Bio test #1
the chemical 3-(3,4-dichloro-phenyl)-1,1-dimethylurea (DCMU) blocks the movement of electrons at thepoint indicated by the black, downward-pointing arrow in the figure below. Which of the following wouldbe an immediate effect of treating a chloroplast with this drug
A proton gradient would not be created, so ATP could not be made
which of the following is either consumed or synthesized in virtually every cellular reaction
ATP
which of these carries the most energy
ATP
as an energy carrier, ATP differs from NADPH in that
ATP transfers energy through phosphorylation, whereas NADPH donates electrons and hydrogen ions
The hypothesis that a common ancestor gave rise to all living organisms is strengthened by what observation?
Almost all cells in all living organisms use DNA to direct their structure, function, and behavior
Of the following values, which indicates the most basic pH
10
An actively dividing cell has six chromosomes. How many sister chromatids are present within this cell atthe end of G2 phase?
12
Nitrogen has seven protons, seven neutrons, and seven electrons. What is the atomic mass of nitrogen
14
Chemists often represent the structure of atoms using p, n, and e to indicate the number of protons, neutrons, and electrons. Which atom would have an atomic weight of 30
15 p, 15 n, 15 e
A duplicated chromosome consists of ________ sister chromatid
2
How many different amino acids are used to build proteins
20
How many atoms are present in a single molecule of C8H10N4O2?
24
if a plant has a total of 18 chromosomes, how many chromosomes would be present in each of its gametes
9
If iodide ions (I) were dissolved in water, they would be attracted to
A and C
When ammonia (NH3) is dissolved in a solution, it accepts hydrogen ions from its surroundings. Ammonia is therefore
A base
____ reactions release energy by breaking down complex molecules
Anabolic
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?
Antibiotics cannot kill a virus because viruses are not living cells with cell walls to puncture, nor do they have their own organelles to replicate DNA
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
Based on the water molecule pictured below, which of the labeled areas possesses a partial negative charge?
B only
Which of the following would be a fact?
Bats with white noses have been observed in the wild
The central element found in organic molecules
Carbon
Which of the following factors explains carbon's prominence in living systems?
Carbon-based molecules can form long chains and rings
Which of the following statements most accurately describes a selectively permeable membrane
Certain solutes move freely across the membrane by simple diffusion while others must behelped across by active or passive transport proteins; some substances are completely excluded from crossing the membrane
Recently, beekeepers have noticed an alarming and sudden disappearance of honeybees from their hives. Some beekeepers and environmentalists worry that crops genetically engineered to contain the gene for the Bt insecticidal toxin may be killing the bees. Which of these experiments tests the hypothesis that Bt is killing the bees?
Collecting hundreds of bees. Half of the bees would be kept in a facility with plants genetically engineered to contain the gene for Bt toxin while the other half would be kept in a facility with plants not genetically engineered to contain the gene for Bt toxin. The survival rate for both sets of bees would be calculated and compared
O2, also termed atmospheric oxygen, is considered to be a molecule but not a compound. Why not?
Compounds are defined as molecules constructed from two or more different elements
.In the chemical reaction that forms hydrogen peroxide (H2O2), hydrogen and oxygen share electrons creating ________ bonds between the two atoms
Covalent
An acid is a polar substance that dissolves in water and
Donates hydrogen ions to the solutions
Which of the following statements is true of proteins, carbohydrates, and nucleic acid
Each of these molecules is built from a common set of monomers
Which of the following is/are part of accepted cell theory?
Every living organism is composed of one or more cells, and all living cells arise from preexisting cell
David Blehert and his research team captured 117 healthy bats to study in the laboratory and divided theminto 4 groups. Group 1 was housed in an area free from Geomyces destructans. 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 thebats were monitored for signs of WNS. What is the specific hypothesis being tested by the inclusion of group 4 in this experiment?
Geomyces destructans causes WNS, and it can be transmitted by direct contact with the fungus; no contact with infected bats is needed for transmission of the fungus
The chemical reaction that represents photosynthesis is 6 H2O 6 CO2 C6H12O6 6 O2. What are the reactants?
