Concepts of Biology Final Exam (Exams 1 - 3)

Of the following values, which indicates the most basic pH? a. 10 b. 7 c. 5 d. 8

a. 10 Explanation: - Higher pH is the most basic while lower pH is the most acidic - Objects that are not very acidic are called basic. - The scale has values ranging from zero (the most acidic) to 14 (the most basic). - pure water has a pH value of 7. This value is considered neutral—neither acidic or basic.

Select the correct statement regarding experimental design. a. An experiment can have multiple dependent variables but only one independent variable. b. In a controlled experiment, the dependent variable is manipulated in the treatment group but not in the control group. c. An experiment can have only one independent variable and only one dependent variable. d. In a controlled experiment, the independent variable is measured in both the treatment and control groups.

a. An experiment can have multiple dependent variables but only one independent variable. Explanation: - Experimental Design is a method of research in which a controlled experimental factor is subjected to special treatment for purposes of comparison with a factor kept constant - The independent variable is the cause. Its value is independent of other variables in your study. - The dependent variable is the effect. Its value depends on changes in the independent variable. - Experimental Design is the effect of one variable (independent variable) towards an experimental group and their dependent variables that are a result of the change in the independent variable.

Rick has high blood pressure and decides to try an herbal supplement recommended by his friend. Which of the following questions should Rick ask first to scientifically evaluate his friend's recommendation before he begins taking the herbal supplement? a. Has this herbal supplement been studied in a clinical trial by trained medical professionals? b. If this supplement was studied, who paid for the study? c. If this supplement was studied, how many people were included as patients in the study? d. What are the credentials of the team investigating the supplement?

a. Has this herbal supplement been studied in a clinical trial by trained medical professionals? Explanation: - In this case, the first question he should ask is "Has this herbal supplement been studied in a clinical trial by trained medical professionals?" because knowing if it has been studied in the past and if it was used in a study by trained medical professionals is the most important. When asking questions you should use the CRAAP Method: Currency (The date or timeliness of the information): - How recent is the information? - When was the information published or updated? - Is the information current enough for your topic? - Are the references cited current? - If the information is older, is it relevant to the topic? Relevance (The appropriateness of the information for your needs): - Does the information relate to the topic of interest? - What kind of information is included in the resource? - Who is the intended audience? - Does the work include references to other sources? Authority (The source of the information): - Who is the author, creator or publisher? - What are their credentials? - Who is the sponsor or publisher Who provides the funding? - Are they reputable? - What kind of organization is the sponsor or publisher? (.com, .edu, .gov, .org, .net) Accuracy (The reliability, truthfulness & correctness of the information): - What is the source of the information? - Does the evidence given support the conclusions? - Is all evidence considered? - Are the research methods used correct? - Can the conclusions be tested and are they valid? Is there later work on the topic? Does it support the conclusions? Purpose (Point of View): - What is the purpose of the information? - What is the author's/publisher's interest (if any) in this information? - Is the information presented fact, opinion or propaganda? - Is it objective and impartial or biased?

Which of the following would NOT be a situation where your own scientific literacy would be helpful in decision-making? a. Is the space travel in Star Wars really possible? b. Should I vote to support a new oil pipeline through a sensitive natural area? c. Should I pay to store umbilical cord blood when my baby is born? d. Should I send my child to a school that requires my child be vaccinated according to the vaccination schedule recommended by the Centers for Disease Control?

a. Is the space travel in Star Wars really possible? Explanation: - Scientific literacy is an understanding of the basics of science and the scientific process. - Scientific literacy can't be used when you are determining the solution to something that has no scientific evidence for being true, or when there is no evidence of why something may be possible.

Which of the following statements about cell division is correct? a. It is the process by which organisms reproduce and grow. b. It is no longer necessary once an organism reaches maturity. c. In all cells it occurs in two sequential stages: mitosis and meiosis. d. It is the process by which fertilization occurs.

a. It is the process by which organisms reproduce and grow. Explanation: - Cell division is the process in which the parent cell divides, eventually giving rise to new daughter cells. - It is an essential biological process in many organisms. - It is the means used by multicellular organisms in order to grow, replenish (repair), and reproduce. - In unicellular organisms, a cell division is equivalent to reproduction. - Choice (b) is not correct because cell division still occurs when organisms reach maturity. Adults (mature organisms) use cell division when repairing cells and reproducing. Adults (mature organisms) also change over time as they age so even though an organism may be mature we are still growing/or changing as we age. - Choice (c) is wrong because although cell division occurs in mitosis and meiosis in eukaryotes, it also occurs in prokaryotes in which undergo a type of cell division known as binary fission. - Choice (d) is wrong because the process of fertilization is only one part of meiosis, is also occurs in other parts of meiosis, in mitosis of eukaryotes, and binary fission in prokaryotes.

Scientific understanding can always be challenged, and even changed, with new ways of observing and with different interpretations. For example, new tools and techniques have resulted in new observations and the discovery of additional information. Hence, there is no certainty in science, only degrees of probability (likelihood) and potential for change. In light of this understanding, which of the following statements is most meaningful? a. Scientific knowledge is based on current knowledge. b. Scientific knowledge is absolute knowledge. c. Scientific knowledge is a rigid collection of invariable facts. d. Scientific knowledge is a static and unchanging collection of facts.

a. Scientific knowledge is based on current knowledge. Explanation: - Scientific knowledge is only based on current knowledge because technology is always improving and as technology improves new tools and techniques can be used to discover new observations and additional information.

A component of the immune system's third line of defense is/are a. T cells. b. macrophages. c. mucus. d. platelets.

a. T cells. Explanation: - Choice (a) is the adaptive immune system, which is the immune system's third line of defense against pathogens, that mounts responses against specific invaders via antibodies (antibody-mediated immunity) and phagocytes and other specialized cells (cell-mediated immunity) such as the two types of white blood cells (lymphocytes) known as B lymphocytes (B cells) and T lymphocytes (T cells). B cells are involved in antibody-mediated immune responses (antibody-mediated immunity), whereas T cells are involved in cell-mediated immune responses (cell-mediated immunity). - Choice (b and d) is the innate immune system, which is the immune system's second line of defense against pathogens, that consists of cells and proteins that recognize the presence of an invader and mount an internal defense to kill, disable, or isolate it such as phagocytes that circulate throughout the body, looking for potential threats, like bacteria and viruses, to engulf and destroy, and macrophages ,which are phagocytic cells that can leave the circulatory system by moving across the walls of capillary vessels. Blood clotting (the formation of platelets) is the role of the innate immune system to close a wound by clotting blood to reduce blood loss. - Choice (c) is an external defense, external defenses are the immune system's first line of defense against pathogens, that reduce the likelihood of harmful organisms or viruses gaining access to internal tissues such as the skin, mucus, earwax, nose hair, sweat, saliva, and tears.

During a primary immune response, a. antibodies are immediately made. b. nonspecific immunity may be of great benefit to the organism. c. the immune system has encountered the pathogen previously. d. the production of memory cells is blocked.

a. antibodies are immediately made. Explanation: - The primary immune response is the slow response mounted by the adaptive immune system against an invading pathogen the very first time a person is exposed to that pathogen. - During a primary immune response, antibodies are immediately made, or at least are in the works of being made.

Each T cell and each B cell binds to only one specific type of a. antibody. b. neutrophil c. antigen. d. histamine.

a. antibody. Explanation: - Each T cell and each B cell is programmed to make one specific type of antibody—for instance, one B cell might be responsible for making antibodies that defend against the common cold virus, while another B cell might be responsible for making antibodies that defend against the flue. One T cell might be responsible for stimulating B-cells to make antibodies and help killer cells develop, while another T cell might be responsible for making antibodies that directly kill cells that have already been infected by a foreign invader. - B cells are involved in antibody-mediated immunity, which is a response mounted by the adaptive immune system in which specific invaders are attacked by antibodies that can latch on and destroy invading viruses or bacteria. - T cells are involved in cell-mediated immunity, which is a response mounted by the adaptive immune system in which specific invaders are attacked by phagocytes and other specialized cells that are direct fighters of foreign invaders and also produced cytokines, which are biological substances that help activate other parts of the immune system. One such part is called macrophages. These macrophages act to clean up the invaders and the dead tissue after an immune response.

