BIOL 1406 Comprehensive Final REVIEW
In some ciliate protozoa, the codons UAA and UAG encode glutamate, rather than acting as STOP codons. How does this compare to other species?
This is unusual - almost all species share the same "universal" genetic code.
The genetic preservation of the features that increase the likelihood of survival and reproduction of some individuals within a population is called the process of
natural selection.
The ends of linear chromosomes that maintain chromosome integrity are called
telomeres
Enzymes function to:
catalyze chemical reactions
A cell biologist produces a karyotype of mouse somatic cells arrested in mitosis. She sees 40 chromosomes, which is completely normal for mice. Based on this information, what is the haploid number of chromosomes for mice?
20
In humans, individuals with trisomy of the ______ chromosome are most likely to survive until adulthood.
21st.
If a virus enters the lytic phase in a host's cell, it will cause the host cell to
lyse due to the action of enzymes.
During protein synthesis in eukaryotes, which molecule passes from the nucleus to the cytoplasm and specifies the sequence of amino acids in the new polypeptide?
mRNA
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. Of the 16 possible gamete combinations in the dihybrid cross between 2 double heterozygotes, how many would produce the phenotype white, tall?
3
In rabbits, there is a gene that controls ear length, with a dominant allele "T" for long ears and a recessive allele "t" for short ears. At another gene locus, there are alleles "B" for black coat and "W" for white coat. Neither the B or W allele is dominant, and BW produces a gray coat. These two allele pairs assort independently. If a gray rabbit that is heterozygous at the gene locus controlling ear length is mated with a white rabbit that is also heterozygous at the gene locus controlling ear length, what is the probability that their first offspring will be gray with long ears?
3/8
If a cell has 32 chromosomes prior to S and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes?
32
If 14% of the nucleotides from a DNA molecule contain the base T, what percent will contain the base G?
36%
A male fruit fly has the genotype PpYYrrTt. In terms of these 4 allele pairs, how many different types of gametes can he form?
4
How many hydrogen bonds can a water molecule form?
4
A geneticist examines a somatic cell from a fly during metaphase of mitosis and determines that 16 chromatids are present. If a germ-line cell from this species divides by meiosis, then at the end of meiosis I (including the first cytokinesis) each cell will contain
4 chromosomes with 8 DNA molecules.
If there were no suppression of DNA replication between meiotic divisions but cytokinesis proceeded normally, what is the most likely outcome of meiosis?
4 diploid cells
A somatic cell from a corn plant normally contains 20 chromosomes. How many sister chromatids would that cell contain during G2 of the cell cycle?
40
Which best describes the process of independent assortment?
The way one pair of homologues lines up along the metaphase plate does not affect how any other pair lines up.
You are performing an experiment to assay phosphorylation of a substrate by a protein kinase. Based on the data in the table below, what do these experimental results suggest?
The substrate can undergo autophosphorylation.
The ultimate source of energy for humans comes from what source?
The sun
The common basilisk lizard will run across water on its hind legs in an erect position when startled by predators. This lizard has large feet and flaps of skin along its toes. What properties of water allow this lizard to walk on water?
The surface tension created by hydrogen bonds is greater than the weight of the lizard initially.
Why are the components of the electron transport chain embedded in the inner mitochondrial membrane rather than floating freely in the cytoplasm of mitochondrial matrix?
To generate and maintain the proton gradient essential for ATP production.
What is the function of a protein kinase?
To add phosphate groups onto proteins
Metabolic reactions fall under two general categories: anabolic and catabolic. What type of chemical reactions are these two classes of metabolic reactions?
Anabolic reactions are endergonic reactions, whereas catabolic reactions are exergonic.
Amanda is a microbiologist who studies the pathogenic bacteria Streptococcus pyogenes. In what ways are they (Amanda and the bacteria) similar?
Both obtain carbon from consuming organic molecules.
Cardiac muscle has prolonged contraction due to a sodium induced-calcium released process into the cytoplasm of the cell. Cardiac cells can communicate through pore-like channels between cells. List the junction and the organelle involved in cardiac muscle contraction?
Gap; Smooth ER.
For a particular chemical reaction, the enthalpy of the reactants is -400 kJ. The enthalpy of the products is -390 kJ. The entropy of the reactants is 0.2 kJ/K. The entropy of the products is 0.3 kJ/K. The temperature of the reaction is 25 degrees Celsius. What can you conclude about this reaction?
It is exergonic
Organisms that depend on the energy stored in chemical bonds by other organisms for their food energy are called ____________.
Heterotrophs
In some human populations, the proportion of individuals who are heterozygous for the sickle cell allele is much higher than would be expected by chance alone. Why?
Heterozygous individuals have an advantage over individuals with two normal alleles.
In a chemical reaction, glyceraldehyde-3-phosphate + NAD+ yields 1,3-bisphosphoglycerate + NADH. In this reaction, what happened to NAD+?
It was reduced to form NADH
If you were able to increase the kinetic energy of the molecules inside your body, how would this affect your body temperature?
It would increase
Many cells of the immune system have receptors that detect peptidoglycans and lipopolysaccharides. How do pathogenic bacteria avoid detection?
Pathogens often encase themselves in a gelatinous capsule
Alcohol consumption adversely affects the synthesis of molecules involved in protein degradation, which can eventually lead to liver damage. Given this information, which organelle in liver cells is most directly affected by alcohol consumption?
Rough endoplasmic reticulum
A duplicate copy of all of the hereditary information contained in the nucleus of eukaryotic cells is made during what stage of the cell cycle?
