Principles of Genetics and Molecular Biology, Exams of Biology

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BIO 111 Assignment Questions, Bio 111

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Bio 111 Assignment Questions 3, BIO 111

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Questions

What is the ultimate source of new alleles in all living organisms? - mutations morphological divergence is the wing of a bat and the ____ - hand of a human Biogeography is the study of the _____. - patterns in the geographical distribution of species Today, all biological research is undertaken with the recognition that ____. - all living organisms share the same common ancestor The wings of bats and birds are ____. - homologous because they have similar internal bone structure inherited from a common ancestor A ____ mutation changes the DNA sequence but has no impact on the fitness of the individual. - neutral Pigs have feet with toes that do not touch the ground. These toes are examples of ____. - vestigial structures According to ____, environmental pressures caused changes in body parts, which were directed by ____ and passed onto offspring. - Lamarack; fluida The fossil record documents ____, providing clear evidence of ongoing change in biological lineages. - continuity in morphological characteristics Darwin hypothesized that advantageous hereditary traits in nature would become more common in populations due to the process of ____. - natural selection

Darwin incorporated Malthus' idea that _____ into his theory of evolution. - populations will always produce more individuals than the environment can support (maybe) Which of the following populations is not in Hardy-Weinberg equilibrium? - a population undergoing natural selection An earthquake causes a river to change course and forms an oxbow lake. A portion of a population of river fish is separated into the new oxbow lake and has no contact with the river populations = Founder Effect A fire burns through a forest killing the majority of a species of tree. The surviving population is a fraction of the size of the original = Bottleneck Effect In a species of cichlid fish, the females will choose to mate with the brightest male. = Nonrandom Mating In a species of yellow flowering plants, some individuals begin to display a red coloration in their flowers that wasn't present in any previous generation. The coloration does not appear to affect selection = Mutation - very small and very large human newborns are less likely to survive than those born at an intermediate weight due to ____. - stabilizing selection Disadvantageous recessive alleles are protected from natural selection due to ____. - diploidy Inbreeding is primarily due to ____. - nonrandom mating Most new alleles probably arise from ____. - small-scalemutations in DNA When male moose engage in their annual battles, butting heads with their oversized antlers, they are exhibiting ____ selection. - intrasexual Any product of natural selection that increases the relative fitness of an organism in its environment is called a(n) ____. - adaptive trait According to the Hardy-Weinberg principle, microevolution occurs when ____. - population experiences a shift in allele frequencies If there are two alleles for a gene in a population, and the frequency of the dominant allele (p) is .5, then the frequency of the recessive allele (q) is ____. -

Two species of hawk are able to mate successfully, but one hunts in the morning and the other hunts at night. Mating between the two species, therefore, does not occur. = Behavioral Isolation The genitals of snakes are analogous to a lock and key mechanism- the "keys' will only fit in certain "locks". = Gametic isolation Two species of skunk coexist and are able to mate successfully, but one reproduces in the spring, whereas the other reproduces in the fall = Temporal isolation Two species or squirrels are separated by a mountain range and cannot interact with each other = Habitat isolation - Which of the following statements is false? - Punctuated equilibrium is most likely to occur in a large population that lives in a stable climate. Correct, this is the false statement. Punctuated equilibrium is likely to occur in smaller populations experiencing rapid change A sterile hybrid plant can form a new fertile species if its chromosomes are doubled. This is referred to as ____. - sympatric speciation Species that live in different habitats exhibit ____ reproductive isolation. - ecological If two species of lizards do not mate because their mating rituals differ greatly, they are exhibiting ____ reproductive isolation. - behavioral The process of speciation always includes ____ isolation. - reproductive Which reproductive isolating mechanism is displayed in a mule, the product of a cross between a horse and a donkey? - hybrid sterility According to the biological species concept, members of the same species look alike primarily because they ____. - share the same gene pool The emergence of hundreds of Hawaiian honeycreeper species from a single flock introduced to this island archipelago millions of years ago is an example of ____. - adaptive radiation The uplift of the Isthmus of Panama, a geological event that occurred about five million years ago, separated populations of marine organisms and led to ____. - allopatric speciation

