Biology:Cells to Self Final
The term that is most closely associated with the secondary immune response is...
"memory"
An actively dividing cell has six chromosomes. How many sister chromatids are present within this cell at the end of G2 phase?
12
Nitrogen has 7 protons, 7 neutrons, and 7 electrons. What is the atomic mass of nitrogen?
14
Based on the water molecule pictured below, which of the labeled areas possesses a partial negative charge? (1 H labeled B, 2 Os labeled A & C)
B only
What would be the result the cell did not have the ability to fix errors in replication?
DNA replication would result in more mutations
If one strand of DNA has the sequence CGATT, the sequence of the other strand of the same molecule will be:
GCTAA
What are the primary stages of interphase?
S, G1, and G2
Which of the following is true of the chromosomes in a homologous pair?
They carry the same genes
The bases present in an RNA molecule are:
U, A, C, and G
If an athlete damages a ligament in his or her knee, he or she has damaged...
a connection between two bones
Which of the following is a molecule that makes blood vessels near a wound more porous?
a histamine
Which of the following is a white blood cell that will arrive in the next stage of inflammation?
a macrophage
During blood clotting, a broken blood vessel triggers a cascade of factors that collectively reduce blood loss. In this example, the clotting factors are functioning as part of...
a positive feedback loop
The chemical 3-(3, 4-dichloro-phenyl)-1, 1-dimethylurea (DCMU) blocks the movement of electrons at the point indicated by the black, downward-printing arrow in the figure below. Which of the following would be an immediate effect of treating a chloroplast with this drug?
a proton gradient would not be created, so ATP could not be made
A difficult wound for the immune system to respond to is...
a puncture wound, because the first and second lines of defense can be bypassed
Shortages of iron in our diet can cause iron deficiency anemia, a condition that reduces the amount of hemoglobin in red blood cells. Iron deficiency anemia is a potentially serious condition that is characterized primarily by...
a reduction in the blood's capacity to transport oxygen
Which of the following is an example of a germ cell?
a sperm
RNA polymerase binds to the promoter more easily. a. transcription up-regulated. b. transcription down-regulated. c. translation up-regulated. d. translation down-regulated.
a transcription up-regulated
All of the following contribute to genetic uniqueness EXCEPT: a. binary fission. b. independent assortment. c. crossing over. d. random fertilization.
a. binary fission
This graph shows which of the following? (Graph shows that as organic food sales go up, so do individuals diagnosed with autism) a. there is a positive correlation between the sale/consumption of organic food and the number of individuals diagnosed with autism between 1998 and 2007. b. the increased consumption of organic food has led to an increase in the rate of autism between 1998 and 2007. c. consuming organic food causes autism. d. there is positive evidence that a cause-and-effect relationship exists between the consumption of organic food and the development of autism.
a. there is a positive correlation between the sale/consumption of organic food and the number of individuals diagnosed with autism between 1998 and 2007
A substance with a pH of 3 would be considered:
acidic
The primary role of the immune system's first line of defence is to...
act as a barrier to prevent entry of pathogens
The human liver produces bile, a substance that...
allows fats to dissolve more easily in the watery contents of the gut
When Stanley Miller zapped a mixture of methane, ammonia, and water vapor with electrical sparks, he produced:
amino acids, components that make up life
Which of the following is an example of passive acquired immunity?
an infant receiving antibodies from its mother's milk
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 correlation but not necessarily evidence of a cause-and-effect relationship
Pancreatic cancer is an especially dangerous disease in humans because the pancreas is...
an organ that manufactures many different kinds of digestive enzymes
A chemical reaction that uses ATP to build cellular components is:
anabolic
Which of the following is a component of the immune system's third line of defense?
antibodies
Each T-cell and each B-cell binds to only one specific type of...
antigen
Scientists working for a major cosmetics company are attempting to determine if a new face cream can reduce the number of fine lines and wrinkles on a person's face. This is an example of:
applied research
Cells that demonstrate anchorage independence...
are primed to be metastatic
Nucleotides:
are the building blocks of nucleic acids
Which of the following statements describe the function of the light reaction in photosynthesis?
