College Bio Final semester 2

If cytosine makes up 22% of the nucleotides in a sample of DNA from an organism, then adenine would make up what percent of the bases? A) 28 B) 56 C) 44 D) 22 E) It cannot be determined from the information provided

A) 28

Which of the following scientists determined that DNA is the hereditary material? A) Hershey and Chase (1952) B) Griffith (1928) C) Watson and Crick (1953) D) Morgan (1950's) E) Meselsin and Stahl (1950's)

A) Hershey and Chase (1952)

A testcross requires a cross between an unknown genotype and A) a homozygous recessive B) a homozygous dominant C) a heterozygote D) an offspring from the F1 generation E) another unknown genotype

A) Homozygous recessive

What kind of chemical bonds are found between paired bases of the DNA double helix? A) hydrogen B) ionic C) sulfhydryl D) phosphate E) covalent

A) Hydrogen

Which of the following conditions is not considered a disease or malfunction of the immune system? A) MHC-induced transplant rejection B) SCID (severe combined immunodeficiency) C) lupus, multiple sclerosis, and type 1 diabetes D) AIDS E) allergic anaphylactic shock

A) MHC-induced transplant rejection

DNA has all of the following characteristics EXCEPT A) The molecules is single stranded B) Contains sugar phosphate backbones C) Nitrogenous bases are linked by hydrogen bonds D) One end has a 5' phosphate group and the other has a 3' hydroxyl group E) the molecule is antiparallel

A) The molecules is single stranded

DNA replication is a semiconservative process because in the double helix A) There are two strands, one from the template and a new complementary strand B) The template molecule remains mostly intact C) There are four strands, each containing a mixture of old and new DNA D) There is only one origin of replication E) DNA polymerase can only add nucleotides to the 3' end of a molecule thereby limiting mutations

A) There are two strands, one from the template and a new complementary strand

Which of the following are considered foreign materials to a given organism and cause that organism to produce an immune response? A) antigens B) antibodies C) agglutinins D) opsonins E) lysins

A) antigens

The remnants of pelvic and leg bones in a snake are... A) are vestigial structures; once useful in ancestors but no purpose in modern form B) show that lizards evolved from snakes C) are homologous structures; structures that show common ancestry D) provide evidence for inheritance of acquired characteristics E) resulted from artificial selection

A) are vestigial structures; once useful in ancestors but no purpose in modern form

Capillaries A) deliver oxygen to the cells B) are impermeable C) transport blood to the arteriole D) are the blood vessels associated with he highest blood pressure E) receive blood from the venule

A) deliver oxygen to the cells

Which of the following sequences expresses the correct order of enzyme function in DNA replication A) helicase--primase--DNA polymerase--ligase B) helicase--primase--ligase--DNA polymerase C) helicase--primase--ligase--hydrolase D) primase--helicase--ligase--DNA polymerase E) primase--helicase--DNA polymerase--ligase

A) helicase--primase--DNA polymerase--ligase

Which of the following statements about the stomach is incorrect A) it emulsifies fat B) it temporarily stores ingested food C) it partially digests protein D) it kills bacteria E) it secretes mucus

A) it emulsifies fat

Which of the destroys a target cell by phagocytosis? A) neutrophil B) a cytotoxic T cell C) a natural killer cell D) complement proteins E) a helper T cell

A) neutrophil

Sexual selection A) selects for traits that enhance an individual's chance of mating B) increases the size of individuals C) results in individuals better adapted to the environment D) produces more offspring

A) selects for traits that enhance an individual's chance of mating

Darwin proposed that new species evolve from ancestral forms by A) the gradual accumulation of adaptations to changing or different environments B) the inheritance of acquired adaptations to the environment C) the struggle for limited resources D) the accumulation of mutations needed for survival E) the excessive production of offspring

A) the gradual accumulation of adaptations to changing or different environments

A transfusion of type B blood in a person who has type A blood would result in A) the recipient's anti-B antibodies reacting with the donated red blood cells B) the recipient's B antigens reacting with the donated anti-B antibodies C) the recipient forming both Anti A and B antibodies D) No reaction; B is a universal donor blood type E) the introduced blood cells being destroyed by innate defense mechanisms

