Bio Exam 2

Front 1

In the calcium pathway, the G protein

Back 1

activates phospholipase C

Front 2

Synaptic signaling involves the release of

Back 2

neurotransmitters

Front 3

What are domains on nuclear hormone receptors?

Back 3

hormone-binding, coactivator-interacting, DNA-binding, inhibitor-binding

Front 4

Receptor tyrosine kinases are inactivated by

Back 4

dephosphorylation or internalization

Front 5

A protein inserted between the receptor and an effector that becomes activated when ligand binds is called a G protein.

Back 5

True

Front 6

During mitosis, the point on the chromatids where microtubules are attached is the

Back 6

kinetochores

Front 7

The G0 phase is actually a pause in the ___ phase.

Back 7

G1

Front 8

Immediately following the S phase, human cells have _____ chromatids.

Back 8

92

Front 9

What is completed during interphase?

Back 9

Microtubule-organizing centers are replicated, DNA is replicated, Chromosomes begin condensing, Organelles are replicated.

Front 10

Assessment of the success of DNA replication occurs at the:

Back 10

G2/M checkpoint.

Front 11

In anaphase I, the _____ are pulled apart.

Back 11

homologous pairs

Front 12

In multicellular organisms, the zygote

Back 12

always divides by mitosis.

Front 13

_____ distinguishes prophase I from mitotic prophase.

Back 13

Synapsis

Front 14

Unique to meiosis is the omission of chromosome replication between

Back 14

telophase I and prophase II.

Front 15

In a hypothetical cell with six chromosome pairs, how many possible orientations of the chromosomes at the metaphase plate are there?

Back 15

64

Front 16

If you cross a true-breeding dominant plant with a true-breeding recessive plant, what will be the phenotype of the resulting progeny?

Back 16

all dominant

Front 17

If you self-fertilize F1 progeny, what will be the dominant to recessive phenotypic ratio of the progeny?

Back 17

3:1

Front 18

How many different phenotypes appear in the F2 generation of a dihybrid cross?

Back 18

4

Front 19

An allele having more than one effect on an individual's phenotype is called

Back 19

pleiotropy.

Front 20

On which of the sex chromosomes is a sex-linked gene usually carried?

Back 20

X

Front 21

Of the two X chromosomes inherited by human females, one becomes

Back 21

inactivated

Front 22

The inheritance of mitochondrial genes is an example of which of the following?

Back 22

uniparental inheritance

Front 23

Genes cannot be modified in genomic imprinting.

Back 23

False

Front 24

According to Chargaff’s rules, if a sample of the nitrogenous portion of DNA is 30% adenine bases, then the sample will also contain:

Back 24

30% thymine

Front 25

_____ synthesize DNA, ____ unwind DNA strands, and _____ reduce torsional strain during replication.

Back 25

DNA polymerases, helicases, DNA gyrases.

Front 26

As a result of having multiple origins of replication, eukaryotic organisms are able to:

Back 26

Replicate larger amounts of DNA than prokaryotes in a short time.

Front 27

Telomeres are an important feature of eukaryotic chromosomes because:

Back 27

They protect the integrity of linear chromosomes.

Front 28

A base substitution mutation within a coding region of DNA always results in a new amino acid sequence.

Back 28

False

Front 29

The region of the tRNA that is complementary to the triplet on the mRNA is

Back 29

The anticodon

Front 30

During translation, the ribosome must move along the mRNA. This movement

Back 30

requires an accessory factor and energy

Front 31

A nonsense mutation

Back 31

will lead to the premature termination of translation

Front 32

What is the most common protein structure used to insert into the major groove of the DNA helix?

Back 32

α-helix

Front 33

In the function of the lac operon in E. coli, the lac genes are transcribed in the presence of lactose because

Back 33

allolactose binds to the repressor.

Front 34

When tryptophan is present in the environment of E. coli, the tryptophan binds to the

Back 34

trp repressor.

Front 35

Enhancers can function at large distances from promoters because

Back 35

the DNA can loop.

Front 36

Addition of a polyubiquitin chain to a protein

Back 36

targets the protein to the proteasome.

Front 37

Reproductive life cycle that involves an alternation between haploid and diploid cells

Back 37

Sexual Reproduction

Front 38

A single cell with a diploid number of chromosomes resulting from the fusion of an egg and a sperm.

Back 38

Zygote

Front 39

Cells (egg or sperm) resulting from a meiotic division of germ-line cells

Back 39

Gamete

Front 40

The non-reproductive cells found in embryos and mature individuals

Back 40

Somatic Cells

Front 41

The cells that will eventually undergo meiosis to produce gametes.