S
If you tagged organic carbon inside a chloroplast with a fluorescent label, the location most likely to have a high concentration of labeled carbon would be in the
Stroma
The theory of chromosomal inheritance was first proposed by
Sutton.
Diseases such as scrapie in sheep, "mad cow" disease in cattle, and Creutzfeldt-Jakob disease in humans are known as
TSEs (transmissible spongiform encephalopathies).
The Law of Thermodynamics that states that energy cannot be created or destroyed is:
The First Law of Thermodynamics
Cells conserve energy and resources by making active proteins only when they are needed. If a protein is not needed, which of the following methods of control would be the most energy-efficient?
block transcription
At the pH of most bodily fluids, which functional group will lose a proton and which functional group will accept a proton?
carboxyl; amino.
Which type of proteins is embedded in the cell membrane in both active transport and facilitated transport?
carrier
Virulent viruses multiply within infected cells and eventually
cause lysis of the host cell, releasing new viruses.
The enzymes for cellular respiration in eukaryotic organisms are located within the mitochondria. In prokaryotic organisms, these enzymes are attached to the
cell membrane.
The point of connection between two sister chromatids, before anaphase II of meiosis separates them, is called the
centromere.
Fall leaf color on deciduous trees is a result of
cessation of chlorophyll production, which allows the accessory pigments to be revealed
In an experiment described in a chemistry lab book, the directions state that after mixing two chemicals (A and B) and waiting 5 minutes that A will be oxidized. This means that:
chemical A has lost electrons to chemical B.
In synaptic signaling, neurotransmitters are released into a space that is referred to as a:
chemical synapse.
In eukaryotes, photosynthesis takes place inside the ________.
chloroplasts
A drug binds to the active site of an enzyme. If it is bound to the active site of the enzyme, it prevents substrate binding. This drug would be considered a(n)
competitive inhibitor.
Because the two strands of a DNA molecule are ________ to each other, either one can be used as a template to reconstruct the other.
complementary
Experiments are carried out to test a hypothesis by changing one variable at a time and including an unchanged variable termed a(n) _____.
control
Homologous chromosomes pair along their length during prophase I of meiosis. While two homologues are paired, genetic exchange may occur between them in a process called ________.
crossing over
If fertilization involves two gametes that contain different alleles of a given gene, the resulting offspring is
heterozygous.
One of the DNA-binding motifs in many eukaryotic organisms that contains a nearly identical sequence of 60 amino acids is known as the
homeodomain.
The maintenance of a constant environment in a cell is called __________.
homeostasis
While you are riding the ski lift up to the top of the mountain on a very cold day you start to shiver involuntarily. You know that the shivering is your body′s attempt to help regulate your body temperature and is an example of what type of mechanism?
homeostasis
A commercially significant human protein now produced in bacteria is
human insulin.
Which isolating mechanism is postzygotic?
hybrid sterility
Prezygotic mechanisms lead to reproductive isolation by preventing the formation of
hybrid zygotes.
Nitrogen has a higher electronegativity than hydrogen. As a result you would expect that ammonia (NH3) molecules can form ____ with each other.
hydrogen bonds
DNA consists of two antiparallel strands of nucleotides held together by
hydrogen bonds.
In DNA, complementary nitrogen bases are held together by
hydrogen bonds.
Turgor pressure is observed when a plant cells environment is ________________.
hypoosmotic
A research laboratory is attempting to collect the content of human red blood cells. The type of solution researchers should use to cause blood cells to lyse (burst) would be
hypoosomotic.
A test cross can be used to do all of the following except
identify the chromosome on which a gene is located.
You are asked to participate in a clinical trial for a new drug that can activate telomerase. Which of the following is a likely risk of such a drug?
increased vulnerability to cancer
You toss a coin twice. Because the outcome of the first toss does not affect the outcome of the second toss, these 2 events are called
independent.
The switch from a lysogenic prophage to a lytic cycle is called
induction.
A yellow jacket, an insect in the order Hymenoptera, stung me. A wasp, an insect in Hymenoptera, stung me. A hornet, an insect in Hymenoptera, stung me. I see a pattern. All insects in this order must have stingers. What type of reasoning does this represent?
inductive reasoning
The method of reasoning that uses specific observations to develop general conclusions is called:
inductive reasoning.
Prions are
infectious proteins with no associated nucleic acid.
The rate of diffusion of molecules would be fastest in a cell with an
internal concentration of 50 percent and an external concentration of 12 percent in warm temperatures.
If 16% of the nucleotides in one strand of a DNA molecule contain the base G, what percent of the nucleotides on the complementary strand will also contain the base G?
it is impossible to determine from the information given.
These biological compounds are nonpolar and insoluble in water:
lipids
Cholesterol functions in the plasma membrane to
maintain fluidity.
In some organisms, the primary function of a gene in a cell is to participate in regulating the body as a whole rather than responding to the cell's immediate environment. These organisms would be
multicellular.
If a population was in Hardy-Weinberg equilibrium, then ____ would occur in that population.
no evolutionary changes
Occasionally, chromosomes fail to separate during meiosis, leading to daughter cells that have an abnormal number of chromosomes. This phenomenon is called
nondisjunction.
A researcher is working to generate a new cancer drug. Thus far, he has identified a compound that can reduce the size of tumors in the lung. However, in order for the drug to work, the lung tumor has to be small. In addition, the tumor cannot have metastasized (spread to other areas of the body). Furthermore, he knows that the drug acts to prohibit the signaling from one tumor cell to another tumor cell. Given the above information, this new drug prohibits:
paracrine signaling between tumor cells.