as electrons move through the light reaction, they release energy that is used to concentrate protons in the thylakoid
The long projection of a neuron that is directed toward the next neuron is called the:
axon
Which of the following statements accurately describes hormone signaling, as depicted in the above figure? a. each endocrine cell has the ability to make all of an organism's hormones. b. hormones act on specific target cells. c. hormones may diffuse into the circulatory system but they cannot diffuse out of it. d. target cells signal each other using hormones.
b. hormones act on specific target cells
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. This has resulted in revised ways of understanding how molecules are moved across the plasma membrane of cells. 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 absolute knowledge. b. scientific knowledge is necessarily contingent knowledge and can change given increased knowledge. c. scientific knowledge is an unchanging collection of facts. d. scientific knowledge is rigid collection of invariable facts.
b. scientific knowledge is necessarily contingent knowledge and can change given increased knowledge
Which of the following explains why ice floats on water? a. the crystal structure of ice is more regular than that seen in liquid water. b. the distance between water molecules in ice is greater than in liquid water. c. the cool temperature of ice reduces the extent of molecular motion relative to liquid water. d. when ice forms, the hydrogen bond in the water molecule becomes nonpolar; ice behaves like oil
b. the distance between water molecules in ice is greater than in liquid water
Which of the following statements about hormones is TRUE? a. they are distributed primarily through the lymphatic tissue. b. they may regulate certain developmental periods of life. c. they are taken up by target cells via endocytosis. d. they have generalized functions but no specific functions.
b. they may regulate certain developmental periods of life
Fewer RNA polymerase enzymes are produced. a. transcription up-regulated. b. transcription down-regulated. c. translation up-regulated. d. translation down-regulated.
b. transcription down-regulated
Some questions fall outside the realm of science. Which of the following questions could NOT be answered using the scientific method? a. what is the function of the appendix in human beings? b. why is it unethical to test newly developed drugs in animals? c. why do smokers develop lung cancer more frequently than nonsmokers? d. how does white nose syndrome kill bats?
b. why is it unethical to test newly developed drugs in animals
Prokaryotes undergo which process for replication?
binary fission
At the site of a wound or cut, platelets combine with proteins in our blood to form...
blood clots
A newborn is diagnosed shortly after birth with a rare heart defect that prevented the valve between the left atrium and the left ventricle from fully forming. Which of the following would be an expected outcome of this defect?
body cells would receive less oxygen-rich blood than normal
Which of the following things would you expect to happen if a knee joint was formed without any cartilage?
bones within the knee would experience friction
A plant cell is mutated so ATP synthase no longer functions. Which process will be affected?
both photosynthesis and respiration
Which of the following questions could NOT be used to develop a testable hypothesis? a. does exposure to secondhand smoke affect the probability of developing lung cancer? b. do organic vegetables contain harmful substances? c. do ghosts impact how children sleep? d. does a can of vegetable juice contain more salt than the same size can of iced tea?
c. do ghosts impact how children
Which of the following statements accurately describes hormonal signaling, as depicted in the above figure? a. endocrine cells take up hormones from target cells. b. signaling molecules are released through ducts. c. hormones may signal cells that are located a considerable distance away from them. d. all hormones are taken up through specialized cell surface receptors.
c. hormones may signal cells that are located a considerable distance away from them
If you were to step on a nail with your right foot, which of the following things would NOT happen? a. sensory input from your right foot would be processed in your central nervous system. b. motor output would travel to both of your legs; your right foot would be raised and your left leg would stiffen to prevent you from falling over. c. motor output from your right leg would be interpreted by your brain as sensory input. d. the thalamus would filter and sort the sensory input that is entering your brain.
c. motor output from your right leg would be interpreted by your brain as sensory input
A human female has a diploid chromosome number of 46 (2n=46). Based on this information, which of the following cells is NOT properly matched with its chromosome number? a. diploid precursor cell: 46 chromosomes. b. egg: 23 chromosomes. c. secondary oocyte: 46 chromosomes. d. first polar body: 23 chromosomes.
c. secondary oocyte:46 chromosomes
Which of the following does NOT facilitate exchange of materials by diffusion? a. cells lying within 0.03 millimeters of blood vessels. b. a large surface area within alveoli. c. the presence of the extracellular matrix within connective tissue. d. thin, porous walls in capillaries
c. the presence of the extracellular matrix within connective tissue
A group of 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 about their samples? a. the compounds must be covered with amonia (NH3) and water vapor. b. the samples must lack water, but contain DNA. c. the samples must contain carbon atoms. d. the specimen must lack water, pesticides, and added hormones.
