BIOL Chapter 1,2,3,4 quiz
This atom can form up to _____ single covalent bond(s).
4
Some athletes use anabolic steroids to build their body mass. Why is this considered a problematic practice, especially in adolescents?
Anabolic steroids can prevent bone growth.
The DNA-containing region of this bacterial cell is indicated by the letter _____.
D
Prokaryotic cells are found in the domain(s) _____.
bacteria and archaea
Which element is closely associated with the field of organic chemistry?
carbon
Which of these is a polysaccharide?
cellulose
Which of the following organelles breaks down worn-out organelles?
lysosomes
What carries instructions for making proteins from the nucleus into the cytoplasm?
mRNA
The lipids that form the main structural component of cell membranes are _____.
phospholipids
The _____ is the bacterial structure that acts as a selective barrier, allowing nutrients to enter the cell and wastes to leave the cell.
plasma membrane
Arrow D is indicating a _____ protein.
receptor
This figure is an example of a(n) _____.
saturated fat
You would expect a cell with an extensive Golgi apparatus to _____.
secrete a lot of material
Hunt and her team designed an experiment to test her hypothesis about the effect of BPA on mice. They administered daily doses of BPA to groups of female mice over three, five, or seven days and then tested these mice for genetic abnormalities that occur during meiosis, the division of chromosomes during egg formation. Drag the labels to identify the components of Hunt's experiment. Labels may be used once, more than once, or not at all.
0ng/g: control 20ng/g: treatment 40ng/g: treatment 100ng/g: treatment -dosage of bpa administered is an independent variable -the length of time over which mice were exposed to bpa is an independent variable -the percentage of mice display genetic abnormalities is the dependent variable
About _____ molecules in a glass of water are dissociated.
1 in 500,000,000
What is the charge on a hydronium ion?
1+
What is the charge on a hydroxide ion?
1-
Why doesn't the antibiotic penicillin harm humans?
Human cells do not have cell walls.
An enzyme speeds up reactions by lowering the ___ .
activation energy
An enzyme is specific because the shape of its ___ matches only particular reactants.
active site
A function of cholesterol that does not harm health is its role _____.
as a component of animal cell membranes
Mitochondria are found in _____.
both plant cells and animal cells
A(n) ___, which is often a vitamin, binds to an enzyme and plays a role in catalysis.
coenzyme
A(n) _____ bond joins these two oxygen atoms.
double covalent
Which technique allowed scientists to figure out that all cells, and not just muscle cells, contained actin filaments?
electron microscopy
Which of these are by-products of cellular respiration?
heat and water Submit
You know that this cell is in a(n) _____ solution because the cell _____.
hypotonic ... swelled
Which of these is a source of lactose?
milk
Which of these is rich in unsaturated fats?
olive oil
Which of these does NOT contain a structural protein?
ovalbumin
In a bacterium, where are proteins synthesized?
ribosomes
One of the ways smooth endoplasmic reticulum (ER) differs from rough endoplasmic reticulum is that rough ER is covered by
ribosomes.
Pancreatic cells produce large amounts of protein. About how many ribosomes would you expect there to be in a pancreatic cell?
several million
A protein's alpha helices and beta sheets fold together to create an overall shape at the _____ level of protein structure.
third
Water crosses the plasma membrane
through facilitated diffusion or diffusion.
Which of these illustrates the secondary structure of a protein?
(squiggle and folds pictures - just one string)
Which of these functional groups is found in all amino acids?
-NH2
_____ are surface appendages that allow a bacterium to stick to a surface.
Fimbriae
Structure B is a _____.
transport protein
1 meter = _____ centimeters.
100
The innermost electron shell of an atom can hold up to _____ electrons.
2
If a strand of DNA has the nitrogen base sequence 5'-ATTTGC-3', what will be the sequence of the matching strand?
3'-TAAACG-5'
A 100 mm x 100 mm x 100 mm cell has a surface area that is _____ and a volume that is _____. When this volume is broken into many smaller cells, that are 10 mm x 10 mm x 10 mm, the sum of the surface areas of the smaller cells is _____ than the surface area of the initial cell.
60,000 mm2 ... 1,000,000 mm3 ... larger
If a DNA double helix is 100 nucleotide pairs long and contains 25 adenine bases, how many guanine bases does it contain?
