Exam #2 Study
Which of the following distinguishes ionic bonds from covalent bonds?
Ionic bonds hold together oppositely charged atoms, whereas covalent bonds hold together atoms that share electrons.
Which of the following differentiates meiosis from mitosis?
Mitosis is used for the repair of cells, whereas meiosis creates cells for sexual reproduction.
A group of astronauts returning from outer space studied samples taken from their lunar landing. They found that one of their samples was coated with organic compounds. Which of the following statements must be correct about their samples?
The samples must contain carbon atoms.
Nitrogen has seven protons, seven neutrons, and seven electrons. What is the atomic mass of nitrogen?
14
Chemists often represent the structure of atoms using p, n, and e to indicate the number of protons, neutrons, and electrons. Which atom would have an atomic weight of 30?
15 p, 15 n, 15 e
A duplicated chromosome consists of ________ sister chromatid(s).
2
If a plant has a total of 18 chromosomes, how many chromosomes would be present in each of its gametes?
9
The chemical 3-(3,4-dichloro-phenyl)-1,1-dimethylurea (DCMU) blocks the movement of electrons at the point indicated by the black, downward-pointing arrow in the figure below. Which of the following would be an immediate effect of treating a chloroplast with this drug?
A proton gradient would not be created, so ATP could not be made.
Which of these carries the most energy?
ATP
Which of the following accurately describes the similarities between mitosis, meiosis, and binary fission?
All three of the processes are used to produce daughter cells.
Which of the following statements describe the function of the light reaction in photosynthesis?
As electrons move through the light reaction, they release energy that is used to concentrate protons in the thylakoid.
________ reactions release energy by breaking down complex molecules.
Catabolic
Which of the following is/are part of accepted cell theory?
Every living organism is composed of one or more cells, and all living cells arise from preexisting cells.
The chemical reaction that represents photosynthesis is 6 H2O + 6 CO2 à C6H12O6 + 6 O2. What are the reactants?
H2O and CO2
Which of the following is likely to participate in ionic bonding?
Li+
Which of the following molecules carries electrons to the electron transport chain of oxidative phosphorylation?
NADH
What is the importance of photosynthesis to organisms other than plants?
Photosynthesis captures energy that other organisms access when they eat either plants or organisms that eat plants.
What are the stages of interphase?
S, G1, and G2
What best summarizes the events of the Calvin cycle?
The cycle uses ATP and NADPH to produce sugars.
Which of the following explains why ice floats on water?
The distance between water molecules in ice is greater than in liquid water.
What is the significance of crossing over?
The resulting gametes will have different gene combinations than their parent cells' gene combinations.
Examine the figure below. If each sugar molecule represents a percentage point of sugar dissolved in the solution, what change would you expect to see in the solution level over time and why?
The solution level on the left side of the figure would rise while the solution level on the right side of the figure would decrease. This is because the solution on the left side of the figure is hypertonic while the solution on the right side of the figure is hypotonic.
Which of the following statements is true of chloroplasts?
They capture energy from sunlight.
Which of the following is true of the chromosomes in a homologous pair?
They carry the same genes.
Why would hydrophilic substances such as sodium ions (Na+), hydrogen ions (H+), sugars, and amino acids be unable to simply diffuse across a plasma membrane?
They do not readily mix with the hydrophobic tails forming the core of the phospholipid bilayer; therefore, they must move across by facilitated diffusion.
Why do scientists repeat their experiments over and over again?
They must make sure the results were not an accident and that they are repeatable.
Which of the following help increase the selective permeability of a phospholipid bilayer membrane?
Transport proteins, channel proteins, and passive carrier proteins all help increase the selective permeability of a phospholipid bilayer membrane.
Which of the following foods is most likely to contain haploid cells?
an egg
Which of the following types of organisms are commonly single-celled (unicellular)?
bacteria, some fungi (yeast), and many protozoans
A researcher is recording the process of bacteria cell division using time-lapse microscopy. Which of the following processes would she be observing?
binary fission
All of the following contribute to genetic uniqueness EXCEPT
binary fission.
Which of the following pairs of processes encompasses the entire cell cycle?
cell division and interphase
The circle near the center of this structure represents a
centromere.