A hybrid zone is defined as an area where two populations may breed and produce ____. - viable; fertile off spring In a cross of a DDRR individual with a ddrr individual, the genotype of all offspring will ____. - DdRr In codominance, ____. - two alleles may be equally expressed In humans, skin color is controlled by several genes. Thus, skin color is a(n) ____ characteristic. - epistatic In the Bombay phenotype, a gene in the recessive condition blocks the expression of A and B red blood cell antigens. Thus, all A, B, and AB genotypes are expressed as the O phenotype. This is an example of ____. - epistasis Observable traits are known in genetics as ____. - phenotypes Purple flower (A) is dominant over white flower (a), and tall stem (B) is dominant over short stem (b). The Punnett square represents a cross between two dihybrids (AaBb ´ AaBb). In the figure above, what would be the genotype of plant #9? - AaBB A testcross is used to ____. - determine if a parent with a dominant trait is heterozygous or homozygous Two snapdragons heterozygous for alleles that encode red and white flower color are crossed. If the red and white alleles show incomplete dominance, what will be the ratios of phenotypes in the offspring? - 25% red, 50% pink, 25% white In humans, skin color is controlled by several genes. Thus, skin color is a(n) epistatic characteristic. - Snapdragon flower color: offspring of white and red flowered parents have pink flowers = Incomplete Dominance Human eye color = Polygenic inheritance Fur color in Labrador retrievers: One gene expresses fur pigments. Another gene controls whether fur pigments are expressed = Epistasis ABO blood type in humans: Individuals who inherit both an A and B allele have an AB blood type. = Codominance - Characters that have a continuous distribution, such as height, weight, and skin color, are called ____, and the individual genes that control them are known as ____. -

quantitative traits; quantitative trait loci In the Bombay phenotype, a gene in the recessive condition blocks the expression of A and B red blood cell antigens. Thus, all A, B, and AB genotypes are expressed as the O phenotype. This is an example of ____. - epistasis An X-linked carrier is a ____. - heterozygous female What is the key difference between incomplete dominance and codominance? - In incomplete dominance, it is possible to detect the expression of a recessive allele; in codominance, both alleles contribute equally to the phenotype. Males are more commonly affected by X-linked recessive genetic disorders than females because ____.

• males have only one X chromosome; therefore, they have multiple alleles for each X-linked gene If a woman has blood type O and a man has blood type AB, what is the probability that they will have a child with blood type O? - 0 Mouse pigmentation is subject to epistasis of the B alleles by the d alleles. B (black) is dominant over b (brown), and D is dominant over d. Homozygous d is epistatic to the black and brown genes. Given this information, what will result from a F1 cross between two mice? - 9/16 black, 3/16 brown, 4/16 white Clear my choice In snapdragons, the red allele CR is incompletely dominant over the white allele CW. Which two plants would you cross to produce a true-breeding pink snapdragon? - a true-breeding pink snapdragon cannot be created In ____, genes at one locus mask the effect of genes at another locus. - epistasis The first suggestion that chromosomes may physically exchange segments came from the microscopic identification of ________. - chiasmata Abnormalities in the number of X chromosomes tends to have milder phenotypic effects than the same abnormalities in autosomes because of ________. - X inactivation Assume a pericentric inversion occurred in one of two homologs prior to meiosis. The other homolog remains normal. During meiosis, what structure—if any—would these homologs assume in order to pair accurately along their lengths? - loop

Nondisjunction refers to the ____. - failure of sister chromatids to separate during mitosis Genetic recombination as a result of crossing over occurs more readily between genes that are ____. - located far apart on the same chromosome Suppose a single nondisjunction event occurs during anaphase II of meiosis in a normal male cell from meiosis I. Of the resulting sperm, ____. - two would be normal, one would have an extra chromosome, and one would be missing a chromosome The change in the chromosome depicted between the top and the bottom in the accompanying figure represents a(n) ____. - Philadelphia chromosome In cells of human individuals with three or more X chromosomes, ____. - all of the X chromosomes remain active According to the chromosome theory of inheritance, ____. - genes and their alleles are carried on chromosomes The process by which chromosomes fail to separate during meiosis is called ____. - nondisjunction We now know that some of the seven alleles Mendel studied are on the same chromosome in pea plants. Despite this, the law of independent assortment still applies. How can you explain this? - The law of independent assortment applies to all alleles regardless of their arrangement on chromosomes. (guess) Genetic map units represent ____. - relative positions of genes with respect to one another When genes are located very close together on the same chromosome, ____. - gametes usually end up with unique combination of alleles Chromosomes are aligned at the middle of the cell during _____. - metaphase The phase of the cell cycle during which cytoplasmic division occurs is _____. - cytokinesis In what phase of the cell cycle does a typical cell spend most of its life? - interphase phase during which the cell prepares for DNA replication - G period prior to mitosis phase that follows DNA replication