75
Which of the following statements accurately describes a typical gene?
A gene is a segment of DNA that directs the synthesis of a specific protein.
How did this molecule form?
A water molecule gained an hydrogen ion from another water molecule.
Which of the following is a difference between active transport and facilitated diffusion?
Active transport requires the expenditure of cellular energy, and facilitated diffusion does not.
_____ is the most abundant organic compound on Earth.
Cellulose
_____ are found only in plant cells, but _____ are found in both plant and animal cells.
Central vacuoles; ribosomes
Which of the following is true with regard to the relationship between ecosystems and communities?
Ecosystems include the nonliving components of an environment; communities include only the living components of an environment.
If you want a molecule that is highly polar, look for one that contains:
H-N
Which of these is the correct equation for the dissociation of water?
H2O + H2O <==> H3O+ + OH-
Which three statements are supported by the data in the graph?
Heart attack patients have higher levels of trans fats in their adipose tissue than non-heart attack patients. Non-heart attack patient would have nearly 3g of trans fats in 200 g of adipose tissue, on average. 1.77% of the total fat in heart attack patients is trans fats. Submit
What does the term amino acid signify about the structure of the molecule?
It consists of an amino group and a carboxyl group.
Which of the following statements regarding lactose tolerance is true?
Lactose tolerance has evolved independently in multiple different human populations.
Which answer correctly ranks the atoms in terms of decreasing electronegativity (the highest electronegativity first)?
O, N, C, H
Which of the following statements is NOT true about discoveries that have been made as a result of comparison of DNA sequences across many species?
Organisms possessing a genetic code drastically different from that used by humans have been discovered.
Which of these is NOT a lipid?
RNA
Use the graph and your knowledge of enzymes to identify the three true statements about enzymes.
Reactants cannot convert to products without an initial input of energy to start the reaction. Enzymes lower the overall energy input needed for a reaction to occur. By binding to reactant molecules, enzymes make it easier for the bonds in the molecules to break apart.
Which of these statements is TRUE with regard to this animation?
Sodium and potassium ions are transported against their concentration gradients. Submit
Which of the following is a function of the central vacuole?
Storing compounds produced by the cell Submit
Which atom in the pictured molecule will have the strongest partial positive charge?
The C that's in C=O.
In the figure below, what leads directly to the reproductive success of these beetles?
The beetles with traits best suited to the environment survive.
Which of the following describes the function of the chloroplast?
The chloroplast converts light energy to chemical energy.
Which of the following is an example of an emergent property?
When gears and other structures are assembled into a bicycle, the entire assembly can propel the rider.
Glycogen is _____.
a polysaccharide found in animals
Which of these is exhibiting kinetic energy?
a space station orbiting Earth
Proteins are polymers of _____.
amino acids
An ionic bond involves _____.
an attraction between ions of opposite charge
An enzyme is considered a(n) ___ because it speeds up a chemical reaction without being used up.
catalyst
What name is given to the rigid structure, found outside the plasma membrane, that surrounds and supports the bacterial cell?
cell wall
Azidothymidine (AZT) is an antiretroviral drug used in the treatment of HIV. It shares a structural similarity to a nucleotide. What might be the mode of action for this drug?
competitive inhibition
What type of bond is joining the two hydrogen atoms?
covalent
The structural framework in a cell is the
cytoskeleton
What is another name for a condensation reaction?
dehydration
High temperatures or changes in pH can ___ an enzyme, causing it to lose its shape and biological activity.
denature
The primary role of _____ is to bind animal cells together.
desmosomes
To view the animation, click here. Then click on the image to start the animation. This animation illustrates the _____ of water.
dissociation
A phrase that applies to covalent bonding and not other kinds of bonds is ...
electron-sharing.