Back 41

Germ-line Cells

Front 42

The number of chromosomes found in gametes (eggs or sperm).

Back 42

haploid

Front 43

The process by which two haploid gametes fuse to form a new diploid cell.

Back 43

Syngamy

Front 44

A specialized reduction division that produces cells with half the normal number of chromosomes.

Back 44

Meiosis

Front 45

Two sets of chromosomes present in the somatic cells of adult individuals.

Back 45

diploid

Front 46

Meiosis II

Back 46

Division

Front 47

Anaphase I

Back 47

Phase of meiosis when chiasmata are broken as spindle fibers shorten and homologous pairs are pulled apart.

Front 48

Anaphase II

Back 48

Phase of meiosis when sister chromatids are pulled to opposite poles of the cells.

Front 49

Telophase I

Back 49

Phase of meiosis in which homologues cluster at the poles of the cells and the nuclear envelope reforms.

Front 50

Telophase II

Back 50

Phase of meiosis in which four different haploid cells are present.

Front 51

S phase

Back 51

The phase in which the cell synthesizes a replica of its genome

Front 52

Cytokinesis

Back 52

The phase in the cell cycle when the cytoplasm divides creating two daughter cells.

Front 53

G2 Phase

Back 53

The phase in the cell cycle during which mitochondria and other organelles replicate.

Front 54

telophase

Back 54

The phase in mitosis when chromosomes are clustered at opposite poles and the spindle apparatus disappears

Front 55

Mitosis

Back 55

The phase in the cell cycle in which the spindle apparatus assembles and sister chromatids move apart.

Front 56

Cell cycle

Back 56

The overall process of genome duplication

Front 57

G0 phase

Back 57

A resting state that cells often enter before resuming cell division.

Front 58

Order the events of a MAP kinase cascade:

1. MAPKKK phosphorylates and activates another kinase

2. MAPKK phosphorylates and activates MAPK

3. External signal binds to membrane receptor and activates receptor kinase

4. Phosphorylation of receptor kinase and interaction with RAS

5. MAPK phosphorylates an inactive response protein and activates it

6. Binding of MAPKKK to RAS

Back 58

3, 4, 6, 1, 2, 5

Front 59

Which of the following events occurs following the binding of a ligand to a G protein-coupled receptor that triggers release of Ca2+?

Back 59

Phospholipase cleavage of PIP2 to IP3 and DAG, IP3-mediated opening of calcium channels in the ER membrane

Front 60

Which statement best explains the way that an abnormal p53 causes normal cells to become cancer cells?

Back 60

The abnormal p53 protein fails to carry out DNA repair.

Front 61

Receptor tyrosine kinases are inactivated by:

Back 61

dephosphorylation or internalization.

Front 62

When a signaling molecule binds to a G protein-coupled receptor that uses adenylyl cyclase as an effector, this enzyme synthesizes a large amount of cAMP that binds to and activates PKA, which adds phosphate groups to target proteins.

Back 62

True

Front 63

What is the function of Ras during tyrosine kinase cell signaling?

Back 63

It links the receptor protein to the MAP kinase pathway.

Front 64

Which of the following best describes the immediate effect of ligand binding to a G protein-coupled receptor?

Back 64

The G protein trimer releases a GDP and binds a GTP.

Front 65

Different receptors can have the same effect on a cell. One reason for this is that

Back 65

signal transduction pathways intersect: the same pathway can be stimulated by different receptors.

Front 66

If two chromosomes are homologous, they

Back 66

Look similar under the microscope, Have very similar DNA sequences, Carry the same types of genes, and May carry different versions of the same gene.

Front 67

Assessment of the success of DNA replication occurs at the:

Back 67

G2/M checkpoint.

Front 68

What is the role of cohesin proteins in cell division?

Back 68

They hold the DNA of the sister chromatids together.

Front 69

What is a nucleosome?

Back 69

A region of DNA wound around histone proteins

Front 70

Somatic and gamete-producing germ-line cells are diploid. Somatic cells undergo meiosis to produce haploid gametes and germ-line cells undergo mitosis to form genetically identical, diploid daughter cells.

Back 70

False

Front 71

Which description best describes meiosis?

Back 71

Two successive divisions with no replication of genetic material between them. All cells are are converted to ones with a single copy of each chromosome.

Front 72

Crossing over occurs in:

Back 72

prophase I

Front 73

If an organism has eight pairs of chromosomes in its somatic tissue, how many chromosomes will it have in its germ-line cells?

