Exam questions Flashcards
All nucleic acids are made up of chains of:
nucleotides
In an experiment to test the effects of surgery on knee pain, individuals in the control had a sham surgery. The control group was needed to:
provide a basis of comparison to determine the effect of the actual surgeries.
A man with an X-linked recessive condition has children with a woman who is heterozygous for the condition. What is the expected frequency of the condition in the children?
The probability that a child will have the condition is 1/2.
Carbohydrates are used by cells:
as a source of energy
Two fruit flies were crossed. Among their offspring, 3/4 had long wings and 1/4 had short wings. This result suggests:
both parents were heterozygous for the gene associated with wing length.
Evaporation from the leaves of a tree will pull water up through the roots as an unbroken column throughout the entire height of the tree. This feat is possible because of which characteristic of water?
cohesion
Phenotypes:
consist of observable traits
are influenced by an individual’s genotype and their environment
is used as a template for making which guides the construction of a_.
DNA; RNA; protein
Dashed lines in figure represent what kind of chemical bonding?
Hydrogen bonding
Which statement best describes Mendel’s law of segregation?
Each gamete contains only one of the two copies of each gene carried by an individual.
Stop codons:
signal the end of the amino acid chain
do not base-pair with tRNA
trigger the ribosome to come part from the mRNA
To signal cells to increase their uptake of glucose from the blood, insulin must bind to a_ in the cell membrane.
receptor protein
Glycogen is made up of lots of glucose molecules held together by covalent bonds. Breaking down glycogen requires:
enzymes.
The fact that water is less dense as a solid than as a liquid explains why:
ice floats on top of liquid water
Genes that do not have a promoter:
will not be copied into RNA.
A dominant trait:
is expressed when an individual is heterozygous.
Cells use_for long-term energy storage.
lipids
In a well-designed experiment:
the results provide useful evidence to support or reject the hypothesis
A difference between DNA and RNA is:
DNA stores information while RNA serves as a temporary copy.
A mutation causes the codon GAU to become GAA. What effect will this have on the protein?
The mutant version of the protein will have one different amino acid compared to the normal version of the protein.
The mRNA codon CCU:
base pairs with tRNA.
A frameshift mutation (a mutation that changes the reading frame):
results from the insertion or deletion of nucleotides in DNA.
A water molecule is a polar molecule because:
oxygen has a greater pull on electrons than hydrogen
Color-blindness is an X-linked recessive trait. A couple has a color-blind daughter. Assuming no new mutation was involved, what do we know about the parents?
The father is definitely color-blind.
What properties of water allow it to form a droplet on a leaf?
water is polar and cohesive
Ribosomes are needed during translation to:
connect amino acids into a chain.
Cell membranes create a hydrophobic barrier that blocks the movement of many molecules. _are the molecules that make that hydrophobic barrier.
Phospholipids
RNA polymerase links nucleotides into a chain by helping:
covalent bonds form between the sugar of one nucleotide and the phosphate of another nucleotide.
Autosomal recessive traits:
can skip generations
A scientific theory is:
supported by lots of data.
DNA with the sequence ACG will pair with the RNA sequence:
UGC
An individual with two identical alleles for a particular gene is:
Homozygous for that gene
Who is known for reducing the frequency of women dying from childbed fever by getting doctors to wash their hands?
Ignaz Semmelweis
Which of the following was used in pregnancy tests?
Frogs
Which of the following is not a mechanism of evolution?
Gene regulation
Which of the following statements about DNA replication is true?
The existing strands of DNA must be separated to act as templates for
making more DNA.
A wrasse (a type of fish) is found eating parasites off of other fishes that stop by its cleaning station. The interaction between the wrasse and the other fish is an example of:
Mutualism
Spindle fibers attach to chromosomes during what part of the cell cycle?
Mitosis
A cell with 20 chromosomes that undergoes mitosis will produce cells that each have:
20 chromosomes
Traditional chemotherapy has side effects like hair loss and nausea because:
It interferes with any rapidly dividing cells, whether they are cancerous or
not.