The enzymes needed to perform photosynthesis in plant cells are closely associated with a. chloroplasts. b. mitochondria. c. smooth ER. d. lysosomes.

a. chloroplasts. Explanation: - Choices (b, c, and d) are found in both plant and animal cells. - Photosynthesis only occurs in plant cells. - Chloroplast are a structure within the cells of plants and green algae that is the site of photosynthesis, the process by which light energy is converted to chemical energy, resulting in the production of oxygen and energy-rich organic compounds.

An acid is a polar substance that dissolves in water and a. donates hydrogen ions to the solution. b. leaves behind an OH- ion. c. becomes nonpolar. d. accepts hydrogen ions from the solution.

a. donates hydrogen ions to the solution. Explanation: - An acid is a chemical species that donates protons or hydrogen ions and/or accepts electrons. - The higher the concentration of hydrogen ions produced by an acid, the higher its acidity and the lower the pH of the solution.

Although it seems contradictory, real science does not intend to "prove" a hypothesis to be true. This is because a. future experiments or discoveries may provide data that refute the hypothesis. b. the scientific method is limited to examination of the natural world. c. science is a human endeavor, and like all human endeavors, it is limited by human understanding. d. all true hypotheses will be rejected by the scientific method because they can be proven false.

a. future experiments or discoveries may provide data that refute the hypothesis. Explanation: - As technology improves there is a possibility that past hypotheses can be proven wrong or past hypotheses can be improved.

Memory cells a. include B cells and T cells that remain in the body for long periods of time after the first exposure to a pathogen. b. are macrophages that store copies of antibodies for decades. c. are T cells that continue to target and remove cells long after the primary response has ended. d. are removed from the body once the primary response is no longer needed.

a. include B cells and T cells that remain in the body for long periods of time after the first exposure to a pathogen. Explanation: - Memory cells are long-lived immune cells capable of recognizing foreign particles they were previously exposed to (thus, the memory in their name). These immune cells do not respond immediately when it first encounters an antigen but facilitates a more rapid secondary response when the antigen is encountered on a subsequent occasion. - Examples of memory cells are memory B cells and memory T cells. Memory B cells are clones of a parent B cell that previously served as an antigen-presenting cell and then activated by a helper T cell to proliferate. As clones, the memory B cells bear the same B cell receptors as those of the parent B cell. Therefore, they would be able to detect the same antigen when re-exposed. Memory B cells produce more robust antibody-mediated immune response during re-infection. - Memory T cells are T lymphocytes that have the similar capability of recognizing foreign particles that they previously encountered. But unlike memory B cells, the memory T cells do not produce antibodies. Re-exposure to the pathogens causes them to clone themselves immediately and as such respond to the infection more strongly.

Chromosomes are lined up at the middle of the cell during the __________ portion of cell division. a. metaphase b. interphase c. anaphase d. telophase

a. metaphase Explanation: - During metaphase chromosomes line up along the equator (in the middle) and are attached to the spindle fibers. - Metaphase stands for "middle."

Announcing "scientific" findings in a press conference before they have been published in an established scientific journal is an example of a. neither primary nor secondary literature because it has not yet undergone peer review to be primary literature, and secondary literature follows primary literature. b. primary literature. c. both primary and secondary literature because it does not need to undergo peer review to be either primary or secondary literature. d. secondary literature.

a. neither primary nor secondary literature because it has not yet undergone peer review to be primary literature, and secondary literature follows primary literature. Explanation: - Peer-reviewed publication is the publishing of original research only after it has passed the scrutiny of experts who have no direct involvement in the research under review, or a scientific journal that follows this standard. - Primary literature is scientific literature in which research is first published - Secondary literature is scientific literature that summarizes and synthesizes an area of research. - Primary and secondary literature can only be published after being peer-reviewed.

The genetic material found in all living things is made of building blocks called a. nucleotides. b. monosaccharides. c. steroids d. phospholipids

a. nucleotides. Explanation: - Nucleotides are the fundamental building blocks of nucleic acid; an organic compound made up of a nitrogenous base, a sugar, and a phosphate group.

Activated B cells are responsible for a. producing antibodies that bind to pathogens. b. generating pathogens. c. increasing systemic body temperature. d. sealing breaks in the skin via clotting reactions.

a. producing antibodies that bind to pathogens. Explanation: - B cells are involved in antibody-mediated immunity, which is a response mounted by the adaptive immune system in which specific invaders are attacked by antibodies that can latch on and destroy invading viruses or bacteria (pathogens). - Activated B cells are nowadays considered to act as important antigen-presenting cells for the activation of T cells and as essential source of pro-inflammatory cytokines.

The process of cell division is different for prokaryotic versus eukaryotic cells because a. prokaryotes have a single circular chromosome. b. prokaryotic cells have multiple linear chromosomes. c. prokaryotic cells are larger than eukaryotic cells. d. prokaryotic DNA resides within a nucleus.

a. prokaryotes have a single circular chromosome. Explanation: - Cell division is simpler in prokaryotes than eukaryotes because prokaryotic cells themselves are simpler. - Prokaryotic cells have a single circular chromosome, no nucleus, and few other cell structures. - Eukaryotic cells, in contrast, have multiple chromosomes contained within a nucleus, and many other organelles.

Glycolysis is an anaerobic process, indicating that the glycolytic reactions a. require no oxygen. b. produce molecular oxygen. c. produce ATP. d. produce citric acid.

a. require no oxygen. Explanation: - Anaerobic means "no oxygen required," and aerobic means "oxygen required."

If a bottle of perfume were spilled in the corner of a large lecture hall, the students sitting near that corner of the room would very quickly smell the perfume. Over time, the students sitting in the far corner of the room would smell the perfume. What phenomenon will have occurred to the perfume molecules that have entered the air? a. simple diffusion b. active transport c. osmosis d. facilitated diffusion

a. simple diffusion Explanation: - Simple Diffusion is a form of diffusion that does not require the assistance of membrane proteins. In essence, the particle or substance moves from higher to lower concentration. However, its movement does not need a membrane protein that will help substances to move downhill. If the perfume is sprayed in one corner of a room, it will be smelt soon after in the opposite corner. Since the perfume molecules are in constant random motion they bump into each other causing some molecules to be occasionally sent hurtling out of the mass. Gradually, the molecules spread out. - Active transport is the process by which materials move from a lower concentration to a higher concentration. In this example materials are moving from an area of high concentration to low concentration. - Osmosis is the diffusion of water molecules. This means that osmosis is a very selective term because it applies only the the movement of water molecules through semi-permeable barriers such as the cell membrane. - Facilitated diffusion is the passive movement of molecules across the cell membrane via the aid of a membrane protein. It is utilized by molecules that are unable to freely cross the phospholipid bilayer (e.g. large, polar molecules and ions). A real life example of facilitated diffusion is the transport of oxygen in the blood and muscles. In blood, hemoglobin is the carrier protein whereas in muscles, the carrier protein in the myoglobin. The diffusion of blood occurs as a result of higher pressure on one side of the membrane and a lower one on the other side.

Which of the following are composed of the same monomers? a. starch and cellulose b. cholesterol and sucrose c. proteins and DNA d. RNA and cellulose

a. starch and cellulose Explanation: - (a) Starch is an example of the monomer, monosaccharides, from Carbohydrates, and cellulose is also an example of the monomer, monosaccharides, from Carbohydrates. - (b) Cholesterol is an example of the monomer, Fatty acid and glycerol, from Lipids, while sucrose is an example of the monomer, monosaccharides, from Carbohydrates. - (c) Amino acids are the monomer of protein, while DNA is an example of the monomer, nucleotides, from Nucleic Acids. - (d) RNA is an example of the monomer, nucleotides, from Nucleic Acids, while cellulose is an example of the monomer, monosaccharides, from Carbohydrates.

