Genetics Final - Exam 3

A plant species has 2n = 18 chromosomes. How many chromosomes would you expect to find in a tetrasomic individual of this species?

20

If guanine makes up 23% of the nucleotides in a sample of DNA, then thymine would make up what percentage of the bases?

27%

In transcription, to which end of the elongated strand are nucleotides always added?

3' end

which terms accurately reflect the nature of replication of the chromosome in E. coli? A. bidirectional and fixed point of initiation B. unidirectional and reciprocal C. unidirectional and fixed point of initiation D. multirepliconic and telomeric E. bidirectional and multireploconic

A. bidirectional and fixed point of initiation

To which of the following does the term heteroplasmy refer A. cells with a variable mixture of normal and abnormal organelles B. heterozygous individuals with more than one gene pair involved C. conditions in which the germ plasm is a mixture of dominant and recessive genes D. a circumstance that is homologous to incomplete dominance E. various stages of development of mitochondria and chloroplasts

A. cells with a variable mixture of normal and abnormal organelles

which DNA sequence important for gene expression is usually found within the NFR? A. core promoter B. CREB binding site C. histone binding site D. transcription termination sequence E. hormone response element

A. core promoter

In a given mapping experiment, you expect that incidence of double crossovers is 3.5%, but you only observe 2.5%. This can be explained by A. interference B. linkage C. coincidence D. segregation

A. interference

which of the following allows the RNA polymerase II to interact with enhancers and specific transcription factors? A. mediator B. FRIIB C. TFIIH D. sigma factors E. none

A. mediator

In a mapping experiment with three linked genes, which phenotype should occur most often in the F2 offspring? A. parental phenotypes B. Phenotypes of SCO C. Phenotypes of DCO all of the phenotypes should occur equally in the F2 generation

A. parental phenotypes

What types of amino acids are most responsible for the binding of DNA to histones? A. positively charged AA's B. Negatively charged AA's C. Hydrophobic AA's D. polar AA's

A. positively charged AA's

The phenomenon known as "RNAi" RNA interference is used experimentally to A. reduce expression of a specific target gene B. reduce transcription rate from a specific gene promoter C. interfere with replication D. enhance gene expression

A. reduce expression of a specific target gene

DNA polymerase III adds nucleotides A. to the 3' end of the primer B. to the 5' end of the primer C. in the place of the primer RNA after it is removed D. to both ends of the RNA primer E. to internal sites in the DNA template

A. to the 3' end of the primer

Some polydactylous persons possess extra fingers or toes that are fully functional, wheras others possess only a small tag of extra skin. This is an example of A. variable expressivity b. complete penetrance c. independent assortment d. complementation e. cytoplasmic inheritance

A. variable expressivity

CpG islands are associated with which of the following? A. nucleosome location B. DNA methylation C. steroid hormone activity D. cAMP pathway

B. DNA methylation

how many compete rotations would most likely correspond to a positively supercoiled DNA molecule that is 100 bp in length A. 5 B. 10 C. 15 D.100 E. 110

C. 15

Which of the following provides for a higher level of stability in the mRNA? A. alternative splicing B. RNA editing C. 3' polyA tailing D. trimming

C. 3' polyA tailing

Assume that a dihybrid cross is made in which the genes loci are autosomal, independently assorting, and incompletely dominant. How many different phenotypes are expected in the offspring A. 3 B. 4 C. 9 D. 12 E. 16

C. 9

Which of the following would be true of double-stranded DNA? A. A = C B. A = G and C = T C. A + C = G + T D. A + T = G + C E. both B and C

C. A + C = G + T

who was one of the scientists that repeated Griffith's experiments, finally showing that DNA is the transformation factor? A. Alfred Hershey B. Francis Crick C. Oswald Avery D> Rosalind Franklin E. Frederick Griffith

C. Oswald Avery (also mcleod and mccarthy)

what happens physically during the process of crossing over? A. two homologous chromatids break and rejoin at random sites along the chromosome B. the genetic information on one chromatid is replaced by copying genetic information from a homologous chromatid without any physical exchange between the chromosomes C. Two homologous chromatids break and rejoin at precisely the same site along the chromosome so that there is no loss or gain of material on either product

C. Two homologous chromatids break and rejoin at precisely the same site along the chromosome so that there is no loss or gain of material on either product

