Biology Questions

Listen Which statement represents the best explanation for the observation that the nuclear DNA of wolves and domestic dogs has a very high degree of sequence homology Dogs and wolves are both members of the order Carnivora Dogs and wolves shared a common ancestor very recently Dogs and wolves belong to the same order Dogs and wolves have very similar morphologies

Listen The common ancestor of all the species displayed in a phylogen it could be any of the above Onode of the tree O tip of the tree root of the tree

Select the correct answer Specialized cells such as white blood cells interact with foreign particles in the body A particular cell belonging to this category recognizes The foreign particles bacteria and forms a covering around it pinching off the vacuole The cell then performs recognized by the particular type of cells differ from the ones recognized by another type of white blood cell This situation indicates that the receptors are

What is structure 27 on the drawing below DEBRE ectoderm endoderm blastopore blastocoel 25 26 hollow space 27 28 29 hole hollow space

What is structure 25 on the drawing below COOR ectoderm endoderm blastopore blastocoel 25 26 space hollow 27 28 hollow space 29 hole

Which of the following taxa indicated by the bracket is paraphyletic A B C BC DE FGHA BC DE FGH BC C DE F G

seedcracker finches from Cameroon small and large billed birds specialize in cracking soft and hard seeds respectively If long term climatic change resulted in all seeds becoming hard what type of selection would then operate on the finch population O directional selection stabilizing selection O No selection would operate because the population is in Hardy Weinberg equilibrium disruptive selection

The only way to eliminate harmful mutations is through natural selection O Mutations occur at random natural selection can preserve and distribute beneficial mutations Natural selection creates beneficial mutations Natural selection is a random process OM Mutations occur when directed by the good of the species natural electio edits out harmful mutations and causes populations to adapt to the bene mutations

The fossil records do not necessary reflect the true biodiversity

Which statement about the beak size of finches on the island of Daphne Major during prolonged drought is true Each bird evolved a deeper stronger beak as the drought persisted Each bird that survived the drought produced only offspring with deeper stronger beaks than seen in the previous generation The frequency of the strong beak alleles increased in each bird as the drought persisted ts Each bird s survival was strongly influenced by the depth and strength of beak as the drought persisted

Most Swiss starlings produce four to five eggs in each clutch Starlings producing fewer or more than this have reduced fitness Which of the following terms best describes this situation O sexual selection stabilizing selection artificial selection disruptive selection directional selection

Which of the following is a true statement concerning genetic variation It must be present in a population before natural selection can act upon the population It is created by the direct action of natural selection It arises in response to changes in the environment It tends to be reduced by the processes involved when diploid organisms produce gametes

In terms of the evolution of animal body plans bilateral symmetry and what other trait appear together on the phylogeny mesoderm sexual reproduction a body cavity any type complete digestive tract deuterostome development

retory structures in an earthworm are Malpighian tubules metanephridia the intestines green glands Question 2 1 point Listen Saved The kidneys connect to the aorta via the ureters

Which heart chamber receives blood coming back from the lungs right atrium right ventricle left atrium left ventricle

HOW WE SEE THE INVISIBLE WORLD customized Drag and drop each statement to determine the type of slide preparation treatment it is involved in Wet Mount Categorize options by drag dra Heat Fixing Chemical fixing Uses a slide warmer Uses a coverslip Terminates tissue degradation Uses formaldehyde Microorganisms are killed Used to view living organisms

To a female a male that has bright colors a good song and elaborate dance moves is O one that was able to find good food sources to eat free of disease and parasites good at out competing other males fit and capable of producing strong offspring all of these

A colleague asks you to interpret an acid fast stain on a patient s sputum sample What is your interpretation The patient does NOT have a mycobacterium infection There are acid fast cells but they don t look like mycobacteria The patient HAS a mycobacterium infection They must have messed up this can t be an acid fast stain

A Most but not all protists are uni cellular and lack peptido glycan B DNA C

A researcher is trying to determine how to stop the transcription of a gene found in hu mans involved in cell growth The researcher wants to stop the binding of RNA polymerase to the DNA sequence to stop transcription of the gene from occurring If the researcher wants to target the structure to which RNA polymerase binds which structure would the researcher need to target A activator B operator

Which of the following characteristics gives nucleic acids such as DNA and RNA the ability to be used as the hereditary material for all living organisms Select all that apply A B C D DNA and RNA are molecules that are protected and stored in the nucleus of all living organisms DNA and RNA both contain a double helical structure which allows for large amounts of genetic information to be stored within a cell DNA and RNA can encode genetic information through the sequence of nucleotides along each strand DNA is a molecule that can replicate which allows Information to be passed down from

