comprehensive final multiple choice Flashcards
a scientific theory is:
a: a suggested explanation that accounts for observations.
b: a way to organize how we think about a problem.
c: a concept that is supported by experimental evidence that explains the facts in an area of study.
d: a way to understand a complex system by reducing it to its working parts.
c: a concept that is supported by experimental evidence that explains the facts in an area of study.
matter is composed of:
a: atoms
b: energy
c: mass
d: molecules
a: atoms
when atoms gain or lose electrons, they can become negatively or positively charged. These charged atoms are known as:
a: ions
b: isomers
c: unstable atoms
d: isotopes
a: ions
sanai was monitoring the oil spill in the Gulf of Mexico from an oil tanker. From her observations, she noted that the oil was moving in large patches through the water. The oil did not appear to dissolve into the water. Why did the oil not dissolve into the water?
a: hydrophobic interactions
b: surface tension
c: sea water acts as a solvent
d: water forms hydration shells
a: hydrophobic interactions
a chemist adds a chemical to pure water and there is a 100-fold increase in the concentration of hydrogen ions. What is the best approximation of the new pH value?
a: 0
b: 5
c: 7
d: 9
b: 5
the atomic number of an element is equal to the number of:
a: neutrons only.
b: neutrons plus electrons.
c: protons only
d: protons plus electrons.
e: protons plus neutrons.
c: protons only
water molecules are attracted to each other due to the opposite charges created by partial charge separations within the molecules. These attractions are called:
a: peptide bonds.
b: covalent bonds
c: ionic bonds.
d: hydrogen bonds
e: double bonds.
d: hydrogen bonds (correct)
water is most dense and thus heaviest at 4°C. At 0°C, ice forms and can float on liquid water. Suppose ice was more dense then water at 0°C. What would happen in a lake at this temperature?
a: the ice would cover the surface of the aquatic system and would never melt.
b: Ice would not form because solids are always less dense than liquids.
c: The cold temperatures and the subsequent ice formation would prevent hydrogen bonds from forming between the water molecules, thus causing the existing ice crystals to become disassociated from each other.
d: The ice would cover the bottom of the aquatic system and would build up in layers over time.
d: The ice would cover the bottom of the aquatic system and would build up in layers over time.
you recently discovered a new element, and find that this particular element has one electron in its outer energy level. What do you expect will happen to an atom of this element if placed in water?
a: it will lose an electron forming a negative ion.
b: It will gain an electron forming a negative ion.
c: It will gain an electron forming a positive ion.
d: It will lose an electron forming a positive ion.
d: It will lose an electron forming a positive ion.
the high heat of vaporization of water helps you to feel cooler when you sweat because the transition of water from a liquid to a gas requires a _________blank of energy to break hydrogen bonds. The energy is _________blank from heat produced by your body, thus helping to lower the surface temperature of your body.
a: release; released
b: release; obtained
c: input; obtained
d: input; released
c: input; obtained
egg whites consist primarily of water and the protein albumin. When you fry an egg, why does the egg white turn from an opaque, thick liquid to a white, solid substance?
a: the protein becomes denatured
b: the protein becomes hydrolyzed
c: the protein becomes dissociated
d: the protein becomes dehydrated
a: the protein becomes denatured
the digestive enzyme pepsin works in the acidic environment of the stomach to hydrolyze peptide bonds. As a result, pepsin affects which macromolecule?
a: DNA molecule
b: lipid
c: carbohydrate
d: protein
d: protein
which of the following is a unique feature of viruses that separates them from bacteria?
a: they cannot exist outside of a host cell
b: They have different nucleotide bases in their hereditary material
c: They are generally much smaller
d: They lack proteins
c: They are generally much smaller
each of the following facts state the major significance of the element carbon in the human body EXCEPT..?
a: carbon is the main component of water
b: carbon-containing molecules can form rings, branches, or coils
c: carbon can form bonds with four different atoms
d: carbon forms the backbone of all organic molecules
a: carbon is the main component of water
proteins are polymers formed of structural units called:
a: fatty acids
b: nucleotide bases
c: amino acids
d: phosphate groups
c: amino acids
In a phospholipid molecule, the “head” is _____.
