of biology, uses fossils to study life's history (see figure 1C-1). Zoology and botany are the study of animals and plants, respectively.

Which of the following statements is an appropriate, testable scientific hypothesis? ◦ Whales are beautiful, majestic animals, whereas sharks are horrible monsters of the deep. Thus, we should protect whales but not sharks. ◦ People who exercise get fewer colds than people who do not exercise at all. ◦ It is unethical to eat meat. Thus, everyone should be a vegetarian. ◦ It is immoral to conduct scientific research on animals.

People who exercise get fewer colds than people who do not exercise at all. THIS ONE

physiologists

Physiologists study the workings of cells, tissues, organs, and organ systems. This is just a small sample of the many fields that biologists can pursue.

What requirements must be met to be considered a living organism?(4 things)

1. Metabolism - Chemical reactions that produce, maintain, and destroy substances, make energy available, and excrete waste. 2. Growth - A gradual increase in size, perhaps to a maximum. 3. Response to the environment or to stimulation - As the environment of the living organism changes, the living organism tries to adapt to survive. If it cannot adapt enough to the change, it may die. The response can also include movement, although it may be difficult to observe movement in some organisms that appear to be stationary, such as plants and barnacles. 4. Reproduction - the living organism can give rise to another, similar form of life. We humans certainly do the 4 things listed above. We metabolize the food that we eat, making energy available to drive our body systems. We also respond to our environment, grow, and reproduce. However, do we need to add to the above list to truly define life? Let's consider fire.

community

A community is the set of populations inhabiting a particular area. For instance, all of the trees, flowers, insects, and other populations in a forest form the forest's community.

double-blind experiment

A double-blind experiment is an even better experimental design. In this case, both the participants and the researcher do not know who is assigned as a treatment versus control. This assures that the researcher will collect objective, unbiased data.

hypothesis

A scientifically valid hypothesis must be testable and falsifiable (in other words, can be shown to be wrong). That means that hypotheses that require the intervention of a supernatural force or that rely on faith cannot be tested scientifically. One thing to note about hypotheses is that scientists tend to prefer simple explanations over more complicated explanations. This is known as Occam's razor, which says that if there are a number of explanations for an observed phenomenon, the simplest explanation is preferred. Scientists do not "prove" hypotheses, or refer to their hypotheses as being "correct," "true," or "fact." Saying that your hypothesis is "correct," a "fact," or "true," or that you have "proven" your hypothesis, gives the impression that you are 100% sure of your results, which is almost never the case in science. The proper, scientific way to refer to hypotheses is to say that they are either supported or rejected based on the evidence that is gathered

What are abiotic factors? Which two levels of organization contain these factors?

Abiotic factors include the non-living components (e.g. air, water, soil, etc.) of an ecosystem. Recall that ecosystems are composed of the living and non-living things found in a particular geographic area. The biosphere is composed of all of the ecosystems, so it also contains abiotic factors.

cell

All living things are made of cells; the cell itself is the smallest fundamental unit of structure and function in living organisms. (This requirement is why viruses are not considered living: they are not made of cells. To make new viruses, they have to invade and hijack a living cell; only then can they obtain the materials they need to reproduce.)

element

All matter is composed of elements, substances that cannot be broken down or transformed chemically into other substances. An element contains only one type of atom

population

All the individuals of a species living within a specific area are collectively called a population. For example, a forest may include many white pine trees. All of these pine trees represent the population of white pine trees in this forest. Different populations may live in the same specific area. For example, the forest with the pine trees includes populations of flowering plants and also insects and microbial populations.

anecdotal evidence

Also, be careful of advice that is based only on someone's personal experience. This sort of information is referred to as anecdotal evidence. Testimonials, as often seen on TV, are anecdotal, and thus are not based on well-designed scientific studies. Anecdotal evidence is only personal opinion, and is often only persuasive because it is being put forward by someone well known, such as a celebrity.

organ system

An organ system is a higher level of organization that consists of functionally related organs. For example vertebrate animals have many organ systems, such as the circulatory system that transports blood throughout the body and to and from the lungs; it includes organs such as the heart and blood vessels.

biosphere

At the highest level of organization, the biosphere is the collection of all ecosystems, and it represents the zones of life on Earth. It includes land, water, and portions of the atmosphere.