A substance that cannot be broken down into other substances by ordinary chemical procedures is known as a(n) _____.
element
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
endocytosis
Fungi are classified into which Domain?
eukarya
A rose bush is classified in domain _____ and kingdom _____.
eukarya...plantea
A human is classified in domain _____ and kingdom _____.
eukaryotes..animalia
The ideal osmotic environment for a plant cell is a(n) ___ environment.
hypotonic
The ___between an active site and its substrate often strains bonds and helps the reaction proceed.
induced fit
Endocytosis moves materials _____ a cell via _____.
into ... membranous vesicles
In salt, what is the nature of the bond between sodium and chlorine?
ionic
glucose + glucose —> _____ by _____.
maltose + water ... dehydration synthesis
Mitochondria appear in the greatest numbers in cells that are _____.
metabolically active
Where is the genetic information of the cell stored?
nucleus
What name is given to the process by which water crosses a selectively permeable membrane?
osmosis
A nucleotide is composed of a(n) _____.
phosphate group, a nitrogen-containing base, and a five-carbon sugar
Of the following organelles, which group is involved in manufacturing the substances needed by the cell?
ribosome, rough endoplasmic reticulum, smooth endoplasmic reticulum
Your body contains thousands of different types of proteins, each with a specific function. A protein's function is largely determined by its _____.
shape
What type of bond joins the carbon atom to each of the hydrogen atoms?
single (nonpolar) covalent Submit
Structure A is a _____.
solute
Arrow A is indicating a(n) _____ protein.
structural
In a catalyzed reaction, a reactant is often called a(n) ___.
substrate
What determines the types of chemical reactions that an atom participates in?
the number of electrons in the outermost electron shell
You are working on a team that is designing a new drug. For this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells?
the similarity of the drug molecule to other molecules that are transported into the target cells
The chemical energy used by most organisms for metabolism and growth ultimately comes from __________.
the sun
Researchers studying the effects of toxic wastes knew that animals were poisoned by the heavy metal cadmium, but they wanted to know where cadmium accumulated in the body. They could find out by _____.
tracing the movement of cadmium isotopes in test animals
The two strands of a DNA double helix are held together by _____ that form between pairs of nitrogenous bases.
hydrogen bonds
The secondary structure of a protein results from _____.
hydrogen bonds Submit
What is the name of the process during which a bond between two monomers is broken?
hydrolysis
What name is given to this molecule?
hydronium ion
What name is given to this molecule?
hydroxide ion
A plant cell placed in a(n) ____ solution will lose water and plasmolyze.
hypertonic
There is a net diffusion of water out of an animal cell when it is placed in a(n) ___ solution.
hypertonic
This cell is in a(n) _____ solution.
hypertonic
You know that this cell is in a(n) _____ solution because it _____.
hypertonic solution ... lost water
. An animal cell placed in a(n) ___ solution will gain water, swell, and possibly burst.
hypotonic
Defensive proteins are manufactured by the _____ system.
immune
The levels of carbon dioxide are expected to _____ of our oceans.
increase and lower the pH
What changes would you expect to see in the liver cells of someone suffering from chronic alcoholism?
increased levels of endoplasmic reticulum activity
The plant cell wall
is a protective structure made of cellulose fibrils.
1. The ideal osmotic environment for an animal cell is a(n) ___ environment.
isotonic
A plant cell surrounded by a(n) ___ solution will be flaccid (limp).
isotonic
The cilia and flagella of eukaryotic cells are composed of _____.
microtubules
When elongated, tube-shaped cells from the lining of the intestine are treated with a certain chemical, the cells sag and become rounded. The internal structures disrupted by this chemical are probably __________.
microtubules
Where in a cell is ATP made?
mitochondria
A(n) _____ refers to two or more atoms held together by covalent bonds.
molecule
In active transport,
molecules move across the plasma membrane against their concentration gradient. Submit
When molecules move down their concentration gradient, they move from where they are ____ to where they are ___.
more concentrated, less concentrated
The synthesis of an amino acid follows this pathway: precursor A > intermediate B > amino acid C. Each reaction is catalyzed by a different enzyme. This metabolic pathway is controlled by feedback inhibition with amino acid C inhibiting the conversion of precursor A to intermediate B. Amino acid C acts as a _____ of the first enzyme in the pathway.
noncompetitive inhibitor
Where is a bacterial cell's DNA found?
nucleoid region
Drag the correct description under each cell structure to identify the role it plays in the cell.
nucleus: Stores the genetic information of the cell. lysosome: Breaks down macromolecules using digestive enzymes. mitochondrion: Converts chemical fuel ino packets of chemical energy that can power the cell. proteins: Works with mRNA to synthesize proteins. smooth er: Site of lipid synthesis
Can you identify the steps in the scientific method that correspond to Hunt's experiments? Drag each statement under the step in the scientific method that it demonstrates.
observations: the eggs of mice in plastic cages... question: could bisphenol a... hypothesis: the frequency of genetic abnorm... prediction: if mice are exposed to elevated... test: hunt set up an experiment... results: hunt gathered experimental data...