H2O and CO2
You often experience numbness and pain in the thumb and first two fingers on your right hand. You go to the 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 are moving up and down your arm. The doctor's preliminary diagnosis of carpal tunnel syndrome is a
Hypothesis
u are a microbiologist working with a species of bacteria that can perform photosynthesis. You know that the enzymes needed to perform photosynthesis in plant cells are closely associated with the membranes in chloroplasts. Where in the bacteria would you expect to find the enzymes needed to perform photosynthesis
I would expect to find the photosynthetic enzymes associated with the plasma membrane of the bacteria
When calcium (Ca) and chloride (Cl) interact with one another they bond using ________ bonds
Ionic
Which of the following distinguishes ionic bonds from covalent bonds?
Ionic bonds hold together oppositely charged atoms, whereas covalent bonds hold togetheratoms that share electron
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
Which of the following is likely to participate in ionic bonding?
Li
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 molecules carries electrons to the electron transport chain of oxidative phosphorylation?
NADH
the Krebs cycle produce
NADH, ATP, and FADH2
Recently, beekeepers have noticed an alarming and sudden disappearance of honeybees from their hives. Some beekeepers and environmentalists worry that crops genetically engineered to contain the gene for the Bt insecticidal toxin may be killing the bees. Without data from a scientific experiment, is it reasonable to state that Bt-containing crops are responsible for the loss of honeybees?
No, because there could be some other unknown or unmentioned factor affecting the survival of honeybees
Prokaryotes and eukaryotes are primarily distinguished by the absence or presence of internal membrane-enclosed organelles. Are prokaryotic cells at an evolutionary disadvantage because they lack organelles?
No; although prokaryotic cells are comparatively less efficient than eukaryotic cells, they are still able to carry out the processes necessary for survival and reproduction
Examine the illustration below. Which statement best summarizes the contribution of Photosystem I (PSI)during photosynthesis
PSI generates the high-energy electrons that are transported by NADPH to the Calvin cycle and will eventually reduce the carbon in CO2
Neighboring water molecules are held together with hydrogen bonds because
Partially negatively charged oxygen atoms and partially positively charged hydrogen atoms on separate water molecules are attracted to one another
Which of the following accurately describes crossing over
Paternal chromosome 7 exchanges segments of DNA with maternal chromosome
What is the importance of photosynthesis to organisms other than plants
Photosynthesis captures energy that other organisms access when they eat either plants or organisms that eat plants
According to the image below, during which phase of the cell cycle does the cell increase in size in preparation for division?
REGION 2
The plasma membrane of some white blood cells contain ________ that bind with proteins of cells such as bacteria that have invaded the human body. These special proteins tell the white blood cells those bacterial cells do not belong to that particular human and to phagocytize (eat) them
Receptor proteins
according to the image below, during which phase of the cell cycle is the genetic material duplication
Region 3
According to the image below, during which phase of the cell cycle is the genetic material evenly partitioned between daughter cells
Region 6
What are the stages of interphase
S, G1, and G2
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?
Scientific knowledge is necessarily contingent knowledge
Which of the following questions could NOT be used to develop a testable hypothesis?
Should everyone drink bottled water only?
Which of the following would be a theory?
Specific pathogens are directly responsible for specific diseases and conditions
Which of the following could be built solely from glucose molecules?
Starch
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 closer together increases the efficiency of the pathwAY
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 whatmolecule is stored
The pH scale measures
The concentration of hydrogen ions in a solution
What best summarizes the events of the Calvin cycle
The cycle uses ATP and NADPH to produce sugar
Which of the following explains why ice floats on water?
The distance between water molecules in ice is greater than in liquid water
A group of researchers conducted an experiment and collected the data presented in this graph. 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 theminto 4 groups. Group 1 was housed in an area free from Geomyces destructans. 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 thebats were monitored for signs of WNS. What were the independent and dependent variables in this experiment?
The independent variable was the type of exposure to Geomyces destructans. The dependent variable was whether or not the bats became sick with WNS
Compare and contrast the nuclear envelope and the plasma membre
The nuclear envelope consists of two concentric phospholipid bilayers while the plasma membrane is only one phospholipid bilayer. Both membranes are selectively permeable and have pores.