G

this is the last stage of interphase - G when DNA is replicated - S the beginning of interphase - G period in which metaphase occurs mitosis phase that precedes cytoplasmic division nuclear division - mitosis phase in which chromatids are not connected by centromeres - G1 maybe? Tumor suppressor genes _____. - encode proteins that inhibit mitosis Which list correctly describes the sequence of events that occurs during cell division, beginning at interphase? - DNA replication, nuclear division, cytoplasmic division A cell cycle checkpoint for S phase would likely inhibit progression through the cell cycle if _____. - there is DNA damage A parent cell with 12 chromosomes will produce daughter cells with _____ chromosomes by mitosis. - 12 Cells with two of each kind of chromosome are _____. - diploid

In prokaryotes, transcription occurs in the _____. - cytoplasm During transcription, ____. - only one of the two DNA strands acts as a template Which bases are found in RNA? - adenine, uracil, guanine, and cytosine The central dogma describes the flow of information of gene expression as ____. - DNA®RNA®protein

The process of transcription refers to the use of information encoded in ____ to make ____. - DNA; a complementary RNA copy DNA molecules contain protein coding sequences called _____. - genes Eukaryotic post-transcriptional modifications occur in the _____. - nucleus Transcription starts at a region of DNA called a(n) _____. - promoter What are the non-coding segments of DNA called? - introns Each DNA nucleotide is composed of ____. - a five-carbon sugar, a phosphate group, and one of four nitrogenous bases A DNA double helix has two strands that are held together by ____. - hydrogen bonds How many times does DNA wrap around a histone? - 2 Adjacent nucleotides on a strand of DNA are connected to each other by a(n) ____. - phosphodiester bond DNA varies from species to species in _____. - the sequence of its base pairs Each DNA strand has a backbone that consists of alternating _____. - sugar and phosphate molecules A eukaryotic chromosome consists of _____. - DNA and protein Rosalind Franklin's research contribution was essential in _____. - establishing most of the principal structural features of DNA RNA transcribed from a protein-coding gene that is ready to be translated - mRNA RNA that forms part of the ribosome - rRNA RNA in eukaryotes that must be processed in the nucleus before it is ready to be translated - pre-mRNA

RNA with an anticodon and a linkage site for a specific amino acid - tRNA How is lac operon transcription regulated by the presence or absence of lactose? - When lactose is present, the repressor protein removes itself from the operator region, allowing RNA polymerase to begin transcribing the gene. How is lac operon transcription regulated by the presence or absence of lactose? - When lactose is present, the repressor protein removes itself from the operator region, allowing RNA polymerase to begin transcribing the gene. What is the genetic code? - the genetic "words" that code for amino acids During translation, mRNA is read in the ____ direction and the polypeptide is assembled from the ____. - 5¢®3¢; N-terminal end to the C-terminal end In both prokaryotes and eukaryotes, the start codon (or initiator codon) is ____, which codes for the amino acid ____. - AUG; methionine For eukaryotes, translation takes place in the _____. - cytoplasm A ribosome contains _____. - RNA and proteins Translation stops when _____. - one of the three stop codons is encountered How many nucleotides comprise one codon? - 3 Which of the following carries amino acids to ribosomes? - tRNA During elongation, ribosomes catalyze formation of a ____ bond between an amino acid and the growing polypeptide. - peptide Answer the question using the accompanying figure. Of the fragments labeled A-D, which is the smallest? - the one closest to the positive charge side (farthest down) PCR is ____. - repeated DNA replication cycles of a specific region of a DNA molecule When cloning TNA into bacteria, the _____. -

DNA sequence is inserted into a plasmid In the reproductive cloning of an animal, the genome of the cloned individual comes from _________.

