Genetics Exam 3

How many Barr bodies would be present in white blood cells of an individual of karyotype 48, XXYY? A. 4 B. 3 C. 2 D. 1

1

If guanine makes up 23% of the nucleotides in a sample of DNA, then thymine would make up what percentage of the bases? A. 15% B. 22% C. 27% D. 30% E. 40%

27%

The number of distinct protein species found in humans and other organisms can vastly exceed the number of genes. This is largely due to __________ A. Protein degradation B. Alternative splicing C. Homologous genes D. mutation

Alternative splicing

The semisterility of genotypes heterozygous for a reciprocal translocation results from the lethality due to the chromosomal abnormalities produced by A. Alternate sgregation B. Adjacent-1 segregation C. Adjacent-2 segregation D. A & B E. B & C

B & C

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

Core promoter

The N-terminal tail of histone H3 can be extensively modified, and depending on the number, location, and combination of these modifications, these changes may promote the formation of heterochromatin. What is the result of heterochromatin formation? A. Increase in gene expression B. Gene silencing C. Recruitment of remodeling complexes D. Displacement of histone H1

Gene silencing

Which of the following structural motifs promotes dimerization? A. Zinc finger B. Leucine zipper C. helix-turn-helix D. Helix-loop-helix

Leucine zipper

Which of the following allows the RNA polymerase II to interact with enhancers and specific transcription factors? A. Mediator B. TFIIB C. TFIIH D. Sigma factors E. none of the answers are correct

Mediator

Which of the following function do you NOT expect to find in the set of genes found in ALL living organisms on Earth? A. DNA replication B. DNA repair C. Protein production D. RNA splicing

RNA splicing

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

Reduce expression of a specific target gebe

Each new DNA strand is initiated by a A. Short RNA primer B. Single-stranded DNA binding protein C. Precursor fragment D. Restriction fragment E. Specific DNA primer

Short RNA primer

What basal transcription factor is most often directly affected by regulatory/ specific transcription factors? A. TFIIB B. TFIID C. TFIIE D. TFIIF

TFIID

A particular gene has a mutation in its NFR that causes it to bind abnormally tightly to histones. What effect would you expect this mutation has on the expression of this gene? A. The expression of the gene would be abnormally high B. The effect on gene expression is impossible to predict C. The gene would encode a different protein instead D. The expression of the gene would be abnormally low or absent E. The promoter of the gene will be constantly available to transcription factors and RNA polymerase

The expression of the gene would be abnormally low or absent

the purine bases are:

adenine and guanine

The condition that exists when an organism gains or loses one or more chromosomes but not a complete haploid set is known as _________ A. polyploidy B. Euploidy C. Aneuploidy D. triploidy E. trisomy

aneuploidy

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

balanced translocation

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

maternal inheritance

A chromosome with its centromere in the middle is a A. Submetacentric B. Acrocentric C. Telocentric D. Holocentric E. Metacentric

metacentric

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

3' polyA tailing

__________ attaches adjacent Okazaki fragments, forming a continuous DNA strand A. DNA ligase B. DNA polymerase II C. Topoisomerase D. DNA polymerase I E. DNA primase

DNA ligase

CpG islands are associated with which of the following? A. Nucleosome location B. DNA methylation C. Steroid hormone acitivity D. cAMP pathway

DNA methylation

The basic structure of a nucleotide includes _______ A. amino acids B. tryptophan and leucine C. base, sugar, and phosphate D. mRNA, rRNA, and tRNA E. phosphorus and sulfur

base, sugar, and phosphate

Post-translation, ______________ further modulates the structure and functions of proteins

covalent modification

A functional protein would contain the information coded for within which of the following regions of DNA? A. Exons B. Introns C. Enhancers D. Promoters E. all of the answers are correct

exons

mtDNA contains all of the genes necessary for the complete function of mitochondrial metabolism True or False?

false

A protein domain is a compact and stable folded region of a polypeptide that can be conserved between different members of a protein _________

family

the pyrimidine bases are:

guanine and cytosine

DNA polymerase I is thought to add nucleotides ___________ A. to the 5' end of the primer B. to the 3' end of the primer C. in the place of the primer RNA after it is removed D. on single-stranded templates without need for an RNA primer E. in a 5' to 5' direction

in the place of the primer RNA after it it removed

The three dimensional conformation of a protein is its __________ structure

tertiary

For the following five sequences, what is the consensus sequence? 5'-GGGAGCG-3' 5'-GAGAGCG-3' 5'-CAGTGCG-3' 5'-GAGAACG-3' 5'-GAGAGCA-3'

5'-GAGAGCG-3'

The classic Hershey and Chase experiment that offered evidence in support of DNA being the genetic material in bacteriophages made use of which radioisotope to label the DNA?

Phosphorus

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. multidirectional and telomeric E. bidirectional and multirepliconic

bidirectional and fixed point of initiation

Alternative splicing allows an organism to ___________________ A. Carry fewer genes B. Carry more genes C. Produce fewer gene products D. More than one of the answers

carry fewer genes

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

cells with a variable mixture of normal and abnormal organelles

A protein __________ is a compact and stable folded region of a polypeptide that can be conserved between different members of a protein family

domain

Which of the following is false regarding mtDNA? A. it is around 17,000 bp in length B. It is a linear chromosome C. Multiple copies exist in each mitochondria D. It mostly contains rRNA and tRNA

it is a linear chromosome

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

mitochondria

If the sperm cell contributes mitochondria to the oocyte it is called __________ A. paternal leakage B. maternal leakage C. paternal inehritance D. mitochondira E. imprinting

paternal leakage

The backbone of the DNA molecule is connected by_______ A. peptide bonds B. ribose sugars C. nitrogenous bases D. phosphodiester bonds

phosphodiester bonds

A protein's amino acid sequence is known as its ______________ structure

primary

A protein such a hemoglobin, which is composed of more than one protein subunit has __________ structure.

quaternary

The alpha and beta sheets are examples of protein ____________ structure

secondary

Each new DNA strand is initiated by a A. Short DNA primer B. Single stranded dna binding protein C. precursor fragment D. Restriction fragment E. Specific DNA primer

short dna primer

A protein such a hemoglobin, which is composed of more than one protein __________ has quaternary structure.

subunit

Reverse Transcriptase is an enzyme found in association with retroviral activity. It has the property of ________ A. synthesis of DNA from an RNA template B. synthesis of RNA from a DNA template C. requiring no template D. translation E. most lysozymes

synthesis of DNA from an RNA template

Which of the following reactions are known to be carried out by a ribozyme? A. DNA synthesis B. Transcription C. tRNA trimming D. Protein hydrolosis E> Polysaccharide hydrolosis

tRNA trimming

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

the 5' to 3' polarity restriction of DNA polymerase

Following transcription, the RNA has an almost identical sequence (U instead of T) of which of the following? A. Regulatory sequences B. Terminationsequences C. The coding strand of DNA D. The template strand of DNA E. none of these

the coding strand of DNA

Trisomy 8 usually leads to early miscarriage of a fetus. However adult individuals have been found with cells with three copies of chromosome 8 in them. How can this be? A. the trisomic cells underwent a mitotic nondisjunction B. the trisomic cells underwent a complete nondisjunction C. the trisomic cells underwent a meiotic nondisjunction D. this individual must be triploid

the trisomic cells underwent a mitotic nondisjunction

DNA polymerase III adds nucleotides ___________ A. to the 3' end of the RNA primer B. to the 5' end of the RNA 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

to the 3' end of the RNA primer

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 of these terms can be used to describe the situation

trisomy 12