Chapter all: Molecular Biology of the Cell

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Maintenance of dna sequences: low mutation rates, bacteria - mutation rate - ~ 3 nucleotide changes per 1010 nucleotides per cell generation, humans - mutation rate - ~ 1 nucleotide change per 108 nucleotides per human generation, humans. 1 mutation/1010 nucleotides/ cell division: importance of low mutation rates, germ cells pass genetic information from one generation to the next. Low mutation rates necessary to maintain the species: somatic cells form the body of the organism high mutation rates leads to cancer. Dna templating mechanism by which parent dna strand acts the template for producing a complementary daughter strand. Dna polymerase nucleotide polymerizing enzyme involved in dna replication: dna replication fork. Dna replication is semi-conservative newly produced dsdna will have 1 newly synthesized strand and 1 parent strand. Replication fork y shaped structure that actively moves along the parental dna during replication it has a multi-enzyme complex which includes dna polymerase.

Related Questions

1. An occurrence of a gene made larger by trinucleotide repeats is:

Allelic expansion

Nucleotide expansion

Translocation mutation

Transformation

2. a chemical that can damage and/or change DNA is called a/an:

Allele

Endonuclease

Vector

Mutagen

3. An occurrence when a section of a chromosome relocates itself to an entirely different (non-homologous) chromosome is called a/an:

Inversion mutation

Translocation mutation

Transformation mutation

Duplication mutation

4. The tandem repeat in the sequence GGGAAGGGAAGGGAAGGGAAGGGAAG is:

GGA

GGGAA

GGAAG

GGAAGGG

A disease characterized by abnormally shaped hemoglobin is called:

Cystic Fibrosis

Sickle Cell Anemia

Marfan Syndrome

Leukemia

5. A point mutation that causes a substitution of a stop codon with an amino acid and leads to the formation of a longer protein is a:

Nonsense mutation

Missense mutation

Sense mutation

Frameshift mutation

6. Addition or deletion of nucleotides in a DNA sequence is known as a:

Nonsense mutation

Missense mutation

Sense mutation

Frameshift mutation

7. The least severe type of chromosomal mutation is:

Point

Frameshift

Inversion

Translocation

8. Chemicals inserting themselves into DNA can cause a:

Missense mutation

Nonsense mutation

Sense mutation

Frameshift mutation

9. A genetic condition caused by allelic expansion is:

Familial hypercholesterolemia

Fragile X syndrome

Alkaptonuria

Galactosemia

10. Which of the following is most likely the original DNA strand if the mutated DNA strand is ATAGUUGATGUA ?

ATAGAAGATGAA

ATAGCCGATGCA

ATAGGGGATGGA

ATAGTTGATGTA

11. An unbalanced chromosomal mutation would include a/an:

duplication (insertion)

inversion

translocation

denaturation

12. Many translocation mutations are found to be involved with:

cancers

sickle cell anemia

Huntington disease

cystic fibrosis

13. A common repeat throughout the human genome that is approximately 300 bases in length is called a/an:

EcoRI repeat

Hind repeat

Exo repeat

Alu repeat

14. A balanced chromosomal mutation includes:

imprintation

denaturation

inversion

deletion

salmondinosaur263

QUESTION 1

A mutation caused by exposure to gamma rays is called a spontaneous mutation

	a.	True
	b.	False
	c.	Sometimes, depending on the type of base change
	d.	Gamma rays do not cause mutations

QUESTION 2

A recessive mutation affecting an essential biochemical pathway can be detected________

	a.	when the organism is heterozygous for that mutation.
	b.	when the organism is homozygous for that mutation.
	c.	in either homozygous or heterozygous conditions.
	d.	only by sequencing (recessive mutations never show a phenotype).

QUESTION 3

During DNA replication, the newly synthesized chain grows by adding

	a.	nitrogenous bases
	b.	the sugar-phosphate backbone
	c.	nucleosides
	d.	dNTPs

QUESTION 4

During replication, the DNA strand 5â- AAGTCTAGCCTAG -3â will serve as a template for the polymerization of:

	a.	5â- CTAGGCTAGACTT -3â
	b.	5â - TTCAGATCGGATC -3â
	c.	5â - GATCCGATCTGAA -3â
	d.	3â - AAGTCTAGCCTAG -5â

QUESTIOn 5

Given the following DNA sequences, select which statement(s) is(are) correct.

Sequence 1:

5â-TGGACGCTAA-3â

3â-ACCTGCGATT-5â

Sequence 2:

5â-AATCGCAGGT-3â

3â-TTAGCGTCCA-5â

Sequence 3:

5â-ACCTGCGATT-3â

3â-TGGACGCTAA-5â

	a.	Sequences 1 and 2 are the same
	b.	Sequences 1 and 3 are the same
	c.	Sequences 2 and 3 are the same
	d.	Sequences 1, 2 and 3 are all different

QUESTION 6

Repetitive sequences in the genome are hotspots for:

	a.	Deamination
	b.	Depurination
	c.	Thymine dimer formation
	d.	Replication errors

QUESTION 7

Select which statement(s) about the Ames test is(are) correct

	a.	it has been designed to understand mutation repair systems in Salmonella typhimurium
	b.	it uses mammalian liver extract
	c.	it allows to study whether chemical compounds or their enzymatic breakdown products are mutagenic
	d.	it is based on whether a chemical compound causes reversion mutations from his+ to his-
	e.	two of the above are correct
	f.	three of the above are correct

QUESTION 8

Select which statement(s) is(are) correct.

	a.	All DNA strands have a direction, and it is specified by the carbons in the sugar backbone.
	b.	All DNA strands have a direction, and it is specified by hydrogen bonds between nucleotides.
	c.	In order to form proper base pairs in a double stranded DNA molecule, the two strands must run in opposite directions.
	d.	A and C are correct.
	e.	B and C are correct.