Most but not all protists are cellular and lack B C

Multicellular organisms contain various types of cells such as muscle cells brain cells and epithelial cells Which of the following is true of the various cell types in a multicellular organism Select all that apply A B C The cells in a multicellular organisms contain different DNA sequences which allow the cells to express different proteins The cells in a multicellular organism all contain the same genome The cells in a multicellular organism can express different proteins due to differential gene expression

A scientist wants to modify the DNA of a plant so that the plant expresses a gene that will allow the plant to become resistant to certain plant viruses Which of the following tech niques could the scientist use to modify the DNA of a plant A bacterial transformation B C reproductive cloning gel electrophoresis

It was discovered that certain cellular processes could lead to aging in humans A scientist is trying to discover how to prevent aging in humans Which of the following is an essential question the scientist could answer to help with the research A B C D Why do mutations occur during DNA replication in gametes How can cell division be inhibited to stop uncontrolled cell growth Why are signal transduction pathways affected by Internal and external factors How can the shortening of telomeres be prevented during DNA replication

Read the scenario given below Recall that the GFP gene or green fluorescent protein gene is the gene that gives jellyfish the ability to glow A scientist observed that some jellyfish produce a brighter glow than other jellyfish The scientist conducts a study in which he compares the sequences of the GFP gene in 12 different jellyfish Two of the 12 jellyfish can produce a brighter glow than the other 10 Upon analyzing the results the scientist finds that the 2 jellyfish with the brighter glow contain a substitution mutation in the GFP gene which produces a slightly different protein The scientist expected to find that the 10 jellyfish with the same more dim glow all had the same sequence for the GFP gene However the scientist found that 1 out of the 10 Jellyfish contained a mutation that changed the genotype of the jellyfish but did not change the phenotype of the jellyfish since the jellyfish still had the same dim glow as the other 9 jellyfish Which of the following mutations results in no change in the phenotype of an organism despite a change in genotype A B silent mutation frameshift mutation

A sequence of nucleotides found in the DNA of house cats Felis catus codes for tail length A mutation in the gene can result in a shortened tail If a mutation is caused by inserting a nucleotide in a DNA sequence how will the mutation affect the DNA sequence or the re sulting protein A B C D The mutation will cause the reading frame of the DNA to shift resulting in different codons following the insertion mutation The protein will contain one changed amino acid but the rest of the amino acids in the protein will remain unchanged The DNA will contain one fewer nucleotide than the original DNA which will cause a change in one amino acid in the protein There would be no effect on the resulting protein due to the sequence being read in mount of three nucleotider

A scientist has extracted DNA from a specimen of an ancient rodent Which of the following techniques can be used to amplify the DNA of the rodent so that it can be analyzed A B C PCR DNA fingerprint DNA sequencing

Which of the following Identifies the mechanism by which a single transcribed DNA se quence can code for more than one polypeptide A transcriptional control B C alternative splicing translational control

A police officer is Investigating a crime scene when she discovers a drop of blood on the window where the criminal broke the window of a house open The officer has five differ ent suspects Which of the following techniques will visualize if the DNA in the blood sample from the crime scene matches the DNA found in the suspects A B C PCR reproductive cloning gene cloning

Malaria is caused by a protist that uses the mosquito as a A parasite C vector B food source D breeding ground

gen can be seen below Estrogen is a substance that promotes the development of reproductive organs in female animals Estrogen is secreted by the ovary and placenta of female animals The receptors for estrogen are found in cells in the uterus vagina breast pelvis skin bladder urethra bones and brain Estrogen works mainly by binding to the G protein coupled estrogen re ceptor GPER When estrogen binds to GPER it activates a signal transduction pathway that regulates gene transcription in the nucleus by turning certain genes on or off estrogen Select all that apply A AKT B GPER expression C P13K MAPK A signal transduction pathway that is activated by estrogen MAPK pathway activation growth proliferation cell cycle progression adenylate cyclase CAMP IV TE VCREB Which of the following is an internal factor that could result in estrogen being unable to regulate gene expression PKA GPER expression A mutation causes DNA to methylate and the GPER gene to become unavailable for transcription Exposure to a pesticide blocks the binding of CAMP to PKA A medicine contains a molecule that works to block the activation of the MAPK pathway