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
You buy a bunch of small, round, red radishes at the grocery store; they are on sale because they have been sitting in the produce aisle for a while. When you get home you remove the stems and clean them. With the first bite, you notice their texture is not as crisp and crunchy as you like. Your friend says you should refrigerate them in a bowl of water overnight. The next day the radishes are crisp and crunchy again. What is the most likely explanation of why they became crunchy again after soaking in water?
The radish cells were hypertonic to the water in which they were soaking. So, the water moved by osmosis across the plasma membranes into the radish cells increasing the turgorpressure inside of the cells and making them crunchier
what is the significance of crossing over
The resulting gametes will have different gene combinations than their parent cells' gene combinations
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 ofthe red blood cells (RBCs) do not look like the nice round donut shaped cells in your lab manual. Instead, the RBCs look very shriveled up. Your lab partner has also made a slide, but the RBCs on their slide do look like the ones in the lab manual; your lab partner used a more dilute solution of saline but the same vial of blood. What is the most plausible explanation for the appearance of the blood cells on your slide
The saline you used was hypertonic to the RBCs; this resulted in water osmosing through the RBC plasma membrane mostly out of the cell
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?
The samples must contain carbon atom
Which of the following statements is true
The scientific method or process can help people make informed medical and environmental decisions
Examine the figure below. If each sugar molecule represents a percentage point of sugar dissolved in the solution, what change would you expect to see in the solution level over time and why
The solution level on the left side of the figure would rise while the solution level on the right side of the figure would decrease. This is because the solution on the left side of the figure is hypertonic while the solution on the right side of the figure is hypotonic
Examine the figure below. If each sugar molecule represents a percentage point of sugar dissolved in the solution, what change would you expect to see in the solution level over time and why
There will be no net movement of water because the solutions are isotonic
Which of the following is a similarity between photosynthesis and respiration
They are both metabolic process
which of the following is true of the chromosomes in a homologous pair
They carry the same genes
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
Which of the following is correct about hydrogen bond?
They form due to partial positive and partial negative charges on atoms
What characteristic is NOT shared by all living organisms
They make their own energ
Why do scientists repeat their experiments over and over agian?
They must make sure the results were not an accident and that they are repeatable
Which of the following help increase the selective permeability of a phospholipid bilayer membrane
Transport proteins, channel proteins, and passive carrier proteins all help increase the selective permeability of a phospholipid bilayer membrane
Which of the following can be used to accurately describe viruse?
Typically just a piece of genetic material encased in proteins, viruses are small, non-cellular infectious agents that are only capable of reproducing when inside a living cell such as those of plants, animals, fungi, protozoans, or bacteria
what is the role of water in photosynthesis
Water provides electrons to the chlorophyll
some questions fall outside the realm of science. Which of the following questions could NOT be answered using the scientific method?
Why is it unethical to test newly developed drugs in animal?
cells contain the molecule GTP (guanosine triphosphate). Would this molecule be useful as an energy carrier (similar to ATP)?
Yes, because it contains the same number of phosphates as does ATP
Is it possible for scientists to study events that happened or animals/plants that lived millions of years ago?
Yes. Apply the laws of physics and nature that we know exist today to evaluate the evidence of past events. For example, observe modern animal behavior, structure, and function, and compare them to the structures of fossilized animals to deduce the function of the fossilized structures
is it important for scientists to communicate their results to 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 fiel
You are coughing and producing a wheezing sound as you breathe; you also have a fever. You go to the doctor who listens to your chest, takes X-rays of your chest, and determines that you probably have something called croup. Which of the following are the facts in this scenario?
You are coughing, wheezing, and have a fever
factory with an office that controls the information sent to separate rooms for each of the manufacturingand shipping processes would be analogous
a eukaryotic cell with a nucleus
A tissue is defined as
a group of cells that performs a unique set of tasks in the body
In making your morning tea, you drop a sugar cube into the hot water. You stir the mixture but no longer see the sugar cube at the bottom of your mug. In this scenario, the sugar is
a solute
Which of the following best exemplifies homologous chromosome
a tetrad
A solution with a pH of 3
acidic
Which of the following accurately describes the similarities between mitosis, meiosis, and binary fission
all three of the processes are used to produce daughter cells
Antibodies are an important class of human proteins that function in immune defense. If scientists fragmented antibodies under laboratory conditions, what chemical building blocks would they recover?
