True Or False Genetics

Front 1

In a bacterial cross where the donor (Hfr) is a + b + and the recipient (F-) cell is a-b-; it is expected that recombinant bacteria will all be a + b +.

Back 1

FALSE

Front 2

Cotransduction of genes is an indication that the genes are linked

Back 2

TRUE

Front 3

To produce recombinants in bacteria, one crossover is better than two.

Back 3

FALSE

Front 4

A plaque is a substance that causes lysis of bacteria.

Back 4

FALSE

Front 5

Lysogeny is most likely associated with transduction

Back 5

TRUE

Front 6

R plasmids often contain genes for antibody production.

Back 6

FALSE

Front 7

The ‘interrupted mating technique’ provides for a genetic map in Drosophila.

Back 7

FALSE

Front 8

Telomerase is an enzyme involved in the replication of the ends of eukaryotic chromosomes

Back 8

TRUE

Front 9

In contrast to euchromatin, heterochromatin contains more genes and is earlier replicating.

Back 9

FALSE

Front 10

Viral genomes are always either double-stranded DNA or single-stranded RNA.

Back 10

FALSE

Front 11

Polytene chromosomes are unique because they are composed of a large number of identical DNA strands

Back 11

TRUE

Front 12

Presence of heterochromatin is characteristic of prokaryotic chromosome.

Back 12

FALSE

Front 13

DNA replicates conservatively, which means that one of the two daughter double-helices is ‘old’ and the other one is ‘new’

Back 13

FALSE

Front 14

During replication, primase adds a short chain of DNA primer.

Back 14

FALSE

Front 15

Replication of DNA occurs in the 5’ to 3’ direction; that is, new nucleoside triphosphates are added to the 3’ end.

Back 15

TRUE

Front 16

A characteristic of the aging cells is that their telomeres become very short

Back 16

TRUE

Front 17

A nucleosome is a structure associated with the nuclear membrane and associated with cellular transport

Back 17

FALSE

Front 18

DNA gyrase is responsible for keeping the uncoiled strands apart

Back 18

FALSE

Front 19

Telomerase is an RNA containing enzyme that adds telomeric DNA sequences onto the ends of linear chromosomes.

Back 19

TRUE

Front 20

In RNA, uracil is present instead of guanine (in DNA)

Back 20

FALSE

Front 21

Chargaff’s rule states that A = T and G = C.

Back 21

TRUE

Front 22

In DNA, strings of nucleotides are joined together by hydrogen bonds

Back 22

FALSE

Front 23

Cytosine, thymine and uracils are purines.

Back 23

FALSE

Front 24

B-DNA is the most prevalent and stable DNA structure

Back 24

TRUE

Front 25

Heat or alkali can be used to denature DNA

Back 25

TRUE

Front 26

Mitochondrial mutations are passed equally to offspring by both males and females

Back 26

FALSE

Front 27

It is safe to say that a maternal effect is caused by the genotype, not the phenotype, of the parent producing the egg

Back 27

TRUE

Front 28

tRNAs and rRNAs are known to be encoded by mitochondrial DNA.

Back 28

TRUE

Front 29

Nondisjunction is considered as a major cause of aneuploidy

Back 29

TRUE

Front 30

Familial Down syndrome can be caused by a translocation between chromosome 1 and 14

Back 30

FALSE

Front 31

A deletion may set up a genetic circumstance known as overdominance

Back 31

FALSE

Front 32

A pericentric inversion includes the centromere.

Back 32

TRUE

Front 33

Assume that an organism has a diploid chromosome number of 14. There would be 56 chromosomes in a tetraploid.

Back 33

FALSE

Front 34

A position effect occurs when a gene’s expression is altered by virtue of a change in the position.

Back 34

TRUE

Front 35

rDNA in eukaryotes is typically redundant.