A molecular biologist is researching the expression of a protein essential to plant growth The biologist observes how the rate of transcription is changed in four plant cells based on the presence of activator and repressor molecules The four plant cells are described below Plant Cell 1 Plant Cell 2 Plant Cell 3 Plant Cell 4 Select all that apply A Activator Present B yes Condition of plant cells being tested for transcription rate C no yes Which of the following best identifies a result the biologist should expect in her study no Plant cell 4 will have the highest rate of transcription Transcription will not occur in plant cell 4 Repressor Present Plant cell 1 will have the highest rate of transcription no yes yes no

The lac operon is an inducible operon that consists of regulatory regions such as a pro moter region along with three structural genes lacz lacy and lacA The three structural genes code for proteins breaking lactose into glucose and galactose Which of the following statements correctly describes transcription of the lac operon in prokaryotes Select all that apply A B C D When glucose is present and lactose is absent a repressor binds to the operator and re presses transcription of the lac operon When glucose is absent and lactose is absent allolactose binds to the repressor to allow transcription to occur When glucose is absent and lactose is present allolactose acts as an inducer and binds to the lac repressor to inactivate it When glucose is present and lactose is present the repressor binds to the operator to

The trp operon is a repressible operon found in prokaryotes The operator sequence in a specific bacterial cell contains a mutation that stops the repressor protein from binding to the operator Which of the following correctly identifies how the mutation described would affect the transcription of the trp operon A B C D Tryptophan will bind to the repressor to activate the repressor but the repressor will be unable to bind to the operator so transcription will occur Tryptophan will bind to the repressor to inactivate the repressor so the repressor can not bind to the operator Tryptophan will bind to the repressor to inactivate the repressor but due to the muta tion the repressor will still be able to bind to the operator Tryptophan will bind to the repressor to activate the repressor and the repressor will

A researcher finds that prokaryotic cells can express genes in significantly less time than that required by eukaryotic cells Which of the following identifies a reason why prokaryotic cells may be able to express genes in a shorter amount of time than eukaryotic cells Select all that apply A B C Eukaryotic cells require posttranscriptional RNA processing to remove introns from the genes Translation occurs in the nucleus of the cells while transcription occurs in the cytoplasm of the cell in eukaryotes The steps of gene expression happen simultaneously in prokaryotic cells Fukaryotic coll of shorter DNA

During transcription DNA is transcribed into mRNA The two strands of DNA must be sepa rated and then one of the strands of DNA is used to create the single stranded mRNA molecule Which of the following identifies the differences between the two strands of DNA in this process A B C D RNA polymerase attaches to the template strand to synthesize mRNA in the 3 to 5 direction RNA polymerase attaches to the template strand to synthesize mRNA in the 5 to 3 direction RNA polymerase attaches to the coding strand to synthesize mRNA in the 5 to 3 direction RNA polymerase attaches to the coding strand to synthesize mRNA in the 3 to 5

Which of the following statements are true concerning posttranscriptional modifications L Spliceosomes remove exons from the transcript and splice together the introns II A 5 cap is added to provide an attachment site for ribosomes during translation III A poly A tail is attached to the 3 end of the transcript N Both the 5 cap and the poly A tail protect the transcript from degradation A B I and IV I II and III C II and III

Which of the following explains a difference in gene expression between a eukaryotic and a prokaryotic cell A B C D An mRNA strand in a eukaryotic cell is only composed of introns An mRNA strand in a prokaryotic cell contains both introns and exons An mRNA strand in a eukaryotic cell can undergo alternative splicing in which several proteins can be produced from one gene An mRNA strand in a prokaryotic cell can undergo alternative splicing in which several proteins can be produced from one gene

During DNA replication Okazaki fragments are formed when synthesizing one of the strands of DNA Which statement correctly identifies Okazaki fragments and how they are formed A Okazaki fragments are long DNA sequences on the leading strand which are synthe sized in the opposite direction of the replication fork B C D Okazaki fragments are short DNA sequences on the leading strand which are synthe sized in the same direction as the replication fork Okazaki fragments are long DNA sequences on the lagging strand which are synthe sized in the same direction as the replication fork Okazaki fragments are short DNA sequences on the lagging strand which are synthe

Which of the following statements about genetic information is true 1 Plasmids may contain information to increase the survival of an organism II Eukaryotic DNA is found in circular chromosomes III Prokaryotic DNA is found in multiple linear chromosomes IV DNA is typically double stranded while RNA is typically single stranded V Only some viruses contain RNA as genetic information while all other organisms contain DNA as genetic information A B C I II III and IV I IV and V II and IV