In terms of hierarchy of life, put the following in order from smallest to largest: organelle, molecule, organ, cell, population, atom, tissue, organism

Atom, molecule, organelle, cell, tissue, organ, organism, population

Contrast ionic and covalent bonds in terms of which one shares electrons and which one does not share electrons?

Atoms that form covalent bonds share electrons, whereas atoms (ions) with ionic bonds don't share electrons. Instead, electrons are actually donated to a receiving participant when forming an ionic bond.

basic science

Basic science, or "pure" science, seeks to expand knowledge regardless of the short-term application of that knowledge. It is not focused on developing a product or a service of immediate public or commercial value. The immediate goal of basic science is knowledge for knowledge's sake, though this does not mean that in the end it may not result in an application.

bias

Preconceived opinions of both the researcher and the participants in the study can unfairly influence, or bias, the results of the experiment

sample size

Sample size refers to the number of times that we repeat our experiment. If we repeat our experiment with several different tortoises, several different times, we should have a large enough sample size, and will be more likely to be able to remove bias

peer review

Scientists critique other researchers' studies by doing what is called peer review. They provide each other feedback on the results and conclusions of the studies.

monosaccharides

Single units, or monomers, of carbohydrate are referred to as monosaccharides These include the sugars glucose and fructose (Figure 2C-2). Notice that when you view their chemical structures, these monosaccharides have a central "ringed" structure with a lot of oxygens attached to hydrogens (-O-H) by way of polar covalent bonds. We say that monosaccharides are hydrophilic, or "water loving," because of their polar nature.

organelles

Some cells contain aggregates of macromolecules surrounded by membranes; these are called organelles. Organelles are small structures that exist within cells and perform specialized functions

radioisotopes

Some isotopes, such as carbon-14, are unstable and will lose protons, other subatomic particles, or energy to form more stable elements. These are called radioactive isotopes or radioisotopes.

atom

The atom is the smallest and most fundamental unit of matter. It consists of a nucleus surrounded by electrons. Atoms form molecules. Atoms are composed of three different types of subatomic particles: protons, neutrons, and electrons

confidence interval

The confidence interval is the range of values that has a high probability (usually 95%) of containing the true population mean. Thus, the mean has a high probability of falling within the confidence interval.

dependent variable

The dependent variable is what is actually recorded as the results of the experiment. It is the outcome. There can be more than one dependent variable in an experiment. graphed on y-axis

ecosystem

The forest itself is an ecosystem. An ecosystem consists of all the living things in a particular area together with the abiotic, or non-living, parts of that environment such as nitrogen in the soil or rainwater

random assignment

The researcher needs to randomly assign each person as either a treatment or control.

Which of the following are assumptions to which scientists adhere when formulating hypotheses? ◦ They accept that many observations cannot be studied objectively, and therefore must often rely on faith. ◦ Some hypotheses are based on metaphysical or supernatural factors or forces. ◦ The simplest explanation that adequately accounts for all the observations is to be preferred over other, more complex explanations. ◦ Many hypotheses are not testable or falsifiable.

The simplest explanation that adequately accounts for all the observations is to be preferred over other, more complex explanations.

standard error

The standard error is a calculation that we will not explain for this course, but you are welcome to research it online, if you wish. Essentially, it is an approximation of the amount of variation in our data. One thing to note is the amount of standard error is usually related to our sample size. The larger our sample size (the more times that we repeat our experiment), the smaller our standard error, and the smaller our confidence intervals. Smaller confidence intervals mean that we are more likely to find a significant result. This will make more sense when you look at the graphical representation of our data.

