BIO 181 U2 EXAM REVIEW

you are given two nucleic acids; one RNA and the other DNA. what are the main features to determine which is the DNA a) DNA will have thymine instead of uracil in its nitrogenous bases b) DNA will have a double stranded structure c) DNA will have ribose as the sugar in its backbone d) DNA will have uracil instead of thymine in its nitrogenous bases e) adenine will be present in the DNA

DNA will have a double stranded structure, DNA will have thymine instead of uracil in its nitrogenous bases

a phospholipid has ______ fatty acids attached to glycerol, whereas a fat has _______

2/3

if a specimen contains 30% adenine in its DNA, how much cytosine will it contain? a) 20% b) 15% c) 30% d) 40%

20%

using amino acids as starting material, you synthesize a new polypeptide that is 38 amino acids long. the chemical reaction used to produce the polypeptide also produced how many molecules of what substance a) 38 b) 39 c) 37 a) water b) oxygen c) carbon dioxide

38/ carbon dioxide

a key is placed into a keyhole then turned and the door opens. when considering the components of cell signaling, the action of turning the key would best correspond to a) the cell response that occurs when the receptor binds to the hormone b) confirmational change in the receptor once bound to the hormone c) the binding side of the receptor d) signal transduction that occurs when the receptor binds to the hormone

conformational change in the receptor once bound to the hormone

what is the strongest chemical bond

covalent

which of the following correctly describes bases that pair with each other in the DNA double helix a) thymine bonds with cytosine b) cytosine bonds with guanine c) adenine bonds with guanine d) guanine bonds with thymine

cytosine bonds with guanine

in order to study a cell at lower temperatures, a researcher must artificially increase its membrane fluidity. what would be a reasonable strategy for increasing plasma membrane fluidity at low temperatures? a) increase the proportion of phospholipids with saturated fatty acid chains b) decrease the proportion of phospholipids with unsaturated fatty acid chains c) decrease the length of the phospholipid fatty acid tails

decrease the length of the phospholipid fatty acid tails

carbohydrate assembly occurs by a) dehydration reaction between monosaccharides that form disaccharides, which then go onto form polysaccharides b) hydrolysis reaction between monosaccharides that form disaccharides which then go on to form polysaccharides c) hydrolysis reaction between monosaccharides that form polysaccharides and disaccharides d) dehydration reaction between monosaccharides that form polysaccharides and disaccharides

a dehydration reaction between monosaccharides that form polysaccharides and disaccharides

how might a plant cell compensate for the excessive membrane fluidity that occurs during prolonged exposures to elevated temperature? a) alter the lipid composition to have shorter phospholipid tails, and more double bonds b) reduce cholesterol content and alter the lipid composition to have shorter phospholipid tails c) alter the lipid composition to have longer phospholipid tails and fewer double bonds d) alter the lipid composition to have shorter and more unsaturated phospholipid tails

alter the lipid composition to have longer phospholipid tails and fewer double bonds

if orange juice has a pH of 4 then it can be described as a) having an H+ concentration of 4 b) an acidic solution c) an alkaline solution d) an acidic solution with an H+ concentration of 4

an acidic solution

______ bind two or more ions or molecules and transport them in opposite directions across a membrane a) uniporters b) channel pumps c) antiporters d) symporters

antiporters

a cell responds to a signal it sent. this is an example of a) contact dependent signaling b) direct intercellular signaling c) autocrine signaling d) paracrine signaling e) endocrine signaling

autocrine signaling

a cell secretes a growth factor that binds to receptors on neighboring cells causing them to proliferate. this is an example of a) endocrine signaling b) paracrine signaling c) contact dependent signaling d) direct intercellular signaling e) autocrine signaling

autocrine signaling

if the tight junctions in the intestine were disrupted a) intestinal cells could not attach to integral membrane proteins b) intestinal cells could not attach to the extracellular matrix c) bacteria could move from the intestines to the bloodstream causing an infection d) small molecules would not be able to move into cells lining the intestine

bacteria could move from the intestines to the bloodstream causing an infection

what process best characterizes Ca2+ movement from the cytosol (low Ca2+ concentration) into the endoplasmic reticulum (high Ca2+ concentration) a) calcium movement occurs by facilitated diffusion using a transporter protein b) calcium movement involves active transport c) calcium movement does not require energy d) calcium movement is spontaneous e) calcium movement occurs by passive diffusion

calcium movement involves active transport

the process through which cells can detect and respond to signals in their extra cellular environment is called a) signal transvection b) cell sensation c) cell reception d) cell communication e) sensory response