Photosynthetic organisms capture energy from sunlight and convert it into chemical bonds by forming a. sugars b. enzymes c. work d. substrates.

a. sugars Explanation: - Photosynthetic organisms capture energy from sunlight and convert it into energy (sugars).

Which of the following prevents both blood loss and the invasion of pathogens in vertebrates? a. the formation of blood clots b. humoral immunity c. phagocytosis d. cell-mediated immunity

a. the formation of blood clots Explanation: - Blood clotting (which forms platelets) is the role of the innate immune system to close a wound by clotting blood to reduce blood loss.

Some antibiotics used to treat bacterial infections kill the bacteria by chemically punching holes in the cell wall of the bacteria, by preventing the bacteria from replicating their DNA, or by many other actions that ultimately cause cell death. Why do these antibiotics not work to kill viruses and cure people of viral infections? a. Viruses are too quick for the antibiotics to work. b. Antibiotics cannot kill a virus because viruses are not living cells with cell walls to puncture, nor do they have the structures necessary for autonomous reproduction. c. Viruses are too virulent to be killed by those antibiotics. d. Viruses mutate at a rate faster than the rate at which antibiotics can kill them.

b. Antibiotics cannot kill a virus because viruses are not living cells with cell walls to puncture, nor do they have the structures necessary for autonomous reproduction. Explanation: - Viruses are different to bacteria; they have a different structure and a different way of surviving. - Viruses don't have cell walls that can be attacked by antibiotics; instead they are surrounded by a protective protein coat.

A scientist notices that a population of birds has decreased dramatically within one year and suspects that a newly introduced snail population may be affecting the bird population. Some individuals within the bird population eat snails primarily, while other individuals avoid eating snails. Which of the following statements represents a prediction based on a well-constructed hypothesis/prediction for this observation? a. If snails that are sick leave their shells, which allows birds to consume them, then snail populations will be protected from illness. b. If the birds are affected by eating snails, then there will be a difference in the survival rate of birds that eat snails and those that avoid snails. c. If birds consume snails, then they will have a higher body mass index than birds that do not eat snails. d. If snails live in moist habitats, then snails will be eaten more frequently by birds.

b. If the birds are affected by eating snails, then there will be a difference in the survival rate of birds that eat snails and those that avoid snails. Explanation: - Predictions are specific statements that can be directly and unequivocally tested in an experiment. - Predictions are often in the form of an "if/then" statement. - (a) is wrong because the observation wasn't based on what happened to snails, it was based on what happened to birds. - (c) is wrong because it has nothing to do with birds and a higher body mass index, it has to do with the decreased population of birds. - (d) is wrong because it has nothing to do with why snails are being eaten but why the bird population is decreasing.

Which of the following molecules carries electrons to the electron transport chain of oxidative phosphorylation? a. ATP b. NADH c. CO2 d. ADP

b. NADH

When Lori was diagnosed with breast cancer, the doctor recommended a lumpectomy followed by radiation therapy. Lori underwent the prescribed treatment recommended by the doctor. However, she also continued to eat lots of fruits and vegetables, walk three miles every day, and practice daily yoga. Within about three months, Lori was cancer-free. Afterward, Lori told everyone that her healthy lifestyle had helped to cure her. Is this conclusion reasonable given the circumstances? a. Yes, this evidence very strongly supports the hypothesis that a healthy diet and exercise regimen probably helped to cure her. b. No, there are too many confounding factors to know exactly what happened. c. Yes, the healthy diet and exercise regimen definitely helped to cure her. d. No, a healthy diet and exercise regimen can never help cure cancer.

b. No, there are too many confounding factors to know exactly what happened. Explanation: - Lori underwent the prescribed treatment recommended by the doctor, she also continued to eat lots of fruits and vegetables, walk three miles every day, and practice daily yoga. - There are too many factors to point out the reason why she might be cancer free now.

Which of the following statements accurately distinguishes tissues from organs? a. Each organ performs multiple functions, whereas a designated tissue performs only one function. b. Organs consist of multiple tissue types, whereas tissues consist of one or more cell types. c. Organs are limited to one location in the human body, whereas most tissues move throughout the body. d. Organs consist of cells, whereas tissues do not.

b. Organs consist of multiple tissue types, whereas tissues consist of one or more cell types. Explanation: - Tissues are groups of similar cells that have a common function. - An organ is a structure that is composed of at least two or more tissue types and performs a specific set of functions for the body.

Which of the following would NOT be a reason for a peer-reviewed paper to be retracted by its publisher untrue or inaccurate? a. The author has made a clear error in the scientific process. b. Other researchers have published work that appears to contradict the paper in question. c. It has been discovered that the author violated ethical guidelines or was involved in other scientific misconduct. d. It has been shown that the author plagiarized someone else's work.

b. Other researchers have published work that appears to contradict the paper in question. Explanation: The point of Peer Review is to compare results of other similar studies. Other studies could be wrong so it is not probable to retract a peer-reviewed paper. - If there is an error it should be retracted. - If it is violating ethical guidelines and there is scientific misconduct it should be retracted. - If the author plagiarized it should be retracted.

Based on the scientific evidence presented in more than 100 peer-reviewed, published research articles that evaluated millions of children, which of the following is NOT the reason for the observed increase of autism in the United States and other countries since the 1970s? a. People are generally more willing to label a broader range of conditions within the spectrum of autism disorders. b. The MMR vaccine is being more broadly administered, so more children are getting autism. c. More schools are screening more students for autism. d. There is a heightened awareness of autism in society.

b. The MMR vaccine is being more broadly administered, so more children are getting autism. Explanation: - More children getting autism because of the MMR vaccine being more broadly administered is not a reason because it is a claim that has no data representing the correlation between the MMR vaccine and autism. - People being generally more willing to label a broader range of conditions within the spectrum of autism disorders, more schools screening more students for autism, and a heightened awareness of autism in society are hypotheses that can be testable and falsifiable.

The primary role of the immune system's first line of defense is to a. mark pathogens for destruction. b. act as a barrier to prevent the entry of pathogens. c. kill intracellular pathogens. d. stimulate fever and inflammation.

b. act as a barrier to prevent the entry of pathogens. Explanation: - Choice (b) are external defenses, which is the immune system's first line of defense against pathogens, that reduce the likelihood of harmful organisms or viruses gaining access to internal tissues such as the skin, mucus, earwax, nose hair, sweat, saliva, and tears. - Choice (a and c) is the innate immune system, which is the immune system's second line of defense against pathogens, that consists of cells and proteins that recognize the presence of an invader and mount an internal defense to kill, disable, or isolate it. - Choice (d) is the adaptive immune system, which is the immune system's third line of defense against pathogens, that mounts responses against specific invaders via antibodies (antibody-mediated immunity) and phagocytes and other specialized cells (cell-mediated immunity).

After receiving a vaccine, a person begins to produce antibodies. This demonstrates a(n) __________ immune response. a. innate b. active c. secondary d. passive

b. active Explanation: - The Innate Immune Response is the immune system's second line of defense against pathogens, consisting of cells and proteins that recognize the presence of an invader and mount an internal defense to kill, disable, or isolate it. - Active Immunity results when exposure to a disease organism triggers the immune system to produce antibodies to that disease. Active immunity can be acquired through natural immunity, which is acquired from exposure to the disease organism through infection with the actual disease, or vaccine-induced immunity, which is acquired through the introduction of a killed or weakened form of the disease organism through vaccination. - Secondary Immune Response is the rapid response mounted by the adaptive immune system against an invading pathogen the second and subsequent times a person is exposed to that pathogen. - Passive immunity is provided when a person is given antibodies to a disease rather than producing them through his or her own immune system, such as when a newborn baby acquires passive immunity from its mother through the placenta, and when people get passive immunity through antibody-containing blood products such as immune globulin, which may be given when immediate protection from a specific disease is needed. - It is the active immune response and not the passive immune response because although the vaccine is from an outside source, the antibodies produced were made by the body itself.