scientific theories

The term "theory" is often used incorrectly by non-scientists. In fact, you will see and hear this word being used incorrectly everyday by reporters, newspaper columnists, radio personalities, and many others. In everyday speech, the word theory means "guess" or "untested hypothesis," but to scientists it means a lot more! Only well supported ideas, backed up by evidence from numerous studies conducted by many independent researchers, are called scientific theories. When you hear someone say "it is my theory" what they usually mean to say is "it is my hypothesis." If a hypothesis gains a sufficient amount of scientific evidence, it could be raised to the level of scientific theory

half life

The time it takes for half of the original concentration of an isotope to decay to its more stable form is called its half-life

independent variable

There is usually only one independent variable. It is the variable that can be freely changed, controlled, or manipulated by the researcher. graphed on x-axis

hydrogen bonds

These are very weak bonds that are formed between two atoms with slight charges on them. For example, the oxygen in a water molecule has a slight negative charge and the hydrogens have slight positive charges. This creates a situation where an oxygen from one water molecule can form a weak hydrogen bond with a hydrogen from another water molecule. We will discuss this in more detail in the lesson on properties of water. Ionic and covalent bonds are very strong, whereas hydrogen bonds are very weak.

Why don't noble gases, such as helium, argon, and neon, form bonds with other atoms?

They all have full valence shells. They don't need electrons to fill their outermost electron shell.

periodic table of elements

This periodic table of elements shows the symbols and atomic numbers for 103 different elements. Each element in the periodic table of elements has a symbolNote in the table that elements are grouped into categories, such as noble gases, types of metals, and nonmetals. Periodic tables often show the atomic masses of each of the elements, along with other useful information. The atoms of the elements in the periodic table of elements are in what we call their neutral states. That means that their numbers of positively-charged protons are canceled out by an equal number of negatively-charged electrons. Thus, if we know the atomic number of an element, we not only know how many protons it has, but also how many electrons it has.

treatments

Treatments receive the experimental manipulation

Two additional criteria that biologists use to define life

Two of the most important distinguishing characteristics of living organisms are that they are composed of cells and have the ability to pass on their genes to their offspring (also known as heredity). Fire does not fit either of these two new criteria, and thus is not considered by biologists to be a living organism.

Virus: living or non living?

Viruses are not composed of cells. They are only made up of protein and genetic material. They often invade a host cell in order to gain access to its cellular machinery so that the virus can produce more viruses. Therefore, viruses do not need to have their own cellular structure. By using the host's cell resources, viruses are able to do metabolism, growth, reproduction, heredity, and response to the environment, but because viruses are not composed of cells, they are often considered not to be living organisms.

correlation

When a relationship is found between two variables, we say that there is a correlation between them, or that they are correlated. Note, however, that correlation does not signify causation! It is difficult to demonstrate a cause-and-effect relationship between two factors simply by showing that they are correlated. Just because we see a relationship between two variables, does not necessarily mean that one caused the other. We can only say that there is a correlation between the variables. This is due to the fact that with correlations we are unable to eliminate alternative hypotheses.

polysaccharide

When many monomers are linked together to form a polymer, we now have a polysaccharide. Examples of polysaccharides include starch, cellulose, and glycogen. Starch is a macromolecule produced by plants as a way to store excess glucose produced through the process of photosynthesis, whereas glycogen is way that animals, such as humans, store excess glucose obtained from their food. This glycogen, which can be broken down when we need energy, is stored in our muscles and liver. Cellulose is found in plant cell walls, and is a major component of "fiber." All three of these polysaccharides are just combinations of many glucose molecules in varying arrangements.

disaccharide

When two monosaccharides are linked together, they form what is called a disaccharide (Figure 2C-3). Examples of disaccharides include the sugars lactose (with a glucose attached to a different sugar called galactose) and maltose (with a glucose attached to another glucose). Maltose is an important component in the process of making beer, whereas lactose is the sugar found in milk. Sucrose, which is more commonly referred to as "table sugar," is a third example of a disaccharide. It is formed by linking the monosaccharide glucose with another monosaccharide, fructose. Like glucose, fructose, maltose, and lactose, sucrose has a lot of hydroxyl groups (-O-H), and is thus a polar, hydrophilic molecule. This is why the sugar that you put in your coffee or tea dissolves so easily. In fact, all of these monosaccharides and disaccharides are polar and hydrophilic, and thus readily dissolve in water.

isotopes

Whereas the number of protons in a particular element is always the same, the amount of neutrons can vary. The alternate forms of an element, such as carbon, are known as isotopes. For example, in carbon-12 there are 6 protons and 6 neutrons, in carbon-13 there are 6 protons and 7 neutrons, and in carbon-14 there are 6 protons and 8 neutrons.