Digestive cells produce and secrete many enzymes that break down ingested food. These cells have a large number of ribosomes __________.
on the rough endoplasmic reticulum Submit
There is (are) _____ eukaryotic domain(s).
one
Flagella and cilia are both composed of tubulin subunits. Despite this similarity, key differences exist between these two structures. For example, __________.
only cilia move as a coordinated team
Diffusion across a biological membrane is called ____.
passive transport
Facilitated diffusion is a type of _____.
passive transport
What type of bond joins the monomers in a protein's primary structure?
peptide
Tertiary structure is NOT directly dependent on _____.
peptide bonds
A white blood cell engulfing a bacterium is an example of _____.
phagocytosis
What structure acts as a selective barrier, regulating the traffic of materials into and out of the cell?
plasma membrane
In plants, __________ are the cell junctions that allow the free exchange of small molecules that assist in communication. In animal cells, similar cell junctions are known as __________.
plasmodesmata ... gap junctions
Which of the following foods would contain the most starch?
potatoes
Chemical energy is a form of _____ energy.
potential
What is the function of a bacterium's capsule?
protection
Which curve shows the course of the reaction in the presence of an enzyme--the black curve or the red curve? Which line represents the activation energy for that reaction--a, b, or c?
red curve; line b
Where are lipids made in the cell?
smooth endoplasmic reticulum (ER)
Grapefruit juice is approximately pH 3, and tomato juice is approximately pH 4. A glass of grapefruit juice contains _____ H+ as a glass of tomato juice.
ten times as much
Which of the following would be affected when a protein is denatured?
tertiary structure
Lysosomes are derived from __________ and function in __________.
the Golgi apparatus and rough endoplasmic reticulum ... digestion of worn-out organelles
You can recognize the process of pinocytosis when _____.
the cell is engulfing extracellular fluid
Osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. What really drives osmosis?
the difference in water concentration across a selectively permeable membrane
Which of these cell junctions form a barrier to the passage of materials?
tight junctions
Aquaporins are proteins that facilitate the transport of __________ across the membrane.
water
Astrobiologists searching for signs of life on other planets primarily search for __________.
water
In the figure below, working from the inside out, what would be the order of components observed?
water, hydrophilic head, hydrophobic tail, hydrophobic tail, hydrophilic head, water
Which of the following clues would tell you whether a cell is prokaryotic or eukaryotic?
whether or not the cell is partitioned into compartments by internal membranes Submit
Polymers that contain sugars ...
(a) may store hereditary information. (b) may store energy. (c) may protect cells.
Which of these is a phospholipid?
(broken leg looking graph)
Which of these figures correctly illustrates the nature of the bonding of H2O?
-,+ -
A chemical bond is a strong attraction between two or more atoms. Can you identify the properties of different types of chemical bonds? Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
1. A(n) ionic bond forms when one atom gives up one or more electrons to another atom. 2. Atoms or molecules with a net electric charge due to the loss or gain of one or more electrons are ions. 3. A(n) covalent bond involves the sharing of electron pairs between atoms, also known as a molecular bond. 4. When one pair of electrons is shared between two atoms, a single bond is formed. 5. When two pairs of electrons are shared between two atoms, a double bond is formed. 6. A polar bond is a type of chemical bond where a pair of electrons is unequally shared between two atoms. As a result, one end of the molecule has a slightly negative charge and the other a slightly positive charge. 7. Atoms involved in a nonpolar bond equally share electrons; there is no charge separation to the molecule. 8. A weak bond called a hydrogen bond results from an attraction between a slightly positive region in a molecule and a slightly negative region in the same or a different molecule.
Can you match the structures with their descriptions? Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
1. DNA is the self-replicating material present in nearly all living organisms; it is the main constituent of chromosomes and the carrier of genetic information. 2. RNA is used in all steps of protein synthesis and carries the genetic information of many viruses. 3. The nucleus is the most prominent membrane-bound organelle in eukaryotic cells, and it houses most of a cell's DNA. 4. The nuclear envelope is the two-layered membrane that encases the nucleus of a eukaryotic cell, separating the nucleus from the cytoplasm. 5. A protein-lined channel in the nuclear envelope that regulates the transportation of molecules between the nucleus and the cytoplasm is called a nuclear pore. 6. The round body that sits inside the nucleus of a eukaryotic cell and makes ribosomal subunits from proteins and ribosomal RNA is known as the nucleolus. 7. Chromosomes are tightly coiled bundles of DNA and protein found in the nucleus of most living cells.
Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used.
1. Lipids are diverse compounds that are grouped together because they are hydrophobic. 2. A fat molecule is composed of two types of smaller molecules: glycerol and fatty acids. 3. A fatty acid consists of a carboxyl group and a long hydrocarbon chain. 4. Unsaturated fatty acids have one or more double bonds in their hydrocarbon chains and are usually found in vegetable oils. 5. The hydrocarbon chains of saturated fatty acids are not kinked, and thus pack closely together, making animal fats solid at room temperature. 6. Phospholipids are a major component of cell membranes. They form a bilayer with their hydrophobic tails mingling together and their hydrophilic heads facing the watery environment on both sides of the membrane. 7. Steroids are lipids with a structure consisting of four fused rings. Many sex hormones are made from this type of lipid.
Experiments in environmental toxicology can sometimes be manipulative experiments in which the researcher actively chooses and manipulates the independent variable. In Hunt's study, for example, dosages of BPA were manipulated and the effects were measured. In manipulative studies, the researcher controls all the other variables in the experiment, so any health effects observed in the test subjects can be attributed to differences in the independent variable.In other cases, researchers use natural experiments in which the dependent variable (typically a measure of organism health) is measured under differing contexts that are not manipulated. Say, for example, that an accidental chemical spill contaminates five ponds. To determine the possible effects of the toxic chemical on frogs, a researcher could compare the hatching rate of frog eggs laid in those five ponds to the hatching rate of eggs laid in five uncontaminated ponds nearby. This would be an example of a natural experiment because concentrations of the toxic chemical in the ponds were not controlled by the experimenter, but rather resulted from the chemical spill. Drag type of experiment on the left to the example of experiment on the right.
1. Natural: Blood concentrations of BPA in college students are compared to their recent consumption of canned food items. 2. Natural: The feeding behavior of fish in streams that receive acidic runoff from strip mines is compared to the feeding behavior of fish in unaffected streams. 3. Natural: The deformity rate in baby birds from nests in pesticide-sprayed fields is compared to the deformity rate in birds from nests in unsprayed fields. 4. Manipulative: Tumor development is compared in mice exposed to five dosages of a known carcinogen in the laboratory. 5. Manipulative: Foraging activity levels are compared in tadpoles exposed to four concentrations of toxic metals in the laboratory. 6. Manipulative: Growth of corn plants is compared in field plots sprayed with three different dosages of weed killer. 7. Natural: BPA concentrations in the urine of people with diabetes are compared to BPA concentrations in the urine of people without diabetes.
Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
1. Nucleic acids are polymers of nucleotides. 2. The monomers of nucleic acids consist of a phosphate group, a five-carbon sugar, and a nitrogenous base. 3. DNA (deoxyribonucleic acid) provides directions for its own replication. It also directs cell activities by providing instructions for building proteins. 4. A gene provides the directions to build a molecule of RNA (ribonucleic acid); the genetic instructions it carries are then translated into the amino acid sequence of a protein. 5. A polynucleotide has a repeating sugar-phosphate backbone. 6. The structure of DNA is a double helix, held together by the complementary base-pairing of cytosine with guanine, and adenine with thymine. 7. RNA usually consists of a single polynucleotide strand.
Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used.
1. Scientists use a general process known as scientific inquiry to ask and answer questions about nature. 2. Using a type of logic known as inductive reasoning, a generalized conclusion can often be drawn from a large number of specific observations. 3. A(n) hypothesis is a proposed explanation for a set of observations. It leads to predictions that can be tested by additional observations or by experiments. 4. Deductive reasoning uses ''if . . . then'' logic to proceed from a general hypothesis to specific predictions of results that can be expected if the general premise is true. 5. A hypothesis must be testable and falsifiable--there must be some observation or experiment that could show that it is not true. 6. A(n) controlled experiment involves both an experimental group and a control group, which are alike except for the one variable that the experiment is designed to test. 7. A(n) theory is broader in scope than a hypothesis, is supported by a large body of evidence, and generates many new hypotheses.