Select the smallest and most basic unit of life. a. genome b. cell c. nucleotide d. DNA

b. cell Explanation: - The levels, from smallest to largest, are: molecule, cell, tissue, organ, organ system, organism, population, community, ecosystem, biosphere - The cell is the smallest and most basic unit of life. - The single-celled or unicellular amoeba performs all the functions of life that are essential for its survival. - Humans are multicellular organisms that have many different types of cells to perform different functions.

In genetic engineering, molecular biologists often combine segments of DNA from two separate organisms. This is an example of genetic recombination that occurs in a laboratory setting. Which of the following is a form of genetic recombination that occurs naturally within cells? a. mitosis b. crossing-over c. independent assortment d. asexual reproduction

b. crossing-over

The subatomic particles that possess a single negative charge and surround the nucleus are the a. neutrons. b. electrons. c. isotopes. d. protons.

b. electrons. Explanation: - A proton is a subatomic particle that has a positive charge and that is found in the nucleus of an atom - For Neutrons the particles of the nucleus that have no charge - Isotopes of an element are atoms with the same number of protons, but a different number of neutrons. Each proton has a charge of +1, each electron a charge of -1, the neutrons have no charge (neutral charge--neutron).

When ATP breaks down into ADP and a phosphate group, a. energy is absorbed by ADP and transferred to enzymes. b. energy is released and can power cellular activities. c. ADP becomes the active site in an enzyme. d. the energy in the broken bond is transferred to the phosphate group.

b. energy is released and can power cellular activities.

Which of the following is associated with mitosis? a. sexual reproduction b. equal distribution of chromosomes c. prokaryotic cells d. binary fission

b. equal distribution of chromosomes Explanation: - Choice (a) is wrong because sexual reproduction is associated with meiosis, while mitosis and binary fission is associated with asexual reproduction. - Choice (c) is wrong because prokaryotic cells use binary fission. - Choice (d) is wrong because binary fission is associated with prokaryotes, while mitosis occurs in eukaryotes.

Recently, beekeepers have noticed an alarming and sudden disappearance of honeybees from their hives. Some beekeepers and environmentalists worry that crops genetically engineered to produce Bt insecticidal toxin may be killing the bees. Select the controlled experiment that tests the hypothesis that Bt toxin is killing the bees. a. collecting hundreds of bees and spraying half of them with Bt toxin and the other half with DDT, another insecticide; the survival rate for both sets of bees would be calculated and compared b. exposing 100 bees to plants that make the protein for Bt toxin, while another 100 bees of the same species are exposed to normal plants; the survival rate for both sets of bees would be calculated and compared c. introducing two different species of bees to a field that was sprayed with the Bt toxin; the number of dead bees from each species would be calculated and compared d. spraying Bt toxin on a field and counting the number of bees present after spraying

b. exposing 100 bees to plants that make the protein for Bt toxin, while another 100 bees of the same species are exposed to normal plants; the survival rate for both sets of bees would be calculated and compared Explanation: - A controlled experiment is an experiment in which all the variable factors in an experimental group and a comparison control group are kept the same except for one variable factor in the experimental group that is changed or altered

The three stages of cellular respiration (in order) are a. photosynthesis, glycolysis, and oxidative phosphorylation. b. glycolysis, the Krebs cycle, and oxidative phosphorylation. c. glycolysis, fermentation, and the Krebs cycle. d. photosynthesis, the Krebs cycle, and fermentation.

b. glycolysis, the Krebs cycle, and oxidative phosphorylation. Explanation: - The 3 stages in order are: glycolysis, Krebs Cycle, and oxidative phosphorylation (electron transport chain).

A patient often experiences numbness and pain in the thumb and first two fingers on his right hand. He goes to his doctor, who suspects that carpal tunnel syndrome is the reason for the numbness and pain. The doctor then orders a simple test to see how fast nerve impulses move up and down the patient's arm. The doctor's preliminary diagnosis of carpal tunnel syndrome is a(n) a. fact. b. hypothesis c. experiment. d. theory

b. hypothesis Explanation: - After an observation (which is what the patient and doctor first made), the researcher should make a clearly testable and falsifiable hypothesis. - The doctor's preliminary diagnosis of carpal tunnel syndrome is a hypothesis because he hasn't formed any predictions and experiments, and hasn't made a conclusion from any experiments yet. - Making a prediction, forming an experiment, and conducting an experiment should come after developing a hypothesis.

A scientist has assembled 1.0 gram of protein, lipid, carbohydrate, and nucleic acids in separate tubes. They add each of these samples to a calorimeter, a device that determines the amount of energy present in the sample. Based on the role of these molecules in the body, predict which test tube will produce the most energy. a. proteins b. lipids c. carbohydrates d. nucleic acids

b. lipids Explanation: - Lipids are a concentrated source of energy and provide almost twice the amount of energy than that supplied by proteins and carbohydrates.

Which two processes combine to create genetic diversity and maintain chromosome number? a. mitosis and meiosis b. meiosis and independent assortment c. binary fission and mitosis d. fertilization and meiosis

b. meiosis and independent assortment Explanation: - Choice (a) is wrong because mitosis creates identical cells (clones) and doesn't have independent assortment or genetic crossing. - Choice (c) is wrong because binary fission creates identical cells (clones) as well as mitosis. - Choice (d) is wrong because fertilization induces the transition from metaphase II to anaphase II in meiosis. - Independent assortment and crossing over creates genetic diversity, and meiosis maintains chromosome number.

Scientists analyzed 62 studies and determined that a strong physician recommendation for the HPV vaccine was a positive determining factor in whether or not parents chose to vaccinate their children. This analysis of various studies is referred to as a. secondary study. b. meta-analysis. c. secondary analysis. d. beta-analysis

b. meta-analysis. Explanation: - A meta-analysis is work that combines results from different studies. - When scientists analyzed 62 studies they combined the results of different studies and made a conclusion.

Human muscle cells need large amounts of ATP to function in the movement of the body, which is why __________ are especially abundant in muscle cells. a. Ribosomes b. mitochondria c. vacuoles d. lysosomes

b. mitochondria Explanation: - To meet this energy demand, muscle cells contain mitochondria. These organelles, commonly referred to as the cell's "power plants," convert nutrients into the molecule ATP, which stores energy. - Mitochondria are responsible for creating more than 90% of the energy needed to sustain life and support organ function. - Heart muscle cells contain about 5,000 mitochondria per cell.

During meiosis I, the chromosome number is reduced to haploid by separating a. each sister chromatid into two different daughter cells. b. one of each homologous chromosome pair into two different daughter cells. c. each sister chromatid into four different daughter cells. d. one of each homologous chromosome pair into four different daughter cells.

b. one of each homologous chromosome pair into two different daughter cells. Explanation: - Choice (a) is wrong because homologous pairs are separated not each sister chromatid. - Choice (c) is wrong because homologous pairs are separated not each sister chromatid. - Choice (d) is wrong because it describes meiosis II.

Which of the following is a product of the light-dependent reactions of photosynthesis? a. water b. oxygen c. carbon dioxide d. glucose

b. oxygen Explanation: - The goal of the light-dependent reactions of photosynthesis is to collect energy from the sun and break down water molecules to produce ATP and NADPH. - Each water molecule breaks down into two hydrogen (H) atoms and one oxygen (O) atom. The oxygen is released as a waste product—oxygen atoms from disassembled water molecules join up in pairs to form oxygen gas (O2).

Ribosomes are very small non-membranous structures that can either exist freely in the cytoplasm or be embedded in the rough endoplasmic reticulum of a cell. They are associated with the synthesis of a. lipids. b. proteins c. carbohydrates. d. nucleic acids.

b. proteins Explanation: A ribosome is a minute, sphere-shaped particle composed of protein and ribonucleic acid (RNA) that serves as the site of protein synthesis.