QUESTION 9

Studies of gene mutation frequencies have shown that:

	a.	mutations are rare, and genomes are generally stable.
	b.	mutation frequencies differ among organisms and also between genes, suggesting certain genes are more susceptible to mutation.
	c.	mutation frequencies are consistent between organisms, and each region of DNA is equally susceptible to random mutations.
	d.	Both A and B are correct.
	e.	Both A and C are correct.

QUESTION 10

The compound 5-bromodeoxyuridine (BrdU) is a derivative of uracil, and if BrdU becomes incorporated during DNA replication, it pairs with adenine. This compound is best classified as which type of mutagen?

	a.	base analog
	b.	base inducer
	c.	intercalating agent
	d.	oxidative agent
	e.	alkylating agent

QUESTION 11

The rate of mutation of the fruit fly is higher than the rate of mutation of Algae

True

False

QUESTION 12

Thymine dimers are most commonly caused by which of the following?

	a.	X-rays
	b.	Alkylating agents
	c.	U.V. irradiation
	d.	DNA intercalating agents

QUESTION 13

What chemical group is found in the 3â end of a DNA strand?

	a.	an alcohol
	b.	a hydroxyl
	c.	a methyl
	d.	a phosphate

QUESTION 14

What chemical group is found in the 5â end of a DNA strand?

	a.	an alcohol
	b.	a hydroxyl
	c.	a methyl
	d.	a phosphate

QUESTION 15

Which is the correct order of molecules binding to DNA during DNA replication?

	a.	Helicase, SSB, primase, DNA pol III, DNA pol I, ligase
	b.	SSB, DNA pol I, ligase, helicase, DNA pol I, primase
	c.	primase, helicase, DNA pol III, ligase, DNA pol I, SSB
	d.	SSB, helicase, primase, DNA pol III, DNA pol I, ligase

QUESTION 16

Which statement(s) is(are) correct about strand slippage?

	a.	It can cause disorders such as Huntingon disease.
	b.	It is a process that causes mutations altering the number of DNA repeats.
	c.	It is a process that incorporates nucleotide base analogs and trinucleotide repeats.
	d.	a and b are correct.
	e.	b and c are correct.
	f.	a, b and c are correct.

help needed asap.

chocolatesea-lion434

QUESTION 10

If you can drink milk as an adult, it means that you have inherited a mutation in the promoter of your lactase gene (the gene that encodes the enzyme you need to break down lactose). Predict the effect of this mutation:

		The mutation changes the number of domains in the enzyme, which makes it work more efficiently
		The mutation changes the amino acid sequence of the lactase protein
		The mutation increases the number of copies of the lactase gene that will be found in your genome
		The mutation changes whether the lactase sequence is found in an intron or exon
		The mutation affects the expression of the lactase gene

1.2 points

QUESTION 11

A competitive inhibitor is decreasing the activity of an enzyme. Predict the effect of adding more substrate to the reaction.

		The substrate will increase the reaction rate by binding to the allosteric site
		The substrate will increase the reaction rate by competing with the inhibitor for the active site
		The reaction rate will not change unless the inhibitor can be removed
		The enzyme adjusts its shape so that the substrate, but NOT the competitive inhibitor, can bind
		The substrate will bind to the competitive inhibitor and block its ability to bind to the enzyme

1.2 points

QUESTION 12

What determines where in the genome a transcription regulator will bind?

		Transcription regulators bind to the 5' UTR region of a gene
		Regulators bind via complementary base-pairing to certain DNA molecules
		Covalent bonds form between the transcription regulator and the atoms of the DNA backbone
		Every eukaryotic gene has a different transcription regulator that will bind to the 5' end of the gene
		Transcription regulators bind to specific DNA sequences via multiple weak non-covalent interactions

1.2 points

QUESTION 13

What is the basic premise of cell theory?

		DNA -> RNA -> protein
		All cells arise from pre-existing cells
		DNA provides the complete instructions to create a cell
		The identity of a cell is determined through gene expression patterns
		All cells contain the same four basic macromolecules

1.2 points

QUESTION 14

What is the benefit of using BOTH the lac activator and the lac repressor to control gene expression?

		Using both an activator and repressor enables cells to more accurately determine the amount of lactose available in the environment
		Enzymes to digest lactose are only made when energy is low and lactose is available
		The activator can override the inhibition of the lac operon by the repressor
		The repressor can control the enhancer, while the activator can control the promoter
		When neither the lac activator or repressor is present, expression of the lac operon is too high

1.2 points

QUESTION 15

What is the histone code used for?

		Phosphorylation and acetylation of DNA affect its ability to be compacted
		Changes to the sequence of DNA change whether DNA will wrap around histone proteins
		Covalent modifications of histones affect the ability of the transcription initiation complex to form
		Histones provide the codon sequences needed for translation to occur
		The histone code affects which amino acids will get added to a polypeptide

Chapter all: Molecular Biology of the Cell

BIO120H1 Full Course Notes

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