amino acids
In the laboratory you identify protein in a food item that you've tested. Which of the following must the food item also contain
amino acids
Which of the following is a monomer that can be commonly made from components in Earth's atmosphere?
amino acids
the G0 phase of the cell cycle is distinguished by
an absence of preparation for DNA synthesis
After adding a small amount of Solution A to Solution B, the pH of Solution B declines from 8 to 3. Solution A must contain
an acid
Which of the following foods is most likely to contain haploid cell
an egg
Bats use echolocation to orient themselves and locate objects. Doing this requires special adaptations in their inner ear, midbrain, and auditory cortex of their cerebrum. The echolocation system of bats is an example of
an organ system
A chemical reaction that uses ATP to build cellular components
anabolic
Cells that demonstrate anchorage independent
are primed to become metastatic
energy carriers NADPH and NADH differ structurally. Functionally they
are somewhat different; NADH is produced from catabolic processes, whereas NADPH is used in anabolic processes
Nucleotides
are the building blocks of nucleic acids
Which of the following types of organisms are commonly single-celled (unicellular)
bacteria, some fungi (yeast), and many protozoans
A researcher is recording the process of bacteria cell division using time-lapse microscopy. Which of the following processes would she be observing
binary fission
All of the following contribute to genetic uniqueness EXCEPt
binary fission.
Which of the following statements comparing photosynthesis and cellular respiration is accurate?
both photosynthesis and cellular respiration require electron transport chainl
plant cell is mutated so ATP synthase no longer functions. Which process will be affect
both photosynthesis and respiration
the process of mitosis is thought to have evolved from binary fission. What similarities exist between these processes
both processes include DNA segregati
Which of the following is a difference between binary fission and mitosis
breakdown of the nuclear envelope
Chemical reactions that break down lipids are
catabolic
Some kinds of drain cleaners use enzymes rather than strong, more dangerous chemicals. These enzymes must be able to
catalyze a catabolic reaction
Experimental studies are an effective way of establishing a ________ relationship between two or more aspects of the natural world because they provide a way of testing predicted interaction(s)
cause-effect
Observational studies typically point out correlations between aspects of the natural world, but they do not establish solid ________ relationships
cause-effect
which of the following pairs of processes encompasses the entire cell cycle
cell division and interphas
Dialysis tubing is a selectively permeable membrane that can be filled with a solution to simulate a cell. Apiece of dialysis tubing has been filled with a cloudy white solution of 5 percent starch, 5 percent egg albumin (protein), and 5 percent glucose (a small sugar) dissolved in water to simulate a cell. This cell is weighed and then placed in a beaker of 3 percent iodine dissolved in water. When iodine and starch are mixed together, they form a bluish-black compound that is easily seen. After soaking in the yellow iodine-water solution for one hour, the cell is once again weighed. You also notice that the solution inside of the cell is now a dark blue color while the solution in the beaker is still a light yellow color from the iodine. What do you expect to happen to the weight of the cell over time and what can you deduce from the colorchange?
cell should gain weight over time because it is hypertonic to the beaker environment and water will enter the cell through osmosis. The color change indicates that the iodine molecules were small enough to diffuse across the membrane and react with the starch inside the cell. No color change in the beaker tells us that the starch was too large to cross the membrane from the cell and into the beaker
Which of the following sequences correctly represents the biological hierarchy of a multicellular organism?
cells tissues organs individual
What should the arrow in the following equation be labeled? Sugar oxygen carbon dioxide water ATP.
cellular respiration
the circle near the center of this structure represent
centromere
A long piece of ribbon wired along both long edges is twisted into a helix and wrapped around individual pipe cleaners that have been rolled into spools; this grouping is then twisted (super coiled) again to condense it. This could be best used as a simple model
chromosome, where the pipe cleaners represent bundles of proteins around which the DNA double helix (wired ribbon) is wrapped
Some daughter cells are described as clones. For this description to be appropriate, the daughter cells must
contain a set of DNA that is identical to that of the parent cell
Carbon atoms are bound to each other by
covalent bond
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 cel
crossing over
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
Which of the following represents conducting an experiment?