cell communication

the protective layer outside the plasma membrane of the plant cell is called a) cellulose b) chitin c) cell wall d) proteoglycans

cell wall

what structure easily distinguishes a plant cell from an animal or baterial cell a) chloroplast b) nucleus c) cell wall d) golgi

chloroplast

following a meal, glucose must move from the gut lumen where there is a high glucose concentration into the intestinal cell where there is a relatively low level of glucose. this movement is called a) exocytosis b) active transport c) facilitated diffusion d) endocytosis e) passive diffusion

facilitated diffusion

a defining characteristic that distinguishes prokaryotic and eukaryotic organisms is the lack of a cell membrane in prokaryotes. true or false

false

a dehydration reaction that builds larger molecules from smaller units requires the addition of a water molecule. true or false

false

most enzymes or bioactive molecules work effectively within a broad range of pH. true or false

false

table salt forms from sodium and chloride via hydrogen bonding. true or false

false

unlike animals, plants lack a cell junction where small molecules can move from one cell to another cell

false

a plant will begin flowering in response to changes in length of daylight, temperature, and light quality. this is an example of which unifying principle of life a) living organisms maintain homeostasis b) living organisms interact with their environment c) living organisms grow and develop

living organisms interact with their environment

due to the lack of an enzyme to break down lipids, excess accumulation of lipids in the brain leads to a human disease called Tay Sachs syndrome. the organelle most likely to lack the proper enzyme needed for lipid breakdown is a) peroxisomes b) mitochondria c) golgi d) lysosomes

lysosomes

cyanide binds and impairs one of the molecules involved in the synthesis of ATP. the target organelle for cyanide must be a) mitochondria b) ER c) lysosomes d) ribosomes

mitochondria

carbon and hydrogen have similar electronegativities and combine together to form hydrocarbon molecules. what type of bonds form between these atoms

nonpolar covalent

the nucleus is to eukaryotes as the ________ is to prokaryotes a) nucleolus b) nucleoid c) ribosome d) RNA strand

nucleoid

an amino acid is to a protein as a ________ is to a nucleic acid a) nucleotide b) fatty acid c) glucose d) glycerol e) cellulose

nucleotide

a substrate binding to an enzyme is most similar to a signal molecule binding to a a) transcriptional factor b) second messenger c) receptor d) kinase

receptor

the process that most involves the selective uptake of a specific cargo molecule into the cell through cell receptor binding and aggregation is a) receptor mediated exocytosis b) phagocytosis c) auto phagocytosis d) receptor mediated endocytosis e) pinocytosis

receptor mediated endocytosis

the route that most accurately describes secretory protein movement through the endomembrane system would be options: rough er, lysosomes, nuclear envelope, vesicles, plasma membrane, cell membrane, golgi

rough endoplasmic reticulum→ golgi apparatus→vesicles →plasma membrane

subunits (monomers) sometimes build up to form a macromolecule (polymer). which of the listed molecules is NOT a monomer of a polymer a) fatty acid b) nucleotide c) steroid d) glucose e) amino acid

steroid

if atp production was regulated by positive feedback, high levels of ATP in muscle cells would a) stimulate more ATP production b) inhibit more ATP production c) not alter ATP production d) stimulate ATP degradation

stimulate more ATP production

the movement of sucrose and H+ into the cell by the same membrane protein reflects the actions of what type of transporter?

symporter

the grouping or classification of species is termed a) kingdom b) genus c) taxonomy

taxonomy

in some cases, just a few hormone molecules binding to the surface of a cell can trigger a very large response because a) the signal is amplified by activation of enzymes that each catalyze multiple reactions b) each hormone can bind to multiple receptors simultaneously causing amplification of the signal c) each hormone can bind to transcription factors simultaneously causing amplification of the signal d) the hormone triggers the cell to release more hormones amplifying the signal

the signal is amplified by activation of enzymes that each catalyze multiple reactions

an explanation for a biological process that is substantiated by a large body of evidence is a

theory

an explanation for a biological process that is substantiated by a large body of evidence is called a

theory

Na+ ion concentrations are higher outside the cell than inside the cell. what type of transport system is required to move Na+ ions in and out of the cell a) Na+ moves in and out the cell by active transport b) Na+ moves into the cell by active transport and out of the cell by facilitated diffusion c) Na+ moves in and out of the cell by passive diffusion d) Na+ moves into the cell by facilitated decision and out of the cell by active transport