In Drosophila, sex is determined by a balance between the number of haploid sets of autosomes and the number of A. telomeres B. centromeres C. X chromosomes D. Y chromosomes e. Nucleolar organizers

C. X chromosomes

which chromosomal change rarely has a phenotypic effect on resulting offspring? A. insertions B. unbalanced translocation C. balanced translocation D. chromosome loss

C. balanced translocation

DNA polymerase I adds nucleotides A. to the 3' end of the primer B. to the 5' end of the primer C. in the place of the primer RNA after it is removed D. to both ends of the RNA primer E. to internal sites in the DNA template

C. in the place of the primer RNA after it is removed

Which type of chromosome mutation increases the amount of genetic material for all chromosomes? A. translocation B. aneuploidy C. polyploidy D. inversion E. transversion

C. polyploidy

Which of the following functions do you not expect to find in the set of genes found on all living organisms on Earth? A. DNA replication B. DNA repair C. protein production D. RNA splicing

D. RNA splicing

Who used X-ray crystallography to show a helical DNA structure/ double helix A. Alfred Hershey B. Francis Crick C. Oswald Avery D> Rosalind Franklin E. Frederick Griffith

D. Rosalind Franklin

What type of inheritance is observed with extranuclear DNA A. mendelian inheritance B. sex-linked inheritance C. paternal inheritance D. maternal inheritance E. maternal effect

D. maternal inheritance

Which of the following is primarily responsible for the maternal effect? A. sperm cells B. Mitochondria C. X-chromosome D. Nurse Cells E. Placenta

D. nurse cells

Which of the following is false regarding TFIID A. it contains TATA binding protein B. it aids in initiation of transcription C. It binds to the core promotor D. it binds to the TATA box E. it is a specific transcription factor

E

Crossing two yellow mice results in 2/3 yellow offspring and 1/3 nonyellow offspring. What percentage of offspring would you expect to be nonyellow if you crossed two nonyellow mice? A. 25% B. 33% C. 66% D. 75% E. 100%

E. 100%

which of the following is a sequence of DNA where transcription is initiated? A. Hairpin loop B. TBP C. initiator D. sigma factor E. promotor

E. promoter

T/F mtDNA contains all of the genes necessary for the complete function of mitochondrial metabolism

False

Predict the potential effect of the Lyon hypothesis on the retina of a human female heterozygous for the X-linked red-green color blindness trait

Females will display mosaic retinas with patches of defective color perception and surrounding areas with normal color perception

In eukaryotes, which RNA polymerase transcribes the genes that encode proteins?

RNA pol II

the basic structure of a nucleotide includes

a base, sugar and phosphate

When does sigma factor normally dissociate from RNA polymerase?

after the process of initiation

The condition that exists when an organism gains or loses one or more chromosomes but not a complete haploid set is known as

aneuploidy

What would be the consequence of a diploid gamete being fertilized by a haploid gamete from the same species?

autotriploid

How would you describe the configuration of alleles (c+d+ and cd)

coupling

The cross l+pq/lp+q+ x lpq/lpq is carried out. The "l" gene is determined to be the middle gene. What would be the genotypes of the DCOs in this cross?

l+p+q+ and lpq

The Drosophila genes for white eyes w, cut wings ct, and tan body t lie at map positions 2, 20 and 28 respectively. Of 1000 progeny, 6 are double crossovers. What is the degree of interference?

58.3%

The purine bases are

A and G

How many Barr bodies would an individual with a XYY genotype possess? A. 0 B. 1 C. 2 D. none of these

A. 0

Klinefelter syndrome in humans, which leads to underdeveloped testes and sterility, is caused by which chromosomal condition? A. 47, XXY B. 47, 21 + 1 C. 45, X D. 47, XYY e. triploidy

A. 47, XXY

Which of the following reactions are known to be carried out by a ribozyme?