A) the recipient's anti-B antibodies reacting with the

In a cross AaBbCc X AaBbCc, what is the probability of producing the genotype AABBCC? A) 1/8 B) 1/64 C) 1/32 D) 1/4 E) 1/16

B) 1/64

A couple who are both carriers for the gene for cystic fibrosis (autosomal recessive) have two children who have cystic fibrosis. What is the probability that their next child will have cystic fibrosis. A) 0% B) 25% C) 50% D) 75% E) 100%

B) 25%

In crossing a homozygous recessive with a heterozygous, what is the chance of getting an offspring with the homozygous recessive phenotype ? A) 0% B) 50% C) 25% D) 100% E) 75%

B) 50%

Which of the following is an acceptable definition of evolution? A) A change in the phenotypic makeup of a population B) A change in the genetic makeup of a population C) A change in environmental conditions D) A change in the number of alleles of an individual E) A mutation that produces a favorable trait

B) A change in the genetic makeup of a population

Which of the following statements about humoral immunity is correct? A) it's a form of passive immunity produced by vaccination B) It defends against free pathogens with effector mechanisms such as neutralization or complement activation C) it protects against pathogens that have invaded body cells as well as cancer cells D) it's mounted by lymphocytes that have matured in the thymus E) it requires recognition of class I MHC molecules-antigen complexes to activate its effector mechanism

B) It defends against free pathogens with effector mechanisms such as neutralization or complement activation

Cells associated with the cell-medicated response are A) B-cells B) T-Cells C) antibodies D) centrioles E) Schwann cels

B) T-cells

Which of the following statements best describes the mechanisms behind autoimmune diseases? A) Stem cells in the bone marrow lose their ability to be pluripotent B) The MHC glycoproteins are no longer recognized by the immune system C) Complement proteins on the plasma membrane of cells can't fuse phagocytes D) Memory cells can no longer circulate within the body E) Cytotoxic T cells are mass produced

B) The MHC glycoproteins are no longer recognized by the immune system

What might you conclude from the observation that the bones in your arm and hand are similar to the bones that make up a bat's wing? A) The bones in the bat's wing are vestigial structures, no longer useful as "arm" bones. B) The bones in a bat's wing are homologous to your arm and hand bones because we share a common ancestor C) Bats and humans evolved in the same geographic area but at different times D) Bats lost their opposable digits during the course of evolution because they didn't need it E) Our ancestors most likely could fly!

B) The bones in a bat's wing are homologous to your arm and hand bones because we share a common ancestor

Which of the following statements doesn't describe a similarity between open and closed circulatory system A) some sort of pumping device helps to move blood through the body B) some of the circulation of blood results from body movements C) The blood and interstitial fluid are distinguishable from each other D) All tissues come into close contact with the circulating body fluid so that the exchange of nutrients and wastes can take place E) all of these apply to both open and closed circulatory system

C) The blood and interstitial fluid are distinguishable from each other

How are neutrophils recruited to damaged cells A) damaged cells secrete lysozyme B) Neutrophils scan the bloodstream for damage C) damaged cells release chemical signals that attract neutrophils D) neutrophils are always attached by the presence of T-lymphocytes E) Neutrophils are always present in every tissue of the body

C) damaged cells release chemical signals that attract neutrophils

Which of the following is NOT considered a reproductive isolating mechanism? A) sterile offspring B) ecological isolation C) feeding behavior D) gametic incompatibility E) timing of courtship display

C) feeding behavior

The chief purpose of villi is to A) store B-lymphocytes B) promote gas exchange in the lungs C) increase SA in the small intestine D) store T-lymphocytes E) decrease blood flow to certain regions of the body

C) increase SA in the small intestine

Which of the following is a white blood cell that is responsible for long term recognition of antigens? A) effector cell B) neutrophil C) memory cell D) helper T cell E) plasma cell

C) memory cell

A Barr body is normally found in the nucleus of which kind of human cell? A) unfertilized egg cells only B) sperm cells only C) somatic cells of a female only D) somatic cells of a male only E) both male and female somatic cells

