AP BIOLOGY MIDTERM Questions
If there are 20 chromatids in the cell, how many centromeres are there?
10
In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of _______.
ATP, CO2, and ethanol (ethyl alcohol)
The accompanying figure shows the electron transport chain. Which of the following is the combination of substances that is initially added to the chain?
NADH, FADH2, and electrons
DNA is replicate at this time of the cell cycle:
S
Regarding mitosis and cytokinesis, one difference between higher plants and animals is that in plants _____.
a cell plate begins to form at telophase, whereas in animals a cleavage furrow is initiated at that stage
Which of the following factors would tend to increase membrane fluidity?
a greater proportion of unsaturated phospholipids
A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from ______.
a plant or animal
Which of the following effects is produced by the high surface tensions of water?
a water strider can walk across the surface of a small pond
Reactants capable of interacting to form products in a chemical reaction must first overcome a thermodynamic barrier known as the reaction's _______ _______.
activation energy
How can one increase the rate of a chemical reaction?
add a catalyst
Which term describes centromeres uncoupling, sister chromatids separating, and the two new chromosomes moving to opposite poles of the cell?
anaphase
In general, a signal transmitted via phosphorylation of a series of proteins ____.
brings a conformational change to each protein
A molecule with the chemical formula C6H12O6 is probably a _____.
carbohydrate and monosaccharide only
Which term most precisely describes the cellular process of breaking down large molecules into smaller ones?
catabolism
Which of the following relationships between cell structures and their respective functions is correct?
cell wall: support, protection
The lowest level of biological organization that can perform all the activities required for life is the _______.
cell-for example, a skin cell
When you have a severe fever, what may be a grave consequence if this is not controlled?
change in the folding of enzymes
One difference between cancer cells and normal cells is that cancer cells ___________.
continue to divide even when they are tightly packed together
Which of the following most accurately describes what is happening along this chain?
each electron carrier alternates between being reduced and being oxidized
The presence of cholesterol in the plasma membrane of some animals _______.
enables the membrane to stay fluid more easily when the cell temperature drops
Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of glucose from the glucose-rich food into their glucose poor cytoplasm. using this information, which transport mechanism is most probably functioning in the intestinal cells?
facilitated diffusion
The mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway is known as ____.
feedback inhibition
Which metabolic pathway is common to both cellular respiration and fermentation?
glycolysis
Which of the following statements is correct about diffusion?
it is a passive process in which molecules move from a region of higher concentration to a region of lower concentration
Which of the following statements is true regarding the molecule illustrated in Figure 5.2?
it is a saturated fatty acid and a diet rich in this molecule may contribute to atherosclerosis
Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor?
lack of appropriate cell death
Binding of a signaling molecule to which type of receptor leads directly to a change in distribution of ions on opposite sides of the membrane?
ligand-gated ion channel
Which is one of the main energy transformers of cells?
mitochondria
The somatic cells derived from a single-celled zygote divide by witch process?
mitosis
When blood glucose level rises, the pancreas secretes insulin, and as a result blood glucose level declines. When blood glucose level is low, the pancreas secretes glucagon, and as a result blood glucose level rises. Such regulation of blood glucose level is the result of____.
negative feedback
Chemical signal pathways _______________.
often involve the binding of signal molecules to a protein on the surface of a target cell
Which of the following produces the most ATP when glucose (C6H12O6) is completely oxidized to carbon dioxide (CO2) and water?
oxidative phosphorylation (chemiosmosis)
Which of the following processes includes all others?
passive transport
Which bonds are created during the formation of the primary structure of a protein?
peptide bonds
Which of the following statements best describes the relationship between photosynthesis and respiration?
photosynthesis stores energy in complex organic molecules while respiration releases it
The difference between pinocytosis and receptor-mediated endocytosis is that __________.
pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offers more selectivity
Once labor begins in childbirth, contractions increase in intensity and frequency until delivery. The increasing labor contractions of childbirth are an example of _____.
positive feedback
Large numbers of ribosomes are present in cells that specialize in producing which of the following molecules?
proteins
Which of the following is present in a prokaryotic cell?
ribosome
What kinds of molecules pass through a cell membrane easily?
small and hydrophobic
Which of the following is a major cause of the size limits for certain types of cells?
the need for a surface area of sufficient area to allow the cell's function
Which of the following statements is (are) true about enzyme-catalyzed reactions?
the reaction is faster than the same reaction in the absence of the enzyme
Cytokinesis usually, but not always, follows mitosis. If a cell completed mitosis but not cytokinesis, the result would be a cell with _____.
two nuclei
The process of transduction usually begins ______.
when the signal molecule changes the receptor protein in some way