Because oxygen is more electronegative than hydrogen, the water molecule is:
polar.
A type of isolating mechanism that leads to reproductive isolation after a hybrid zygote has formed is called a _____________ isolating mechanism.
postzygotic
A Punnett square is generally used to
predict the genotypic ratio among the offspring.
Recently a class of infectious proteins with no associated nucleic acid have been identified. They are referred to as
prions.
In eukaryotes, each type of RNA polymerase recognizes a different
promoter
Crossing over between homologous chromosomes takes place during
prophase I.
What immediately follows meiosis I?
prophase II
The digestive enzyme pepsin works in the acidic environment of the stomach to hydrolyze peptide bonds. As a result, pepsin affects which macromolecule?
protein
A rare disease is now understood to be caused by a single mutant gene. When the researcher learns that the gene encodes a ______, he says "Oh good! We may be able to treat the disease with recombinant protein produced in E. coli and delivered by injection."
protein hormone
Most viruses form a capsid around their nucleic acid core. This capsid is composed of
proteins
The plasma membrane is a thin sheet of lipid embedded with
proteins.
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. If the uppercase letters represent the dominant alleles, what is the phenotype of a plant with the genotype PpTt?
purple flowers, tall
In glycolysis, a major portion of the energy remains in the final product, which is called
pyruvate
An allele for a particular trait that is only expressed in the presence of a second copy of the same allele is called
recessive.
The major histocompatibility complex is important in a T-cell's ability to:
recognize self from nonself.
Some protists use multiple fission (cell division preceded by several nuclear divisions) as a means of reproduction. Multiple fission is also referred to as
schizogony.
After DNA replication is complete, each strand of the original molecule is bound to a new complementary strand. This process is known as
semiconservative replication.
Replication of DNA is
semiconservative.
According to the biological species concept, two groups of organisms that are unable to form fertile, viable hybrids are considered to be different
species.
Two populations that inhabit the same area but remain genetically distinct can best be called
species.
During transcription of mRNA in eukaryotes, some sequences are cut out of the primary transcript and the remaining sequences are joined together. This processing of mRNA is called _________.
splicing
Eukaryotes have ____ type(s) of RNA polymerase.
three
Flattened sacs of internal membranes associated with photosynthesis are called
thylakoids.
Organisms containing DNA from an outside source are called
transgenic organisms.
Ribosome movement along the mRNA is called
translocation.
The two nitrogen atoms in nitrogen gas (N2) share six electrons forming a _____.
triple covalent bond
During meiosis, sister chromatids are held together by
a common centromere and a protein called cohesion.
The covalent bonds connecting monomer units in sugars can be formed by the removal of a water molecule. This reaction is referred to as:
a dehydration reaction.
In aerobic respiration, chemiosmotic generation of ATP is driven by:
a difference in H+ concentration on the two sides of the inner mitochondrial membrane.
The energy needed to destabilize existing chemical bonds and start a chemical reaction is called
activation energy
The type of movement that is specific and requires carrier molecules and energy is
active transport.
Plants are raised under artificial lights turned off and on by an electric clock. Some are given long periods of light, others short periods. This is an example of:
an experiment
In humans, if nondisjunction led to an individual with a genotype of XXY, that person would
be male because each cell has one Y chromosome.
The biological species concept of Ernst Mayr cannot be applied to
asexually-reproducing organisms.
Of the 23 pairs of human chromosomes, 22 pairs are homologous and are found in both males and females. These are called ________.
autosomes
A codon is composed of how many bases?
three
Most individuals in academia are basic researchers, funded through research grants from agencies or foundations. Based on your knowledge of applied research, an industrial company would most likely employ individuals
who develop alternative fuel sources.
The cell's plasma membrane mediates which of the following transactions with the environment? Choose all that apply.
- Ingesting food molecules and sometimes entire cells - Returning waste and other molecules back to the environment - Responding to a host of chemical cues -Passing messages to other cells
Choose all that apply. A concentration gradient is exhibited when
- intracellular fluid has 5% solute and extracellular fluid has 0.8% solute concentration. - during rest, muscle and liver cells contain high glycogen concentration and blood contains lower concentrations. -the pCO2 changes from 45 to 35 mmHg in the alveoli of lungs.
A protein that has been transported past the outer chloroplast membrane would have to pass how many more membranes to reach the stroma and thylakoid lumen, respectively?
1,2
If you are tossing a six-sided die, what is the probability of getting either a 1 or a 2 on your first toss AND a 1 or a 2 on your second toss?
1/9
You are studying meiosis in an organism where 2n = 24. How many chromosomes will each nucleus have after meiosis II is complete?
12
If there are 32 sister chromatids in a normal somatic cell, how many chromosomes are there?
16
A cuboidal shaped cell with six sides is 1mm x 1mm x 1mm. What is the volume and the surface area of the cell?
1mm^3 : 6mm^2.
Non-disjunction is the failure of homologous chromosomes to separate during meiosis I, or the failure of sister chromatids to separate during meiosis II or mitosis. As a result, both homologous chromosomes or both sister chromatids migrate to the same pole of the cell. This produces daughter cells with an imbalance of chromosomes. If 18 pairs of sister chromatids segregate normally during meiosis II in cats (n=19) but we have non-disjunction of 1 pair, then at the end of meiosis II we will have
2 cells with 19 chromosomes, 1 with 20 and 1 with 18
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?
5
If you take into account the amount of ATP generated by ATP synthase per molecule of NADH produced in aerobic respiration, the net number of ATP molecules produced by substrate-level phosphorylation, and the fact that NADH molecules produced in the cytoplasm have to be transported into the mitochondria, what is the predicted energy yield of glycolysis in eukaryotic cells?
