comprehensive final true / false Flashcards
molecules in different organisms that perform the same function are likely to have the same structure.
true or false
true
energy enters the environment in many forms, but the most common source of energy in our body is from the sun.
true or false
false
all living organisms are composed of one or more cells.
true or false
true
hydrogen has only one neutron and no protons in its nucleus.
true or false
false
electrons are maintained in their orbitals by their attraction to the positively charged nucleus.
true or false
true
atoms tend to react in ways that give each atom a stable valence shell of electrons.
true or false
true
the four most common elements present in living organisms are carbon, oxygen, hydrogen, and calcium.
true or false
false
correct: there are 12 (oxygen, carbon, hydrogen, nitrogen, phosphorus, calcium, sulfur, sodium, chlorine, iron, magnesium, and potassium)
because oxygen has a greater electronegativity than hydrogen, water molecules are polar with two partial negative charges near the oxygen atom and one partial positive charge near each hydrogen atom.
true or false
true
liquid water is less dense than solid water.
true or false
false
experiments are carried out to test a hypothesis by changing one variable at a time and should include an unchanged variable known as the control.
true or false
true
viruses are protein-coated fragments of DNA or RNA.
true or false
true
a saturated fatty acid has the maximum number of oxygen atoms bonded to its hydrocarbon chain.
true or false
false
phospholipid bilayers form the basic framework of biological membranes.
true or false
true
the key reason a virus is likely to infect a particular cell is because a virus will only infect host cells with the correct surface receptors.
true or false
true
viruses are self-replicating, but the replication is much faster in a host cell.
true or false
false
three water molecules are produced during the formation of a triglyceride from fatty acids and glycerol.
true or false
true
the base pairing rule for the DNA molecules states that an adenine (A) nucleotide base of one of the DNA strands bonds to a thymine (T) nucleotide base of the other DNA strand, and a cysteine (C) nucleotide base of one of the DNA strands bonds to a guanine (G) nucleotide base of the other DNA strand.
true or false
true
the monomers that are used to build lipids are nucleotide bases.
true or false
false
once emerging viruses are officially recognized, they are easy to treat and eradicate with existing drugs.
true or false
false
cellulose is the main storage carbohydrate in plants while glycogen is an important storage carbohydrate in our muscles.
true or false
true
during transcription of mRNA, some sequences are cut out of the primary transcript and the remaining sequences are joined together. this processing of m RNA is called coding.
true or false
false
correct: this process is called splicing
the plasma membrane functions as a selective barrier that allows the passage of enough solute molecules into and out of the cell for healthy cell function. thinking about this movement, you determine this is why cells are so small.
true or false
true
all cells are related by their descent from earlier cells.
true or false
true
nuclear pores permit the passage of mRNA from the nucleus to the cytoplasm.
true or false
true
the 5’ cap on the end of the mRNA guides the molecule to the ribosome to facilitate transcription.
true or false
false
the distinctive feature of a chloroplast is that it is the site of photosynthesis.
true or false
true
disruption of the function of the smooth endoplasmic reticulum would result in a dramatic decrease in ATP synthesis in cells.
true or false
false
correct: disruption of this function would decrease the mitochondria in result to that.
lysosomes function in the destruction and recycling of old organelles.
true or false
true
the connection that exists between genes and hereditary traits is based on using the information encoded in genes to synthesize proteins.
true or false
true
the primary function of the ribosome is to translate the triplet code on the mRNA transcript into a new language, which then produces a functional protein.
true or false
true
osmosis occurs as water crosses the lipid bilayer through specialized channels for water movement called pumps.
true or false
false
correct: water movement through pumps would be active transport and the specialized water channels are called aquaporins.
the lipid layer that forms the foundation of cell membranes is primarily composed of molecules called phospholipids.
true or false
true
the process of active transport and facilitated diffusion both will move solutes from an area of lesser concentration to an area of greater concentration.
true or false
false
in a biochemical pathway, the product released by the first enzyme becomes the substrate for the second enzyme.
true or false
true
in osmosis, water moves to equalize solute concentrations on either side of the membrane.
true or false
true
an enzyme catalyzes a chemical reaction in the cell but can only be used once.
true or false
false
correct: it can be used more than once.
an enzyme binds the product more tightly than the substrate.
true or false
false
the amount of energy available to do work is called free energy.
