Chapter 12 Molecular Biology Of The Gene

Question 1

What is DNA?

Answer 1

DNA is the molecule that carries genetic information.

Question 2

What are nucleotides?

Answer 2

Nucleotides are the building blocks of DNA.

Question 3

What are the 4 nitrogenous bases in DNA?

Answer 3

Adenine, Thymine, Guanine, and Cytosine.

Question 4

What is the shape of DNA?

Answer 4

DNA is shaped like a double helix.

Question 5

What does ‘complementary base pairs’ mean?

Answer 5

A pairs with T, and G pairs with C.

Question 6

What is the sugar-phosphate backbone?

Answer 6

It’s the outer part of DNA made of sugar and phosphate.

Question 7

What does DNA helicase do?

Answer 7

It unzips the DNA strand.

Question 8

What does DNA polymerase do?

Answer 8

It builds the new strand of DNA.

Question 9

What does DNA primase do?

Answer 9

It helps start the new DNA strand.

Question 10

What does DNA ligase do?

Answer 10

It joins pieces of DNA together.

Question 11

What is DNA replication?

Answer 11

It’s how DNA copies itself.

Question 12

What is mRNA?

Answer 12

mRNA carries DNA’s message to the ribosome.

Question 13

What is tRNA?

Answer 13

tRNA brings amino acids to the ribosome.

Question 14

What is rRNA?

Answer 14

rRNA helps make up the ribosome.

Question 15

What is transcription?

Answer 15

Transcription is making mRNA from DNA.

Question 16

What is translation?

Answer 16

Translation is making a protein from mRNA.

Question 17

What is a codon?

Answer 17

A codon is 3 bases on mRNA that code for an amino acid.

Question 18

What is an anticodon?

Answer 18

An anticodon is 3 bases on tRNA that match the codon.

Question 19

What is an exon?

Answer 19

Exons are coding parts of RNA.

Question 20

What is an intron?

Answer 20

Introns are non-coding parts of RNA.

Question 21

What does RNA polymerase do?

Answer 21

It builds RNA from DNA.

Question 22

What is the promoter?

Answer 22

It’s the DNA section where RNA polymerase starts.

Question 23

What are the stages of transcription?

Answer 23

Initiation, Elongation, Termination.

Question 24

What is a polypeptide?

Answer 24

It’s a chain of amino acids that becomes a protein.

Question 25

What is the chemical structure of DNA (Watson & Crick model)?

Answer 25

Double helix, sugar-phosphate backbone, base pairs (A-T, C-G).

Question 26

What enzymes are involved in DNA replication?

Answer 26

Helicase = unzips DNA. DNA polymerase = adds bases. Ligase = seals gaps. Primase = starts the process.

Question 27

What happens during transcription?

Answer 27

DNA → mRNA using RNA polymerase. A pairs with U (not T).

Question 28

How is eukaryotic mRNA processed and exported?

Answer 28

Introns cut out, exons kept. mRNA exits nucleus to cytoplasm.

Question 29

What happens in translation?

Answer 29

mRNA → protein. Ribosome reads codons. tRNA brings amino acids.