Drag the terms on the left to the appropriate blanks on the right to complete the sentences. Not all terms will be used.
1. The equation shows a chemical reaction --the breaking and forming of chemical bonds that leads to a change in the composition of matter. 2. In the equation, CO2 is a reactant. 3. In the equation, C6H12O6 is a product. 4. In O2, the type of bond that holds the two oxygen atoms together is a nonpolar covalent bond. 5. In H2O, the type of bond that holds one of the hydrogen atoms to the oxygen atom is a polar covalent bond. 6. The number of oxygen atoms on the left side of the equation is equal to the number of oxygen atoms on the right side.
Match the words in the left column to the appropriate blanks in the sentences on the right.
1. The term for a solution with a low pH number, such as lemon juice or vinegar, is acidic. 2. The term for a solution that has an equal concentration of H+ and OH- is neutral. 3. The term for a solution with a high pH number, such as ammonia or bleach, is basic. 4. An acid is a compound that donates H+ to a solution. 5. The higher the pH number, the higher the concentration of OH- in a solution. 6. A substance that accepts H+ when they are in excess and donates H+ when their concentration drops is called a(n) buffer.
Can you match these key science terms with their definitions? Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
1. The type of test that changes only one variable at a time in order to isolate the results is known as a controlled experiment. 2. The one variable that is manipulated by a scientist as a potential cause in an experiment is the independent variable. 3. The dependent variable is the factor a scientist observes to see the effect of the change made. 4. A control group establishes a base line for an experiment. 5. A negative control is a group in which no response is expected. 6. A positive control is a group in which a known response is expected. 7. In a single-blind experiment, the researchers--but not the participants--know who receives the treatment and who does not, to eliminate subjective bias. 8. In a double-blind experiment, neither the participants nor the researchers know who receives the treatment and who does not.
There are many elements to the scientific method. Can you match the terms with their definitions below? Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
A(n) hypothesis is a proposed, testable explanation for an observation. A(n) variable is a factor that changes during an experiment. A(n) control group in an experiment yields data against which other groups are compared. A(n) experimental group differs from the control group by the one variable that is being tested in the experiment.
It is helpful to form hypotheses because they help focus your investigation on a single idea to be tested. Suppose that a farmer wants to determine what the best growing conditions are for almond trees on his farm. Which of the following are appropriate hypotheses that the farmer could test? Select all that apply.
Almond trees grow taller when they are planted in direct sunlight. Almond trees live longer if fertilizer is mixed into the soil once every three months. Almond trees produce more almonds if they are watered once a day.
Drug-resistant tuberculosis is a major health issue in many countries. Treatment for these resistant forms of bacteria is longer and requires more expensive antibiotics. Scientists attribute this to natural selection. Under these circumstances, what does natural selection mean?
An environment was created in which the tuberculosis bacterium carrying the antibiotic-resistant genes had an increased likelihood of survival and reproduction.
Can you match the terms with their definitions? Drag the terms on the left to the appropriate blanks on the right to complete the sentences.
Atomic number is the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table. The number of protons plus neutrons in an atom, represented as an average of all naturally occurring forms of the element, is known as atomic weight. Trace elements, also called micronutrients, are any chemical element required by living organisms in miniscule amounts, but cells require them to survive. Nitrogen is one of the four elements that make up 96.3% of living cells. Calcium is one of the seven elements that make up a small fraction, approximately 3.7%, of living cells. Zinc is one of the fourteen trace elements and is a component of certain digestive enzymes and other proteins.
Cells A and B are the same size and shape, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell _____ because _____.
B ... the diffusion gradient there is steeper
The structure that regulates the passage of material into and out of this bacterial cell is indicated by the letter _____.
C
Can you match the characteristics with the correct organelle? Sort each structure or function depending on whether it describes a chloroplast or a mitochondrion.
Chloroplast: organelle of photosynthesis found only in plant cells and some algae converts solar energy to chemical energy contains thylakoids produces O2 as a waste product Mitochondrion: organelle of cellular respiration found in both animal cells and plant cells harvests chemical energy from food produces CO2 as a waste product
__________ is the most prevalent glycoprotein in the extracellular matrix
Collagen
Which of the following analogies best describes the process of science?