Back 35

TRUE

Front 36

A chromosome may contain one or two chromatids in different phases of the mitotic or meiotic cell cycle

Back 36

TRUE

Front 37

If a typical G1 nucleus is 2n and contains two complements (2C) of DNA, a prophase I cell is 2n and contains 4C DNA

Back 37

TRUE

Front 38

During meiosis chromosome number reduction takes place in anaphase II

Back 38

FALSE

Front 39

The centromere of a chromosome separates during anaphase.

Back 39

TRUE

Front 40

The meiotic cell cycle involves two cell divisions and two DNA replications.

Back 40

FALSE

Front 41

To isolate a bacterium with a plasmid that carries a desired DNA fragment along with an ampicillin-resistance gene; we should grow the bacteria in a medium that contains ampicillin

Back 41

TRUE

Front 42

A common term for a plasmid or other DNA element that serves as a cloning vehicle is vector

Back 42

TRUE

Front 43

In a typical PCR, primers are used to cleave specific regions of the DNA template

Back 43

FALSE

Front 44

Some restriction endonucleases produce sticky ends, while others produce blunt ends

Back 44

TRUE

Front 45

In restriction mapping, map units are expressed as m.u

Back 45

FALSE

Front 46

Mendel’s law of segregation is supported by a 1:1 testcross ratio.

Back 46

TRUE

Front 47

The non-functional form of a gene is called a wild-type allele.

Back 47

FALSE

Front 48

A gene can have maximum two alleles

Back 48

FALSE

Front 49

To test Mendel’s Law of Independent Assortment, the experimenter needs a minimum of two different genes and their two alleles.

Back 49

TRUE

Front 50

A 1:1 phenotypic ratio is expected from a monohybrid testcross with complete dominance.

Back 50

TRUE

Front 51

The ABO blood group locus in humans provides an example of epistasis

Back 51

FALSE

Front 52

Sex-linked inheritance is same as sex-limited inheritance

Back 52

FALSE

Front 53

A typical epistatic ratio is 9:3:4.

Back 53

TRUE

Front 54

Pattern baldness is an example of X-linked inheritance.

Back 54

FALSE

Front 55

A 9:7 ratio indicates incomplete dominance

Back 55

FALSE

Front 56

Penetrance’ specifically refers to the expression of lethal genes in heterozygotes

Back 56

FALSE

Front 57

Hemizygosity describes the state of a gene that has no allele on the opposing chromosome

Back 57

TRUE

Front 58

Normally in humans, all the sons of a female homozygous for a sex linked recessive gene will inherit the trait

Back 58

TRUE

Front 59

Sex-influenced genes are those which cause males to be males and females to be females

Back 59

FALSE

Front 60

In Drosophila, sex is determined by the ratio of the number of X chromosomes to the number of haploid sets of autosomes

Back 60

TRUE

Front 61

An individual with Turner syndrome has one Barr body.

Back 61

FALSE

Front 62

Dosage compensation is accomplished in humans by inactivation of the Y chromosome

Back 62

FALSE

Front 63

mRNA is usually polycistronic in eukaryotes.

Back 63

FALSE

Front 64

hnRNA is a primary transcript in eukaryotes that is processed prior to involvement in translation

Back 64

TRUE

Front 65

Transcription factors function to help move ribosomes along the mRNA

Back 65

FALSE

Front 66

RNA processing occurs when amino acids are removed from nascent proteins.

Back 66

FALSE

Front 67

An intron is a section of an RNA that gets spliced out.

Back 67

TRUE

Front 68

Proteins are composed of strings of nucleotides connected together by phosphodiester bonds

Back 68

FALSE

Front 69

rDNA ( <-- I think that should be rRNA?) is the portion of the genome that is involved in the production of ribosomal RNA.

Back 69

TRUE

Front 70

The secondary structure of a protein is dependent on polar interactions among the side chains of the amino acids.

Back 70

FALSE

Front 71

If the Kozak sequence is missing, initiator tRNA does not select that AUG codon to start initiation

Back 71

TRUE

Front 72

Fetal hemoglobin contains two alpha and two gamma chains

Back 72

TRUE

Front 73

Amino acids are divided into polar, nonpolar and neutral groups.