C) somatic cells of a female only

What is a measure of Darwinian fitness in a population? A) longevity in a species B) survival under adverse conditions C) the number of fertile offspring D) strength, in a predator E) fleetness, in a prey animal

C) the number of fertile offspring

In a monohybrid cross, the expected proportion of offspring showing the recessive trait is A) 0 B) 1 C) 1/2 D) 1/4 E) 3/4

D) 1/4

White eyes is a sex-linked recessive characteristic in fruit flies. If a female having white eyes is crossed with a wild-type male, what proportion of the F1 males will ave white eyes? A) 25% B) none C) 50% D) 100% E) 75%

D) 100%

A particular eukaryotic protein is 300 amino acids long. Which of the following could be the number of nucleotides in the DNA that codes for this protein? A) 3 B) 100 C) 300 D) 900 E) 1800

D) 900

Gene frequencies in a gene pool may shift randomly and by chance. This is called A) Artificial selection B) Adaptive radiation C) Climatic shift D) Genetic drift E) Natural selection

D) Genetic drift

Which of the following state meets correctly describes the main difference between innate immunity and adaptive immunity? A) Innate immunity responds only to free pathogens in a localized area; adaptive immunity responds only to pathogens that have enter body cells B) Innate immunity involves only leukocytes, whereas adaptive immunity involved only lymphocytes C) Innate immunity relies on phagocytes to destroy pathogens, whereas adaptive immunity does not involve phagocytes D) Innate immunity recognizes molecules common to a set of pathogens whereas adaptive immunity reacts to specific microbes on the basis of their unique antigens E) Complement proteins participate in adaptive immunity but not in innate immunity

D) Innate immunity recognizes molecules common to a set of pathogens whereas adaptive immunity reacts to specific microbes on the basis of their unique antigens

What is the function of the operator of an inducible operon? A) producing repressor molecules B) identifying the substrate lactose C) producing messenger RNA D) Permitting transcription E) Binding steroid hormones

D) Permitting transcription

Which region signals the chain of events that causes the heart to beat? A) AV node B) Purkinji fibers C) AV valve D) SA node E) SL valve

D) SA node

Which of these types of selection is mismatched with its example? A) disruptive--a population of black-bellied seed-creakers consists of birds with either small bills (more effective at eating soft seeds) or large bills (able to crack hard seeds) B) intrasexual--elephant seal males are more than four times larger than females; males fight over areas of beach where females congregate during breeding season C) Intersexual--female gray tree frogs choose mates that give long mating calls D) stabilizing--the frequencies of A, B, AB and O blood groups remain constant in a population E) Non, they are correctly matched with an appropriate example

D) Stabilizing--the frequencies of A, B, AB and O blood groups remain constant in a population

THECATATETHERAT A) THERATATETHECAT B) THETACATETHERAT C) THECATARETHERAT D) THECATATTHERAT E) CATATETHERAT Which of the above is analogous to a frameshift mutation?

D) THECATATTHERAT

The smallest unit that can evolve is A) an individual B) a mating pair C) a species D) a population E) a community

D) a population

In mammals, excretory filtrate contains water, salt sugar, amino acids, and nitrogenous wastes. What happens to this fluid once it reaches the excretory system? A) it's converted into urea and absorbed by the small intestine B) it's ent tot he liver for further processing C) hydrostatic pressure forces the fluid into the collecting duct D) active transport returns essential molecules to the body fluid while allowing other to be expelled E) it's expelled through the urinary tract and through the skin with the help of sweat glands.

D) active transport returns essential molecules to the body fluid while allowing other to be expelled

In mammals, the transfer of O2 to the blood occurs in the A) bronchioles B) epiglottis C) trachea D) alveoli E) spiracles

D) alveoli

Genetic drift is likely to be seen in a population A) that has a high migration rate B) that has a low mutation rate C) in which natural selection is occurring D) for which environmental conditions are changing

D) for which environmental conditions are changing

A 1:2:1 phenotypic ratio in the F2 generation of a monohybrid cross is a sign of A) complete dominance B) pleiotropy C) multiple alleles D) incomplete dominance E) polygenic inheritance