In photosynthesis, the carbon used to make sugars is a. provided by enzymes. b. provided by carbon dioxide. c. extracted from DNA. d. oxidized to make sugars.

b. provided by carbon dioxide. Explanation: - The process of photosynthesis is often described as turning sunlight into sugars, and while that's broadly true, there are two distinct biochemical reactions taking place. - The first uses the sunlight to create energy inside the cell and the second takes carbon dioxide and uses it to make sugars.

As shown in the following figure, the highest concentration of free hydrogen ions is found in a. household ammonia. b. stomach acid. c. human blood d. lemons

b. stomach acid. Explanation: - The scale has values ranging from zero (the most acidic, highest concentration of free hydrogen ions) to 14 (the most basic, the lowest concentration of free hydrogen ions). - In the graph, stomach acid was at 1.5 - 2.0, which was the lowest number (the most acidic, highest concentration of free hydrogen ions), compared to household ammonia, human blood, and lemons.

A group of researchers conducted an experiment and collected the data that is presented in the following graph. The hypothesis that the fungus is sufficient to cause death is __________ by the data because all members of the control group __________ while most of the members of both treatment groups __________ by the end of the study. a. not supported; died; survived b. supported; survived; died c. proven; survived; died d. proven beyond a doubt; survived; died

b. supported; survived; died Explanation: - The hypothesis is supported because 18 bats were injected with the North American fungus and most died and 18 bats were injected with a closely related fungus and most died, - The control group survived because 18 bats that didn't receive the fungus had none that died - Both treatment groups died

Each time a person takes a breath, they are bringing in the oxygen needed to stay alive. The ultimate source of the oxygen used by all aerobic organisms comes from a reaction that breaks down a. carbon dioxide b. water c. ATP. d. NADPH.

b. water Explanation: - The process of photosynthesis breaks down water to form oxygen for humans to breath.

If a giraffe skin cell has a total of 18 chromosomes, how many chromosomes would be present in each of its gametes? a. 36 b. 18 c. 9 d. 6

c. 9 Explanation: - Each gametes produced such as egg and sperm contain half the number of chromosomes compared to the total number of chromosomes in the body.

Which of the following statements comparing photosynthesis and cellular respiration is accurate? a. Photosynthesis is a catabolic pathway, whereas cellular respiration is an anabolic pathway. b. Water is formed during photosynthesis but broken apart during cellular respiration. c. Both photosynthesis and cellular respiration require electron transport chains. d. Both photosynthesis and cellular respiration produce CO2 as metabolic end products.

c. Both photosynthesis and cellular respiration require electron transport chains. Explanation: - Choice (a) is wrong because photosynthesis is anabolic, and cellular respiration is catabolic. - Choice (b) is wrong because water isn't formed during photosynthesis, water is given to start photosynthesis, and during cellular respiration, a glucose molecule is gradually broken down into carbon dioxide and water. - Choice (b) is wrong because only cellular respiration forms CO2, photosynthesis uses CO2 from humans.

Which of the following is a part of accepted cell theory? a. All living cells arise from preexisting cells, and all living cells have membrane-enclosed organelles. b. Every living organism is composed of one or more cells, and all living cells have membrane-enclosed organelles. c. Every living organism is composed of one or more cells, and all living cells arise from preexisting cells. d. All living cells have membrane-enclosed organelles.

c. Every living organism is composed of one or more cells, and all living cells arise from preexisting cells. Explanation: - Cell Theory is the idea that all living things are composed of cells (one or more cells), cells are the basic units of structure and function in living things, and new cells are produced from existing cells (preexisting cells).

If crossing-over does not occur and homologous chromosome pairs are not independently assorted during meiosis I, resulting in all maternal chromosomes being sorted to one cell while all paternal chromosomes are sorted to another cell, what would be the genetic results in the gametes produced at the end of meiosis II? a. Twenty-five percent of the gametes would contain only maternal DNA and 75 percent of the gametes would contain only paternal DNA. b. Seventy-five percent of the gametes would contain only maternal DNA and 25 percent of the gametes would contain only paternal DNA. c. Fifty percent of the gametes would contain only maternal DNA and 50 percent of the gametes would contain only paternal DNA. d. All gametes would contain equal amounts of maternal and paternal DNA.

c. Fifty percent of the gametes would contain only maternal DNA and 50 percent of the gametes would contain only paternal DNA. Explanation: Crossing over and independent assortment creates 50% of maternal chromosomes and 50% of paternal chromosomes in each gamete. - Each gamete has half the number of chromosomes from each parent. It doesn't have all the paternal chromosomes in one gamete and all the maternal chromosomes in the other gamete.

Homeostatic pathways are a sequence of steps that reestablish the "normal state" of a living organism's internal environment. What determines the parameters of this "normal state"? a. Actually, most living systems do not regulate temperature or water content, so these features typically fluctuate a great deal. b. Living systems monitor positive feedback mechanisms and shut off negative feedback loops to regulate these processes. c. Organisms have a genetically predetermined set point that must be internally maintained. d. Living systems depend on signals from the environment to regulate these conditions.

c. Organisms have a genetically predetermined set point that must be internally maintained. Explanation: - Set point theory states that our bodies have a preset baseline (a genetically predetermined set point) hardwired into our DNA. - Homeostasis is the tendency of biological systems to maintain relatively constant conditions in the internal environment while continuously interacting with and adjusting to changes originating within or outside the system. - The maintenance of homeostasis in the body typically occurs through the use of feedback loops that control the body's internal conditions.

Why is it important that white blood cells are able to travel outside the human circulatory system? a. To form a complement, white blood cells must leave the circulatory vessels. b. White blood cells are the antibodies that target parasites. c. Pathogens may be found in other areas of the body besides the circulatory vessels. d. White blood cells must leave the circulatory system in order to return red blood cells to the circulatory vessels.

c. Pathogens may be found in other areas of the body besides the circulatory vessels. Explanation: -Macrophages, a type of white blood cell, are efficient phagocytic cells that can leave the circulatory system by moving across the walls of capillary vessels. - The ability to roam outside of the circulatory system is important, because it allows macrophages to hunt pathogens with less limits.

Which of the following observations would naturally lead to a hypothesis that increased studying improves student performance on assessments? a. Students who frequently finish tests quickly tend to earn better grades. b. Students working in groups demonstrate a mastery of concepts more consistently than students working independently. c. Students who appear to spend more time engaging with course materials have the highest exam scores. d. Students who retake exams typically improve their test scores.

c. Students who appear to spend more time engaging with course materials have the highest exam scores. Explanation: - Choice (a) is wrong because the hypothesis has to do with increased studying not finishing tests quickly. - Choice (b) is wrong because the hypothesis has to do with increased studying not working in groups. - Choice (d) is wrong because the hypothesis has to do with increased studying not retaking exams.

A study of the effect of neckties on blood circulation randomly divides a group of 1,000 male executives into two groups. For one week, half the participants wear ties at work while the other half do not. The researchers hypothesized that the sustained pressure of the necktie could lead to a detectable reduction in blood circulation to the brain. Using MRI scans, they found a 10 percent decrease in blood flow to the brain, on average, in the tie-wearing group. No decrease in blood flow was observed in the group without ties. Select the appropriate conclusion for these findings. a. Employers should discourage neckties at work for the safety of their employees. b. The experiment shows a correlation but does not establish a cause-and-effect relationship between neckties and blood circulation. c. The data support the hypothesis that wearing a necktie reduces blood circulation to the brain. d. Dizziness and headaches in male executives at work are caused by wearing neckties.

c. The data support the hypothesis that wearing a necktie reduces blood circulation to the brain. Explanation: - The hypothesis was that neck ties decrease blood circulation. - Using the statement that shows the results of experiment, "Using MRI scans, they found a 10 percent decrease in blood flow to the brain, on average, in the tie-wearing group. No decrease in blood flow was observed in the group without ties," it is shown that the hypothesis can be supported.

