Biology Questions

An animal cell lacking carbohydrates on the external surface of its plasma membrane would likely be impaired in which function cell cell recognition attaching the plasma membrane to the cytoskeleton establishing a diffusion barrier to charged molecules transporting ions against an electrochemical gradient

Listen Which of the following processes is driven by chemiosmosis ATP hydrolysis reduction of NAD to NADH substrate level phosphorylation oxidative phosphorylation

Which of the following statements is a reasonable explanation for why unsaturated fatty acids help keep a membrane more fluid at lower temperatures Unsaturated fatty acids are more nonpolar than saturated fatty acids The double bonds form kinks in the fatty acid tails preventing adjacent lipids from packing tightly The double bonds block interaction among the hydrophilic head groups of the lipids Unsaturated fatty acids have a higher cholesterol content which prevents adjacent lipids from packing tightly

4 Listen What is the relationship between the wavelength of light and the quantity of energy per photon They are inversely related They are separate phenomena They have a direct linear relationship They are logarithmically related

Familial hypercholesterolemia is characterized by O a poorly formed lipid bilayer that cannot incorporate cholesterol into cell membranes inhibition of the cholesterol active transport system in red blood cells poor attachment of the cholesterol to the extracellular matrix of cells defective LDL receptors on the cell membranes

The evolution of eukaryotic cells most likely involved evolution of an endomembrane system and subsequent evolution of mitochondria from a portion of the smooth endoplasmic reticulum endosymbiosis of an oxygen using bacterium in a larger bacterial host cell the endosymbiont evolved into chloroplasts endosymbiosis of an oxygen using bacterium in a larger bacterial host cell the endosymbiont evolved into mitochondria O endosymbiosis of a photosynthetic archaeal cell in a larger bacterial host cell to escape toxic oxygen the anaerobic archaea evolved into chloroplasts

Which of the following processes generates a proton motive force in mitochondria O pumping of hydrogen ions from the mitochondrial matrix across the inner membrane and into the intermembrane space O the reduction of NAD by the first electron carrier in the electron transport chain Olowering of pH in the mitochondrial matrix the flow of protons through ATP synthase down their concentration gradient

Vinblastine a drug that inhibits microtubule polymerization is used to treat some forms of cancer Cancer cells given vinblastine would be unable to form cleavage furrows during cell division maintain the shape of the nucleus separate chromosomes during cell division migrate by amoeboid movement

Which of the following statements about the 5 end of a polynucleotide strand of RNA is correct The 5 end has a carboxyl group attached to the number 5 carbon of ribose The 5 end has a phosphate group attached to the number 5 carbon of ribose The 5 end has phosphate attached to the number 5 carbon of the nitrogenous base The 5 end has a hydroxyl group attached to the number 5 carbon of ribose

A number of systems for pumping ions across membranes are powered by ATP Such ATP powered pumps are often called ATPases although they do not often hydrolyze ATP unless they are simultaneously transporting ions Because small increases in calcium ions in the cytosol can trigger a number of different intracellular reactions cells keep the cytosolic calcium concentration quite low under normal conditions using ATP powered calcium pumps For example muscle cells transport calcium from the cytosol into the membranous system called the sarcoplasmic reticulum SR If a resting muscle cell s cytosol has a free calcium ion concentration of 10 7 while the concentration in the SR is 10 2 then how is the ATPase acting O ATPase activity must be pumping calcium from the cytosol to the SR against the concentration gradient ATPase activity must be powering an inflow of calcium from the outside of the cell into the SR ATPase activity must be opening a channel for the calcium ions to diffuse back into the SR along the concentration gradient O ATPase activity must be transferring P to the SR to enable this to occur i

Where are ATP synthase complexes located in plant cells Oinner mitochondrial membrane only thylakoid membrane and inner mitochondrial membrane thylakoid membrane and plasma membrane thylakoid membrane only

Which of the following statements describes a key component of the induced fit hypothesis of enzyme catalysis Substrate binds to an allosteric site rather than to the active site of an enzyme Binding of substrate to the active site changes the shape of the active site of an enzyme Binding of an activator molecule changes the shape of the active site of an enzyme The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme

Cooking oil and gasoline a hydrocarbon are not amphipathic molecules because they are highly reduced molecules have hydrophobic and hydrophilic regions do not have a polar or charged region olar region