c. the samples must contain carbon atoms
More ribosomes are produced. a. transcription up-regulated. b. transcription down-regulated. c. translation up-regulated. d. translation down-regulated.
c. translation up-regulated
The structure of capillaries is designed for gas exchange because:
capillaries have a large surface area AND capillaries have thin, porous walls
The central element found in organic molecules is:
carbon
Some kinds of drain cleaners use enzymes rather than strong, more dangerous chemicals. These enzymes must be able to:
catalyze a catabolic reaction
Antidiuretic hormone (ADH) is produced by the pituitary gland when the brain detects lower-than-optimum levels of water in the body. In the kidneys, ADH promotes the uptake of water, creating more concentrated urine. ADH travels from the pituitary gland to the kidneys through the:
circulatory system
What characteristics are shared by all living organisms? (hint:7)
composed of one or more cells, reproduce using DNA, obtain energy from their environment, sense environment and respond to it, can evolve as groups, maintain constant internal environment (homeostasis), living
In the chemical reaction that forms hydrogen peroxide (H2O2), hydrogen and oxygen share electrons creating ______ bonds between the two atoms.
covalent
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?
crossing over
The final stage of the cell cycle when two daughter cells are formed is called:
cytokinesis
Of the following values, which indicates the most basic pH? a. 5 b. 7 c. 8 d. 10
d. 10
Therapeutic touch (TT) is a type of "energy" medicine that involves the practitioner moving his/her hands over the energy field of the patient, without actually touching the patient, but redirecting the energy field to heal the patient. If a researcher were to design a survey of TT practitioners and their patients to determine the validity of TT, which of the following questions would NOT be helpful in determining the validity of the survey? a. is the researcher a regular TT practitioner or patient? b. do the survey participants have a working relationship with the researcher or were they paid to participate? c. are any non-TT patients involved in the survey? d. how old is the researcher?
d. how old is the researcher?
Which of the following is LEAST likely to include unchecked bias when making scientific statements? a. political groups b. religious groups c. marketing groups d. peer-reviewed scientific journals
d. peer-reviewed scientific journals
Which of the following statements about the process of science is NOT accurate? a. science is a systematic method of procedures designed to answer questions by evaluating empirical evidence. b. science attempts to solve a problem by systematically evaluating the plausibility of various solutions. c. science enables us to advance our understanding of evidence and data collected. d. science can answer all questions regarding the human experience and personal values.
d. science can answer all questions regarding the human experience and personal values
Based on the scientific evidence presented in Chapter 24 of Biology Now, which of the following is NOT the reason for the observed increase in incidence of autism in the United States and other countries since the 1970s? a. there is a heightened awareness of autism in society. b. more schools are screening more students for autism. c. people are generally more willing to label a broader range of conditions within the spectrum of autism disorders. d. the MMR vaccine is being more broadly administered, so more children are getting autism.
d. the MMR vaccine is being more broadly administered, so more children are getting autism
Which of the following would NOT be a particularly negative consideration when regarding a researcher's possible bias? a. the researcher has an ideological, political, or religious belief that will be supported by the scientific claims being made. b. the researcher stands to make money if others accept the claims being made. c. the researcher stands to gain in prestige if others accept the claims being made. d. the researcher has a Ph.D., MD, or at least an MS and years of experience in the field in which he is making a scientific claim
d. the researcher has a Ph.D., MD, or at least an MS and years of experience in the field in which he is making a scientific claim
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 NOT be helpful in evaluating his assumption? a. the researcher should develop a clearly testable and falsifiable hypothesis. b. the researcher should carefully design a reproducible experiment. c. the researcher's experiment should include thousands of participants from all gender, socioeconomic, racial, and ethnic groups both wth and without autism. d. the researcher should use a small sample size (20 participants) of autistic children and their mothers to support the hypothesis.
d. the researcher should use a small sample size (20 participants) of autistic children and their mothers to support the hypothesis
The steroid hormones testosterone, estradiol, and progesterone enter target cells and bind intracellular receptors to regulate gene expression. Based on this information, which of the following statements about steroid hormones must be correct? a. they are large and polar. b. they are hydrophilic. c. they are cationic or anionic, and they are water soluble. d. they are mainly nonpolar and hydrophobic.