Na+ moves into the cell by facilitated diffusion and out of the cell by active transport

sodium ions move from one cardiac muscle cell to an adjacent cell causing them to contract in unison. this is an example of a) paracrine signaling b) autocrine signaling c) contact dependent signaling d) endocrine signaling e) direct intercellular signaling

direct intercellular signaling

when insulin is secreted from the pancreas and acts on muscle cells to increase glucose uptake, this is an example of a) endocrine signaling b) autocrine signaling c) direct intercellular signaling d) paracrine signaling

endocrine signaling

what structural component makes fat an efficient macromolecule able to store large amounts of energy a) fats have long chains of C-H bonds, which store large amounts of energy b) lipids have many chains of C-OH bonds, which store large amounts of energy c) a lipids size is small and can be easily broken down, releasing large amounts of energy

fats have long chains of C-H bonds, which store large amounts of energy

if you were asked to build a model of a nucleotide, what structures would you need to represent in the model a) ribose sugar b) five carbon sugar c) phosphate group d) methyl group e) base

five carbon sugar, phosphate group, base

for heart muscles to beat in a coordinated rhythm ions must move from one cell to the next through a) hemidesmosomes b) desmosomes c) gap junctions d) adherens junctions e) focal adhesions

gap junctions

you inject a dye into a cell and observe that it moves into adjacent cells. this would occur through ________ a) desmosomes b) tight junctions c) gap junctions

gap junctions

our species is called Homo sapiens. the first word refers to which taxonomical grouping a) phylum b) genus c) species d) kingdom

genus

scientists working on an arctic glacier discover a population of microbes living in frigid temperatures. which component of the cell membrane might contribute to maintaining the fluidity of plasma membranes under freezing conditions? a) high levels of long phospholipid tails within the lipid bilayer b) absence of cholesterol c) peripheral proteins d) high levels of saturated phospholipid tails within the lipid bilayer e) high levels of unsaturated phospholipid tails within the lipid bilayer

high levels of unsaturated phospholipid tails within the lipid bilayer

lipids in the form of triglycerides, phospholipids, steroids, and waxes are all important for life to occur. select the processes that relate to lipid functions a) hormone production b) ATP binding c) energy storage d) cell formation e) prevention of water loss

hormone production, energy storage, cell formation, prevention of water loss

all organic molecules contain a) oxygen and carbon b) nitrogen and oxygen c) hydrogen and oxygen d) carbon and nitrogen e) hydrogen and carbon

hydrogen and carbon

in water, MgCl2 dissociates into Mg2+ and Cl-. based on this information what type of bond is involved in the formation of MgCl2

ionic

passive diffusion a) requires energy b) will occur so long as the membrane is freely permeable to the solute c) requires the presence of a transmembrane protein d) is a spontaneous process

is a spontaneous process

many different structures make up a cell and have unique functions. each cell structure is associated with a critical function in the cell. these pairings include a) microfilaments- cytoskeleton b) lysosomes - protein synthesis c) nucleus- dna replication d) membrane - division of labor e) golgi - modification, processing & sorting macromolecules

nucleus- dna replication membrane - division of labor microfilaments- cytoskeleton golgi - modification, processing & sorting macromolecules

the least hydrophilic substance is a) gas b) ion c) an amphipathic molecule d) oil

oil

what are the two major components of cell membrane a) phospholipids and carbohydrates b) phospholipids and proteins c) cholesterol and proteins d) glycolipids and phospholipids

phospholipids and proteins

a researcher created a synthetic, semifluid, monolayer material, formed from lipids embedded with proteins that allow the passage of other molecules. this is similar to a plasma membrane except for what difference? a) plasma membranes have proteins, but not lipids b) plasma membranes are not semifluid c) plasma membranes are bilayers not monolayers d) plasma membranes have lipids, but not proteins

plasma membranes are bilayers not monolayers

what type of bonds form from the unequal sharing of electrons

polar covalent

when forming a list to describe the structures and organization of the nucleus the main areas you would want to include are _____ a) pores allow molecules to enter and exit the nucleus b) mitochondria are made via budding from the nucleus c) rRNA is made in the nucleolus d) mRNA is transcribed in the nucleus e) chromatin made up of protein in DNA is stored in the nucleus

pores allow molecules to enter and exit the nucleus rRNA is made in the nucleolus mRNA is transcribed in the nucleus chromatin made up of protein in DNA is stored in the nucleus

water diffuses through certain organs such as the kidneys and bladder much faster than would occur by passive diffusion through a lipid bilayer alone. what accounts for this more rapid rate of water transport in these organs? a) presence of a water pump b) presence of aquaporin channels for facilitated diffusion of water c) presence of an ATP driven enzyme for water transport d) the presence of molecules that bind water and change its membrane permeability properties