Listen Carbon dioxide is split to form oxygen gas and carbon compounds in which of the following metabolic pathways only photosynthesis only respiration Ophotosynthesis and respiration neither photosynthesis nor respiration

The application of scientific knowledge for some specific purpose is known as inductive science technology pure science

In the fractionation of homogenized cells using differential centrifugation which of the following will require the greatest speed to form pellets at the bottom of the tube mitochondria chloroplasts ribosomes nuclei

Which of the following structures form cytoplasmic channels that connect adjacent plant cells through the cell walls desmosomes plasmodesmata tight junctions gap junctions

Which of the following statements is most likely true of a protein that cotransports glucose and sodium ions into the intestinal cells of an animal A substance that blocks sodium ions from binding to the cotransport protein will also block the transport of glucose Sodium and glucose compete for the same binding site in the cotransporter Glucose entering the cell down its concentration gradient provides energy for uptake of sodium ions against the electrochemical gradient Sodium ions can move down their electrochemical gradient through the cotransporter whether or not glucose is present outside the cell

Which of the following statements describes a characteristic feature of a carrier protein in a plasma membrane It has no hydrophobic regions It exhibits specificity for a particular type of molecule It works against diffusion It requires the expenditure of cellular energy to function

When nucleotides polymerize to form a nucleic acid a covalent bond forms between the sugar of one nucleotide and the phosphate of a second hydrogen bonds form between the bases of two nucleotides covalent bonds form between the bases of two nucleotides a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second

According to the fluid mosaic model of cell membranes phospholipids have hydrophilic tails in the interior of the membrane occur in an uninterrupted bilayer with membrane proteins restricted to the surface of the membrane frequently flip flop from one side of the membrane to the other can move laterally along the plane of the membrane

A decrease in entropy is associated with which type of reaction Odehydration O catabolic Ohydrolysis depolymerization

When a plant cell such as one from a tulip leaf is submerged in a hypertonic solution what is likely to occur Plasmolysis will shrink the interior of the cell The cell will burst The cell will become turgid The cell will become flaccid

A newspaper ad for a local toy store indicates that an inexpensive toy microscope available for a small child is able to magnify specimens nearly as much as the more costly microscope available in your college lab What is the primary reason for the price difference The toy microscope usually uses a different wavelength of light source The toy microscope magnifies a good deal but has low resolution and therefore poor quality images The toy microscope does not have the same fine control for focus of the specimen The toy microscope produces less contrast in the specimens

Question 24 of 25 How does fertilization increase genetic variation among family members A It allows crossing over to produce new combinations of alleles on a chromosome B It allows independent assortment to produce new combinations of chromosomes OC It combines gametes from different individuals to produce unique sets of traits D It produces gametes with unique combinations of alleles that can be combined during sexual reproduction SUBMIT

Question 4 of 25 Exposure to a mutagen causes a person to develop an abnormal growth on their skin The person s children do not develop the condition What must be true A A mutation in a gamete caused the condition and it cannot be inherited by future generations B A mutation in a somatic cell caused the condition and it cannot be inherited by future generations C A mutation in a somatic cell caused the condition and it can be inherited by future generations D A mutation in a gamete caused the condition and it can be inherited by future generations SUBMIT

Question 5 of 10 This graph shows the heights of 50 14 year old male students Heights were recorded to the nearest centimeter cm Heights of Male Students Number of students 25 20 15 10 5 0 150 154 155 159 What approximate range of heights represents the middle 80 of the data A 150 cm 174 cm B 160 cm 164 cm 160 164 165 169 170 174 Height cm C 155 cm 169 cm

Use the following label to complete the problem Round to the nearest tenth if applicable Record NUMERIC answer on Rx Only 823 RO NDC 68094 599 59 Precision Dose NYSTATIN Oral Suspension USP 500 000 units per 5 mL Pig Precision Dose Inc S Belot IL 61080 Delivers 5 mL Shake Well Alcohol 1 V Store at 20 to 25 C 68 to 77 F The nurse is preparing to administer 250 000 units of this medication to a patient How many mL should the nurse administer

Calculate the time that the infusion will be compete Record the answer in military time Record NUMERIC answer only Order 500 mL of D5 1 2NS to infuse at 125 ml hr The nurse has started the infusion at 0900 What time will the infusion be completed

What membrane potential triggers the opening of the voltage gated Na channels O 55 mv 55 mv 0 70 mv 070 mv 0 90 mv 0 90 mv

typical neuron where do you find the voltage gated calcium channels Oon the dendrites O O at the axon terminals on the cell body O at the axon hillock along the entire length of the n