dialing a telephone numbe
The caves in upstate New York, where Alan Hicks' team first noticed the deaths of thousands of bats, represent the
ecosystem where the bats lived
The subatomic particles that possess a single negative charge and surround the nucleus are
electrons
Carbon, hydrogen, and nitrogen are all examples of
elements
The first law of thermodynamics states that
energy cannot be created nor destroy
When ATP breaks down into ADP and a phosphate group
energy is released and can power cellular activities
the energy required for life processes must be extracted from an organism
environment
In the reaction H2O CO2 carbonic anhydrase H HCO3 carbonic anhydrase, carbonic anhydrase is a(n)
enzyme
useing the compound light microscope in the lab room, you observe a wet mount slide preparation. You observe layers of cells that have a definite, rigid, rectangular shape; there appears to be a nucleus in all of the cells and there are many oval-shaped green structures that seem to be moving around inside of the cells in an orderly fashion. What general cell type are you most likely observition
eukaryotic and plan
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 mitos
The human heart pumps blood throughout the blood vessels in the body. This is a scientific
fact
the enzyme rubisco is important to the process of
fermentation
hich two processes work in conjunction to create genetic diversity and maintain chromosome number
fertilization and meiosis
Which of the following is NOT a factor that influences a cell's progression through the cell cycle
gametes
In 1890, Robert Koch developed a hypothesis regarding the cause of communicable diseases. He designed an experiment and collected data that supported his hypothesis. Later, his experiment was repeated by many other scientists who used other pathogens and documented similar results that not only supported their hypotheses but also supported Koch's original hypothesis. These many experiments that supported multiple hypotheses regarding the cause of communicable diseases contributed to the development of the
germ theory of disease
Which step of cellular respiration occurs outside the mitochondria
glycolysis
the three stages of cellular respiration (in order) are
glycolysis, the Krebs cycle, and oxidative phosphorylation
David Blehert and his research team captured 117 healthy bats to study in the laboratory and divided theminto four groups. Group 1 was housed in an area free from Geomyces destructans. 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 thebats were monitored for signs of WNS. Which group is the control group?
group 1
Cancers are groups of cells that divide rapidly and uncontrollably. Thus, cancer cells
have a relatively short G1 phase
Living organisms maintain a constant internal environment by sensing and responding to their internal conditions. This stable maintenance of internal conditions is known
homeostasis.
Individual water molecules orient toward each other because of the ________ bonds that form between them.
hydrogen
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 hotwater, you properly conclude that the sugar
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 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
The possible combinations of alleles in gametes ________ due to independent assortment and crossing over
increases
A given enzyme
increases the rate of a particular reaction
New medications undergo extensive human testing before receiving FDA approval. These tests represent an experiment and variations in the dosage given to participants represents the
independent variable
A pool of cells is treated with a chemical that halts progress through the cell cycle. In which stage of the cell cycle would most cells be found
interphase
When sodium chloride (NaCl) is dissolved in water, the sodium ion
is attracted to the oxygen atoms of water molecule
he smooth endoplasmic reticulum
is the site where lipids destined for other cellular compartments are manufactution
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
Which of the following statements about cell division is correct
it is the process by which organisms grow and maintain their tissue
solid waste (garbage) transfer facility that sorts and breaks down garbage into recyclables and waste to be thrown away in the landfill would be a suitable analogy for which cellular organelle
lysosome
which of the following is associated with mitosis
maintenance of chromosome number
odel organisms (like mice) used in the study of genetic disease
may accurately reflect how diseases like cancer occur in human
Gametes are produced by meiosis rather than mitosis becacuse
meiosis reduces the chromosome number so that zygotes produced will have one full genome
The capture and use of energy by living organisms involves numerous chemical reactions. Collectively these processes are known
metabolism
Chromosomes are lined up at the middle of the cell during the ________ portion of cell division
metaphase
Which of the following is an organic compound?
methane (CH4)
Which of the following amino acids begins the construction of all proteins in the human body?