What is wrong with the following statement: "Basic science has no real practical use, and therefore should not be funded with public money" (e.g. government grants)?

Without basic science, it is unlikely that applied science would exist. Scientific discoveries in basic, or "pure," science usually precede their applications. A lot of very important scientific discoveries would not have been made if we were only focused on solving problems or creating new things for profit.

Nurses and doctors in hospitals spend a lot of effort trying to keep our bodies in homeostasis. If we get too far out of homeostasis we get sick and perhaps even die, and then of course we are no longer a "living" organism. Thus, homeostasis is an integral part of being a living organism. Suppose you were placed in a hot environment, such as the desert during the summer. What are some ways in which your body tries to cool you off? (see if you can come up with these on your own or do a quick Internet search)

Your body sweats creating an "evaporative cooling" effect and your brain triggers a thirst response to encourage you to drink water.

placebo

a placebo, or ineffective treatment, can be used to fool the control participants. In this case, the placebo would look just like the vitamin C pill, but contain no vitamin C or anything else that might be expected to give the desired response that we are looking for in the experimental group.

atomic number

all atoms of a particular element have the same number of protons, giving the element its atomic number. For example, the element carbon is atomic number 6. That means that carbon always has 6 protons.

applied science

applied science, or "technology," aims to use science to solve real-world problems, making it possible, for example, to improve a crop yield, find a cure for a particular disease, or save animals threatened by a natural disaster. In applied science, the problem is usually defined for the researcher.

mean

average

alternative hypotheses

be alternative hypotheses, which could also explain the observed phenomenon. Just because you find support for your hypothesis, does not mean that there are not other explanations. We must always consider that there may be alternative hypotheses.

A ________ subject is treated as closely as possible to an experimental subject except that he or she does not get the experimental treatment.

control

controls

do not receive the experimental manipulation

electron

have a negative charge Electrons determine the chemical bonding properties of the atom. That is, how the atom will interact and perhaps bond with other atoms.

neutron

have a neutral charge

protons

have a positive charge

inductive reasoning

inductive reasoning involves making generalizations based on past experiences. This type of reasoning, which you use when forming a hypothesis, is somewhat biased and subjective.

What type of reasoning, inductive or deductive, was used to form our hypothesis? What type of reasoning, inductive or deductive, was used to make our prediction and perform our test?

inductive, deductive

molecule

is a chemical structure consisting of at least two atoms held together by a chemical bond

A scientific hypothesis has all the following features, except that: ◦ it is able to be proven true. THIS ONE ◦ it is falsifiable. ◦ it is a possible explanation for something. ◦ it is based on observations.

it is able to be proven true.

model organisms

model organisms are often used in situations in which human subjects cannot. Mammals are the best model organisms because their anatomy and physiology is most similar to humans. Rodents, such as mice, guinea pigs, and rats, are most often used. However, sometimes it is necessary to have an animal, such as a pig or dog, that is closer to the size of a human. Problems with correlations

molecular biology

molecular biology studies biological processes at the molecular level, including interactions among molecules such as DNA, RNA, and proteins, as well as the way they are regulated.

nucleus

nucleus of an atom contains the protons and neutrons, and the electrons orbit around its nucleus. Thus, it is the smallest unit of matter.

Prokaryotes

single-celled organisms that lack organelles surrounded by a membrane and do not have nuclei surrounded by nuclear membranes

cell theory

states that all living things are composed of cells. This theory has very strong evidence.

neurobiology

studies the biology of the nervous system, and although it is considered a branch of biology, it is also recognized as an interdisciplinary field of study known as neuroscience. Because of its interdisciplinary nature, this sub discipline studies different functions of the nervous system using molecular, cellular, developmental, medical, and computational approaches.

What is the smallest unit of life?

the cell

eukaryotes

the cells of eukaryotes do have membrane-bound organelles and nuclei.

sampling error

the effect of chance on our experimental results

hydroxyl groups

the pairs of one oxygen covalently bound to one hydrogen are what are referred to as hydroxyl groups. Molecules that contain a lot of hydroxyl groups are usually polar, and given that water is also polar, and polar dissolves polar, that means that monosaccharides will readily dissolve in water.

blind experiment

the participants are unaware of whether they are receiving the experimental treatment, or are instead in the control group.