D) incomplete dominance

Histamines are released by cells in response to injury. This an example of A) phagocytosis B) humoral immunity C) primary immune response D) inflammatory response E) chemotaxis

D) inflammatory response

Water reabsorption from the lumen occurs in this structure of the digestive system A) mouth B) stomach C) small intestine D) large intestine E) liver

D) large intestine

A woman who belongs to blood group A has a daughter who is blood type O and a son who is blood type B. Which of the following must be the genotypes for the mother and father of these children? A) mother is type A and father is type B B) mother is type A and father is type AB C) mother is AA and father is Bi D) mother is Ai and father is Bi E) more than one answer above is correct

D) mother is Ai and father is Bi

All of the following important concepts of populations genetics are due to random events or chance EXCEPT A) mutation B) the bottleneck effect C) the founder effect D) natural selection E) sexual recombination

D) natural selection

In a system with double circulation A) a blood is usually pumped at two separate locations as it circulates through the body B) there is a countercurrent exchange in the gills C) hemolymph circulates both through a pumping blood vessel and through body sinuses D) outgoing blood is pumped to the gas-exchange organ, and returning blood is dumped to a systemic circuit E) There are always two ventricles and other two atria

D) outgoing blood is pumped to the gas-exchange organ, and returning blood is dumped to a systemic circuit

Crossing over occurs during which phase of meiosis A) prophase II B) anaphase I C) metaphase II D) prophase I E) telophase I

D) prophase I

During which of the following stages do chromosomes first appear visible in the nucleus A) anaphase B) interphase C) metaphase D) prophase E) telophase

D) telophase

The nurse tells you that your blood pressure ins 112/70. The "70" refers to A) your heart rate B) the velocity of blood during diastole C) the systolic pressure from ventricular contraction D) the diastolic pressure from the recoil of the arteries E) the venous pressure caused by the compression of the blood pressure cuff

D) the diastolic pressure from the recoil of the arteries

Which of the following would normally contain blood with the least amount of O2 A) the left ventricle B) the left atrium C) the pulmonary veins D) the pulmonary arteries E) capillaries that line the small intestine

D) the pulmonary arteries

Catalyzes synthesis of a new strand of DNA

DNA polymerase

Fossil evidence indicates that horses have gradually increases over time

Directional selection

Pathogenic bacteria found in many hospitals are antibiotic resistant

Directional selection

A certain species of land snail exists as either a cream color or a solid brown color. Intermediate individuals are rare

Disruptive selection

An african butterfly species exists in two strikingly different color patterns, each of which closely resembles other species that are distasteful to birds

Disruptive selection

The cilia in the trachea and bronchi A) move air into and out of the lungs B) increase the SA for gas exchange C) vibrate when air rushes past them to produce sound D) filter the air that ruses through them E) sweep mucus containing rapped particles up and out of the respiratory tract

E) sweep mucus containing rapped particles up and out of the respiratory tract

Brightly colored peacocks mate more frequently than do drab colored peacocks.

Sexual selection

Most Swiss starlings produce 4-5 eggs in each clutch

Stabilizing selection

The average birth weight for human babies is about 7 pounds

Stabilizing selection

Which of the following is an example of polygenic inheritance? A) white and purple color in sweet peas B) pink flowers in snapdragons C) the ABO blood groups in humans D) sex-linkage in humans E) skin pigmentation in humans

E) skin pigmentation in humans

What accounts for the huge diversity of antigens to which B cells can respond? A) The antibody genes have millions of alleles B) The recombination of a light and heavy chain gene during development results in millions of possible antigen receptors C) The antigen-binding sites at the arms of the molecule can assume a huge diversity of shapes in response to the specific antigen encountered D) B cells have thousands of copies of antibodies bound to their plasma membranes E) Cells have be antigen-presenting cells when they take in antigens and display fragments in their MHC molecules

B) The recombination of a light and heavy chain gene during development results in millions of possible antigen receptors

The gene pool can be best be described as the A) Total number of allele loci that occur in each species B) Total number of alleles in a population at any time C) group of alleles responsible for polygenic traits D) Total number of alleles that are changing in population