methionine
Your muscle cells need large amounts of ATP to function in the movement of your body. Which of the following organelles would you expect to be especially abundant in muscle cells
mitochondria
which of the following differentiates meiosis from mitosis
mitosis is used for the repair of cells, whereas meiosis creates cells for sexual reproduction
a human cell
nearly all chemical reactions are catalyzed by enzyme
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 measuredthe 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. Wasshe doing something scientific?
no, because she had no hypothesis to direct her data collection or interpretati
The boundary that surrounds the contents of the nucleus is
nuclear envelope
Adenine (A), thymine (T), guanine (G), and cytosine (C) are the ________ building blocks for DNA; theyare organized in different combinations to code for all of the proteins needed to accomplish everything thecell does
nucleotide
the genetic material found in all living things is made of building blocks called
nucleotides
Homologous chromosome
onsist of a maternal and paternal copy of each chromosome
Cells naturally without using energy, respond to changes in water concentration through the process
osmosis
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
During exercise, the increase in respiration rate and heartbeat speed are driven by the need to replenish the oxygen used to support
oxidative phosphorylation in muscle cell mitochondria
Which of the following solutions has the highest concentration of free H ions?
pH 1
the leaves of a plant typically have different tissue layers that function in different ways. The epidermis layer functions like a covering of skin to protect the leaf while vascular bundles carry water and nutrients through the leaf. The palisade mesophyll layer is responsible for most of the photosynthesis that occurs while the spongy mesophyll layer underneath it aids in the exchange of gases (CO2 and O2) and water vapor. In which leaf tissues would you expect to find the highest density of chloroplast
palisade mesophyll
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 importantscientific 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 publication
amoeba, a protozoan that moves by pseudopodia, approaches a smaller protozoan and extends its pseudopodia (extensions of cytoplasm in plasma membrane) around the smaller protozoan. Once the amoeba's pseudopodia completely surrounds the other protozoan, the amoeba's plasma membrane pinches off by folding back into the amoeba and creating a vesicle containing the smaller protozoan. This vesicle is now within the amoeba itself and will soon fuse with other vesicles containing digestive enzymes. This is an example
phagocytosis
white blood cell (WBC) encounters bacteria in a scrape on the knee of a child who has fallen off of his bicycle. The WBC's job is to take the bacteria inside of itself and destroy the bacteria. If the bacteria cannot be moved across the WBC membrane, how will the WBC most likely take in
phagocytosis
Living cells have an intact phospholipid bilayer that separates the cell from its external environment; this structure is commonly referred to as the
plasma membrane
Many important cellular functions in eukaryotic cells occur within membrane-enclosed organelles, such as cellular respiration occurring within the mitochondria. The membranes of the mitochondria provide a place for enzymes needed for cellular respiration to anchor and function. Prokaryotic cells must also carryout respiration but do not have mitochondria. Where is the most likely place that enzymes needed for cellular respiration are anchored and functioning
plasma membrane
Which of the following types of bonds hold hydrogen and oxygen atoms together within an individual water molecule?
polar covalent bond
Macromolecules are typically formed by repetitively adding small monomers together. Which macromolecule is properly matched with the appropriate monomer
polypeptide—amino acid
Experimentation is the primary, but not only, means used to verify or refute the ________ made by a hypothesis
predictions
The goal of meiosis is to
produce eggs and sperm
In the reaction C6H12O6 6 O2 6 CO2 6 H2O, the 6 CO2 molecules are some of them are
products
which of the following choices states a correct reason why the process of cell division is different for prokaryotic than for eukaryotic cells?
prokaryotes have a circular DNA molecule
which of the following is known to result from the disruption of mitosis and meiosis
prostate cancer
Ribosomes are very small nonmembranous organelles that can either exist freely in the cytoplasm or be embedded in the endoplasmic reticulum of a cell; they are associated with the synthesis
proteins.