Driving to and from work every day but needing to travel via different streets to avoid traffic
Which Domain(s) includes unicellular orgainsms?
Eukarya, Archaea, Bacteria
_____ aid in the coordination of the activities of adjacent animal cells.
Gap (communicating) junctions
Which of the following is part of the endomembrane system?
Golgi apparatus
When water freezes, ice floats. Why?
In ice, the water molecules are farther apart than in liquid water.
What happens to the shape and function of a protein if one of the amino acids is replaced with a different type of amino acid?
It depends on the role of the amino acid that is altered. One amino acid might be replaced with no measurable effect on the protein's function; replacing another might cause a total loss of function.
Which plant cell organelle converts chemical fuel into packets of chemical energy that can power the cell?
Mitochondrion.
Which of these is a scientific hypothesis?
My excessive urination may mean that I have high blood pressure.
Use your knowledge of electronegativity to pick out the most polar bond in the list below.
O-H
In the video, you saw that making cookies is an example of using the scientific method. Match the steps of the scientific method with the examples.
Observation You like some chocolate chip cookie recipes better than others. Question Does the type of flour you use make a difference? Hypothesis Cake flour works better than regular flour. Experiment You make one batch of cookies with regular flour and another with cake flour. Results Using cake flour makes the cookies soft, which you prefer.
Match the monomers with their polymers.
Protein polymers are made up of amino acid monomers. Nucleic acid polymers are made up of nucleotide monomers. Carbohydrate polymers are made up of simple sugar monomers.
There are many elements to the process of science. Can you match the elements to the examples that occurred in Yoel's story? Drag the terms on the left to the appropriate blanks on the right.
Scientific community analysis and feedback: Yoel submitted an article describing his results, which was reviewed by other scientists. Forming and testing hypotheses: Yoel collected data on the size of green anole toe pads. Societal benefits and outcomes: Politicians may develop new policies to protect species from environmental changes. Exploration and discovery: Yoel read literature about Todd Campbell's work with green and brown anoles.
Part complete What is the benefit of the red panda's enlarged radial sesamoid?
The enlarged radial sesamoid acts as a "false thumb," enabling the red panda to grasp objects by pressing one or more of its parallel digits to this "thumb."
Biologists use the fluid mosaic model to describe membrane structure. Which statements about the fluid mosaic structure of a membrane are correct? Select the three correct statements.
The framework of a membrane is a bilayer of phospholipids with their hydrophilic heads facing the aqueous environment inside and outside of the cell and their hydrophobic tails clustered in the center.Because membranes are fluid, membrane proteins and phospholipids can drift about in the membrane.The diverse proteins found in and attached to membranes perform many important functions.The kinky tails of some proteins help keep the membrane fluid by preventing the component molecules from packing solidly together.
Experimental results often can be explained by multiple hypotheses. This is one reason why a thorough peer review process is required so as to ensure that scientists fully consider all possibilities. Which of the following alternate hypotheses could explain Yoel's results that on some islands, green anole lizards live higher in the trees and have larger toe pads?
The introduction of a predator that lives on the ground caused the green anole lizard population to evolve.
Which of these relationships is true of an uncharged atom?
The number of protons is equal to the number of electrons.
One function of the central vacuole in plant cells is facilitating cell growth: the central vacuole absorbs water and increases in size, expanding the volume and size of the plant cell while doing so. Animal cells, however, do not grow by this method. What is an essential difference between animal and plant cells that could explain how a plant cell can withstand this expansion of the central vacuole?
The plant cell wall provides a more rigid structure.
Taq polymerase is an enzyme isolated from the organism Thermophilus aquaticus. This organism has been found living in the hot springs of Yellowstone National Park. This enzyme is used to copy human DNA from crime scenes. Most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme?
The temperature should be raised. Submit
How does the level of trans fats in non-heart attack patients compare to the level of trans fats in heart attack patients?
The trans fats level in non-heart attack patients is 84% of the level in heart attack patients.
Lactase is essential for digesting lactose in milk. This enzyme is specific for this sugar. Why?
There is a precise compatibility between the active site and the lactose molecule.
Consider the figure shown below. What one characteristic is shared by sucrose and maltose?
They are all disaccharides.
What do the rough endoplasmic reticulum, Golgi apparatus, and lysosomes have in common?