d. they are mainly non polar and hydrophobic
Which of the following does NOT take place in the nucleus? a. transcription. b. intron removal. c. replication. d. translation.
d. translation
Fewer tRNA molecules are produced. a. transcription up-regulated. b. transcription down-regulated. c. translation up-regulated. d. translation down-regulated.
d. translation down-regulated
The mRNA molecules are broken down quickly. a. transcription up-regulated. b. transcription down-regulated. c. translation up-regulated. d. translation down-regulated.
d. translation down-regulated
Which of the following would NOT be a situation where your own scientific literacy would be helpful? a. should I take a cinnamon capsule every morning to help regulate my blood sugar? b. should I spend the extra money to buy a particular pair of shoes that claims to help tone my leg muscles better than other athletic shoes? c. will my cell phone cause me to have cancer? d. which movie should I watch this weekend?
d. which movie should I watch this weekend?
Which of the following events is the first to occur during inflammation?
damaged cells release key signaling molecules
You are given an unknown substance and asked to determine whether it is polar or nonpolar. The easiest way to do this would be to:
determine whether the compound dissolves in water
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 has occurred to the perfume molecules that have entered the air?
diffusion
Why do humans rely on a circulatory system to distribute oxygen?
diffusion is very slow over all but the shortest distances, so oxygen must be delivered to our cells to speed up the process
Which of the following is a component of the immune system's first line of defense?
earwax
Carbon, hydrogen, and nitrogen are all examples of:
elements
Which of the following is/are part of accepted cell theory?
every living organism is composed of one or more cells, all living cells arise from preexisting cells
A scientist wishing to generate cancerous cells in vitro could subject the cells to which of the following procedures?
expose cells to chemicals that disrupt mitosis
In the vertebrate immune response to a pathogen, which of the following would occur first?
external defenses
Which of the following statements correctly describes oogenesis due to menstrual hormones?
follicle-stimulation hormone (FSH) launches a new menstrual cycle by stimulating the ovarian follicles
Although it seems contradictory, real science does not intend to "prove" a hypothesis to be true. This is because:
future experiments or discoveries may provide data that refutes the hypothesis
Cancers are groups of cells that divide rapidly and uncontrollably. Thus, cancer cells...
have a relatively short G1 phase
The process of maintaining a constant internal environment despite changes in the external environment is termed:
homeostasis
Which of the following statements accurately describes how hormones can affect a cell, as illustrated in this figure?
hormones are effective at low concentrations
Which of the following statements distinguishes gamete formation in human males from gamete formation in human females?
human males make sperm throughout their lives, beginning at puberty, whereas human females are born with all the eggs that may or may not mature over their lifetime
If you were to compare the filtrate that is leaving the glomerulus to urine that is exiting the body, you would find that some substances - such as hydrogen ions and toxins - are more concentrated in the urine. Which of the following statements explains this process?
hydrogen ions and toxins are secreted from capillaries
In making your morning tea, you drop a sugar cube into some hot water. You stir the mixture but no longer see the sugar cube at the bottom of your mug. Based on your observation of sugar dissolving in hot water, you properly conclude that the sugar is:
hydrophilic
Phospholipids are large organic molecules with a ______, polar phosphate head connected to ______, nonpolar fatty acid tails. How do these molecules arrange themselves to form a mostly impermeable barrier between a liposome and its environment?
hydrophilic; hydrophobic; they line up they line up hydrophobic tails facing each other at the center line of the membrane with the hydrophilic heads facing outward, away from the center line of the membrane
When scientists generate a single, informed, logical, and plausible explanation for a question and observations of the natural world, they are proposing a scientific:
hypothesis
Gene regulation is the ability to:
increase or decrease protein synthesis from a given gene
The body responds to tissue damage by mounting an immediate and coordinated sequence of events called the:
inflammatory response
In bacteria, the antibiotic chloramphenicol prevents amino acids from bonding together. The most likely reason that bacteria die from treatment with chloramphenicol is because the antibiotic:
inhibits translation
In bacteria, the antibiotic erythromycin prevents ribosomes from functioning. The most likely reason that bacteria die from treatment with erythromycin is because the antibiotic:
inhibits translation
When calcium ions and chloride ions interact with one another they bond using ______ bonds.