5 ATP
Nucleotides have a phosphate group attached at the ___ carbon atom of the sugar.
5'
If there are 32 sister chromatids in a normal somatic cell, what is the haploid number for that cell?
8
Which of the following reactions is a dehydration reaction?
A + B → C + H2O
Chargaff's rules for the pairing of nitrogen bases is
A = T and G = C.
What best describes whether a virus is likely to infect a particular cell?
A virus will only infect host cells with the correct surface receptors.
Which of the following reactions is a hydrolysis reaction?
A+ H20 -> B+ C
Three babies were recently mixed up in a hospital. Based on the data in the table above, the couple with blood types A and B are the actual parents of the child with blood type
AB
When substrate-level phosphorylation occurs, it means that:
ADP is converted into ATP by the addition of phosphate group.
The template strand of a DNA segment that codes for mRNA has the sequence: ATGCGT. Which tRNA anticodons would pair with the mRNA that is coded for by this sequence?
AUG CGU.
Based on a variety of experiments, it is known that the rate of photosynthesis is highest when wavelengths of light between 400 and 500 nm are used, and when wavelengths around 700 nm are used. What does this indicate about the relative importance of chlorophyll a and b in photosynthesis?
Absorption of light by chlorophyll a and b is essential for the process of photosynthesis.
Your dog becomes ill and you rush him to the veterinarian's office. A technician draws blood from your dog's leg for a vet-ordered lab test. After a few minutes the lab results are given to the vet, who immediately grabs a bottle from a shelf and begins to fill a syringe with an unknown fluid. You inquire about the fluid, and the vet informs you that the fluid is necessary to manage your dog's metabolic acidosis. Based on the information provided, what is acidosis, and what is the likely effect of the veterinarian's injection?
Acidosis means that your dog's blood pH has decreased from its normal level, and an injection of buffering solution is required to reverse the condition.
A microbiologist suspects a strain of Staphylococcus aureus is resistant to methicillin. What would be the best approach to test this suspicion?
Add methicillin to the growth plates.
A key difference between transforming plant cells and human cells is
Agrobacterium is commonly used as a tool to directly transform plant cells but not human cells.
Mendel's Principle of Independent Assortment states that different pairs of
Alleles segregate independently of each other.
What would be strong evidence to suggest a protist is phagotrophic?
An abundance of lysosomes
The organism with the highest fitness is:
An animal that lives 10 years and produces 10 offspring per year.
You have been assigned to analyze some extraterrestrial material recently collected from Mars. After examining a sample using a microscope you jump up excitedly and shout to your colleagues that you have confirmed the existence of life on Mars. One of your colleagues takes a look at your sample and remarks that all he sees is a single-celled "blob" with little internal structure. Assuming that life on Mars can be classified into similar domains and kingdoms as Earth, to which domain does your "blob" belong?
Archaea
Which one of these groups is not one of the six supergroups that protists are contained in?
Ascomycota
The protein Sonic Hedgehog (SHH) plays a role in specifying the identity of digits (such as fingers and toes) in mammals. Several digits arise directly from cells that both express and respond to secreted SHH. What type of signaling would this be considered?
Autocrine
The formula for glucose is C6H12O6. What is the formula for a polymer made by linking ten glucose molecules together by dehydration synthesis?
C60H102O51
The specific white blood cells that HIV attaches to are the ____________ cells.
CD4+
Cell theory is one of the foundations of biology. What are the tenets of the cell theory? Check all that apply
Cells carry genetic material passed to daughter cells during cellular division. Cells arise from other cells through the process of cell division. All living organisms consist of cells
Who proposed that in any DNA molecule, A = T and G = C?
Chargaff
Prior to using PCR to introduce mutations into DNA in vitro, what was a common method of mutagenesis used by scientists?
Chemicals to induce mutations
Which of the following statements about crossing over is false?
Crossing over takes place between sister chromatids.
The physical distribution of cytoplasmic material into the two daughter cells in plant cells is referred to as:
Cytokinesis
The stage of the cell cycle during which the cytoplasm divides to form two cells is called:
Cytokinesis
You are the scientific consultant for a television show about forensic analysis. In an upcoming episode, investigators will compare the DNA of a suspect and a DNA sample collected from the victim's fingernails. You are to write up a brief explanation of the technique required for comparing the DNA. Which technique should you explain?
DNA fingerprinting
Which statement represents the biological characteristics that kittens, oak trees, swans, earth worms, elephants and crickets have in common?
DNA nucleotides form the basis of all inherited life, with cells that are formed from other cells.
Regulatory proteins can identify specific sequences on the DNA double helix without unwinding the helix. This is accomplished by inserting
DNA-binding motifs into the major groove of the double helix where the edges of the nitrogen bases protrude.
Mitochondria and chloroplasts are the other organelles besides the nucleus that contain:
DNA.
In the reaction: C4H6O4 + FAD →C4H4O4 + FADH2, what type of reaction took place to remove the protons from C4H6O4?
Dehydrogenation
The PCR technique requires a DNA polymerase from an organism that can endure high heat, such as Thermus aquaticus. What step of the protocol makes the heat-stability most necessary?
Denaturation
One cell sends second messengers to another cell through gap junctions. What type of signaling would this be considered?
Direct contact
______ could not be involved in gene flow.
Disassortative mating within a population
An example of an "emerging virus" (a virus in a new host) with a lethality rate in excess of 50% is
Ebola virus.