• a body cell What is a transgenic organism? - An organism that has genes from another species In gene therapy, what is typically used to insert non-mutated genes into affected cells so that those cells can begin expressing the working protein. - Remember that we need to attach these genes into a human chromosome, otherwise the gene will not be expressed. This means that we need biological machinery that can attach new DNA to a chromosome. The non-mutated gene is usually introduced into diseased cells as part of a vector transmitted by a virus, such as an adenovirus, that can infect the host cell and deliver the foreign DNA into the genome of the targeted cell Genomics and proteomics are biotechnological fields that allow scientists to look at whole sets of molecules and compare them between organisms. The field of genomics studies with the ___________, whereas proteomics studies _____________. - complete genome of organisms; the entire set of proteins produced by a specific cell type What is the natural function of restriction endonucleases? - defense against viruses that infect bacteria Gene therapy is performed by ____. - transferring a normal or a modified gene into an individual with the goal of treating a genetic defect Recombinant DNA is ____. - DNA fragments from two or more different sources that have been joined together to form a single molecule GMO - An organism whose genome has been engineered to include or change a genetically controlled trait is called a ____. In agarose gel electrophoresis, DNA molecules move towards the ____ pole because they ____. - positive; are negatively charged PCR is ____. - repeated DNA replication cycles of a specific region of a DNA molecule The key elements of a PCR reaction are ____. - DNA with the target sequence to be amplified, a pair of primers, the four nucleoside triphosphates, and DNA polymerase What is a SNP? -

a variation in a single nucleotide of a DNA sequence The characterization of whole genomes, including their structures (sequences), functions, and evolution is called ____. - genomics In light-dependent reactions, hydrogen ions are transported into the thylakoid membrane. What drives the movement of these ions? - active transport of ions driven by energy from the electron transport chain The primary purpose of splitting the water in the light-dependent reactions of photosynthesis is to ____.

• release electrons for electron transport phosphorylation In the light-dependent reactions of photosynthesis, how do hydrogen ions get back into the stroma? - passive diffusion through ATP synthase Light-independent reactions occur in the ____. - stroma Plant cells produce oxygen gas ____. - by splitting molecules of water Pigments are ____. - organic molecules that absorb specific wavelengths of light Answer the following questions using the accompanying figure. Identify each structure in the figure below. Some choices may be used more than once. - ss In the light-dependent reactions of photosynthesis,NADP+ gets its electrons to become NADPH from ____. - electron transfer chains The primary purpose of the light-dependent reactions is to ____. - provide electrons and energy for the light-independent reactions The conversion of solar energy into chemical energy occurs during ____. - photosynthesis In eukaryotes, the electron transfer chain of aerobic respiration is located ____. - on the inner membrane of mitochondria In alcoholic fermentation, the final product is ____. - ethanol Oxidative phosphorylation is the process by which ____. - a final electron acceptor is used indirectly to facilitate the production of ATP

What is directly responsible for pumping protons out of the mitochondrial matrix? - protein complexes I, III, and IV What is the role of oxygen gas in aerobic respiration? - To accept electrons from electron transport Glycolysis takes place in ____. - the cytoplasm If an aerobic organism stopped taking in oxygen, which process would stop first? - electron transfer phosphorylation The net result of glycolysis is ____. - 2 NADH, 2 ATP, and 2 pyruvates The three main categories of energy-producing foods are ____. - fats, carbohydrates and proteins How are NADH and FADH2 similar? - They both contain high energy electrons. The fluid mosaic model states that the components of the plasma membrane are ______________. - able to move freely around the surface of the membrane O2 crosses from the lungs into red blood cells while CO2 passes from the red blood cells to the lungs = Diffusion A red blood cell is placed in pure water, where it proceeds to grow in size until it bursts = Osmosis: Hypotonic solution Sodium ions (Na+) flows into a cell according to its concentration gradient through a specialized protein = Facilitated transport Glucose, a large molecule, enters a cell with a low glucose concentration through a specialized protein. This process does not consume energy = Facilitated transport Water flows into and out of a blood cell in your veins in equal proportions. The blood cell does not change shape = Osmosis: Isotonic solution A red blood cell is placed in a salty bath. It shrinks in size and has a shriveled appearance = Osmosis: Hypertonic solution A drop of red food coloring is placed into a glass of hot water. The water turns red = Diffusion - plasma membrane vocab A solute passively diffuses through a transport protein out of the cell, therefore, ____. - the concentration of the solute is higher inside the cell than outside it A concentration gradient ceases to exist when ____. - there is equilibrium between the two sides of a membrane

