Modern Genetics 2

Question 1

What is the basic structure of DNA?

Answer 1

DNA is a double helix composed of two strands of nucleotides.

Question 2

What are the four nucleotide bases in DNA?

Answer 2

Adenine, Thymine, Cytosine, and Guanine.

Question 3

Which base pairs with Adenine in DNA?

Answer 3

Thymine.

Question 4

What type of bond holds the two strands of DNA together?

Answer 4

Hydrogen bonds.

Question 5

What is the process of DNA replication?

Answer 5

The process by which DNA makes a copy of itself.

Question 6

True or False: DNA replication is semi-conservative.

Answer 6

True.

Question 7

What enzyme unwinds the DNA during replication?

Answer 7

Helicase.

Question 8

What is the role of DNA polymerase?

Answer 8

It synthesizes new DNA strands by adding nucleotides.

Question 9

Fill in the blank: The leading strand is synthesized _____ during DNA replication.

Answer 9

continuously.

Question 10

What is the function of ligase in DNA replication?

Answer 10

It joins Okazaki fragments on the lagging strand.

Question 11

What is protein synthesis?

Answer 11

The process by which cells generate proteins from amino acids.

Question 12

What are the two main stages of protein synthesis?

Answer 12

Transcription and translation.

Question 13

Where does transcription occur in eukaryotic cells?

Answer 13

In the nucleus.

Question 14

What is the role of mRNA in protein synthesis?

Answer 14

It carries the genetic information from DNA to the ribosome.

Question 15

What is the function of ribosomes in translation?

Answer 15

They facilitate the assembly of amino acids into proteins.

Question 16

True or False: The lac operon is involved in the metabolism of lactose in bacteria.

Answer 16

True.

Question 17

What are the three structural genes of the lac operon?

Answer 17

lacZ, lacY, and lacA.

Question 18

What is the role of the repressor in the lac operon?

Answer 18

It inhibits transcription when lactose is not present.

Question 19

Fill in the blank: The presence of _____ induces the lac operon.

Answer 19

lactose.

Question 20

What is transformation in biology?

Answer 20

The process by which a cell takes up foreign DNA from its environment.

Question 21

True or False: Transformation can occur naturally in some bacteria.

Answer 21

True.

Question 22

What is a mutation?

Answer 22

A change in the DNA sequence of an organism.

Question 23

What are the three types of mutations?

Answer 23

Substitution, insertion, and deletion.

Question 24

What is a point mutation?

Answer 24

A mutation that affects a single nucleotide.

Question 25

Fill in the blank: A _____ mutation changes one amino acid in a protein.

Answer 25

missense.

Question 26

What is a frameshift mutation?

Answer 26

A mutation that shifts the reading frame of the genetic message.

Question 27

True or False: Mutations can be beneficial, harmful, or neutral.

Answer 27

True.

Question 28

What is the role of the promoter in gene expression?

Answer 28

It is a DNA sequence that initiates transcription.

Question 29

What is the difference between prokaryotic and eukaryotic transcription?

Answer 29

Eukaryotic transcription occurs in the nucleus, while prokaryotic transcription occurs in the cytoplasm.

Question 30

What is an operon?

Answer 30

A group of genes regulated together.

Question 31

Fill in the blank: The _____ is a regulatory protein that can turn off the lac operon.

Answer 31

repressor.

Question 32

What is the purpose of the operator in an operon?

Answer 32

It controls access of RNA polymerase to the genes.

Question 33

What is the first step of transcription?

Answer 33

RNA polymerase binds to the promoter.

Question 34

What is the role of tRNA in translation?

Answer 34

It brings amino acids to the ribosome based on codon recognition.

Question 35

What is a codon?

Answer 35

A sequence of three nucleotides that encodes an amino acid.

Question 36

Fill in the blank: The start codon for protein synthesis is _____

Answer 36

AUG.

Question 37

What is the significance of the 5' cap and poly-A tail in mRNA?

Answer 37

They protect mRNA from degradation and assist in translation.

Question 38

What is the process by which RNA is converted into a protein?

Answer 38

Translation.

Question 39

What does the term 'gene expression' refer to?

Answer 39

The process by which information from a gene is used to synthesize a functional gene product.

Question 40

What is the role of the terminator in transcription?

Answer 40

It signals the end of transcription.

Question 41

True or False: All mutations lead to changes in protein function.

Answer 41

False.

Question 42

What is an example of a mutagen?

Answer 42

Radiation, chemicals, or viruses.