Addison's disease is a disorder that results from a reduction in production of glucocorticoids and mineralocorticoids. Individuals with Addison's disease suffer from a variety of systemic symptoms including: muscle weakness, fever, issues with the gastrointestinal tract, and increased tanning. Considering this information, what type of signaling do you think that glucocorticoids and mineralocorticoids stimulate?
Enocrine
According to most car mechanics, plain water is the best coolant to use in an engine provided the engine is not being exposed to freezing temperatures. If the car is subject to freezing temperatures then a mixture of water and ethylene glycol (antifreeze) is recommended but it does not cool as efficiently as plain water. Why would ethylene glycol reduce the cooling efficiency of water?
Ethylene glycol has a lower heat capacity than water.
Prokaryotic cells are smaller than eukaryotic cells. What is a plausible explanation?
Eukaryotes have compartmentalization, which allows for specialization.
A researcher observed a reduction in the number of chromosomes during cell division for a microbe, he concludes that the microbe must be
Eukaryotic
DNA replication and gene expression in archaeans more closely resemble eukaryotic cells than the same processes in bacteria. However both Bacteria and Archaea are prokaryotic. What does this suggest?
Eukaryotic cells shared a more recent common ancestor with Archaeans than with bacterial cells.
Which statement about the genetic code is false?
Every codon codes for one amino acid.
A medical researcher is trying to develop a diagnostic technique for a disease which is characterized by replication of a particular chromosomal region. What would be the most appropriate technique?
FISH
Who provided X-ray diffraction photographs of purified DNA fibers that suggested a helical structure with a consistent diameter of about 2 nm and a complete helical turn every 3.4 nm?
Franklin
The portion of the cell cycle when the cell is growing and does not contain a replicated genome is referred to as:
G1
What is the sequence of events in a typical eukaryotic cell cycle?
G1 to S to G2 tp mitosis to cytokinesis
This stage of the cell cycle is characterized by growth and it contains a checkpoint to verify that all of the DNA has been replicated prior to mitosis.
G2
What aspect of cellular respiration occurs in the cytoplasm in eukaryotic cells?
Glycolysis
When oxygen is unavailable during heavy exercise what process do muscle cells use for energy generation?
Glycolysis coupled with lactate fermentation.
What stage of cellular respiration can occur in human cells with or without oxygen present?
Glycolysis.
You have identified an enzyme that appears to be involved in the addition of palmityl group (a fatty acid) to certain proteins. Knowing that palmitoylated proteins are usually targeted for delivery to the plasma membrane, in which organelles might this enzyme be expressed?
Golgi apparatus and endoplasmic reticulum
The eukaryotic organelle that is directly involved in the transport of proteins synthesized on the surface of the rough ER is called the:
Golgi body.
Why is eating carrots thought to be useful for enhancing vision?
High levels of beta-carotene can lead to the production of a pigment used in vision.
Osmometer cells in the brain sense an increase in the salt concentration of plasma. This information is sent to the hypothalamus, which notifies the pituitary gland to release the hormone, ADH. ADH causes the kidney to save water, which lowers the salt concentration of the plasma. What characteristic of life does this overall pathway represent?
Homeostasis
The two copies of each type of chromosome found in normal somatic (body) cells in an organism, throughout the cell cycle, are called:
Homologous chromosomes
Plants transport water to their leaves through the xylem when water evaporates from the leaves. The evaporating water pulls other water molecules up the xylem through ____ .
Hydrogen bonds
Sue was monitoring the oil spill into the Gulf of Mexico from an oil tanker. From her observations, she noted that the oil was moving as large patches in the water. It did not appear as though the oil was dissolving into the water. Why did the oil not dissolve into the water?
Hydrophobic interactions
In humans, the male has an X and a Y sex chromosome. The human female has two X chromosomes. In birds, the female has a Z and a W sex chromosome while the male has two Z chromosomes. Which of the following statements is accurate about which parent determines the gender of the offspring based on inheritance of the necessary sex chromosome?
In humans, the male determines the gender of the offspring, and in birds the female determines the gender.
Proteins are three dimensional molecules made of strands of amino acids (imagine a ball of string). There are 20 different amino acids used in proteins found in living organisms. Some of these amino acids are polar and others are nonpolar. Where would a series of nonpolar amino acids most likely be located in a protein that is found in the cytosol of an animal cell?
In the interior of the protein
A dental student wants to test if fluoride is an effective additive against tooth decay. The student studies tooth decay in a population of people who live in neighborhoods supplied with fluoridated water. This student would like to ask whether access to fluoridated water prevents tooth decay. What would be an effective control group to ask this question?
Individuals with access to water with no fluoride added
You are working with a specific enzyme-catalyzed reaction in the lab. You are a very careful experimentalist, and as a result, at the beginning of each of your experiments, you measure the temperature in the lab. On days 1 through 5, the temperature in the lab was 20oC. Today is day 6 of your experiment, and the temperature in the lab is 30oC. How do you predict that this will alter the rate of your enzyme-catalyzed reaction?
It could possibly increase of decrease the rate,
A researcher wants to create a mouse model for a disease, to allow her team to study possible therapies. The disease is known to be caused by a small deletion that removes a certain gene. Which type of mouse would be the best choice for this purpose?
Knockout mouse
You have identified a molecule, molecule X, that can bind to the ATP binding site of a specific protein kinase, and prevent ATP binding. You are conducting a kinase assay using this protein kinase and a known substrate of this kinase, and have set up the reaction using the proper conditions and cofactors to allow for optimal protein kinase activity. If you add molecule X to the reaction, what do you predict will be the outcome?
Less phosphorylation of the substrate will be seen in the presence of molecule X.