ionic
Once a hormone enters the bloodstream, it...
is broken down after it has bound to a receptor in or on the target cell
People with sickle-cell disease have deformed hemoglobin molecules and often suffer muscle pains, even at low levels of exertion. These symptoms might occur because the deformed hemoglobin...
is unable to carry the amount of oxygen required for normal muscle activities
Blood flows rapidly within the arterial system but slows dramatically as it enters the capillaries. What is the benefit of having blood move slowly through the capillaries?
it ensures that the blood has enough time to exchange material with the surrounding cells
A single hormone molecule can have dramatic effects on a target cell, because:
it initiates a chain of events that amplifies its effect
DNA is one of the features common to all known forms of life;
it is the blueprint that guides the growth, development, behavior, and reproduction of all organisms
A carwash attendant offers to treat your windshield with a protective agent. This substance coats the glass, causing beads of water to easily roll off during a rain shower. Which of the following must be correct about the protective agent?
it must be hydrophobic
A scientific hypothesis must be constructed with which of the following characteristics?
it provides a reasonable explanation to a question and is consistent with current observations; it must also be testable and falsifiable
One of the most common knee injuries is the tearing of the anterior cruciate ligament (ACL). How would an injury like this affect the function of the knee?
ligaments hold the bones of the knee in the proper orientation. Tearing the ligament could disrupt the alignment of the knee, making the knee difficult to bend
Given what you know about making oil from algae, what component could you infer would be the most important in developing algal fuel?
lipids
From what substance do liposomes spontaneously form and why are they important?
liposomes form from phospholipid bilayers and provide a barrier between an external environment and an internal environment; this creates an internal environment where specific chemical reactions needed to establish a living cell can occur separately from the external environment
Which of the following is an example of the immune system's second line of defense?
macrophages engulfing pathogens during inflammation
White blood cells of the innate immune response ______, whereas white blood cells of the adaptive immune response ______
may function in inflammation; may secrete antibodies
Gametes are produced by meiosis rather than mitosis because...
meiosis reduces the chromosome number so that zygotes produced will have one full genome
White blood cells of the adaptive immune response provide what advantage that is lacking in white blood cells of the innate immune response?
memory
Chromosomes are lined up at the middle of the cell during the ______ portion of cell division.
metaphase
Which of the following differentiates meiosis from mitosis?
mitosis is used for the repair of cells, whereas meiosis creates cells for sexual reproduction
In humans, the herbicide atrazine helps RNA polymerase bind to the promoter of the gene for the enzyme aromatase. As a result,
more RNA for aromatase is produced
If a drug attacked and destroyed involuntary muscle cells only, which of the following body functions would be affected?
movement of materials through the digestive system
In a human cell,
nearly all chemical reaction are catalyzed by enzymes
An example of a cell that spends most of its life in the G0 phase is a...
neuron
Victoria, who is 10 years old, wants to be a zoologist when she grows up because she loves animals. So, she decided to begin her training by "doing something scientific." Specifically, she weighed and measured the lengths of all the earthworms she could find in her yard and recorded the data in a notebook. She then made a graph showing the maximum, minimum, and average weights and heights of the earthworms. Was she doing something scientific?
no, because she had no hypothesis to direct her data collection or interpretation
When Lori was diagnosed with breast cancer, the doctor recommended a lumpectomy followed by radiation therapy. However, she also continued to eat lots of fruits and vegetables, walk 3 miles every day, and complete a daily yoga practice. Within about 3 months Lori was cancer free. Afterwards, Lori told everyone that her healthy lifestyle had helped to cure her. Is this conclusion reasonable given the circumstances?
no, there are too many confounding factors to know exactly what happened
During a primary immune response...
nonspecific immunity may be of great benefit to the organism
Adenine (A), thymine (T), guanine (G), and cytosine (C) are the ______ building blocks for DNA; they are organized in different combinations to code for all of the proteins needed to accom[lish everything the cell does.
nucleotide
Developing a scientific understanding of a natural phenomenon typically begins by:
observing the quantifiable natural phenomena
Serotonin, one of the hormones thought to be involved in depression, is a water-soluble molecule. Where on the target cell would you expect to find receptors for this hormone?