Which of the following statements is true of chloroplasts? a. They give an animal cell its shape. b. They contain an entire copy of a cell's genetic material. c. They capture energy from sunlight. d. They produce proteins used by other parts of the cell.

c. They capture energy from sunlight. Explanation: - Chloroplasts are plant cell organelles that convert light energy into relatively stable chemical energy via the photosynthetic process. - Chloroplasts are plant cell organelles that convert light energy into relatively stable chemical energy via the photosynthetic process.

The roots of a sunflower plant growing downward while the shoot grows upward and the flower turns toward the sun are examples of what characteristic of all living organisms? a. They make their own energy. b. They evolve through time. c. They sense the environment and respond to it. d. They reproduce using DNA.

c. They sense the environment and respond to it. Explanation: - Anything that causes a living organism to react is called a Stimulus (plural is stimuli). - Living organisms have some senses (sight, smell, touch, taste, etc.) that can help them to detect changes in their external environment, as well as their internal balance and respond to them.

The processes of mitosis, meiosis, and binary fission all a. generate offspring cells through asexual reproduction. b. occur in both eukaryotic and prokaryotic cells. c. are used to produce daughter cells. d. generate clones.

c. are used to produce daughter cells. Explanation: - Choice (a) is wrong because although binary fission and mitosis are types of asexual reproduction in which the parent cell divides to form two identical daughter cells, meiosis is a type of sexual reproduction. - Choice (b) is wrong because mitosis and meiosis only occur in eukaryotic cells while binary fission occurs only in prokaryotic cells. - Choice (d) is wrong because only mitosis and binary fission generate clones, while meiosis generates gametes that are not clones of the original cell, because each gamete has exactly half as many chromosomes as the original cell.

The reaction sugar + oxygen > carbon dioxide + water + ATP is part of a. photosynthesis b. the Krebs cycle c. cellular respiration. d. the Calvin cycle.

c. cellular respiration. Explanation: The formula for cellular respiration is: sugar + oxygen -> carbon dioxide + water + ATP

Some daughter cells are described as clones. For this description to be appropriate, the daughter cells must a. result from sexual reproduction. b. belong to a multicellular organism. c. contain a set of DNA that is identical to that of the parent cell. d. have been produced by meiotic cell division.

c. contain a set of DNA that is identical to that of the parent cell. Explanation: - Choice (a) is wrong because sexual reproduction is associated with meiosis, and in meiosis gametes that are not clones of the original cell, because each gamete has exactly half as many chromosomes as the original cell. - Choice (b) is wrong because although multicellular organisms use mitosis, which generates clones, multicellular organisms also use meiosis, which doesn't generate clones. - Choice (d) is wrong because meiotic cell division doesn't generate clones, each gamete produced by meiosis has exactly half as many chromosomes as the original cell.

The graph below shows that after the childhood vaccination program was initiated in the United Kingdom in 1999, the annual number of meningitis cases in children a. decreased to zero by 2000, as did the meningitis rate for adults. b. did not decrease or increase; there was also no change in the meningitis rate for adults. c. decreased to nearly zero by 2004, as did the meningitis rate for adults. d. increased to over 700 in 1999 before slowly decreasing in 2000, as did the meningitis rate for adults.

c. decreased to nearly zero by 2004, as did the meningitis rate for adults. Explanation: - In the graph, you can tell that the line for children with meningitis is horizontal, as well as the line for adults, which means it is zero.

Living organisms maintain a constant internal environment by sensing and responding to their internal conditions. This stable maintenance of internal conditions is known as a. evolution. b. sensation. c. homeostasis d. reproduction.

c. homeostasis Explanation: - Homeostasis is the state of steady internal, physical, and chemical conditions maintained by living systems. - This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits.

Individual water molecules orient toward each other because of the __________ bonds that form between them. a. peptide b. ionic c. hydrogen d. covalent

c. hydrogen Explanation: - The oxygen-hydrogen (O-H) bonds in water make it a polar molecule. - This polarity makes water molecules attracted to each other. - Hydrogen bonds are the weak electrical attraction between a hydrogen atom with a partial positive charge and a neighboring atom with a partial negative charge.

The figure below, based on data collected by The National Institute of Allergy and Infectious Diseases, graphically illustrates that as a. individuals in a community become ill, increasingly more individuals either become ill or think they are becoming ill as they find out about the illness from friends, family, and the media. b. a population of individuals is infected with a particular pathogen, more and more people will become infected. This is beneficial because everyone will always survive, and their offspring will be immune to any future infections. c. increasingly more individuals in a community are vaccinated against a particular pathogen, future outbreaks of the disease are limited to fewer individuals because fewer people will become infected and then pass it on. d. increasingly more individuals in a community are vaccinated against a particular pathogen, future outbreaks of the disease are limited to fewer individuals because fewer people think they can become ill. Just the idea of vaccines protecting from disease will make people think they are protected so they will not experience any symptoms.

c. increasingly more individuals in a community are vaccinated against a particular pathogen, future outbreaks of the disease are limited to fewer individuals because fewer people will become infected and then pass it on. Explanation: - In the figure it shows at the end that when most people are vaccinated the result is that there are very few sick and contagious people, and the disease does not spread as much. - This is known as herd immunity.

Which of the following is an example of the immune system's second line of defense? a. the low pH environment of the stomach b. saliva containing antimicrobial enzymes c. macrophages engulfing pathogens during inflammation d. tears containing antimicrobial enzymes

c. macrophages engulfing pathogens during inflammation Explanation: - Choice (a, b, and d) are physical, mechanical and chemical defenses, which is the immune system's first line of defense against pathogens, that reduce the likelihood of harmful organisms or viruses gaining access to internal tissues such as physical barriers such as the skin, mucus, earwax, nose hair, sweat, saliva, and tears, mechanical defenses such as shedding of the skin, the production of mucus, earwax, sweat, saliva, and tears, and chemical defenses such as chemicals and enzymes in body fluid (the low pH environment of the stomach) , antimicrobial peptides, plasma protein mediators, cytokines, and inflammation-eliciting mediators - Choice (c) is the innate immune system, which is the immune system's second line of defense against pathogens, that consists of cells and proteins that recognize the presence of an invader and mount an internal defense to kill, disable, or isolate it such as phagocytes that circulate throughout the body, looking for potential threats, like bacteria and viruses, to engulf and destroy, and macrophages , which are phagocytic cells that can leave the circulatory system by moving across the walls of capillary vessels. The ability to roam outside of the circulatory system is important, because it allows macrophages to hunt pathogens with less limits. Macrophages can also release cytokines in order to signal and recruit other cells to an area with pathogens.

Cardiac, smooth, and skeletal are all types of __________ tissue; they generate force to move structures within the body by contracting. a. nervous b. connective c. muscle d. epithelial

c. muscle Explanation: - Muscle which is responsible for moving extremities and external areas of the body is called "skeletal muscle." - Heart muscle is called "cardiac muscle." - Muscle that is in the walls of arteries and bowel is called "smooth muscle." - Muscles generate force to move structures within the body by contracting.

During exercise, the increase in respiration rate and heart rate are driven by the need to replenish the oxygen used to support a. lactic acid fermentation. b. carbon dioxide synthesis in the lungs. c. oxidative phosphorylation in muscle cell mitochondria. d. the Calvin cycle of photosynthesis.

c. oxidative phosphorylation in muscle cell mitochondria.

In animals, the outcome of meiosis is the a. creation of genetically identical offspring. b. protection of cells from cancer. c. production of eggs and sperm. d. regulation of the progression through the cell cycle.

c. production of eggs and sperm. Explanation: - Meiosis is a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes (eggs and sperm) and plant spores.

Select the correct order of mitotic cell division stages. a. prophase, anaphase, metaphase, telophase b. anaphase, metaphase, telophase, prophase c. prophase, metaphase, anaphase, telophase d. telophase, prophase, metaphase, anaphase

c. prophase, metaphase, anaphase, telophase

According to the Centers for Disease Control (CDC), by the end of September 2014, roughly 8,000 cases of whooping cough had been reported in California for that year; more than 250 patients (mostly infants and young children) were hospitalized, with 58 of them requiring intensive care. Several other childhood diseases that were once common but then eradicated through high vaccination rates have returned since the anti-vaccination movement grew in the 1990s. The epidemiological data collected by the CDC indicates this resurgence of childhood diseases is most likely the result of a. increased virulence of the pathogens causing these diseases. b. simply the increased number of people present in the United States. c. reduced herd/community immunity. d. reduced vaccine effectiveness.

c. reduced herd/community immunity. Explanation: - Herd Immunity is the resistance to the spread of an infectious disease within a population that is based on pre-existing immunity of a high proportion of individuals as a result of previous infection or vaccination.

