bio practice exam 1 corrected

Exam
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) Which of the following is a trace element in the human body?
A) zinc
B) hydrogen
C) nitrogen
D) oxygen
2) Which of the following statements best describes a compound?
A) A compound is exemplified by sodium.
B) A compound contains two or more different elements in a fixed ratio.
C) A compound is a pure element.
D) A compound is a solution.
3) Which of the following statements about cells is true?
A) All cells are attached to other cells.
B) All cells are motile.
C) All cells have cell walls.
D) All cells have internal structures that move.
4) Which of the following particles is found in the nucleus of an atom?
A) only electrons
B) protons and neutrons
C) only protons
D) protons and electrons
5) A(n) ________ forms when two atoms share electrons.
A) ion
B) covalent bond
C) hydrogen bond
D) ionic bond
6) Light microscopes
A) are generally not used to view bacteria.
B) use light and glass lenses to magnify an image.
C) typically provide more resolution than an electron microscope.
D) work by reflecting electrons off the surface of an object being studied.
7) A solution with a pH of 7 is
A) neutral.
B) weakly acidic.
C) weakly basic.
D) strongly acidic.
8) Which of the following statements about ecosystems is false?
A) Plants and other photosynthetic organisms are producers in ecosystems.
B) In the process of energy conversions within an ecosystem, some energy is converted to
heat.
C) Chemical nutrients cycle within an ecosystem.
D) Bacteria and fungi recycle energy within an ecosystem.
9) One centimeter = ________ millimeters.
A) 0.01
B) 10
C) 0.10
D) 100
10) A scientist wants to magnify a pollen grain 8,000 times and examine the ridges and pores on its
surface. Which one of the following instruments would be best?
A) an inverted light microscope
B) a transmission electron microscope
C) a fluorescence confocal microscope
D) a scanning electron microscope
11) Which of the following statements is not consistent with Darwin's theory of natural selection?
A) Natural selection can lead to the appearance of new species.
B) Individual organisms exhibit genetic change during their life spans to better fit their
environment.
C) Individuals in a population exhibit variations, some of which are passed from parents to
offspring.
D) Factors in the environment result in some organisms having better reproductive success
than others.
12) What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?
A) 8
B) 6
C) 18
D) 12
13) To be scientifically valid, a hypothesis must be
A) part of a theory.
C) controlled.
B) reasonable.
D) testable and falsifiable.
14) How are genes used by cells to build proteins?
A) The genes in RNA direct the synthesis of proteins directly.
B) The genes in DNA direct the synthesis of an RNA molecule, which is used to build a
protein.
C) The genes in RNA direct the synthesis of a DNA molecule, which is used to build a protein.
D) DNA is transcribed into an amino acid sequence.
15) You work for a company that manufactures food products. A new "wonder food" is being
distributed by a rival company. The researchers in your company determine that the "wonder
food" contains only carbon, oxygen, and hydrogen. At this point, your researchers can say with
certainty that the food
A) includes proteins.
B) does not include proteins or nucleic acids.
C) could only be made of carbohydrates.
D) could only be made of triglycerides.
16) Which of the following best represents an example of technology?
A) sequencing the human genome
B) identifying the cause of a new contagious disease
C) figuring out what mountain gorillas eat
D) developing a test for genetic diseases
17) Which of the following is not an example of evolution that has resulted from human activity?
A) Some insect species are now resistant to pesticides.
B) Because of hunting, species such as bears and wolves are in danger of extinction.
C) Many strains of bacteria are now resistant to some commonly used antibiotics.
D) Like certain other crops, domesticated strawberries are larger than wild strawberries.
18) Photosynthesis requires many steps to make glucose. As a result of the synthesis process,
A) more atoms are present at the beginning than at the end.
B) all the carbons from the six carbon dioxide atoms are found in glucose.
C) more carbon dioxide is released from the plant than is absorbed.
D) water is synthesized by the plant from H2 and O2.