Back 73

16

Front 74

The DNA content of a diploid cell in the G1 phase of the cell cycle is measured. If this DNA content is X, then the DNA content of the same cell at metaphase I would be:

Back 74

2X

Front 75

The DNA content of a diploid cell in the G1 phase of the cell cycle is measured. If this DNA content is X, then the DNA content of the same cell at metaphase of meiosis II would be:

Back 75

X

Front 76

How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n=8)?

Back 76

16

Front 77

A student is looking at cells under the microscope. The cells are from an organism that has a diploid number of 14 (n = 7). In one particular case, the cell has seven replicated chromosomes (i.e., seven pairs of sister chromatids) aligned at the metaphase plate of the cell. Which of the following statements could be true of this particular cell?

Back 77

The cell is in metaphase of meiosis II.

Front 78

Heterozygous

Back 78

The offspring produced when two haploid gametes containing different alleles fuse during fertilization.

Front 79

Alleles

Back 79

The alternative forms of a single gene that exist in a population.

Front 80

Genotype

Back 80

The total set of alleles that an individual contains

Front 81

Monohybrid cross

Back 81

To follow the behavior of two variations of a single trait in a cross.

Front 82

Principle of Segregation

Back 82

The first law of heredity states that two alleles for a gene segregate during gamete formation and rejoin randomly.

Front 83

Homozygous

Back 83

The offspring produced when two haploid gametes containing the same allele fuse during fertilization.

Front 84

pleiotropic

Back 84

An allele that has more than one effect on the phenotype of an individual.

Front 85

incomplete dominance

Back 85

The heterozygote is intermediate in appearance between the two homozygotes.

Front 86

continuous variation

Back 86

A gradation that results from a contribution of different combinations of alleles to a single trait.

Front 87

codominant

Back 87

Each allele has its own effect and some aspect of both alleles is seen in the heterozygote.

Front 88

polygenic inheritance

Back 88

The action of more than one gene can affect a single trait.

Front 89

epistasis

Back 89

A situation in which the expression of one gene can interfere with the phenotypic effects of a second.

Front 90

Genomic imprinting leads to non-Mendelian inheritance because in genomic imprinting:

Back 90

The expression of an allele varies depending on which parent it was inherited from.

Front 91

A potato has a diploid number of 48. If an egg of this plant has 23 chromosomes, the most likely explanation is that

Back 91

Nondisjunction occurred during meiosis I.

Front 92

Assuming complete dominance, the F1 generation of the monohybrid cross purple (PP) x white (pp) flower pea plants should:

Back 92

All have purple flowers

Front 93

Phenotypes like height in humans, which show a continuous distribution, are usually the result of:

Back 93

The action of multiple genes on a single phenotype.

Front 94

A dihybrid cross between a plant with long smooth leaves and a plant with short hairy leaves produces a long smooth F1. If this F1 is allowed to self-cross to produce an F2, what would you predict for the ratio of F2 phenotypes?

Back 94

9 long smooth: 3 long hairy: 3 short smooth: 1 short hairy

Front 95

You discover a new variety of plant with color varieties of purple and white. When you intercross these, the F1 is a lighter purple. You consider that this may be an example of blending and self-cross the F1. If Mendel is correct, what would you predict for the F2?

Back 95

1 purple: 2 light purple: 1 white

Front 96

In an organism's genome, autosomes are:

Back 96

All of the chromosomes other than sex chromosomes.

Front 97

Which of the following genotypes due to nondisjunction of sex chromosomes is lethal?

Back 97

OY

Front 98

Back 98

The mother (generation I) is heterozygous for the trait.

Front 99

Which gamete will be formed in an individual with genotype aaRR?

Back 99

aR

Front 100

During meiosis, gene pairs, such as Mm and Pp will assort independent and a random combination of genes can end up in the gametes. When the big M and little m segregate during meiosis, each is just as likely to end up in the same gamete as the big P as the little p.

Back 100

True

Front 101

If there is 25% chance that a child will inherit a recessive disease from it parents, what is the probability that one of a couple's first three children will have the disease?

Back 101

75%

Front 102

What determines the sex of a human?

Back 102

presence or absence of a Y chromosome

Front 103

Because the 2 strands of a DNA molecule run in opposite directions, they are said to be bidirectional.

Back 103

False

Front 104

DNA polymerases can add new DNA nucleotides only to the 5' end of an existing strand.