A(n) ____ gradient is created as ions diffuse across membranes. - electrochemical Transporting a solute against its concentration gradient requires ____. - energy How do sodium-potassium pumps work? - Sodium is pumped out of the cell and potassium diffuses in. For osmosis to occur, ____. - a selectively permeable membrane must be present According to the fluid mosaic model of cell membranes, the fluid part of the model refers to ____. - the phospholipid molecules which vibrate, spin, and exchange places within the same layer of the bilayer Identify each structure found in a typical plasma membrane as shown in the figure below. - screenshotted In the pictures below of red blood cells emerged in three different solutions, identify which picture corresponds to each of the following solutions. a. isotonic (bagel looking) b. hypertonic (shriveled) c. hypotonic (puffed up) - Movement of a substance from an area of low concentration to an area of high concentration using energy obtained from ATP is called ____. - active transport The "mosaic" part of the fluid mosaic model refers to the membrane ____. - proteins Cells undergo exocytosis ____. - to secrete protein and wastes from the cell The Na+/K+ pump creates a ____ charge inside the cell and a ____ charge outside the cell. - negative; positive Transport proteins _____. - allow ions and polar molecules to cross the membrane Organisms must constantly bring in certain molecules and ions while keeping others out. This function is accomplished by ____. - the plasma membrane Pinocytosis and phagocytosis are accomplished in the cell by the ____. - plasma membrane

Most of the active functions of plasma membranes are carried out by ____. - proteins A series of enzyme-mediated reactions by which cells build, remodel, or break down organic molecules is known as ____. - metabolic pathways A substrate is another term for a(n) ____. - reactant An enzyme's specificity is based on ____. - shape of activation site The energy in chemical bonds is what type of energy? - potential According to the first law of thermodynamics, ____. - energy only changes forms Allosteric inhibitors are often ____. - products of the reactions that they regulate The ultimate fate of the energy used by organisms is ____. - conversion into heat What happens to an enzyme after it has catalyzed a reaction? - it returns to its original state lowers the activation energy of a reaction - enzyme an excess of end-product molecules shuts down a metabolic pathway - feedback inhibition the currency in a cell's economy - adenosine triphosphate lowers the activation energy of a reaction - enzyme proteins and molecules that generate the energy for the phosphorylation of ADP to ATP - electron transfer chain loss of protein structure by excessive pH, temperature and other factors - denaturation attaching a phosphate group by forming a higher energy bond - phosphorylation

often a vitamin or mineral that improves enzyme functioning - cofactor part of the enzyme that is specific for the reaction it will catalyze - active site Enzymes speed up a chemical reaction by ____. - lowering the activation energy Most enzymes are composed of ____. - protein only NAD+ is considered a(n) ____. - coenzyme When a protein denatures, it ____. - changes shape Which of the following occurs in feedback inhibition? - Products of metabolic reactions block enzyme activity. If an enzyme is saturated, ____. - the reaction is being catalyzed at the maximum rate In order to verify a hypothesis, scientists ____. - perform experiments and/or make observations An experimenter wanted to test the effects of cigarette smoking on rats. She infused the cages of 50 rats with cigarette smoke and the cages of another 50 rats with pure, clean air. The rats that received the clean air were the ____. - control group In science, all results ____. - have a probability of being incorrect If a hypothesis stands after years of repeated testing, is consistent with all data gathered, and helps make successful predictions about other phenomena, it is considered to be a ____. - scientific theory A scientific theory ____. - is widely accepted and supported by several evidences The final step in the scientific method for a scientist is ____. - report his or her results A control group ____. - is an untreated group of individuals or subjects