In your research, you have discovered that Protein X is often ubiquitinated in people with a certain disease. What would you predict about levels of Protein X in these patients?
Levels of Protein X will be low due to degradation in the proteasome.
Carbon dioxide and water can combine to form glucose, water and oxygen. What is required for that process to occur?
Light energy from the sun
Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered a cofactor of Kinase 1?
Metal A
Choose the best cause and effect sequence for the process of speciation by natural selection.
Mutation-Variation-selection-Reproductive isolation-Speciation
What is different about the way that NADH and FADH2 donate electrons to the electron transport chain?
NADH contributes its electrons to the first transmembrane complex in the electron transport chain and FADH2 contributes its electrons after the first transmembrane complex.
Courtship for Anolis lizards involves the male displaying a dewlap (skin under the throat area) that varies in appearance based upon the species. Lizards that are found in darker, more shaded environments will have dewlaps that are lighter in color because they are more noticeable by potential mates. Which of the following mechanisms best explains how speciation is at work in this example?
Natural selection
Can a virus be killed?
No, viruses are nonliving and cannot die.
You eat a bowl of beans as part of your dinner. As you digest the beans, the proteins that are present get broken down to their component amino acids. As your body destroys the macromolecules that were present in the beans, is the energy present in those molecules destroyed?
No. The energy contained within these macromolecules is converted into other forms of chemical energy and kinetic energy, though some is lost as heat.
The accommodation of the very long DNA strands that are part of a chromosome into the limited space of the nucleus is achieved by coiling the DNA around beads of histones into repeating subunits. These DNA-wrapped histones are called:
Nucleosomes
Leptin is a circulating hormone that is produced by fat cells and plays a role in body metabolism and obesity. It normally binds to receptors in the brain and inhibits appetite. Studies have demonstrated that when obese mice that are leptin deficient are injected with leptin they quickly lose their excess weight. Interestingly, however, many overweight people have high levels of leptin in their bloodstream. Why do you think that the high levels of leptin in obese individuals are insufficient to curb their appetite?
Obese people who have high levels of leptin may have a leptin receptor with decreased sensitivity.
Based on the function of mitochondria, what substance is able to pass through the outer membrane of the mitochondria easily?
Oxygen
Let P = purple flowers and p = white, and T = tall plants and t = dwarf. What are the genotypes of the gametes that are produced by a plant that is heterozygous for both traits?
PT, Pt, pT, and pt
In response to injury, cell fragments called platelets get activated to induce clotting. Activated platelets release factors that can in turn bind to specific membrane receptors on nearby cells. What type of signaling would this be considered?
Paracrine
The cells wall of bacteria Z contains high concentrations of phospholipids along with proteins and relatively low amounts of lipopolysaccharide. When bacteria Z is gram stained, it will most like be colored?
Pink
A novice gardener notices that many plants in his garden look wilted. What osmotic solution would you suggest the novice gardener use to best return the plants to full health?
Place the plants in a 5% solute solution so water can diffuse into the plant cells.
Kinases are enzymes that can phosphorylate (transfer phosphate groups onto) macromolecules such as proteins. A particular kinase, Kinase 1 is known to promote cell division. It promotes cell division by phosphorylating Protein X. Phosphorylation of Protein X activates Protein X. Once activated, Protein X stimulates the production of other proteins such as Protein Y and Z that directly promote cell division. In order to function, Kinase 1 requires the presence of Metal A. However, in the presence of Protein A, Kinase 1 is nonfunctional. From the description, what is considered the substrate of Kinase 1?
Protein X
You label cells with a radioactive isotope of sulfur (35S). The only molecules that would be radioactively labeled in these cells are:
Proteins
The most diverse of the four eukaryotic kingdoms is the
Protista Kingdom.
If the label on a slide reads Gram-positive bacillus, what would a students expect to see?
Purple rod shaped cells
Luke sprained his ankle, tearing some of the collagen protein that forms his ligaments. Some types of collagen consist of three polypeptide chains twisted together to form a rope-like strand. What level of protein structure does this rope-like strand represent?
Quaternary
You are attempting to synthesize rRNA in a test tube using DNA isolated from mouse cells. In addition to the template DNA, ribonucleotides, and the necessary transcription factors, you should also add _________ to the test tube.
RNA polymerase I
In order for transcription to be initiated
RNA polymerase must have access to the DNA double helix and must also be capable of binding to the gene's promoter.
During translation in prokaryotes, formation of the initiation complex requires all of the following except
RNA polymerase.
The carbonic acid and bicarbonate buffer in blood is extremely important to help maintain homeostasis. What would happen to the pH of the blood if bicarbonate were removed?
Removing bicarbonate from the blood would decrease the pH
The Principle of ________ states that the 2 alleles present at each gene locus separate from one another during gamete formation and remain distinct.
Segregation
Before cell division of somatic cells, each chromosome must be replicated. After replication, the resulting two parts of each chromosome are held together by cohesin at the centromere. These two parts are referred to as:
Sister chromatids
Why are phosphorylation and dephosphorylation reactions commonly used to regulate signal transduction pathways?
The addition or removal of a phosphate group can expose or hide potential binding sites in proteins or change protein activity
In the graph above, which baby characteristics would explain the percent infant mortality curve and any subsequent effects on fitness?
The baby needs to be large enough to survive after birth, but small enough for a safe delivery
The point of constriction on chromosomes that contains certain repeated DNA sequences that bind specific proteins is called:
The centromere
In DNA, a purine must always pair with a pyrimidine and vice versa in order to ensure that
The distance between the two phosphodiester backbones remains constant.