Which of the following examples indicates a situation where the researcher is MOST likely to have a possible bias regarding his or her work? a. A researcher, funded by a pharmaceutical company, is testing the clinical effectiveness and safety of a new vaccine. b. A researcher, funded by a public grant, is testing the clinical effectiveness and safety of a new vaccine. c. A federally funded researcher is working on developing a genetically engineered microbe to quickly digest oil spills. d. A privately funded researcher is working on developing a genetically engineered and patented microbe to quickly digest oil spills. If successful, the microbe would be marketed worldwide.

d. A privately funded researcher is working on developing a genetically engineered and patented microbe to quickly digest oil spills. If successful, the microbe would be marketed worldwide. Explanation: - Privately funded research is found to have more bias than research funded by pharmaceutical, federal, and public companies because in the past privately funded research was found to be more bias because they often manipulated results and information in studies to favor their products so that they can gain more profit from the sale of their products.

Which of the following is either consumed or synthesized in virtually every cellular reaction? a. sugars b. enzymes c. DNA d. ATP

d. ATP Explanation: - ATP is consumed for energy in processes including ion transport, muscle contraction, nerve impulse propagation, substrate phosphorylation, and chemical synthesis. These processes, as well as others, create a high demand for ATP.

Which of the following statements is true of proteins, carbohydrates, and nucleic acids? a. None of these macromolecules mixes well with water. b. All three are used to store genetic information. c. All of these molecules are primarily used as energy-storage molecules. d. Each of these molecules is built from a common set of monomers.

d. Each of these molecules is built from a common set of monomers. Explanation: Proteins, carbohydrates, and nucleic acids are all polymers created from monomers (amino acids, monosaccharides, and nucleotides): - amino acids build protein - monosaccharides (simple sugars) build carbohydrates - nucleotides build nucleic acids

Which scenario demonstrates a cause-and-effect relationship? a. A population of dead bats is discovered with noses that are coated with a white fungus. b. Agricultural regions with high infestations of insect pests are located near caves that contain a white fungus and very few bats. c. Bats with microscopic damage to wing membranes are found to be infected with a cold-loving fungus. d. In a laboratory, 100 healthy bats exposed to a fungus develop white-nose syndrome and die.

d. In a laboratory, 100 healthy bats exposed to a fungus develop white-nose syndrome and die. Explanation: - Causation explicitly applies to cases where action A (100 healthy bats exposed to a fungus) causes outcome B (the development of white-nose syndrome and death). - Correlation is simply a relationship. Action A relates to Action B—but one event doesn't necessarily cause the other event to happen. - (a) is wrong because it is an observation, but doesn't describe what caused the death of the bats, it just states what was observed/seen. - (b) is wrong because it is an observation, but doesn't describe what caused the high infestation of insects, it just states what was observed/seen. . - (c) is wrong because it is an observation, but doesn't describe what caused the microscopic damage to wing membranes, it just states what was observed/seen. - (d) is right because it describes an outcome caused by the effect of something (in this case, the fungus).

Select the observation that supports endosymbiotic theory. a. Eukaryotic organisms can be either unicellular or multicellular. b. Plant cells and many prokaryotes have cell walls surrounding the plasma membrane. c. Nuclear envelopes have small openings called nuclear pores. d. Mitochondria and chloroplasts contain DNA just like prokaryotic cells.

d. Mitochondria and chloroplasts contain DNA just like prokaryotic cells. Explanation: - Endosymbiotic Theory is an evolutionary theory stating that eukaryotic cells evolved through a process in which a larger prokaryotic cell engulfed smaller free-living prokaryotes that were not digested and eventually developed into mitochondria, chloroplasts, and possibly other organelles.

Which of the following examples accurately describes how crossing-over results in genetic diversity? a. Sister chromatids of maternal chromosome 1 exchange segments of genetic information with one another. b. Maternal chromosome 3 exchanges segments of DNA with paternal chromosome 21. c. Sister chromatids of paternal chromosome 1 exchange segments of genetic information with one another. d. Paternal chromosome 7 exchanges segments of DNA with maternal chromosome 7.

d. Paternal chromosome 7 exchanges segments of DNA with maternal chromosome 7.

What is the importance of photosynthesis to organisms other than plants? a. All other organisms require carbon dioxide for life processes. b. The sugars made during photosynthesis are the direct building blocks of DNA. c. All cells must contain chloroplasts in order to survive. d. Photosynthesis captures energy that other organisms access when they ingest or absorb nutrients from photosynthetic organisms.

d. Photosynthesis captures energy that other organisms access when they ingest or absorb nutrients from photosynthetic organisms. Explanation: - Without photosynthesis, animals couldn't gain energy from eating plants or eating animals that ate plants.

A researcher noticed that as the prevalence of cell phone usage increased between the years of 1998 and 2010, so did the number of individuals diagnosed with autism. He decided that cell phone usage by expectant mothers was causing autism. Which of the following would be the first step in evaluating his assumption? a. The researcher's experiment should include thousands of participants from all gender, socioeconomic, racial, and ethnic groups both with and without autism. b. The researcher should carefully design a reproducible experiment. c. The researcher should use a small sample size (20 participants) of autistic children and their mothers to support the hypothesis. d. The researcher should develop a clearly testable and falsifiable hypothesis.

d. The researcher should develop a clearly testable and falsifiable hypothesis. Explanation: - After an observation (which is what the researcher noticed), the researcher should make a clearly testable and falsifiable hypothesis. - The first step of the scientific method is an observation, the second step is to form a hypothesis. - Making a prediction, forming an experiment, and conducting an experiment should come after developing a hypothesis.

Astronauts returning from outer space studied samples taken from their lunar landing. They found that one of their samples was coated with organic compounds. Which of the following statements must be correct? a. The specimen must lack water, pesticides, and added hormones. b. The compounds must be covered with ammonia (NH3) and water vapor. c. The samples must lack water but contain DNA. d. The samples must contain carbon atoms.

d. The samples must contain carbon atoms. Explanation: - All organic compounds are molecules that contain carbon atoms covalently bonded to hydrogen atoms (C-H bonds). - This means that all organic compounds have in common the presence of carbon atoms and hydrogen atoms. - In addition, different organic compounds may contain oxygen, nitrogen, phosphorous, and other elements.

The graph below shows which of the following? a. The increased consumption of organic food has led to an increase in the rate of autism between 1998 and 2007. b. There is strong evidence that a cause-effect relationship exists between the consumption of organic food and the development of autism. c. Consuming organic food causes autism. d. There is a strong correlation between the sale/consumption of organic food and the number of individuals diagnosed with autism between 1998 and 2007.

d. There is a strong correlation between the sale/consumption of organic food and the number of individuals diagnosed with autism between 1998 and 2007. Explanation: The graph shows autism and organic food sales. - While causation and correlation can exist at the same time, correlation does not imply causation. - Causation explicitly applies to cases where action A causes outcome B (consumption of organic food causes autism). - Correlation is simply a relationship. Action A relates to Action B—but one event doesn't necessarily cause the other event to happen (Consumption of organic food and autism cases have both increased and show a correlation, but there is no evidence to suggest organic food causes autism).

A researcher in a laboratory tests a food item and identifies protein in it. The food item must also contain a. glucose. b. lipids. c. nucleotides. d. amino acids.

d. amino acids. Explanation: - Amino acids are molecules that combine to form proteins. - Amino acids and proteins are the building blocks of life. - When proteins are digested or broken down, amino acids are left. - The human body uses amino acids to make proteins to help the body and perform many other body functions.