Back 104

False

Front 105

The DNA strand that grows away from the replication fork is synthesized continuously from one initial primer.

Back 105

False

Front 106

The DNA strand that grows toward the replication fork is synthesized discontinuously in short pieces called Okazaki fragments.

Back 106

False

Front 107

Each Okazaki fragment has its own primer.

Back 107

True

Front 108

The DNA strand that is synthesized continuously is called the lagging strand.

Back 108

False

Front 109

The DNA strand that is synthesized discontinuously is called the leading strand.

Back 109

False

Front 110

DNA ligase joins adjacent Okazaki fragments together into a complete strand.

Back 110

True

Front 111

DNA polymerases cannot initiate synthesis of a new DNA strand; they can only add bases to an existing strand.

Back 111

True

Front 112

DNA polymerase I removes the RNA primer and synthesizes a short sequence of DNA that will base pair with the parent strand of DNA.

Back 112

True

Front 113

When RNA polymerase reaches a _______ the RNA transcript and RNA polymerase separate from the DNA

Back 113

Terminator sequence

Front 114

RNA polymerase binds to a region of the DNA called the _______.

Back 114

Promoter

Front 115

_______ begins to unwind and separate the 2 strands of the DNA double helix.

Back 115

Helicase

Front 116

Actual synthesis of the RNA transcript begins at the _______.

Back 116

Start site

Front 117

Successive RNA nucleotides are added to the 3'-end of the growing RNA chain during a process called _______.

Back 117

Elongation

Front 118

A small ribosomal subunit binds to a molecule of ______ near its 5'-end.

Back 118

mRNA

Front 119

A charged ______ molecule with a UAC codon binds to the first AUG codon in the mRNA strand.

Back 119

tRNA

Front 120

A large ribosomal subunit associates with the ______ ribosomal subunit

Back 120

small

Front 121

A charged tRNA with the ______ that is complementary to the codon in the A site enters and binds to the A site.

Back 121

anticodon

Front 122

A peptide bond forms between the amino acid attached to the tRNA in the A site and the growing polypeptide chain attached to the tRNA in the ______ site.

Back 122

P

Front 123

The ribosome moves along the mRNA so that the tRNA that was in the ______ site is now in the P site and the tRNA that was in the P site is now in the E site.

Back 123

A

Front 124

The tRNA in the ______ site is ejected.

Back 124

E

Front 125

The movement of the ribosome is called _______.

Back 125

translocation

Front 126

When the ribosome encounters a stop codon _____ binds to the A site.

Back 126

release factor

Front 127

The release factor breaks the covalent bond that links the newly synthesized ______ to the tRNA in the P site.

Back 127

polypeptide chain

Front 128

The mRNA, tRNA, and _____ ribosomal units dissociate from each other.

Back 128

two

Front 129

DNA sequence found upstream of the start site in eukaryotic promoters

Back 129

TATA box

Front 130

Proteins used to recruit RNA polymerase II to eukaryotic promoters to initiate transcription.

Back 130

Transcription factors

Front 131

An addition of a methyl group that protects the 5' end of the mRNA from degradation and participates in translation initiation.

Back 131

Methyl G-cap

Front 132

Added to the 3' end of a transcript by poly-A polymerase to protect the mRNA from degradation.

Back 132

3' poly A tail

Front 133

The final processed form of the mRNA after 5' capping

Back 133

mature mRNA

Front 134

Modification of the 5' end of a transcript by the addition of methylated GTP to the 5'PO4 group.

Back 134

5' cap

Front 135

The original RNA synthesized by RNA polymerase before it undergoes processing.

Back 135

primary transcript

Front 136

If one strand of a DNA is 5′ ATCGTTAAGCGAGTCA 3′, then the complementary strand would be:

Back 136

5′ TGACTCGCTTAACGAT 3′.

Front 137

During translation, the codon in mRNA is actually "read" by

Back 137

the anticodon in a tRNA.

Front 138

In the genetic code, one codon

Back 138

consists of three bases and specifies a single amino acid

Front 139

Changing the codon AGC to AGA represents a

Back 139

missense mutation

Front 140

If an allele has more than one effect on the phenotype it is said to be

Back 140

pleiotropic

Front 141

In _________, a ribosome assembles a polypeptide, whose amino acid sequence is specified by the nucleotide sequence in the mRNA.

Back 141

translation

Front 142

Separation of sister chromatids occurs during

Back 142

anaphase

Front 143

The pairing of chromosomes along their lengths which is essential for crossing over is referred to as 


Back 143

synapsis

Front 144

Dosage compensation is needed to

Back 144

balance expression of sex chromosomes in both sexes

Front 145

Nucleotides have phosphates attached at the ___ carbon atom of the sugar.