19) Which of the following is an example of secondary structure in a protein?
A) a globular shape
B) the joining of two polypeptide chains
C) an alpha helix
D) a particular amino acid sequence
20) Mad cow disease serves as an example of how interdependent ________ and ________ are to
protein.
A) solubility . . . texture
B) adaptability . . . development
C) form . . . construction
D) structure . . . function
21) Which of the following characteristics of protein will remain intact if the protein is denatured?
A) the shape of the protein
B) the number of amino acids in the protein
C) the function of the protein
D) the binding properties of the protein
22) A scientist suspects that the food in an ecosystem may have been contaminated with radioactive
nitrogen over a period of months. Which of the following substances could be examined for
radioactivity to test the hypothesis?
A) the hair produced by humans living in the ecosystem
B) the cholesterol in the cell membranes of organisms living in the ecosystem
C) the sugars produced during photosynthesis by plants growing in the ecosystem
D) the cell walls of plants growing in the ecosystem
23) Structural proteins
A) are found in hair and tendons.
B) include ovalbumin, a protein found in egg white.
C) include receptor molecules.
D) include hemoglobin.
24) Proteins cannot be denatured by
A) freezing.
C) changes in salt concentration.
B) heat.
D) changes in pH.
25) Glucose molecules are to starch as ________ are to proteins.
A) amino acids
B) oils
C) monosaccharides
D) fatty acids
26) Which of the following substances is a lipid?
A) steroids
B) enzymes
C) cellulose
D) DNA
27) Proteins differ from one another because
A) each protein contains its own unique sequence of sugar molecules.
B) the sequence of amino acids in the polypeptide chain differs from protein to protein.
C) the number of nucleotides found in each protein varies from molecule to molecule.
D) the peptide bonds linking amino acids differ from protein to protein.
28) Which one of the following would be correctly classified as a protein?
A) cellulose
B) cholesterol
C) enzymes
29) Peptide bonds
A) form between fatty acids.
C) are formed by a hydrolysis reaction.
D) starch
B) are used to form amino acids.
D) link amino acids.
30) You are told that the cells on a microscope slide are plant, animal, or bacterial. You look at them
through a microscope and see cell walls and membrane-bound organelles. You conclude
correctly that the cells
A) are plant cells.
C) could be either plant or bacterial cells.
B) are animal cells.
D) are bacterial cells.
31) Which of the following statements about cellular metabolism is false?
A) Cellular metabolism can occur within organelles.
B) Cellular metabolism often occurs on the surfaces of internal membranes.
C) Cellular metabolism includes different processes that require different conditions.
D) Cellular metabolism occurs in animal but not plant cells.
32) A cell is exposed to a substance that prevents it from dividing. The cell becomes larger and
larger. This situation
A) should present no problem to the cell, because the surface area of the cell will increase as
the volume of the cell increases.
B) should be beneficial, since the cell will be able to divert the ATP normally used for cell
division to other processes.
C) will eventually be problematic, since the cell's ability to absorb nutrients through its outer
membrane will not keep increasing as quickly as its cytoplasmic needs.
D) should present no problem to the cell, since it can continue to perform all other necessary
functions.
33) During cell reproduction, chromatin fibers coil up into structures called
A) ribosomes.
B) nucleoli.
C) chromosomes.
D) lysosomes.
34) The endomembrane system includes all of the following organelles except the
A) plasma membrane.
B) Golgi apparatus.
C) peroxisome.
D) endoplasmic reticulum.
35) Which of the following cells has the greatest surface-to-volume ratio?
A) human muscle cell
B) bacterium
C) ostrich egg
D) human red blood cell
36) Which of the following statements regarding the Golgi apparatus is false?
A) The Golgi apparatus decreases in size when a cell increases its protein production.
B) The Golgi apparatus works closely with the endoplasmic reticulum.
C) The Golgi apparatus serves as a molecular warehouse and finishing factory.