Crossing over produces:
Chromosomes that are a mix of maternal and paternal DNA
What environmental factor may have promoted the evolution of complex
multicellularity?
Increased oxygen in the oceans and atmosphere
A population is:
a group of individuals of the same species that have the potential to
interbreed.
a group of individuals of the same species that live in the same general
location and have the potential to interbreed.
Which of the following is true of negative cell-cycle regulators?
Negative cell-cycle regulators stop the movement of a cell through the cell cycle.
Tumor-suppressor genes include negative cell-cycle regulators.
P53 is an example of a negative cell-cycle regulator.
All of the above are true.
Predation and co-option of existing genes are two of the explanations for the evolution of:
Simple multicellularity
Corals provide everything EXCEPT ___ to their mutualistic zooxanthellae.
Energy
Variation in skin color in humans is a result of:
Natural Selection
Homologous chromosomes:
Are separated when gametes form
What essential nutrient is broken down by UV light?
Folate
A mutation results in a DNA sequence changing from ACCGA to ATCGA. Which of the
following could cause that kind of mutation to occur?
An error during DNA replication
A mutation occurs that causes a chromosome to go from having only one copy of a
particular gene to having two copies of that gene. Which of the following could cause
that?
An error during crossing over
The phrase “survival of the fittest” means:
Organisms with certain traits will survive and reproduce better than
organisms without those traits
Natural selection does not lead to the production of perfect organisms because:
Environments change too rapidly for organisms to become perfectly adapted
The Urey-Miller experiment demonstrated that:
Complex organic molecules could be made from molecules present in the
early Earth atmosphere
Gene regulation:
is the control of when and where a gene is expressed
can involve a regulatory protein binding to a specific DNA sequence
can involve transcription of a gene being turned on or off
all of the above
A human cell has 46 chromosomes. If it undergoes a normal meiosis, the cells that are
produced:
Have one of each chromosome (e.g. only one copy of chromosome 9)
The theory by which eukaryotes evolved from prokaryotes is:
The theory of endosymbiosis
Multicellularity evolved:
Several times in the history of life on Earth
___ is the ultimate source of genetic variation.
Mutation
CRISPR is used by scientists to:
make changes to specific DNA sequences
Evolution results in a genetic change in ___ over time.
A population
At metaphase of mitosis, chromosomes are aligned in the middle of the cell. Which of the
following is not true of these chromosomes?
Homologous chromosomes are paired up.
Melanocytes help protect against UV damage by:
Forming a cap over the nucleus
Complex multicellularity differs from simple multicellularity in that:
Only some cells are capable of reproduction in complex multicellular
organisms
The increase in oxygen concentrations in the Earth’s atmosphere 2.5 billion years ago
was due to:
Photosynthetic prokaryotes
A karyotype can be used to test for a condition such as Down Syndrome because it:
Shows the number of chromosomes present in a cell
A non-toxic organism looking like a toxic organism is an example of:
Batesian mimicry
UV light can be both harmful and beneficial to humans because:
It damages DNA and helps us make vitamin D
___ is a random process most effective in small populations that can lead to a loss of
genetic variation.
Genetic drift
Prokaryotes and eukaryotes are similar in that they both:
Have DNA and ribosomes
Artificial selection is:
A form of natural selection
Completed by plant and animal breeders
Human driven
All of the above
Which of the following is a consequence if spindle fibers do not attach correctly to
chromosomes?
Chromosomes will not be properly divided between the daughter cells.
All of the following are key events in the history of life on Earth except:
the origin of dinosaurs
Darwin’s observations while traveling on the Beagle helped him develop which theory?
Species might change over time.
During her lecture, Rene showed a video of a pearlfish finding a safe home in:
The intestines of a sea cucumber
Why do cells require oxygen gas?
Cells need oxygen to convert sugar into ATP energy.
What does your body use to increase blood glucose levels if your blood glucose levels drop
when you are engaged in a lot of activity (e.g. running a marathon)?