presence of aquaporin channels for facilitated diffusion of water

a cell wall is present in a) prokaryotic cells only b) plant cells only c) animal cells only d) prokaryotic and plant cells

prokaryotic and plant cells

what structure best represents a polymer a) a fatty acid b) a monosaccharide c) an amino acid d) a protein

protein

large numbers of ribosomes are present in eukaryotic cells that produce a) steroids b) glucose c) lipids d) proteins

proteins

why would a diet containing unsaturated fats that form triglycerides be better for an athlete when considering energy levels and health? a) unsaturated fats are parked closer together, making them higher energy in storage levels and fluid within the body b) saturated fats are parked closer together, making their breakdown for energy release less efficient and forming unnecessary fat deposits c) saturated fats have double bonds, making them harder to breakdown for energy release and creating artery clogging structures

saturated fats are parked closer together, making their breakdown for energy release less efficient and forming unnecessary fat deposits

when designing a butter with a higher ratio of unsaturated to saturated fats you would need to take care not to remove all saturated fats. what is the main reason for this a) unsaturated fatty acids on their own would make the butter too hard as they form strong hydrophobic bonds at room temperature b) saturated fatty acids are linear in structure and form closely packed structures that are more solid at room temperature c) saturated fatty acids have more carbon in them creating a denser formation at room temperature d) interactions between unsaturated and saturated fatty acids are required to form solid structures at room temperature

saturated fatty acids are linear in structure and form closely packed structures that are more solid at room temperature

sodium concentrations are higher outside and glucose concentrations are higher inside the cell. using the same membrane protein for Na+ and glucose transport, what is it called when a Na+ electrochemical gradient is used to drive glucose transport into the cell against its concentration gradient? a) secondary facilitated diffusion b) passive diffusion c) primary active transport d) secondary active transport

secondary active transport

the best way to describe cellular membranes is a) impermeable to gasses and small molecules b) semifluid with lipid rafts c) found in eukaryotes not prokaryotes d) solely composed of lipids e) composed of a single layer of amphipathic molecules

semifluid with lipid rafts

diabetics can be given insulin that binds to receptors on cells throughout the body increasing glucose uptake. insulin is an example of a a) signal b) response element c) transcription factor d) kinase

signal

after a night of drinking too much alcohol, a person will rely on which organelle to help detoxify and recover? a) lysosomes b) ribosomes c) smooth er d) mitochondria

smooth endoplasmic reticulum

the gonads produce steroids. the specific steroid producing organelles in gonad cells are a) lysosomes b) ribosomes c) smooth er d) rough er e) mitochondria

smooth endoplasmic reticulum

when considering nomenclature for scientific names, what is the difference between the two primaries: Homo sapiens and Homo erectus a) animals of different order b) animals of different species c) animals of a different genus d) one is a primate the other is not

they are animals of a different species

if contents of the intestines can leak into the blood then _____ must have been damaged a) tight junctions b) desmosomes c) hemidesmosomes d) gap junctions

tight junctions

determine the order of the processes occurring as a protein travels through the endomembrane system attachment of protein to cargo receptors release of protein out cell pinching of vesicle into cytoplasm translation of protein in rough ER transportation to the golgi movement through cis, medial, trans regions

translation of protein in rough ER attachment of protein to cargo receptors pinching of vesicle into cytoplasm transportation to the golgi movement through cis, medial, trans regions release of protein out cell

which membrane component is most important for allowing large charged molecules to pass through the membrane a) peripheral proteins b) cholesterol c) transmembrane proteins d) carbohydrate channels

transmembrane proteins

a polyunsaturated fat contains fatty acids with multiple double bonded carbons. true or false

true

diffusion is the movement of a molecule from an area of high to low concentration

true

lipids and carbohydrates can both be used by animals to store energy

true

movement of molecules down their concentration gradient can drive the movement of a different molecule against its concentration gradient. true or false

true

osmosis describes the movement of water froman area of low to high solute concentration

true

the capacity to maintain a fairly constant body temperature is a homeostatic process. true or false.

true

the cell is the basic structural/functional unit common to all living organisms. true or false

true

when body temperature drops below normal, a person starts shivering uncontrollably. this is an example of negative feedback. true or false

true

when table salt dissolved in water, the salt is the solvent. true or false

true

whether a signaling molecule operates locally or over long distances, it must bind to a specific receptor to elicit a cellular response. true or false

true

the function of a cell is related to the amount of surface area it has. true or false

true. a cell with the same mass can increase surface area with structures like microvilli that enhance absorption functions