Back 145

5 prime

Front 146

Height and eye colors are two examples of continuous variation in humans. Whereas in pea plants the tall allele is dominant over the short allele, there are no intermediate heights in peas. Which of the following is the best explanation for the differences described above? 


Back 146

Many genes, rather than one gene for a characteristic, control some variations in species.

Front 147

_____________ rely on ___________, such as Ca2+ and cyclic AMP, to activate (or inactivate) a variety of pathways within the cell.

Back 147

G protein coupled receptors; secondary messengers

Front 148

A diploid cell that has two different alleles for the same trait is called _______ for that particular trait. 


Back 148

heterozygous

Front 149

You discover a new variety of plant with color varieties of purple and white. When you intercross these, the F1 is a lighter purple. You consider that this may be an example of incomplete dominance and self-cross the F1. If your hypothesis is correct, what would you predict for the F2?

Back 149

1 purple:2 light purple:1 white

Front 150

The same signal can have different effects in different cells because there

Back 150

are different receptor subtypes that initiate different signal transduction pathways, may be different second messengers in different cells, or may be different target proteins in different cells’ signal transduction pathways

Front 151

If a cell has 30 chromosomes prior to S phase of the cell cycle and undergoes mitosis followed by cytokinesis, each new daughter cell will have how many chromosomes? 


Back 151

30

Front 152

Contraction of the heart muscle is synchronized in time to promote pumping of blood throughout the body. What type of connection between muscle cells would enable calcium to be transmitted from cell to cell to facilitate this synchronization?

Back 152

Gap junction (connexins)

Front 153

Hormone receptors have several binding domains including:

Back 153

a hormone binding domain, a transcription activating domain and a DNA binding domain

Front 154

Before cell division of the body cells, each chromosome replicates. These replicates are connected by a centromere and are called 


Back 154

sister chromatids

Front 155

If the activity of DNA ligase was removed from replication, this would have a greater affect on

Back 155

synthesis on the lagging strand versus the leading strand

Front 156

The synthesis of the growing chain of RNA is carried out by adding nucleotides to the ___ end. 


Back 156

3' 
hydroxyl group

Front 157

A human germ line cell normally contains 46 chromosomes in its nucleus. How many chromosomes go to each spindle pole during meiosos II?

Back 157

23

Front 158

Alternate forms of a gene are called ______. 


Back 158

alleles

Front 159

A researcher is trying to produce a new cancer drug to be tested on small tumors. To be effective this drug must prohibit signaling between neighboringtumor cells. Given the above information, this new drug will prohibit:


Back 159

paracrine signaling between tumor cells.

Front 160

The primary growth phase and longest phase of the cell cycle is:

Back 160

G1 (gap phase 1)

Front 161

The lagging strand is replicated with stretches of Okazaki fragments and that is why its synthesis is considered to be 


Back 161

discontinuous

Front 162

Consider the following sequence:
5'AUGGCUACAGAUAGCUGGGGCUGAAAAAAAAAAAAAAAA3'

Translated, the corresponding protein contains how many amino acids? 


Back 162

7

Front 163

During translation, the codon in mRNA is actually “read” by

Back 163

the anticodon in a tRNA

Front 164

Fourteen percent of the DNA nucleotides from a certain organism contain T. What amounts of the other bases would you expect to be present in this particular DNA? 


Back 164

14 % A, 36 % C, 36 % G


Front 165

After a long week of sunbathing on the beach (and being exposed to UV light), what type of DNA damage might you be concerned about? 


Back 165

thymine dimers

Front 166

Eukaryotic mature mRNAs differ from prokaryotic mRNAs in that they

Back 166

are not colinear with the genes that encode them

Front 167

The strand of DNA that is transcribed is called the ______ strand. 


Back 167

template

Front 168

Most eukaryotic genes contain coding sequences called ________ that are interspersed with noncoding sequences. 


Back 168

exons

Front 169

Transcription in prokaryotes is carried out by the enzyme _______, which transcribes the gene. 


Back 169

RNA polymerase

Front 170

An enzyme that adds a phosphate to a protein.

Back 170

kinase

Front 171

A protein that binds to Cdks to control passage through thecell cycle.

Back 171

cyclin

Front 172

A pair of chromosomes that have the same genes as oneanother but not necessarilythe same alleles.