Cytochromes contain a heme group similar to that in hemoglobin. The iron atom (Fe) in the center of the group can be oxidized and reduced. If someone was suffering from iron deficiency anemia, what stage of cellular respiration would be most affected?
The electron transport chain
As electrons move along the electron transport chain, they lose potential energy. How is the energy that is released used by the cell?
The energy is used to transport protons against their concentration gradient
As a forensic pathologist, you have just completed an autopsy of a poisoning victim. After a thorough examination, you conclude that the victim died of cyanide poisoning. You know that cyanide binds to the cytochrome oxidase complex, and therefore list the official cause of death as suffocation due to cyanide exposure. However, if you wanted to provide a more technical explanation as to the cause of death, which process was specifically inhibited directly by cyanide?
The formation of water from oxygen
All of the reactions of cellular respiration that occur after glycolysis take place in what part of the eukaryotic cell?
The mitochondria
Based on the graph, what are the optimal temperatures for the human enzyme (blue line) and hotsprings prokaryote enzyme (red line)?
The optimal temperature for the human enzyme is 40 degrees C. The optimal temperture for the hotsprings prokaryote enzyme is 72 degrees
What would be strong evidence to suggest a protist is phototrophic?
The presence of chloroplasts
A protein that is destined to reach the plasma membrane is making its way through the Golgi. At that moment, a drug was added to cells, blocking trafficking at the trans face of the Golgi. As a result, what would happen to the protein?
The protein would be stuck in the Golgi.
You identify an enzyme involved in a cellular reaction. How does the enzyme affect the reaction equilibrium between reactants and products and the time needed to reach equilibrium?
The reaction equilibrium is unaffected, but it shortens the time needed to reach equilibrium.
A student set up an experiment to test if plants give off water vapor. Fifty pea plants, growing in pots, were covered with individual glass containers and left overnight. The next morning, the inside of each lid was covered in droplets of water. The lab student concluded that plants generally give off water vapor. What critique would you make of the experimental design?
There was no control so the water could have come from other sources such as air in the jar or the soil.
Protists are classified into a single kingdom because of which of the following features?
They are eukaryotes, but not fungi, plants, or animals.
Which type of disease is LEAST likely to be able to be treated using genome editing with TALEN or CRISPR?
Trisomy-21
Vasopressin is a hormone that is primarily released when the body is low on water. Release of vasopressin causes the kidneys to conserve water by concentrating urine and decreasing urine output. However, vasopressin also has additional functions in other tissues such as the brain and blood vessels, which are not directly involved in urine production. How could it be possible for vasopressin to trigger different responses in different tissues?
Vasopressin can bind to, and act on, different receptor subtypes, leading to different cellular responses in different tissues.
Which of the following statements about TSEs (transmissible spongiform encephalopathies) is false?
Viroids are the likely cause of TSEs.
Who proposed that the structure of DNA is a double helix with two polynucleotide chains running in opposite directions and held together by hydrogen bonding between pairs of nitrogenous bases?
Watson and Crick
In 1910, Morgan did a series of experiments with the fruit fly Drosophila, an organism where females are XX and males are XY. When a mutant male fly with white eyes was crossed with a wild type female with red eyes, none of the F1 progeny had white eyes but 18% of the F2 progeny had white eyes. Unexpectedly, all of these white-eyed F2 flies were males. Based on these results, Morgan concluded that white eyes is caused by a recessive X-linked allele. Suppose Morgan had found that half of the F1 progeny had white eyes but all of these white-eyed F1 flies were females. In this case, a valid hypothesis would be
White eyes is caused by a dominant X-linked allele
A student poses the question: How does the presence of dissolved salt affect the freezing point of water? To answer this question, the student set up two conditions. In the first condition, the student added salt to water in a container and referred to this condition as the variable. In the second condition, the student did not add any salt to water in a second container and referred to this condition as the control. The student took both containers and attempted to freeze the water at various temperatures to assess the freezing point. Would this be a valid experiment?
Yes, because there is one variable and a control
Phospholipids are made up of:
a phosphate, two fatty acids and a glycerol.
You have identified a novel cytoplasmic protein. Through sequence analysis you are able to identify the presence of a number of serine/threonine phosphorylation motifs. Based on these data, you hypothesize that this protein may be a substrate for what kind of enzyme?
a protein kinase
Carotenoids are important to many plants because these pigments are able to
absorb wavelengths of light that neither chlorophyll a nor b can absorb.
You walk down into your basement to find that the carpeting on the floor is damp. Concerned, you look around for large puddles of water or broken pipes, but find none. In fact, only the basement floor and carpeting is damp. You realize that water must have wicked into the carpet from the floor by ______.
adhesion and cohesion
In the Hardy-Weinberg equation, p and q are _____.
allele frequencies
Alternate forms of the same gene are called
alleles.
The type of speciation that results in the formation of separate species as a result of geographic isolation is called ____________ speciation
allopatric
A restriction in genetic variability caused by a drastic reduction in population size is called a
bottleneck effect.
On the outer surface of the plasma membrane there are marker molecules that identify the cell type. Often these molecules are
carbohydrate chains.
Two bird species have different mating calls, occupy different habitats in nature, and when they hybridize, the hybrids are infertile. Which isolating mechanisms maintain these species?
ecological isolation, behavioral isolation, and hybrid sterility
You stain a cell with a dye that reacts with an enzyme found in the lysosome. You would also expect to see this dye in the:
endoplasmic reticulum
Certain prokaryotes can withstand drying and hotter temperatures because of their ability to form
endospores.
