Midterms Flashcards
Which of the following is true regarding a biological community?
A. It includes abiotic factors.
B. A community includes multiple species.
C. It is the unit upon which natural selection acts.
D. A population is composed of more than one community.
A community includes multiple species
Which of the following correctly describes the difference between DNA and RNA?
A. DNA is a polynucleotide and RNA is not.
B. DNA has pyrimidine bases and RNA does not.
C. The DNA sugar monomer contains fewer oxygen atoms.
D. DNA has a 6 carbon sugar and RNA has a 5 carbon sugar.
E. DNA is usually single stranded and RNA is double stranded.
The DNA sugar monomer contains fewer oxygen atoms.
Which of the following is false regarding prokaryotic and eukaryotic cells?
A. Prokaryotes possess DNA.
B. Only eukaryotic cells have ribosomes.
C. Prokaryotes do not have plasmodesmata.
D. Some eukaryotes are single celled organisms.
E. Prokaryotes and some eukaryotes possess cell walls.
Only eukaryotic cells have ribosomes.
Which of the following is the best description of a contractile vacuole?
A. It is present in prokaryotic cells.
B. It has the same contents as the cytosol.
C. It is used by some pond organisms to store food.
D. It controls water balance in some pond organisms.
E. It is formed when a food particle is consumed by the cell.
It controls water balance in some pond organisms.
Which of the following is true regarding chloroplasts?
A. Chloroplasts grow and divine with the cells.
B. They metabolize the sugars made by the mitochondria.
C. Ribosomes are located in the thylakoid membranes of the chloroplasts.
D. The inter membrane space of the chloroplast is located inside the cristae.
E. According to the theory of endosymbiosis, chloroplasts were formed from an in folding of the plasma membrane.
Chloroplasts grow and divine with the cells.
An animal cell is specialized to secrete a glycoprotein. It imports sugars from other cells in the tissue to add to proteins synthesized inside. This cell is likely joined to others via \_\_\_\_\_ junctions and likely has \_\_\_\_\_. A. Gap, many lysosomes B. Gap, many bound ribosomes C. Desmosomes, free ribosomes D. Tight junctions, few lysosomes E. Tight junctions, many free ribosomes
Gap, many bound ribosomes
Which of the following is true regarding passive transport?
A. It requires ATP.
B. It occurs only across the plasma membrane.
C. It transports molecules from high to low concentration.
D. It is a phenomenon associated with only the water molecule.
E. It describes how molecules can be kept in higher concentrations inside a cell than outside the cell.
It transports molecules from high to low concentration
Which of the following is incorrect regarding evolution by natural selection?
A. Natural selection can result in molecular adaptations.
B. Natural selection acts on traits which show variation.
C. Populations are the units on which natural selection acts.
D. Overproduction of offspring is sufficient to lead to evolution by natural selection.
E. Individuals can survive but fail to contribute adaptations to the next generation of the population.
Overproduction of offspring is sufficient to lead to evolution by natural selection.
Which of the following is true regarding a decrease in pH from 7 to 3?
A. It indicates that the solution has become more basic.
B. It represents a 4 fold increase in the H+ ion concentration.
C. It represents a 10^4 fold increase in the H+ ion concentration.
D. It represents a 10^4 fold increase in the OH- ion concentration.
E. It represents a 4 fold increase in the OH- ion concentration.
It represents a 10^4 fold increase in the H+ ion concentration.
Which of the following is correct regarding the three dimensional structure of proteins?
A. Tertiary structure is maintained by peptide bonds.
B. Secondary structure is not maintained by covalent bonds.
C. Quaternary structure usually involves only one polypeptide strand.
D. Primary structure is maintained by hydrogen bonds among atoms of the backbone.
E. Once formed, protein three dimensional structure is fixed and cannot be altered by physical factors.
Secondary structure is not maintained by covalent bonds.
Which of the following correctly states the relationship between protein production and the endomembrane system?
A. The rough endoplasmic reticulum adds carbohydrates to proteins.
B. Membrane proteins are synthesized by ribosomes in the nucleus.
C. Proteins which will be inserted into membranes are synthesized by ribosomes on the Golgi complex
D. The membrane proteins facing the inside of a transport vesicle will face the inside of the plasma membrane after they are inserted.
E. Free ribosomes synthesize membrane proteins. They fuse with the trans Golgi reticulum where the proteins are modified.
The rough endoplasmic reticulum adds carbohydrates to proteins.
Which of the following correctly describes plasma membranes?