Poaching is the illegal hunting of wild animals Poachers typically kill exotic animals for profit Elephant tusks are made of ivory and used for various ornaments and jewelry Between 1979 and 1989 the worldwide demand for ivory caused African elephant popula tions to decline to dangerously low levels Both male and female African elephants produce tusks Assuming that the size of the tusks is heritable which of the following is the most likely long term effect of poachers targeting African elephants with large tusks A B C an increase in average tusk size because of the need to provide more ivory for the poaching hunters an increase in average tusk size to provide the elephants with a defensive mechanism against poachers a decrease in average tusk size because elephants with large tusks are less likely to sur vive to reproduce

Evolution constantly occurs in all organisms Which of the following examples is most likely to provide evidence for the continual evolu tion of organisms Select all that apply A B C D stomachs in reptiles wings in ostriches wisdom teeth in humans vertebrae in dogs

Evolutionary biologists use several pieces of evidence to prove phylogenic relationships be tween different species Which methods have been established most recently and are the most conclusive in de termining phylogenetic relationships among organisms A comparing morphology B C comparing embryonic development comparing physiology

It can take millions of years for large changes in a population or species to be observed These major changes are often referred to when studying the process of evolution During a classroom debate a student states that examples of natural selection cannot be seen in everyday life The student argues that fossils and other records are the only sources that can be used to observe the process of natural selection Which statement describes whether or not the student s argument is correct and why A B C The student is correct While changes occur in current populations of organisms such as insects and bacteria these changes are too rapid to be considered natural selection events The student is correct To define an event as an act of natural selection the event must have taken place over an extended period and have fossil record evidence to support the claim The student is incorrect An individual is capable of evolving over the span of their life time by growing and gaining new skills to be more successful The student is incorrect Natural selection and evolution can be observed in many cur

Genetic variation is essential for the survival of a species over time Environmental changes can apply selective pressure on a population Due to environmental changes many individ uals in the population may die Individuals with advantageous variations however will have a better chance of survival and passing on the advantageous genes to their offspring As a result the species survives over time Which of the following statements identifies a mechanism for increasing genetic variation in populations of both animals and bacteria A B C Crossing over during meiosis produces new combinations of genes in gametes Random mating results in unique individuals in a population being produced The process of transformation produces genetic variation in cells anger to the phenotype of organisms

Observe the process of transduction in the image below Cell 1 is represented by A Cell 2 is represented by B and Cell 1 s DNA is represented by a The blue color represents the components of the bacteriophage m Process of transduction A m B C 2 B n Wo Which of the following correctly identifies a process that occurs during transduction 3 a Genetic information is being transferred between bacterial cells using a pilus During meiosis crossing over occurs which combines the genetic information of Cell A and Cell B Cell A s DNA was inserted into Cell B and incorporated into the genome of Cell B m

Horses and donkeys have similarities in taxa such as belonging to the same family but not the same species While horses and donkeys often occupy the same pastures hybrid off spring can be produced between the two species However the hybrids are typically sterile Which of the following best explains why horses and donkeys are reproductively isolated A The males of one species and the females of the other species are fertile at different times B C D The two species have a different number of chromosomes resulting in a postzygotic barrier Horses and donkeys are reproductively isolated because the two species have different mating calls Geographic isolation creates a prezygotic barrier between the two species

are trying to determine the relationship between various groups of organisms The researchers analyze the amino acid sequence of the protein cytochrome c in various groups of organisms Once they sequence cytochrome cin all organisms they determine the number of amino acid substitutions in each group The results can be seen in the graph below which plots the data with respect to the time since the divergence of the members of paired groups from a common ancestor A mammals and reptiles B Number of Amino Acid Substitutions per 100 amino acids in Cytochrome c C 60T 50 40 30 20 10 0 0 fish and land vertebrates 400 200 600 800 1 000 1 200 Time Since Divergence from a Common Ancestor millions of years O birds and reptiles A graph showing when various groups of organisms diverged from a common ancestor mammals and reptiles Based on the graph above can you conclude which of the following organisms are most distantly related amphibians birds and mammals fish and land vertebrates insects and vertebrates Vinsects and vertebrates flowering plants and animals birds and mammals

Occasionally environments will experience periods of rapid change Which of the following correctly identifies what may happen to a species well suited to the former environment A Traits favorable in the original environment may be detrimental in the new B C D environment The population may change so much in adapting to the new environment that it is con sidered a new species If the species cannot adapt to the changing environment the species could eventually go extinct Individuals with particular traits that provide an advantage in the new environment will have higher reproductive success