When bacteria are exposed to nutrient-poor conditions, they form thick-walled structures that contain the chromosome and a small amount of cytoplasm. These structures are called
endospores.
In eukaryotes, mitochondria are the organelles primarily involved in:
energy release/capture
A layer of lipoprotein and glycoprotein that covers the outer surface of some viruses is the
envelope.
Sometimes, one gene pair will interfere with the expression of a second gene pair in an interaction called _______.
epistasis
Nondisjunction of a single pair of autosomes can lead to all of the following except
euploidy.
Carrier-mediated transport of a substance down its concentration gradient is called
facilitated diffusion.
The type of movement of molecules that is specific and passive, and which becomes saturated if all of the protein carriers are in use is
facilitated diffusion.
In 95% of cases of Down's syndrome, there is one extra chromosome (number 21) in every cell. This aneuploid condition is most likely the result of
failure of 1 homologous pair to segregate during meiosis.
Reproductive success of an individual is known as:
fitness.
When fisheries managers move fish from one lake to another, this causes gene ______.
flow
Organic molecules have a carbon backbone and _____ such as -OH and -NH2 that affect their chemical properties.
functional groups
What color of light is not strongly absorbed by chlorophyll?
green
A defining characteristic of eukaryotic organisms is that they
have their transcription occurring in the nucleus and translation in the cytoplasm.
The most common DNA-binding motif is the
helix-turn-helix
You have been asked to design a synthetic DNA motif, able to bind transcriptional regulatory proteins. The location on this motif that you will design for protein binding is the
major groove of the DNA double helix.
The chemistry of living systems representing all chemical reactions is called
metabolism.
Which of the following produces new cells that are genetically identical to the original cell?
mitosis
All of the following increase genetic variation EXCEPT
mitosis.
During translation, translocation refers to
moving the ribosome along the mRNA molecule.
In all of the following characteristics, prokaryotes differ from eukaryotes except in
nucleic acids as the hereditary material.
A microbiologist explains to one of her biology classes that her research focuses on the nucleoid region of the cholera bacteria. This means that she is studying a region within the bacterium that contains the
nucleic acids.
A distinctive feature of eukaryotes is the organization of tightly packaged chromosomal DNA with proteins into a membrane-bound structure called a:
nucleus.
In eukaryotes, translation takes place
on ribosomes.
At the end of meiosis II, each of the four resulting cells contains
one full set of chromosomes, each with 1 molecule of DNA.
Which is an example of temporal isolation?
one plant species blooms in June-July and a second plant species blooms in August-September.
The cytoplasmic space in eukaryotic cells is occupied by many diverse membrane-bound structures with specific cellular functions called:
organelles.
When a polypeptide is being assembled, the bond that forms between a newly added amino acid and the previous amino acid in the chain is a _________ bond.
peptide
Denaturation disrupts the secondary and tertiary structure of proteins. However, denaturation is not strong enough to disrupt what interaction that is relevant to protein structure?
peptide bonds
Proteins are created with:
peptide bonds.
Prokaryotic cell walls consist of a network of polysaccharide molecules connected by cross-bridges of
peptides.
Organelles that breakdown hydrogen peroxide into water and oxygen are:
peroxisomes.
The observable expression of the genes present in an organism is called its
phenotype.
The chemical bond connecting one nucleotide with the next along one strand of a DNA molecule is called a
phosphodiester bond.
The lipid layer that forms the foundation of cell membranes is primarily composed of molecules called __________
phospholipids
Clusters of chlorophyll and accessory pigments are called ________.
photosystems
Molecules that absorb light are called
pigments.
In multicellular organisms, the mechanism most directly responsible for directing development and maintaining homeostasis is gene
regulation.
The basic tool of genetic regulation is the ability of certain proteins to bind to specific
regulatory DNA sequences.
Based on the literature, you hypothesize that students in traditional biology lectures will have the same grades as students in online biology lectures. You decide to test your hypothesis by comparing grades of students in traditional and online biology lectures over a semester. As a result of the experiment, you observe that the grades in the traditional lectures and the grades in the online lectures are not significantly different. What do these observations allow you to do?
retain the hypothesis
While they are simple relative to cells, viruses often have a very diverse collection of components. Which one of the following choices is LEAST likely to be found as part of a virus?
ribosomes
Traits that are controlled by genes located on the X chromosome are said to be ________________.
sex-linked
The DNA-binding proteins of almost all regulatory proteins use one of a small set of shapes that enable them to fit into the DNA major groove. These shapes are called
structural motifs.
In an enzyme-catalyzed reaction, the reactant is called the
substrate
If populations within the same area split into species, the process is known as
sympatric speciation.
If a new species is produced by the interbreeding of two members of distinct species, this would be __________ speciation achieved via _________.
sympatric; allopolyploidy
Which of the following events occurs first during meiosis?
synapsis of homologous chromosomes
This type of lipid is found in pigments such as chlorophyll, in the visual pigment retinal, and in rubber:
terpene.
For a gene with two alternative alleles, B and b, the term q2 in the Hardy-Weinberg equation represents
the frequency of the bb genotype.
The independent assortment of allele pairs is due to
the independent segregation of homologous chromosome pairs during anaphase I.
Certain proteins can bind to specific DNA regulatory sequences by entering
the major groove of the DNA and reading the nucleotide base pairs.
Archaea differ from Bacteria in all of the following EXCEPT
the presence of a nucleoid region.
Cheetahs have been through a genetic bottleneck; evidence for this is that
there is very little genetic variability.
The number of chromosomes in diploid eukaryotic cells
varies considerably from 2 to over 1000 in different species