A. Membrane proteins are fixed in place
B. The two halves of the membrane are identical.
C. The membrane lacks connections to the cell’s cytoskeleton.
D. Membrane phospholipids often drift laterally within a bilayer.
E. Membranes often flip flop from one layer of the membrane to another.
Membrane phospholipids often drift laterally within a bilayer.
A biologist bathes some isolated cells, which are low in ATP concentration, in a medium containing solute A. After two hours they find that solute A is inside the cell. In a second experiment, with new cells of the same type, they disable a membrane protein. This time they do not find A inside the cell, even though initial concentration of A in the medium was the same and there is no difference in the state of the cells. What can you conclude about the nature of molecule A and how A is transported into the cell?
A. A is a small polar molecule
B. A is being transported into the cell via pinocytosis
C. A is a large molecule transported via facilitated diffusion.
D. A is a large non polar molecule that must be actively transported into the cell.
E. A is a small non polar molecule that must be actively transported into the cell.
A is a large molecule transported via facilitated diffusion.
Which organelle aids digestion of molecules in both autophagy and phagocytosis through contribution of acid and enzymes? A. Vesicle B. Vacuole C. Lysosome D. Pseudopod E. Mitochondrion
Lysosome
Which of the following is an incorrect function of a biological molecule?
A. Triglycerides- energy store
B. Lipids- catalyze chemical reactions
C. Protein- provide structure and support
D. Cellulose- provide structure and support
E. Glycogen- store of monosaccharides
Lipids- catalyze chemical reactions
How does the sodium-potassium pump contribute to the electrochemical gradient of the cell?
A. It expels a net negative charge from the cell.
B. It exchanges equal number of sodium and potassium ions.
C. It expels three sodium ions and takes in two potassium ions.
D. It expels two sodium ions and takes in three potassium ions.
E. It expels a different number of anions than the number of anions it takes in.
It expels three sodium ions and takes in two potassium ions.
Which of the following is false regarding extracellular structures?
A. Animal cells lack cell walls.
B. Cilia are composed of microtubules.
C. Plant cells lack collagen in their cell walls.
D. Prokaryotic cell walls are composed of cellulose.
E. The extracellular matriculates of animals includes some polysaccharide components.
Prokaryotic cell walls are composed of cellulose.
A fisheries biologist wishes to test the effects of a new molecule in river waters on the swimming speed of trout. there is some suspicion, given its chemistry, that it may affect males and females differently. What are the essentials of the experimental set up to test the hypothesis that the presence of the chemical lowers swimming speed?
Set up experimental tanks (or ponds/streams)with the addition of the molecule ; and control tank (or ponds/streams) s lacking the molecule. Control tanks should be the same in all aspects except for the addition of the molecule. There should be equal numbers of fish and of males and females in common tanks; or control and experimental tanks for males and females with equal numbers of fish in each.
A newly synthesized chemical is miscible with vegetable oil but not water. What can you conclude about the bonds of this new molecule?
Since the chemical mixes with vegetable oil whose triglycerides have non polar bonds, and not with water which has polar bonds, the new chemical must have non polar bonds.
How would a buffer respond to increase pH?
The acid form of the buffer would donate a proton to the solutionlowering the pH/preventing the pH from rising.)
Explain how and why cell membrane phospholipid composition would change to maintain fluidity in the case of an increase in temperature (include what is the effect of an increase in temperature).
An increase in temperature would otherwise cause an increase in fluidity-might make the membrane too permeable/be too fluid. To counter this there would be a decrease in the unsaturated fatty acid content andan increase in the saturated fatty acid content. This would help to decrease fluidity because saturated fatty acids can pack together more tightly than unsaturated fatty acids.
Define catabolism and anabolism. What is the relationship between these processes and ATP?
Anabolism is metabolism/metabolic reactions/set of reactions that make larger more complex molecules and requires ATP.
Catabolism is metabolism/metabolic reactions/set of reactions that break down/oxidize larger molecules and generates ATP.
What are the roles of NAD+ and NADH in cellular respiration? Include glucose, and electron transport chain in your answer.
NAD+ accepts electrons from /oxidizes an intermediate in glycolysis which is the oxidation of glucose.
NADH releases electrons and protons to the electron transport chain when NADH is oxidized by a protein complex.
What products of light reaction are needed for the Calvin cycle? For what is each used (ie which stage)?
NADPH is needed for the reduction stages of the Calvin Cycle. ATP is needed for the carbon fixation, regeneration stages.