on the outside of the plasma membrane
Which of the following statements accurately distinguishes tissues from organs?
organs consist of multiple tissue types, whereas tissues consist of one or more cell types
During the process of ______, water diffuses across a semipermeable membrane from an area where water is more concentrated to an area where water is less concentrated (it moves along the water concentration gradient).
osmosis
Site of oocyte production and maturation
ovary
Hollow tubule where fertilization occurs?
oviduct
During exercise, the increase in respiration rate and heartbeat speed are driven by the need to replenish oxygen used to support:
oxidative phosphorylation in muscle cell mitochondria
People who experience pain might argue that they would be better off without pain receptors. Why is it important for humans to have pain receptors?
pain receptors are important in preventing damage to tissues AND pain receptors could prevent life-threatening injuries
Why is it important that white blood cells are able to travel outside the human circulatory system?
pathogens may be found in other areas of the body besides the circulatory vessels
Scientists are human beings and are, like all human beings, susceptible to personal and group biases that may influence how they interpret evidence. Before original research work is accepted and added to a growing body of scientific understanding, perhaps even contributing to our understanding of an important scientific theory, it must be scrutinized by experts in the field who have no direct connection to the research under review. The main mechanism for doing this is:
peer-reviewed publications
Male reproductive structure that deposits sperm into the female
penis
A detective finds a minuscule spot of blood on a murder suspect's shirt. What method would she expect the police lab to use to get enough DNA from the blood droplet to perform DNA fingerprinting?
polymerase chain reaction (PCR)
The goal of meiosis is to...
produce eggs and sperm
The polymerase chain reaction (PCR) is used to:
produce many copies of a selected DNA sequence
Activated B cells are responsible for...
producing antibodies that bind to pathogens
When certain hormones are added to the uterus, they induce thickening in the cells lining its walls. Which of the following hormones is likely to be responsible for this change?
progesterone
The advantage of chewing food is that this process...
provides mechanical digestion and increases the surface are of the food for further digestion
Glycolysis is an anaerobic process, indicating that the glycolytic reactions:
require no oxygen
Which of the following sequences correctly describes the organization of muscle tissue from smallest to largest component?
sarcomeres to myofibrils to muscle fibers
You are reading a review paper in the journal "Vaccine" that gave a general summary of the knowledge of the field, including summarizing the results from multiple papers comparing children with autism to children without autism. The paper you are reading is best recognized as a:
secondary literature source
The table above is from a review article. Review articles are considered a:
secondary source
In the fall of 2012, a veterinarian from Texas issued a press release stating that her team of scientists had completed a 5-year DNA study confirming the existence of "sasquatch" or "bigfoot." Which of the following statements, if true, would lend support to her claims?
she consulted experts in the field of human genomics and made her DNA samples available to them for analysis
When appropriately prompted, diploid individuals of "Ulva prolifera" form spores that germinate to become haploid individuals. How might diploid individuals be created to complete the life cycle?
some individuals differentiate to become haploid gametes and then fuse to produce a diploid zygote
Which of the following are composed of the same monomers?
starch and cellulose
When examining the rapidly dividing cells of a fish embryo, you notice a cell that seems to contain two nuclei. The middle of the cell is pinched inward. This cell must be in:
telophase
A scientific hypothesis must be ______; if not, science cannot evaluate it.
testable
Sites of spermatogenesis in sexually-mature males?
testes
At high altitudes, gasses are less concentrated. You might gasp for air, because...
the amount of oxygen that could diffuse into your blood will be decreased
Photosynthesis and cellular respiration are both complementary and relatively balanced, but early history of life on Earth showed increasing oxygen concentrations. This indicates that:
the amount of photosynthesis occurring exceeded the amount of cellular respiration
Plants and animals use different energy storage molecules, yet they both use the same mechanism to "burn" their stored energy. How can plants and animals both be successful, even though they "burn" different energy storage molecules?
the breaking of the chemical bonds of a storage molecule transfers energy, no matter what molecule is stored
By what mechanism do most hormones travel through the organism that produces them?
the circulatory system
Which of the following situations might present a logical reason for accepting a scientific claim made by a person who did not have appropriate credentials for making that claim?