In science, a theory is defined as ____. - an explanation that is well documented and consistent with the evidence The control in an experiment ____. - allows for comparisons with the experimental group What name is given to the scientific study of life? - biology Which of the following words describes a tentative explanation to a given question? - hypothesis What practice helps scientists avoid bias in their findings? - designing experiments that yield quantitative results Scientists perform ____ in order to ____ a given ____. - experiments; test; hypothesis What is the right sequence of events applied in the scientific method? - initial observation; hypothesis; test; data analysis; conclusion Evolution has been tested in various ways. Genetic, fossil, anatomical, physiological and behavioral studies all confirm that evolution is the mechanism of the origin of species. Thus, in science evolution is considered a scientific ____. - theory The level of organization that encompasses all regions of Earth's crust, waters, and atmosphere in which organisms live is known as ____. - the biosphere Which organisms are single-celled and lack a nucleus? - bacteria and archaea A population is composed of individuals of ____. - the same species Who developed the two-part naming system scientists use today to classify newly found organisms? - Carolus Linnaeus Which of the following is the correct order of taxa from most inclusive to least inclusive? - domain, kingdom, phylum, class, order, family, genus, species Which level of taxonomy encompasses all of the others? - class The emergent property of "life" appears at the level of the ____, when many molecules become organized. - cell

What is a characteristic of eukaryotes? - Their DNA is contained in a nucleus. Two or more atoms bonded together - molecule Individual that consists of one or more cells - organism All populations of all species in a given area - community All regions of Earth where organisms live - biosphere Group of interbreeding individuals of the same species that live in a given area population - population Fundamental building block of all matter - atom A community interacting with its environment - ecosystem Smallest unit of life - cell Homeostasis is ____. - the ability to respond and sense change Sodium has one valence electron in its third energy level. To reach a stable energy configuration, sodium will tend to____. - give up an electron to another atom 14C is heavier than 12C because it has ____. - two more neutrons than C- Chemical bonds that are formed when one atom with a partial positive charge (created from unequal sharing of electrons) is electrically attracted to another atom with a partial negative charge (also created from unequal sharing of electrons) are called ____. - hydrogen bonds The smallest unit that retains the chemical and physical properties of an element is a(n) ____. - atom Occurs between water molecules hydrogen bonds - hydrogen bonds

Creates a region that is hydrophobic nonpolar covalent bonds - nonpolar covalent bonds Attraction that arises when the constant movement of electrons, by chance, produces temporary zones of partial positive and partial negative charges - van der waals forces Occurs in molecular oxygen (O2) - nonpolar covalent bonds The weakest of the chemical linkages listed - van der waals forces Characteristic of molecules that contain atoms of only one kind - nonpolar covalent bonds Forms when atoms gain or lose valence electrons completely - ionic bonds Occurs when electrons are shared unequally between two atoms - polar covalent bonds Generates regions of partial positivity and partial negativity within a molecule - polar covalent bonds Occurs in sodium chloride (NaCl) - ionic bonds matter - anything that occupies space and has mass compound - a molecule whose component atoms are different from eachother isotope - an atom with the same number of protons as atom but different number of neutrons orbital - the locations around an atomic nucleus where an electron occurs most frequently element - A pure substance that cannot be broken down into simpler substances by ordinary chemical or physical techniques An orbital describes the ____ of an electron. - most frequent locations

Geckos are able to cling to vertical walls due to ____. - van der Waals forces Which type of chemical linkage is the weakest? - van der Waals forces Which of the three atomic particles are charged? - electrons and protons ____ is a monosaccharide. - Fructose A nucleotide consists of ____. - a five carbon sugar, a nitrogenous base, and a phosphate group A(n) ____ is a protein monomer. - amino acid All steroids have ____. - four carbon rings Fats are major components of the cell's ____. - membranes Glycogen is a polysaccharide used for energy storage by ____. - animals In a polymer of nucleotides, how does one nucleotide attach to another? - The phosphate group of one nucleotide is attached to the sugar of the next. Which is an organic molecule? - methane (CH4) Which type of bond exists between two amino acids in a protein? - peptide Which type of bonds hold the two chains of DNA together in a DNA molecule? - hydrogen ____ are cellular structures that act like propellers to move a cell through fluid environments. - Flagella According to cell theory, ____. - all cells come from preexisting cells Cell shape is reinforced by ____. - cytoskeletal filaments The plasma membrane is composed mostly of ____. -

phospholipids Which organelle completes protein modifications and packages the protein for export? - Golgi body