D) The Golgi apparatus modifies chemicals received from the endoplasmic reticulum.
37) Insulin is a protein that is produced by pancreatic cells and secreted into the bloodstream. Which
of the following options correctly lists the order of the structures through which insulin passes
from its production to its exit from the cell?
A) rough ER, Golgi apparatus, smooth ER, cell membrane
B) rough ER, lysosomes, transport vesicles, cell membrane
C) rough ER, transport vesicles, Golgi apparatus, vacuole, cell membrane
D) rough ER, transport vesicles, Golgi apparatus, transport vesicles, cell membrane
38) A manufacturing company dumps its wastes into a nearby pond. One of the wastes is found to
paralyze the contractile vacuoles of certain protists. A biologist looking at individual samples of
these organisms taken from the pond would find that they
A) have gained water and burst.
B) have lost water and shrunk.
C) have died of malnutrition.
D) have died because wastes have built up in the cytoplasm.
39) Most animal cells are
A) embedded in an extracellular matrix.
B) surrounded by a cell wall.
C) attached to each other via plasmodesmata.
D) embedded in a lipid matrix.
40) Dynein feet
A) are found on microtubules in cilia and flagella and cause movement by grabbing and
pulling at adjacent microtubule doublets.
B) are knobs of carbohydrate that are essential to the movement of cilia and flagella.
C) are the anchoring proteins in basal bodies.
D) are present in cilia but not in flagella.
41) It is essential for heart muscle cells to beat in a coordinated fashion. The cell junctions that would
best facilitate this are
A) gap junctions.
B) anchoring junctions.
C) tight junctions.
D) occluding junctions.
42) Which of the following statements regarding cells is false?
A) All cells are enclosed in a membrane that maintains internal conditions different from the
surroundings.
B) All cells have DNA as their genetic material.
C) All cells can interconvert forms of energy.
D) All cells have a cell wall.
43) Skin cells are fastened into strong sheets by
A) communicating junctions.
C) anchoring junctions.
B) tight junctions.
D) basal bodies.
44) Cyanide inhibits mitochondrial function; as a result, the rate of
A) photosynthesis increases.
B) ATP synthesis decreases.
C) ATP synthesis increases.
D) protein synthesis increases.
45) Osmosis can be defined as
A) the diffusion of water.
C) the diffusion of a solute.
B) active transport.
D) the diffusion of nonpolar molecules.
46) Some protozoans have special organelles called contractile vacuoles that continually eliminate
excess water from the cell. The presence of these organelles tells you that the environment
A) is hypertonic to the protozoan.
B) contains a higher concentration of solutes than the protozoan.
C) is hypotonic to the protozoan.
D) is isotonic to the protozoan.
47) Which of the following statements regarding diffusion is false?
A) Diffusion occurs when particles spread from areas where they are less concentrated to
areas where they are more concentrated.
B) Diffusion occurs even after equilibrium is reached and no net change is apparent.
C) Diffusion is a result of the thermal energy of atoms and molecules.
D) Diffusion requires no input of energy into the system.
48) Which of the following substances would have the most trouble crossing a biological membrane
by diffusing through the lipid bilayer?
A) Na+
B) O2
C) CO2
D) a small, nonpolar molecule such as butane (C4H10)
49) Which characteristic promoted the utilization of lipids as the first cell membrane?
A) formation of a semi-solid membrane
B) spontaneous degradation of the intracellular environment
C) ability to form an impermeable membrane
D) self-assembly into a simple membrane
50) White blood cells (WBCs) are more resistant to lysis than red blood cells (RBCs). When looking
at a sample of blood for WBCs, what could you do to reduce interference from RBCs?
A) Mix the blood in an isotonic solution and allow the WBCs to float to the top.
B) Mix the blood in a hypotonic solution, which will cause the RBCs to lyse.
C) Mix the blood in a salty solution to cause the RBCs to lyse.
D) Mix the blood in a hypertonic solution, which will cause the RBCs to lyse.