A. DNA synthesis B. transcription C. tRNA trimming D. protein hydrolysis E. polysaccharide hydrolysis

What is the function of eukaryotic RNA Pol I, transcription of.. A. rRNA genes B. mRNA genes C. tRNA genes D. snRNAs E. initiation

A. rRNA genes

the semisterility of genotypes heterozygous for a reciprocal translocation results from the lethality due to the chromosomal abnormalities produced by A. alternate segregation B. adjacent-1 segregation C. adjacent-2 segregation

B and C

which of the following is not required for transcription? A. ribonucleotides B. RNA primers C. DNA template D. RNA Pol E. promotor

B. RNA primers

The classic Hershey and Chase experiment that offered evidence in support of DNA being the genetic material in bacteriophages made use of which of the following radioisotopes to label the protein? A. phosphorus B. sulfur C. nitrogen D. hydrogen E. A and B

B. Sulfur

what gene is most responsible for X-inactivation? A. Xic B. Xist C. Tsix D. Xce

B. Xist

crossing over is more likely to occur between genes that are ______ on a chromosome A. close together B. far apart C. it depends on the types of genes D. there is no correlation

B. far apart

Approximately _____ of the gametes produced by an individual heterozygous for a translocation will be nonviable A. all B. Half C. none D. a quarter E. an eigth

B. half

Where is extranuclear DNA located in mammalian cells? A. Endoplasmic reticulum B. Mitochondria C. Ribosome D. Plasma membrane

B. mitochondria

Which of the following terms should not be used to describe a human with three copies of chromosome 12? A. aneuploid B. triploid C. 2n + 1 d. Trisomy 12 e. all terms can

B. triploid

Expression of _______ would inhibit X-inactivation A. Xic B. Xist c. Tsix D. all of the answers E. None of the answers

C. Tsix

the discontinuous aspect of replication of DNA in vivo is caused by A. Polymerase slippage B. trinucleotide repeats C. the 5' to 3' polarity restriction of DNA polymerase D. topoisomerases cutting the DNA in a random fashion E. sister-chromatid exchanges

C.the 5' to 3' polarity restriction of DNA polymerase

The phenomenon in which one crossover decreases the likelihood of crossovers in nearby regions is called A. chiasma B. negative interference C. reciprocal genetic exchange D. positive interference E. mitotic recombination

D. positive interference

Connects adjacent Okazaki fragments, forming a continuos DNA strand

DNA ligase

Two human disorders, Prader-Willi syndrome and Angelman syndrome, occur when a small deletion in a specific region of chromosome 15 is contributed by either the father or mother, respectively. Why does this small deletion not behave as a recessive allele for either syndrome, that is, why is its loss not made up for by the good copy of the region on chromosome 15 contributed by the other parent? A. this portion of chromosome 15 is invariably mutated, so the other parent contributes recessive alleles that are thus homozygous and perturb development b. the copy of chromosome 15 from the other parent has a gene in the region of the deletion that is imprinting, and thus inactive; in the absence of any active copies of these genes, development cannot proceed normally c.

b.

In domestic chickens, some males display a plumage pattern called cock feathering. Other males and all females display a pattern called hen feathering. Cock feathering is an autosomal recessive trait that is exhibited in males only. What type of inheritance is exhibited by this trait? A. sex-linked b. sex-limited c.sex-influenced d. autosomal recessive e. autosomal dominant

b. sex-limited

In humans, there are ________ autosomal linkage groups, plus an X and Y chromosome linkage group A. 23 b. 46 c. 22 d. 92

c. 22

A modification that occurs to a nuclear gene that alters gene expression without modifying the DNA sequence is called _______ inheritance A. complementation b. cytoplasmic c. Epistasis d. Epigenetic e. nuclear

d. epigenetic

A functional protein would contain the information coded for within which regions of DNA

exons

A telomere is an example of which type of DNA sequence in eukaryotes? A. moderately repetitive DNA B. Highly repetitive DNA C. short interspersed elements D. long Interspersed elements E. unique-sequence DNA

highly repetitive DNA

This molecule is made of nucleotides joined by phosphodiester bonds that connect the 2'OH to the 5' phosphate. Is it RNA or DNA

neither (3'OH to 5' phosphate)

If the sperm cell contributes mitochondria to the oocyte, it is called

paternal leakage

the backbone of the DNA molecule is connected by

phosphodiester bonds

how would you describe the configuration of alleles (c+d and cd+)

repulsion

Each new DNA strand is initiated by a

short RNA primer

In prokaryotic RNA polymerases, the holoenzyme consists of the core enzyme and the

sigma factor

What does the enzyme reverse transcriptase do?

synthesis of DNA from an RNA template