A research team funded by a pharmaceutical company is studying the adaptation of grasshopper mice to the neurotoxic venom of scorpions in an attempt to determine how the mice's adaptation could be used as a possible solution to pain management in humans. This is an example of ______ research. a. random b. pseudoscientific c. basic d. applied

d. applied Explanation: - Basic research is a research approach that is entirely theoretical and aimed at improving or expanding the knowledge-base of a particular field of study. It focuses on "knowledge for its own sake" and it is primarily driven by curiosity and the need to explore the unknown. It is also known as fundamental or pure research and it is a systematic investigation set to achieve a better and more detailed understanding of a research subject or phenomenon, not to solve a specific problem. - Applied research is designed to focus on providing practical solutions to a specific problem. It is a form of investigation that entails solution-oriented inquiries into a phenomenon, a field of study or research subject generally employing empirical methodologies. In many cases, applied research is a follow-up research design for basic research because it further investigates the outcomes of pure or basic research in order to validate these findings and apply them to create innovative solutions to specific problems.

Which of the following pairs of processes encompasses the entire eukaryotic cell cycle? a. G1 phase and mitosis b. G1 phase and G2 phase c. interphase and metaphase d. cell division and interphase

d. cell division and interphase Explanation: The eukaryotic cell cycle is composed of the stages: - Interphase (G1, S, and G2 phases) - Mitosis (prophase, metaphase, anaphase, and telophase) - Cytokinesis (two genetically identical daughter cells are produced through division of the cells cytoplasm).

Mitochondria are required for a. photosynthesis b. mitosis c. export of proteins. d. cellular respiration.

d. cellular respiration.

The chromosomes in a homologous pair a. both came from the organism's mother. b. both came from the organism's father. c. do not line up together during meiosis. d. consist of one maternal and one paternal chromosome.

d. consist of one maternal and one paternal chromosome. Explanation: - A homologous pair consists of one paternal and one maternal chromosome. In humans, there are a total of 46 chromosomes in the nucleus of a somatic cell. Half of them (22 autosomes + X or Y chromosome) are inherited from the father and the other half (22 autosomes + X chromosome), from the mother.

The fact that the onset of autism symptoms typically occurs at about the same age children receive many of their vaccinations, including the MMR, is an example of an observed a. cause-effect relationship but not necessarily a correlation. b. cause-effect relationship supported by empirical evidence. c. correlation and strong evidence of a cause-effect relationship. d. correlation but not necessarily evidence of a cause-effect relationship.

d. correlation but not necessarily evidence of a cause-effect relationship. Explanation: - While causation and correlation can exist at the same time, correlation does not imply causation. - Causation explicitly applies to cases where action A causes outcome B (consumption of organic food causes autism). - Correlation is simply a relationship. Action A relates to Action B—but one event doesn't necessarily cause the other event to happen (Consumption of organic food and autism cases have both increased and show a correlation, but there is no evidence to suggest organic food causes autism).

Which of the following is a component of the immune system's first line of defense? a. antibodies b. T cells c. histamine d. earwax

d. earwax Explanation: - Choice (a, b, and c) is the adaptive immune system, which is the third line of defense. - Choice (d) is the first line of defense, in which earwax is an external defense that reduces the likelihood of harmful organisms or viruses gaining access to internal tissues.

When scientists generate a single informed, logical, and plausible explanation for a question and observations of the natural world, they are proposing a scientific _____. a. observation. b. theory. c. correlation d. hypothesis

d. hypothesis Explanation: - A scientific hypothesis is an idea that proposes a tentative explanation about a phenomenon or a narrow set of phenomena observed in the natural world. - They are usually only one sentence/statement.

Hypotheses can be tested through observational studies or experimental studies. Which of the following represents an experimental approach to testing a hypothesis? a. predicting migration routes for monarch butterflies in light of anticipated future climate change b. measuring crop yields to better document the impacts of a severe drought c. searching for fossils in a recently exposed outcropping of rock d. injecting trees with insecticide to determine whether it protects against a certain insect pest

d. injecting trees with insecticide to determine whether it protects against a certain insect pest Explanation: - The experimental method involves manipulating one variable to determine if changes in one variable cause changes in another variable. - This method relies on controlled methods, random assignment and the manipulation of variables to test a hypothesis. - Injecting trees with insecticide to determine whether it protects against a certain insect pest is an experiment.

A solution with a pH of 4 is _______ acidic than a solution with a pH of 5. The solution with the pH of 4 has a ______ concentration of hydrogen ions than the solution with a pH of 5. a. less; higher b. less; lower c. more; lower d. more; higher

d. more; higher Explanation: - An acidic solution has a high concentration of hydrogen ions, greater than that of pure water. - A basic solution has a low concentration of hydrogen ions, less than that of pure water. - The scale has values ranging from zero (the most acidic) to 14 (the most basic).

If the concentration of sugar molecules in water on side A of a selectively permeable membrane is 5 percent, and the concentration of sugar molecules in water on side B of a selectively permeable membrane is 15 percent, the water molecules will a. not move at all because the water concentrations are isotonic. b. mostly move from side B to side A because the water concentration is higher on side "B." c. mostly move from side A to side B because the water concentration is higher on side "B." d. mostly move from side A to side B because the water concentration is higher on side "A."

d. mostly move from side A to side B because the water concentration is higher on side "A." Explanation: - water molecule will move from lower concentration side to higher concentration side via osmosis process that water will move from side A to side B.

After about an hour of basking in the sun, the body temperature of the marine iguana reaches 37°C. Then it dives into the water to feed. Once in the water, its body temperature rapidly drops and the iguana must return to the rocks to warm up. This process is an example of a. positive feedback. b. set point control. c. tissue shock. d. negative feedback

d. negative feedback Explanation: A negative feedback loop is a feedback loop that causes a system to change in the opposite direction from which it is moving. It is a step that decreases its output. - The iguana is moving towards reaching a higher body temperature, jumping in the water is moving in the opposite direction because it drops his body temperature instead.

Prokaryotes and eukaryotes are primarily distinguished by the absence or presence of a. ribosomes. b. cell walls. c. plasma membranes. d. organelles.

d. organelles. Explanation: - The primary distinction between these two types of organisms is that eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not.

A white blood cell (WBC) encounters bacteria in a scrape on the knee of a child who has fallen off a bicycle. The WBC's job is to take the bacteria inside itself and destroy it. If the bacteria are too large to be transported via transported proteins, how will the WBC most likely take them in? a. facilitated diffusion b. exocytosis c. pinocytosis d. phagocytosis

d. phagocytosis Explanation: - Phagocytosis is the process by which certain living cells called phagocytes ingest or engulf other cells or particles. - The phagocyte may be a free-living one-celled organism, such as an amoeba, or one of the body cells, such as a white blood cell. - In some forms of animal life, such as amoebas and sponges, phagocytosis is a means of feeding. - In higher animals, phagocytosis is chiefly a defensive reaction against infection and invasion of the body by foreign substances (antigens).

In science, when a hypothesis or group of hypotheses supported by repeated experimental evidence holds true through time, it can be developed into a a. scientific fact. b. proven explanation. c. peer-reviewed prediction. d. scientific theory.

d. scientific theory. Explanation: - A scientific theory is a hypothesis, or a group of related hypothesis, that has received substantial confirmation through diverse lines of investigation by independent researchers. - There is no such thing as a scientific fact because hypotheses can be changed or improved over time through the improvement of technology. - Scientific Laws are much more flexible than scientific theories. They can have exceptions, be proven wrong or evolve over time.

The Golgi apparatus a. captures energy from sunlight and sends it to the mitochondria. b. stores the cell's genetic material. c. manufactures lipids and hormones. d. sorts proteins and lipids and sends them to their final destination.

d. sorts proteins and lipids and sends them to their final destination. Explanation: - The Golgi Apparatus is a stack of membranes in the cell that modifies, sorts, and packages proteins and lipids from the endoplasmic reticulum.