In a phospholipid molecule, the “tail” is _____.
a: hydrophilic
b: hydrophobic
macromolecules that are used by all organisms to store hereditary information are called:
a: carbohydrates
b: DNA molecules
c: lipids
d: proteins
b: DNA molecules
what is the best reason why people are vaccinated once a year for influenza?
a: the immune system only “remembers” vaccines for several months
b: the vaccine is removed by the body after 12 months
c: the virus binds to all of the vaccine after a few months
d: mutations cause antigenic drift in HA and NA proteins
d: mutations cause antigenic drift in HA and NA proteins
these biological compounds are nonpolar and insoluble in water:
a: nucleic acids
b: lipids
c: proteins
d: carbohydrates
b: lipids
humans are unable to derive metabolic energy from cellulose because:
a: cellulose contains very little chemical energy
b: cellulose is not part of a normal diet
c: cellulose digesting enzymes are absent from the human gut
d: cellulose does not taste good
c: cellulose digesting enzymes are absent from the human gut
the covalent bonds connecting monomer units in sugars can be broken by the addition of a water molecule. This reaction is referred to as:
a: a hydration reaction
b: a hydrolysis reaction
c: a dehydration reaction
d: an oxidation-reduction reaction
b: a hydrolysis reaction
a person writes a malicious computer program and embeds it in an email. When someone receives the email, the program makes copies of itself on their hard drive, and also sends new emails with the program to other recipients. However, if a user has installed security software, it blocks the email.
Match the features of the computer “virus” to the similar features of a biological virus.
host cell (computer)
viral genome (malicious program)
immune system (security software)
viral spike protein (email)
in a(n) ________ cell, the DNA is not enclosed in a membrane.
in a(n) ________ cell, most of the DNA is located in the nucleus.
a: prokaryotic
b: eukaryotic
which of the following intercellular junctions forms a seal around the adjacent epithelial cells of the small intestine to prevent partially digested molecules from passively leaking into the abdominal cavity?
a: gap junctions
b: desmosomes
c: plasmodesmata
d: tight junctions
d: tight junctions
The cytoplasmic space in cells is occupied by many diverse membrane-bound structures with specific cellular functions called ___________.
a: organelles
b: chromosomes
c: extracellular matrix
d: cilia
a: organelles
The semifluid matrix that surrounds organelles in a cell is called the __________.
a: stroma
b: ribosome
c: cytoplasm
d: nucleolus
c: cytoplasm
Integrins are glycoproteins that help link the cytoskeleton and the _______.
a: nucleus
b: cytoplasm
c: extracellular matrix
d: cell wall
c: extracellular matrix
the Central Dogma of biology can be stated asa:
a: DNA→ Proteins→ RNA
b: RNA→ DNA→ Proteins
c: DNA→ RNA→ Proteins
d: Proteins→ RNA→ DNA
c: DNA→ RNA→ Proteins
the genetic code uses ____ nucleotide(s) to specify one amino acid.
a: 64
b: 2
c: 1
d: 3
d: 3
brain cells and muscle cells contain the same DNA in their nuclei. The main reason they differ in their structure and function is because they _____.
a: contain different chromosomes
b: express different genes
c: use different genetic codes
d: have unique ribosomes
b: express different genes
which of the following characteristics is directly related to the coding of a single amino acid during the process of translation?
a: the three-base sequence of mRNA
b: the anticodon sequence of the tRNA
c: the base pair complementarity of the DNA and RNA
d: more than one codon can specify the addition of the same amino acid
a: the three-base sequence of mRNA
rank the following DNA molecules in order based on their size in length, starting with the smallest (#1) and ending with the largest (#4)
(1) nucleotide base
(2) codon
(3) gene
(4) chromosome