B) Total number of alleles in a population at any time

A particular triplet of bases in the coding sequence of DNA is AGT. The corresponding codon for the mRNA transcribed is A) AGU B) UCA C) Either UCA or TCA, depending on wobble in the first base. D) AGT E) TCA

B) UCA

All lymphocytes are produced in the A) thymus B) bone marrow C) lymph nodes D) lymph vessels E) blood vessels

B) bone marrow

Blood flows more slowly in arterioles than in arteries because arterioles A) have thoroughfare channels to venues that are often closed off B) collectively have a larger cross-sectional area than do arteries C) must provide opportunity for exchange with interstitial fluid D) have sphincters that restrict blood flow to capillary beds E) are narrower than arteries

B) collectively have a larger cross-sectional area than do arteries

Most microbes swallowed with food are A) transported to the small intestine unharmed B) destroyed in the acidic environment of the stomach C) consumed by E. coli bacteria in the large intestine D) captured by mast cells E) destroyed by antigens

B) destroyed in the acidic environment of the stomach

The majority of CO2 travels in the blood A) in the form of dissolved CO2 B) in the form of HCO3 C) in red blood cells D) in the plasma E) bound to hemocyanin

B) in the form of HCO3

Bile is produced in the A) stomach B) liver C) gall bladder D) small intestine E) esophagus

B) liver

The interstitial fluid of vertebrates A) is the internal environment within cells B) surrounds cells and provides for the exchange of nutrients and wastes C) makes up blood plasma D) is not necessary in flat, thin vertebrates E) is less abundant in ectoderms than in endotherms

B) surrounds cells and provides for the exchange of nutrients and wastes

Which statement below best describes crossing-over? A) deletion of one or more parts of the chromosomes B) swapping segments of homologous chromosomes C) exchange of segments of sister chromatid D) swapping of genes between non-homologous chromatid E) exchange of genetic material that leads to mutation

B) swapping segments of homologous chromosomes

A recessive allele on the X chromosome is responsible for red-green color blindness in humans. A woman with normal vision whose father is color-blind marries a color-blind male. What is the probability that this couple's son will be color-blind? A) 25% B) 100% C) 50% D) 75% E) 0%

C) 50%

What are the coding segments of a stretch of eukaryotic DNA called? A) Codons B) Transposons C) Exons D) Introns E) Replicons

C) Exons

Natural selection tends to reduce variation in gene pools. Which process serves to balance natural selection by creating new alleles? A) Meiosis B) sex C) Mutation D) Migration E) Reproduction

C) Mutation

Why do some adaptive traits, such as ticker fur or flowers of different colors, evolve over time within a population of organisms? A) Such traits are necessary to ensure the survival of the species B) These traits evolved randomly, and just happen to persist over time C) Organisms with these traits had more offspring than other organisms in the population, so the traits were passed on to more offspring D) These traits evolve in response to environmental challenges, ensuring that the population will survive any change in its habitat.

C) Organisms with these traits had more offspring than other organisms in the population, so the traits were passed on to more offspring

What prevents the gastric enzyme, pepsin from destroying the lining of the stomach? A) The acidic environment of the stomach neutralizes the enzyme B) Acid chime prevents the destruction of the lining C) Pepsin is secreted in an inactive form until it enters the stomach cavity D) Pepsin only acts on proteins, which aren't present in the stomach lining E) The stomach is lined with many villi which increase SA

C) Pepsin is secreted in an inactive form until it enters the stomach cavity

In snapdragons, heterozygotes have pink flowers, whereas the two homozygotes have red flowers or white flowers. When plants with red flowers are crossed with plants with white flowers, what proportion of the offspring will have pink flowers? A) 50% B) 75% C) 0% D) 25% E) 100%

E) 100%

If the liver cells of an animal have 24 chromosomes, the sperm cells would have how many chromosomes? A) half the haploid number B) 24 C) 48 D) twice the diploid number E) 12

E) 12

Which of the following is true of a species that has a chromosome number of 2n=16 A) The species is diploid with 32 chromosomes B) The species has 16 different types of chromosomes C) There are 16 homologous pairs D) During the cell cycle there will be 32 separate chromosomes E) A gamete from this species has 8 chromosomes