Back 73

FALSE

Front 74

Tertiary structure of protein is stabilized by peptide bonds between cysteine residues

Back 74

FALSE

Front 75

Certain base-analogs such as 5-bromouracil cause mutations by chemically altering nitrogenous bases in non-replicating DNA.

Back 75

FALSE

Front 76

The shorter the wavelength of a radiation source, the greater its likelihood of causing damage.

Back 76

TRUE

Front 77

Acridin orange is an alkylating agent

Back 77

FALSE

Front 78

A missense mutation causes premature chain termination

Back 78

FALSE

Front 79

Strand discrimination during the process of DNA repair is based on DNA methylation in E.coli

Back 79

TRUE

Front 80

Postreplication repair is a system that responds after damaged DNA has escaped repair and failed to be completely replicated

Back 80

TRUE

Front 81

The genetic alteration found in muscular dystrophy is changes in the trinucleotide repeats

Back 81

FALSE

Front 82

CAP-cAMP binds to the CAP-binding site on the promoter and blocks the binding of RNA polymerase to transcribe the lac genes.

Back 82

FALSE

Front 83

IPTG, like allolactose can bind to the lac repressor and induce transcription of the lac operon

Back 83

TRUE

Front 84

In an inducible operon, transcription is normally turned on and has to be repressed to shut off gene expression.

Back 84

FALSE

Front 85

Like the lac repressor, the trp repressor has two binding sites; one that binds to the DNA at the operator site and another that binds to the activator, tryptophan

Back 85

TRUE

Front 86

If tryptophan is plenty, the ‘antiterminator hairpin’ is formed

Back 86

FALSE

Front 87

Ara operon is the repressible arabinose operon in E.coli.

Back 87

FALSE

Front 88

Clusters of genes along with their regulatory elements are called operon, which is a single transcription unit.

Back 88

TRUE

Front 89

A homeobox is a DNA sequence of about 180 bp that specifies a 60 amino acid homeodomain

Back 89

TRUE

Front 90

Alternative RNA splicing generates different mRNAs that start with different introns.

Back 90

FALSE

Front 91

Transcription factories are specific nuclear sites where most of the RNP II mediated transcription occurs

Back 91

TRUE

Front 92

SWI/SNF complex helps in repositioning of the nucleosomes

Back 92

TRUE

Front 93

Heavily methylated DNA is associated with activation of transcription in vertebrates and plants

Back 93

FALSE

Front 94

Silencers are trans-acting elements that repress gene expression

Back 94

FALSE

Front 95

Zinc-finger is a type of DNA-binding domain

Back 95

TRUE

Front 96

The gene p53 is called guardian of the genome because it corrects mutations in the spindle apparatus before non-disjunction can occur

Back 96

FALSE

Front 97

In the familial form of retinoblastoma, one generally inherits a defective gene from one of the parents

Back 97

TRUE

Front 98

All the checkpoints in cell cycle are either in the S or G1 phase.

Back 98

FALSE

Front 99

When referring to tumor-suppressor genes and cancer, loss of heterozygosity is likely to suppress cancer formation

Back 99

FALSE

Front 100

Any agent that causes damage to DNA is a potential carcinogen

Back 100

TRUE

Front 101

Given an inheritance pattern of incomplete dominance and 81 flowers being R1R1 (red), 18 flowers R1R2 (pink) and 1 flower R2R2 (white); the frequency of the R1 allele is 0.9

Back 101

TRUE

Front 102

In large random mating populations, genetic drift is usually a significant factor in changing gene frequencies.

Back 102

FALSE

Front 103

Regarding the calculation of allele frequencies in a population with two alternative alleles, p+q=1.

Back 103

TRUE

Front 104

Inbreeding increases homozygosity

Back 104

TRUE

Front 105

Selection against a recessive gene is more significant in changing gene frequencies than selection against a dominant gene

Back 105

FALSE