the claim could be supported by other nonbiased and credentialed scientists who have conducted similar research and arrived at the same conclusion and been reviewed by their peers
What best summarizes the events of the Calvin cycle?
the cycle uses ATP and NADPH to produce sugars
Which of the following prevents both blood loss and the invasion of pathogens in vertebrates?
the formation of blood clots
Which of the following organs coordinate(s) communication between the endocrine system and the nervous system?
the hypothalamus
A group of researchers conducted an experiment and collected the data presented in this graph. (Graph shows bats injected with fungus slowly dying off while bats that were sham-infected survive.) Which of the following statements are supported by the information in this graph?
the hypothesis was supported because all members of the control group survived while most of the members of both treatment groups died by the end of the study
David Blehert and his research team captured 117 healthy bats to study in the laboratory and divided them into 4 groups. Group 1 was housed in an area free from "Geomyces destructans", known to cause white nose syndrome (WNS). Group 2 was housed in an area that shared the same air as bats infected with WNS, but they did not have direct contact with the infected bats. Group 3 was housed in direct contact with other bats infected with WNS. Group 4 was directly exposed to "Geomyces destructans" when it was applied to their wings. During the study period the bats were monitored for signs of WNS. What were the independent and dependent variable in this experiement?
the independent variable was the type of exposure to "Geomyces destructans". The dependent variable was whether or not the bats became sick with WNS
A chemical that disrupts hydrogen bonds is added to a test tube containing DNA. What would be the result of this reaction?
the individual strands of DNA would separate and the tube would contain single-stranded pieces of DNA
Food passing through our digestive tract would contain the fewest nutrients when it reaches which of the following organs?
the large intestine
One side of the heart pumps blood into the pulmonary circuit, and the other side of the heart pumps blood to the systemic circuit. How do these different functions affect the structure of the heart?
the left side of the heart has a thicker muscular wall than the right side
In which of the following organs would you be LEAST likely to find mature lymphocytes?
the liver
What would occur if the mitochondria of a cell did not have a membrane?
the mitochondria would be unable to maintain the proton gradient required for ATP production
What species do you think would be the best to choose when producing algal fuels?
the one with the highest concentration of lipids
An example of an organ that is both an endocrine and exocrine gland is:
the pancreas
We use soap to clean ourselves better than we could with water alone. Soaps contain phospholipids that are responsible for the cleansing action. Which of the following statements is the most likely explanation for how soaps work?
the phospholipid tail attaches to the oily dirt while the phospholipid head interacts with the rinse water and carries the dirt (and soap) away with it
Which of the following pieces of evidence would best demonstrate that a bacterium found on an asteroid originated in outer space?
the presence of right-handed amino acids in the bacterium's proteins
Which of the following statements about an immune response is correct?
the primary immune response develops slowly over two weeks or more
A mutation occurs in the promoter of a protein-encoding gene. How might this mutation affect the production of the protein encoded by the gene?
the promoter might not be recognized by RNA polymerase, so the enzyme would be unable to attach to the promoter and start transcription
Some species of fish that live in the cold waters of the Arctic Ocean have evolved an "antifreeze" protein. Why might this protein be important to homeostasis?
the protein might prevent ice crystals from forming inside fish cells, which would prevent damage to the plasma membrane when temperatures are low
You are in lab attempting to prepare a slide of cow blood for observation in a wet mount. You place a small drop of the blood on a slide, add a drop of strong saline (salt) solution, and then cover all of it with a coverslip. After returning to your desk, you observe the slide with your microscope and notice that all of the red blood cells (RBCs) do not look like the nice round donut-shaped cells in your lab manual. Instead, the RBCs look to be exploding. What is the most plausible explanation for the appearance of the blood cells on your slide?
the saline solution you used resulted in water osmosing through the RBC plasma membrane mostly into the cells
How many phosphate groups are present in a single strand of DNA?
the same number as there are adenine, thymine, guanine, cytosine bases
Which of the following organs plays a role in producing vitamin D?
the skin
When examining the two complementary strands of nucleotides in one DNA molecule, you would expect to find that:
the sum of Gs and Cs in one strand would be equal to the sum of Gs and Cs in the other strand
How rapidly an organism can absorb nutrients generally depends on...