E) A gamete from the species has 8 chromosomes

How does the sexual life cycle increase the genetic variation in a species A) By producing gametes with different combinations of parental chromosomes B) By allowing the combination of chromosomes from two different individuals C) By allowing recombination of alleles on chromosomes D) None of these are correct E) A, B, C are correct

E) A, B, C are correct

Which of the following are generated by the immune system in order to target specific invaders? A) phagocytes B) interferons C) histamine D) eosinophils E) B cell and T cells

E) B cell and T cells

Antibodies are A) proteins or polysaccharides usually found on the surface of invading bacteria B) proteins embedded in T cell membranes C) proteins circulating in the blood that tag foreign cells for complement destruction D) proteins that consist of two light and two heavy polypeptide chains E) Both C and D are correct

E) Both C and D are correct

Humoral immunity differs from cell-mediated immunity because A) Cell mediated immunity results from the production of antibodies that circulate in blood plasma B) Humoral immunity is important in recognizing cells as "non self" C) HI involves the activation of T lymphocytes D) CMI is inactive in the presence of protozoa and parasites E) HI involves B cell activation

E) HI involves B cell activation

Allopatric speciation is more likely to occur when A) the species is reintroduced to its original homeland B) the population is exposed to the same selection pressures in its new habitat C) the population inhabits an island close to the mainland D) The population is large and has little genetic variation E) None of the above is true

E) None of the above is true

What is the primer that is required to initiate the synthesis of a new DNA strand? A) DNA B) protein C) ligase D) primase E) RNA

E) RNA

A particular triplet of bases in the coding sequence of DNA is AGT. What is the corresponding triplet in the complementary strand of DNA? A) GAC B) AGT C) TCA in eukaryotes, but UCA in prokaryotes D) UCA E) TCA

E) TCA

The tryptophan synthetase operon used glucose to synthesize tryptophan. Repressible operons such as this one are A) Permanently turned on B) Turned on only when tryptophan is present in the growth medium C) Turned off only when glucose is present in the growth medium D) Turned on only when glucose is present in the growth medium E) Turned off whenever tryptophan is added to the growth medium

E) Turned off whenever tryptophan is added to the growth medium

The anticodon for methionine (Met) is A) AUG B) ATG C) TAC D) UAC E) UAG

E) UAG

During diastole A) the atria filled with blood B) blood flows passively into the ventricles C) the elastic recoil of the arteries maintains hydrostatic pressure on the blood D) semilunar valves are closed, but atrioventricular valves are open E) all of the above are occurring

E) all of the above are occurring

Major histocompatibility complex molecules A) are involved in the ability to distinguish self from non self B) are a collection of cell surface proteins C) may trigger T cell responses after transplant operation D) present antigen fragments on infected cells E) are or do all of the above

E) are or do all of the above

In humans, lung volume increases as a result of A) a relaxation of both rib and diaphragm muscles B) a relaxation of rib muscles while the diaphragm contracts C) an increase in internal lung pressure D) contraction of rib muscles while the diaphragm relaxes E) contraction of both rib and diaphragm muscles

E) contraction of both rib and diaphragm muscles

All of the following are part of the body's first line of defense except A) skin B) mucous membrane C) sweat D) saliva E) lymphocytes

E) lymphocytes

A secondary immune response is more rapid and effective than a primary immune response because A) histamines cause rapid vasodilation B) the second response is an active immunity, whereas the primary one was passive immunity C) helper T cells are available to activate other white blood cells D) chemical signals cause the rapid accumulation of phagocytic cells E) memory cells respond to the pathogen and rapidly proliferate into effector cells

E) memory cells respond to the pathogen and rapidly proliferate into effector cells

Which of the following helps to stabilize mRNA by inhibiting its degradation? A) spliceosomes B) TATA box C) Introns D) snRNPs E) poly (A) tail

E) poly (A) tail

Which of the following occurs during the alteration after translation? A) excision of introns B) excision of eons C) addition of a poly (A) tail D) formation of peptide bonds E) proteins form secondary, tertiary and quaternary structure.

E) proteins form secondary, tertiary and quaternary structure.

Enhances separation of DNA strands during replication

Helicase

Covalently connects segments of DNA

Ligase