Glycogen in your liver
Which of the following best describes what happens to hemoglobin as your blood circulates
throughout your body?
The lower the oxygen level in your body tissues, the more oxygen molecules the
hemoglobin releases.
Low oxygen conditions cause cells to resort to fermentation. This will cause yeast to produce
ethanol. In the case of human muscle cells, fermentation results in the production of:
Lactic acid
___ are where most of the ATP is produced during cellular respiration.
Mitochondria
Which of the following about the phosphate groups in ATP is true?
They are negatively charged.
The bonds between them are unstable.
They release energy when the bonds between them are broken.
All of the above statements are true.
As food molecules are broken down to generate ATP, which of the following is true?
Some of the potential energy stored in the food molecules is lost as heat.
Bacterial cells contain all of the following except:
Mitochondria
Bacteria play a role in:
Converting nitrogen to a form that other organisms can use to make amino acids and nucleotides Photosynthesis The development of our immune systems All of the above
Giant tube worms living on the floor of the Pacific Ocean around hydrothermal vents have no
digestive tract. They rely on bacteria to:
Provide them with carbohydrates produced via chemosynthesis
Which of the following is true about bacterial communication?
Bacterial communication makes it possible for bacteria to turn on expression of
some genes only when there are lots of bacteria present.
An antibiotic-resistant infection is caused by:
Bacteria that are able to survive and multiply in the presence of antibiotics.
Which of the following are ways that bacteria can acquire new DNA sequences?
Mutations
DNA can be transferred between bacteria by viruses.
Bacteria can pick up DNA from the surrounding environment, for example when another
bacterium dies.
All of the above
The antibiotics that we use to treat infections:
Are drugs that kill or inhibit the growth of bacteria
The taxonomic rank that includes species but not families is
genus
An evolutionary tree
is a hypothesis about evolutionary relationships.
According to the biological species concept, species are natural populations of organisms that
have the potential to interbreed and that are _____________ isolated from other such
populations.
reproductively
The more morphological characteristics that two species of animals share, the more likely it
is that they
share a common descent.
The dark gray dots along the trunk of this evolutionary tree represent both common ancestors
and
speciation of events
All birds have feathers because they inherited that trait from a common ancestor. Features
that are inherited from a common ancestor are called
homologous features
Which of the following list of groupings or taxons is in descending order, from most
inclusive to least inclusive? Some lists may be missing some of the intermediate taxons.
kingdom, class, family, genus, species
The group of mollusks that contains the nautilus species as well as squids and octopuses is
called
cephalopods
What is the key difference between protostomes and deuterostomes?
The protostome gut develops from front to back, so the first opening is the mouth.
The deuterostome gut develops back to front and the first opening is the anus.
Two important features that distinguish mammals from any other type of animal are
hair and mammary glands
Which group grows by molting?
roundworms and arthropods
Which feature of echinoderms means that they are more closely related to humans than any
other invertebrate group?
They are deuterostomes
Which statement is true about all animals?
All acquire energy by eating other organisms.
Which is a common characteristic of the arthropod phylum?
exoskeleton made of chitin
Of the groups mentioned below, the fungi are most closely related to
animals
Which terms is most inclusive and describes all of the plants in a-e?
vascular plant
Which statement is true about bryophytes (mosses)?
The spongy mass that we think of as ‘moss’ is haploid.
The cell wall of fungi is made of
chitin
Which of the following characteristics do most plants share with land animals?
an embryo that develops within a protected environment.
Humans are considered
chemoheterotrophs
The energy and carbon utilization classification that includes plants and algae is
photoautotrophy
The energy and carbon utilization classification that includes only bacteria and archaea is
chemoautotrophy
Extremophiles are
prokaryotes that thrive in extreme environments
Thermoacidophiles are
prokaryotes that thrive in hot, acidic environments.
Lichens are multiple organisms in a mutualistic relationship between:
Fungi and algae
The tendency of bacteria to respond in a group behavior when enough individuals are
present:
is called quorum sensing.