The subatomic particles that possess a single negative charge and surround the nucleus are the
electrons
When ATP breaks down into ADP and a phosphate group,
energy is released and can power cellular activities.
In the reaction H2O + CO2 + carbonic anhydrase à H+ + HCO3-+ carbonic anhydrase, carbonic anhydrase is a(n)
enzyme
Using the compound light microscope in the lab room, you observe a wet mount slide preparation. You observe layers of cells that have a definite, rigid, rectangular shape; there appears to be a nucleus in all of the cells and there are many oval-shaped green structures that seem to be moving around inside of the cells in an orderly fashion. What general cell type are you most likely observing?
eukaryotic and plant
A scientist wishing to generate cancerous cells in vitro could subject the cells to which of the following procedures?
expose cells to chemicals that disrupt mitosis
Which two processes work in conjunction to create genetic diversity and maintain chromosome number?
fertilization and meiosis
Which step of cellular respiration occurs outside the mitochondria?
glycolysis
The three stages of cellular respiration (in order) are
glycolysis, the Krebs cycle, and oxidative phosphorylation.
Individual water molecules orient toward each other because of the ________ bonds that form between them.
hydrogen
Phospholipids are large organic molecules with a ________, polar phosphate head connected to ________, nonpolar fatty acid tails. How do these molecules arrange themselves to form a mostly impermeable barrier between a liposome and its environment?
hydrophilic; hydrophobic; They line up hydrophobic tails facing each other at the center line of the membrane with the hydrophilic heads facing outward, away from the center line of the membrane.
The possible combinations of alleles in gametes ________ due to independent assortment and crossing over.
increases
A solid waste (garbage) transfer facility that sorts and breaks down garbage into recyclables and waste to be thrown away in the landfill would be a suitable analogy for which cellular organelle?
lysosome
Which of the following is associated with mitosis?
maintenance of chromosome number
Gametes are produced by meiosis rather than mitosis because
meiosis reduces the chromosome number so that zygotes produced will have one full genome.
The capture and use of energy by living organisms involves numerous chemical reactions. Collectively these processes are known as
metabolism.
The boundary that surrounds the contents of the nucleus is the
nuclear envelope.
Cells naturally, without using energy, respond to changes in water concentration through the process of
osmosis.
During exercise, the increase in respiration rate and heartbeat speed are driven by the need to replenish the oxygen used to support
oxidative phosphorylation in muscle cell mitochondria.
A white blood cell (WBC) encounters bacteria in a scrape on the knee of a child who has fallen off of his bicycle. The WBC's job is to take the bacteria inside of itself and destroy the bacteria. If the bacteria cannot be moved across the WBC membrane, how will the WBC most likely take it in?
phagocytosis
Living cells have an intact phospholipid bilayer that separates the cell from its external environment; this structure is commonly referred to as the
plasma membrane.
The goal of meiosis is to
produce eggs and sperm.
In the reaction C6H12O6 + 6 O2 à 6 CO2 + 6 H2O, the 6 CO2 molecules are some of the
products
In photosynthesis, the carbon used to make sugars is
provided by carbon dioxide
Glycolysis is an anaerobic process, indicating that the glycolytic reactions
require no oxygen.
You are a scientist observing a membrane through which water and some small hydrophobic molecules can freely pass along a concentration gradient from high to low. However, some sugar molecules are too large to pass through the membrane either way without the assistance of passive transport proteins. Additionally, small Na+ ions and some proteins can pass through the membrane against the concentration gradient, but both require the assistance of active transport proteins. What general type of membrane are you observing?
semipermeable
The Golgi apparatus
sorts proteins and lipids and sends them to their final destination.
Which of the following cell types is produced by meiosis?
sperm cells
When examining the rapidly dividing cells of a fish embryo, you notice a cell that seems to contain two nuclei. The middle of the cell is pinched inward. This cell must be in ________ of mitosis.
telophase
Photosynthesis and cellular respiration are both complementary and relatively balanced, but early history of life on Earth showed increasing oxygen concentrations. This indicates that
the amount of photosynthesis occurring exceeded the amount of cellular respiration.
Enzymes can catalyze a reaction only if
they encounter a substrate that fits their active site.
Oil and water do not mix together well because
water is polar and oil is nonpolar.
The successful union of one male and one female gamete forms a new single cell known as a
zygote