Back 172

homologous

Front 173

A point of constriction on the chromosome containing certainrepeated DNA sequencesthat bind kinetochores.

Back 173

centromeres

Front 174

A process that enables homologues to exchange chromosomalmaterial (and promotegenetic diversity).

Back 174

crossing over

Front 175

Duringself-fertilization, this genotype gives rise to offspring of one genotype.

Back 175

true-breeding

Front 176

A male calico cat is an example of this kind of chromosomalseparation error during meiosis.

Back 176

nondisjunction

Front 177

An extension to Mendelian genetics that is relevant when multiple genes are involvedin controlling the phenotype of a trait.

Back 177

polygenic inheritance

Front 178

An extension to Mendelian genetics that is relevant when the heterozygote shows somecharacteristics of the phenotypes of both homozygotes (Type AB blood).

Back 178

codominance

Front 179

A base that is found only in RNA.

Back 179

Uracil

Front 180

Protein(s)that is/are involved in the repair of mismatched bases in DNA.

Back 180

uvr complex

Front 181

Segment of DNA that contains several guanine and cytosineresidues followed by anumber of consecutive adenine residues.

Back 181

Termination site

Front 182

Segmentof DNA to which repressors bind.

Back 182

Operators

Front 183

A protein that binds to activators or repressors to positively or negatively impacttranscription.

Back 183

Effector proteins

Front 184

DNA Polymerase III adds newnucleotides to the 3’ end of a growing chain of nucleotides.

Back 184

True

Front 185

Iftwo chromosomes are homologous they may carry different versions of the samegene.

Back 185

True

Front 186

The DNA strand that issynthesized away from the replication fork is synthesized continuously requiring one initial primer.

Back 186

False

Front 187

RNApolymerase binds to a region of the DNA called the operator.

Back 187

False

Front 188

Terminatorsequences in DNA are rich in Uracil nucleotides.

Back 188

False

Front 189

Thefirst codon in mRNA that is translated is AUG

Back 189

True

Front 190

When the ribosome encountersa stop codon, a tRNA molecule with a complementary stop anticodon binds to the A site

Back 190

False

Front 191

Ribosomesmove along the mRNA chain in the 3 prime to 5 prime direction.

Back 191

False

Front 192

Repressors bind to enhancersequences in DNA to promote gene expression.

Back 192

False

Front 193

Transcriptionfactors bind to mRNA to initiate protein translation.

Back 193

False

Front 194

An activator protein that uses cAMP as an effector and can stimulate transcription of catabolic operons.

Back 194

catabolite activator protein (cap)

Front 195

Regulatory sequences in the DNA that can prevent or decrease transcription of catabolic operons.

Back 195

operators

Front 196

Allosteric, regulatory proteins that bind DNA and stimulate transcriptional initiation.

Back 196

activators

Front 197

Regulatory proteins that bind to specific sites on the DNA and prevent or decrease transcription.

Back 197

repressors

Front 198

A regulatory sequence found in the DNA that is bound by RNA polymerase to initiate transcription.

Back 198

promoter

Front 199

Regulatory sequences in the DNA bound to proteins that affect the basal level of transcription.

Back 199

enhancers

Front 200

Proteins required for transcription initiation

Back 200

general transcription factors

Front 201

Protein that bind to regulatory sequences in the DNA and increase the basal level of transcription.

Back 201

specific transcription factors

Front 202

Regulatory proteins interact with DNA by

Back 202

binding to the major groove of the double helix and interacting with base pairs

Front 203

Repression in the trp operon and induction in the lac operon are both mechanisms that

Back 203

allow the cell to control the level of enzymes to fit environmental conditions

Front 204

The lac operon is controlled by two main proteins. These proteins

Back 204

act in the opposite fashion, one negative and one positive

Front 205

The lac repressor, the trp repressor and CAP are all

Back 205

allosteric proteins that bind to DNA and an effector

Front 206

Which of the following are NOT found in DNA-binding proteins?

Back 206

CpG islands

Front 207

A region in the middle of an intron is removed from a chromosome. The size of the mRNA does not change, but the amount of mRNA produced decreases. Which of the following would explain this result?

Back 207

The deleted region contained an enhancer.

Front 208

_____ tend to cause RNAs to be degraded between transcription and translation.

Back 208

siRNAs

Front 209

Methylation is a modification of the DNA or of the histone proteins that is associated with inactive regions of chromatin.

Back 209

True

Front 210

Acetylation is the modification of the histone tails that allows DNA to be accessible for transcription.

Back 210

True