true or false
true
a mixed solution of water and small molecules is exposed to a cell membrane and allowed to interact for an hour. the molecule that would be able to diffuse across the membrane the fastest without the aid of transport proteins would be o2.
true of false
true
when taking oral medications, many cells with their phospholipid bilayer barriers will have to be passed before the polar drug (charged molecule) can reach blood circulation. the most likely transport mechanism the drug would use to cross these membranes would be pinocytosis.
true or false
false
the function of the enzyme ATP synthase in cell respiration and the light-dependent reactions of photosynthesis is to utilize the energy of the proton motive force to convert ADP to ATP.
true or false
true
in cell respiration, the electron transport chain consists of a series of membrane-bound carriers that shuttle protons and electrons to NADH.
true or false
false
the overall process of cell respiration results in the regeneration of 30-36 ATP molecules from the oxidation of one glucose molecule.
true or false
true
in alcohol fermentation, NADH is oxidized back to NAD+, whereas, in lactic acid fermentation, FADH2 is oxidized back to FAD.
true or false
false
chloroplasts synthesize sugars through the reverse steps of cellular respiration.
true or false
false
the process of glycolysis requires both an input of ATP and produces an output of ATP.
true or false
true
substrate-level phosphorylation is used for the formation of ATP in the citric acid (krebs) cycle.
true or false
true
one common feature of electron carriers such as NAD+ is that they can be reversibly oxidized and reduced.
true or false
true
carbon dioxide brings high-energy electrons to the electron transport chain.
true or false
false
NADPH is the electron carrier molecule that shuttles energy to the Calvin cycle for the synthesis of glucose.
true or false
true
cancer cells generally have high levels of telomerase activity, which allows them to divide indefinitely without the chromosomes getting shorter and shorter.
true or false
true
in addition to errors that occur during DNA replications, cells are constantly exposed to agents that can damage DNA, such as UV light, x-rays, and chemicals in the environment.
true or false
true
following s phase, a human cell would have 46 pairs of sister chromatids and 92 individual DNA molecules.
true or false
true
during DNA replication, the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together.
true or false
false
correct: leading strand is synthesized continuously - lagging strand is synthesized in short fragments called okazaki fragments.
during DNA replication, the newly synthesized DNA is packaged into one nucleus, and the original DNA is packaged into another nucleus.
true or false
false
a cell must be in g0 before it can enter into the cell cycle.
true or false
false
correct: cell doesn’t have to be in g0 before entering the cell cycle.
because the 2 strands of a DNA molecule run in opposite directions, and because DNA polymerases can synthesize new strands only in the 5’ to 3’ direction, polymerases on opposite strands must synthesize DNA in opposite directions.
true or false
true
during DNA replication, nucleotide bases specifically complement each other, each strand of the DNA molecule acts as a template that specifies the exact sequence of nucleotides in the other strand. this process is described as conservative replication.
true or false
false
correct: this process is a semiconservative replication.
complementary base pairing across the DNA double helix allows information to be transferred via RNA transcription and DNA replication.
true or false
true
before the lagging strand can begin assembling new DNA nucleotides - primase constructs a short RNA primer.
true or false
true
heterozygous genotypes can mask harmful traits in an individual.
true or false
true
when alleles at one gene locus can interfere with the expression of alleles at another gene locus, this is called pleiotropy.
true or false
false
correct: a condition where an individual allele has more than one effect on a phenotype
a recessive allele on the X chromosome is responsible for red-green color blindness in humans. a woman with normal vision whose father is color-blind has a male child who is color-blind. she marries a man who has normal vision. the probability that this couple’s first son will be color blind is 25%.
true or false
false
correct: the child would be aa
many genetic disorders are inherited as simple recessive traits. most affected individuals are children of parents who are both phenotypically normal carriers of the recessive allele.
true or false
true
AB blood type is an example of codominance inheritance.
true or false
true
a color-blind father will transmit the mutant allele to all his sons but not to his daughters.
true or false
false
if sister chromatids failed to separate during meiosis II, then two gametes will be normal, one gamete will have two of the affected chromosomes, and one gamete will not contain the affected chromosomes.
true or false
true
a punnett square is generally used to predict the genotypic ratio among the offspring.
true or false
true
one of the significant conclusions that Mendel drew from his experiments with pea plants was that recessive alleles occur more frequently in the F2 generation than do dominant alleles.
true or false
false
crossing over increases the variation in a population because it produces offspring with combinations of alleles that neither parent carried.
true or false
true