the surface area available for absorption
After certain knee injuries, patients experience a swelling because of an accumulation of fluid within the knee. This condition is referred to as "water on the knee." Which of the following is a likely source of this fluid?
the synovial sac
The polymerase chain reaction (PCR) technique could be developed only after the discovery of bacterial enzymes that were able to withstand high temperatures. Why would this be necessary to use such enzymes?
the temperature required to separate DNA strands during PCR degrades most normal enzymes
What prevents pathogens from entering our bodies through the delicate tissues of the lungs?
the tubes that enter the lungs are lined with mucus that traps pathogens and is then removed from the respiratory system
If the concentration of salt in water on side "A" of a selectively permeable membrane is 5%, and the concentration of salt in water on side "B" of a selectively permeable membrane is 15%, which way will the water move and why?
the water will mostly move from side "A" to side "B" because the water concentration is higher on side "A"
Examine the figure below of 2 concentrations of sugar water in a beaker separated by a semipermeable membrane that will only allow water to pass. What would happen? (Figure shows more sugar on left, more water on right)
the water would move from the right side to the left side of the membrane
A researcher wanted to determine if consuming diet sodas causes diabetes. He conducted a study in which subjects were asked to recall how many diet sodas they drank each day, on average; the subjects' blood sugar levels were then measured. The average blood sugar levels were determined in the test subjects. Each group included an equal number of male and female participants and the groups were standardized for average weight and age. Which of these statements most accurately describes what is seen in the graph? (Graph shown with a positive slope)
there appears to be a positive correlation between the number of diet sodas consumed each day and the average blood sugar levels measured in mmol/L. However, no definite cause-effect relationship has been established.
What makes liver cells different from heart cells of the same organism?
these cell types express different genes
In many organelles, groups of different enzymes are located on membranes in close proximity to each other because:
these enzymes are involved in the same metabolic pathway and keeping them close together increases the efficiency of the pathway
Which of the following statements best explains why starch molecules must be broken down before they can be absorbed by the small intestine?
they are too large to pass through the plasma membrane of the intestinal cells
Why would hydrophilic substances such as sodium ions (Na+), hydrogen ions (H+), sugars, and amino acids be unable to simply diffuse across a plasma membrane?
they do not readily mix with the hydrophobic tails forming the core of the phospholipid bilayer; therefore, they must move across by facilitated diffusion
Vanessa has been lifting weights to increase strength in her arms. Which of the following statements about the muscles she is strengthening is true?
they have tendons that are connected to bones
Which of the following statements about memory cells is true?
they include B cells and T cells that remain in the body for long periods of time after the first exposure to a pathogen
A sunflower responds and turns towards the sun is an example of what characteristic of all living organisms?
they sense their environment and respond to it
T-cells are white blood cells that mature in which organ?
thymus
A gene in a region of DNA that is wound more tightly around proteins in the nucleus will be:
transcribed less often than other genes
True or False: Both human males and females produce all three sex hormones but at different ratios?
true
True or False: During childbirth the labor contractions are the result of a positive feedback loop?
true
It may take the adaptive immune system how long to fully mount a response to the initial exposure of a particular pathogen?
two weeks
Female reproductive tract where sperm is deposited?
vagina
Babies may receive an injection of vitamin K at birth. Which of the following is the most likely reason why an injection of vitamin K would be given?
vitamin K is required to prevent bleeding, and babies are born with low levels of this vitamin
Each time you take a breath you are bringing in the oxygen you need to stay alive. The ultimate source of the oxygen used by all aerobic organisms comes from a reaction that breaks down:
water
Oil and water do not mix together well because:
water is polar and oil is nonpolar
People with xeroderma pigmentosum frequently exhibit skin cancer. The disease is a result of a mutation in a gene that produces a DNA repair protein. Why would these patients exhibit skin cancer more frequently?
without this protein, cells cannot fix changes in their DNA sequence caused by exposure to ultraviolet (UV) light, causing more damage to cells promoting cancer
Is it important for scientists to undergo peer review of their results by other fellow scientists?
yes, the quality and accuracy of the scientific work can be enhanced by input, further review, and possibly even repetition by other scientists working in the same field
Due to the pressure differential between the air and your pleural cavity, does...
your chest expand and lungs inflate