They are constructed of interrelated membranes.
Which of the following statements is true about the chemical nutrients in an ecosystem?
They cycle within the ecosystem and are constantly reused.
Dr. Haxton says the O-O bond is polar and the C-C bond is nonpolar. A good student would say ...
Wrong again, Ralph. Both bonds are nonpolar.
Suppose that in addition to measuring the size of the green anole lizards' toe pads, Yoel also decided to examine their diet to see if it had changed as a result of living higher in the trees. Which experiment would best determine if the green anole lizards' diet was affected by their change in habitat?
Yoel should compare the diet of green anole lizards from islands where no brown anole lizards live to the diet of green anole lizards from islands where green and brown anole lizards live.
In this diagram of the plasma membranes of two adjoining cells, identify the protein indicated by the white arrow, including its function.
a receptor protein that binds with a signaling molecule and relays the message into the cell by activating other molecules inside the cell
Drag the labels to their appropriate locations in this diagram. First use pink labels to identify the atoms and charges. Then use blue labels to identify the bonds. Labels can be used once, more than once, or not at all.
a. H b. O c. H d. + e. - f. polar covalent bond g. hydrogen bond
Can you label the structures of a plant cell? To review the structure of a plant cell, watch this BioFlix animation: Tour of a Plant Cell.
a. central vacuole b. cell wall c. chloropast d. golgi apparatus e. smooth endoplasmic (er) f. rough endoplasmic (er g. nucleus h. mitochondrion
Drag the labels onto the diagram to identify the structures of an animal cell.
a. cytoskeleton b. ribosomes c. nucleus d. smooth endoplasmic (er) e. cytosol f. golgi apparatus g. rough endoplasmic (er) h. mitochondrion i. plasma membrane
Drag the labels to the appropriate locations in this diagram. First drag pink labels to pink targets to label the two host cells. Then drag blue labels to blue targets to label the structures and endosymbionts of the two cells.
a. oxygen-using prokaryotes b. mitochodrion c. nucleus d. endoplasmic reticulum e. host cells: ancestors of all eukariots f. photosyntheic prokaryotes g. chloroplast h. host cell: ancestors of photosynthetic eukaryotes
Drag the labels to the appropriate locations in this diagram. Drag labels to targets in Group 1 to identify the main functions of membrane proteins. Drag labels to targets in Group 2 to identify some components associated with the plasma membrane.
a. phospholipid bilayer b. fibers of extracellular matrix c. enzymatic activity d. microfilaments of cytoskeleton e. attachments to emc and cytoskeleton f. signal reception and relay g. transport h. intercellular junctions i. cell-cell recognition
Drag the vocabulary terms onto this concept map about the components of an atom.
a. protons b. neutrons c. electrons d. +1 e. nucleus f. -1 g. atomic number h. mass number
When in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. This molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. Using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane?
active transport
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
active transport.
Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____.
actively pump water back into their cells to counter its loss due to osmosis
What property of water makes it move upward from the roots of plants?
adhesion cohesion
The scientific method is a process that is used by everyone in their daily lives, not just by scientists in a research lab. Which of the following scenarios describe people using steps of the scientific method? Select all that apply.
all
The primary structure of a protein is like the arrangement of beads on a string. In this analogy, the beads are _____.
amino acids
A typical soda contains sugar, flavorings, coloring agents, and carbon dioxide that have been dissolved in water. Soda is therefore _____.
an aqueous solution
Atoms with the same number of protons but with different electrical charges _____.
are different ions Submit
Drag the correct label under each cell structure to identify whether it is found only in animal cells, only in plant cells, or in both types of cells. Labels can be used once or more than once.
cell wall: Found in PLANT cells but not animal cells nucleus: Found in both PLANT and ANIMAL cells lysosome: Found in ANIMAL cells but not most plant cells chloroplast: Found in PLANT cells but not animal cells rough endoplsmic (ER): Found in both PLANT and ANIMAL cells
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
cellular respiration
A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via __________.
endocytosis
"Conservation of energy" refers to the fact that _____.
energy cannot be created or destroyed but can be converted from one form to another
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
facilitated diffusion.
Large proteins, like DNA polymerase and hemoglobin, are often composed of several polypeptides that are linked together. The _____ level of protein structure describes how the polypeptides are joined to create a larger complex.
fourth