The release of acetylcholine from the terminal of a motor neuron is most directly linked to O the entry of calcium into the axon terminal O the exit of sodium from the axon terminal O the exit of potassium from the axon terminal O the entry of potassium into the axon terminal O the entry of sodium into the axon terminal

In which of the following pairs of structures do you find counter current exchange O the renal artery and renal vein O the ureters and the urethra er V Othe proximal tubules and the distal tubules the vasa recta and the loops of Henle the collecting duct and the distal tubules

A toxin that binds specifically to voltage gated sodium channels in axons would be expected to Oprevent graded potentials Oprevent the hyperpolarization phase of the action potential Oincrease the release of neurotransmitter molecules O have most of its effects on the dendritic region of a neuron Oprevent the depolarization n er W

How are gills and lungs similar How are they different

Functionally which cellular location is the neuron s decision making site as to whether or not an action potential will be initiated Oaxon hillocks Odendritic membranes Omitochondrial membranes Oaxonal membranes presynaptic mombu

man red blood cell in an artery of the left arm is on its way to deliver oxygen to a cell in the thumb To travel from the artery in the arm to the left ventricle this red blood cell must pass through Othree capillary beds Ofive capillary beds Otwo capillary beds one capillary bed O four capillary beds

When you exhale the diaphragm O contracts and arches but only when you are exercising vigorously O relaxes and arches O relaxes and flattens contracts and flattens contracts and arches O

This is one of the only places in the body where there are NO aquaporins the proximal tubule O the lining of the collecting duct the upper part of the ascending loop of Henle Othe lower part of the descending loop of Henle the distal tubule

Counter current exchange system of the kidney which two fluids are moving opposite one another wser the fluid in the nephron and the blood in the vasa recta O the blood on the renal artery and the blood in the renal vein O the blood in the glomerulus and the fluid in the Bowman s capsule O the fluid in the collecting duct and the blood in the renal vein the fluid in the collecting duct and the

Which structure is found in the inner medula of the kidney Oloop of Henle Bowman s capsule O proximal convoluted tubule glomerulus

Valuable molecules like glucose amino acids and vitmains are reabsorbed into the blood at which location in the nephron Ocollecting duct O glomerulus Loop of Henle Bowman s capsule O proximal convoluted tubul

In a typical neuron where do you find the voltage gated calcium channels along the entire length of the axon at the axon hillock on the dendrites at the axon terminals on the cell body

are bird lungs considered much more efficient that mammal lungs bird lungs have large air sacs for gas exchange but mammal lungs only have small alveoli Obirds have shorter tracheas than mammals Oin bird lungs but not mammals air moves through in one direction only Obird lungs have more alveoli than mammal lungs Obird lungs can expand much more than mammal lungs Question 3 1 point Listen In mammals most gas exchange between the atmosphere and the pulmonary blood occurs in the

fluid from the glomerulus to Bowman s capsule transfers large molecules as easily as small ones O is mainly a consequence of blood pressure in the capillaries of the glomerulus O usually includes the transfer of red blood cells into Bowman s capsule O results from active transport is very selective as to which subprotein sized molecules are transferred Question 20 1 point Listen Which of the following happens first as a nephron processes blood

Opiates like morphine and heroin bind to the same receptors as acetylcholine endorphins Oglutamate serotonin dopamine Question 6 1 point Listen

8 21 gen ions produced within human red blood cells are prevented from significantly lowering plasma pH because they bind to plasma buffers plasma proteins carbon dioxide carbonic acid hemoglobin Question 2 1 point Listen Why are bird lungs considered much more efficient that mammal lungs bird lungs have large air sars for gas exchango but mammell

Several EPSPS arrive at the axon hillock from different dendritic locations and depolarize the postsynaptic cell to threshold for an action potential This is an example of temporal summation Ospatial summation tetanus the refractory state O an amazing coincidence

The nucleus and most of the organelles in a neuron are located in the axon Odendritic region cell body axon hillock axon terminals Question 11 1 point

of acetylcholine from the terminal of a motor neuron is most directly linked to the entry of sodium into the axon terminal the exit of potassium from the axon terminal the entry of calcium into the axon terminal the entry of potassium into the axon terminal the exit of sodium from the axon terminal Question 12 1 point Listen In the sequence of permeability changes for a complete action potential the these events that occurs is