In photosynthesis, the carbon used to make sugars is
provided by carbon dioxide
A protein molecule, transferrin, embedded in the plasma membrane recognizes iron molecules and causes the plasma membrane to fold in around the iron and take it into the cell. This is an example of
receptor-mediated endocytosis
Which of these characteristics of living organisms are present in viruses?
reproduce using DNA (or RNA); sense their environment and respond to it; can evolve as groups
Glycolysis is an anaerobic process, indicating that the glycolytic reaction
require no oxygen
Carbon dioxide is one product of a metabolic process, which occurs in both plants and animals. This process is called
respiration
you are a scientist observing a membrane through which water and some small hydrophobic molecules can freely pass along a concentration gradient from high to low. However, some sugar molecules are too large to pass through the membrane either way without the assistance of passive transport proteins. Additionally, small Na ions and some proteins can pass through the membrane against the concentration gradient, but both require the assistance of active transport proteins. What general type of membrane are you observing?
semipermeable
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?
simple diffusion
whiich of the following would be likely to require facilitated diffusion to move across the plasma membrane?
sodium ions (Na), hydrogen ions (H), sugars, and amino acid
when appropriately prompted, diploid individuals of Ulva prolifera form spores that germinate to becomehaploid 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
The Golgi apparatus
sorts proteins and lipids and sends them to their final destination
which of the following cell types is produced by meiosis
sperm cells
once supported by a predictable experimental outcome, a scientific hypot
still cannot be considered to have been proven true
A disaccharide consists of two
sugars
photosynthetic organisms capture energy from sunlight and convert it into chemical bonds by forming
sugars
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 ________ of mitosis
telophase
A scientific hypothesis must be ________; if not, science cannot evaluate it
testable
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
The illustration below indicates that photosynthesis and cellular respiration are both complementary and balanced. An excess of sugars produced fossil fuels like coal and petroleum; this suggest that in the
the amount of photosynthesis occurring exceeded the amount of cellular respiration
An experiment mixed together oil (lipids), organophosphate-containing detergent in water, and copper ions to act as a catalyst for a chemical reaction. Membranes budded off of the oil in this mixture. Which of the following is a reasonable and possible explanation of the experimental results?
the chemical reaction caused the organophosphates from the detergent to chemically combine with lipids from the oil to form phospholipids with hydrophilic heads and hydrophobic tails. The hydrophobic tails lined up towards each other with their hydrophilic heads pointing out towards the water; this configuration formed a phospholipid bilayer that pulled into a spherical liposome
Which of the following would promote a cell to move through the G2 checkpoint
the genetic information has been duplicate
What would occur if the mitochondria of a cell did not produce an inner membrane
the mitochondria would be unable to maintain the proton gradient required for ATP production.
screen door allows breezes to enter and aromas to exit but keeps out insects. Its function most resembles
the plasma membran
In science, when a hypothesis or group of hypotheses supported by repeated experimental evidence holds true through time, it can be developed into a ________. It is not a guess. It is not static. It is tentative and dynamic and can be adjusted when new, compelling evidence is discovered. It is typically an overarching explanation that best fits all of the available information or evidence
theory
A researcher wanted to determine if consuming diet sodas causes diabetes. He conducted a study in whichsubjects 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?
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 establish
A species of butterflies gradually becomes darker in color over many generations; this is an example of which characteristic of living organisms?
they can evolve as group
Which of the following statements is true of chloroplast?
they capture energy from sunligh
Enzymes can catalyze a reaction only
they encounter a substrate that fits their active site
The roots of a sunflower plant growing downwards while the shoot grows upwards and the flower turns towards the sun are examples of what characteristic of all living organism
they sense the environment and respond to it
Whenever we ________, we are proceeding scientifically
try to solve a problem by systematically evaluating the plausibility of various solutions
In living systems, a critical component of many reaction is
water
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
which of the following would be likely to move through a plasma membrane by simple diffusion
water (H2O), carbon dioxide (CO2), oxygen (O2)
Oil and water do not mix together well because
water is polar and oil is nonpolar
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, which way will the water move and why
water will mostly move from side "A" to side "B" because the water concentration is higher on side "A.
the image below diagrams the action of an enzyme. Notice that the enzyme is depicted as being more tightly wrapped around the substrates in step 2 than it is in step 1. Why is this?
when a substrate locks into the active site of an enzyme, the enzyme changes shape to mold itself around the substrates
Which of the following would be the best analogy for the function of the Golgi apparatus
worker in a factory who places labels on products and then packs them into a shipping box
the successful union of one male and one female gamete forms a new single cell known
zygote
