Chapter 25 DNA

Question 1

DNA is the “_____” for all proteins

Answer 1

Written instructions

Question 2

These “written instructions” include:

Answer 2

1. Letters (bases)
2. Words (codons)
3. Sentences (gene)
4. Punctuation (promoters, stop codons)

Question 3

Who built a double helix model to demonstrate the concept of DNA?

Answer 3

James WATSON and Francis CRICK

Question 4

mRNA

Answer 4

Messenger RNA

-takes message from DNA to the ribosomes

Question 5

rRNA

Answer 5

Ribosomal RNA

Translates the information in mRNA.

Question 6

tRNA

Answer 6

Transfer RNA

Carry amino acids to the ribosomes to make proteins

Question 7

Gene

Answer 7

a segment of DNA that specifies the amino acid sequence of a protein (or RNA)

Question 8

Gene Expression

Answer 8

Making a protein from the gene

Question 9

What are the stems in protein synthesis? (multi-step process…4 steps)

Answer 9

• DNA (master building plans)
• mRNA (blueprints)
• rRNA (construction site)
• tRNA (construction worker)

Question 10

What 2 steps are required in gene expression?

Answer 10

1. Transcription

2. Translation

Question 11

Transcription (gene expression)

Answer 11

• making a readable copy of gene from DNA
• “transcribe” = to make a written copy
• happens inside the nucleus

Question 12

Translation (gene expression)

Answer 12

• Using the gene’s instructions to construction protein
• “translate” = to turn from one language to another
• happens at ribosome on E.R. or in cytoplasm

Question 13

Gene Mutation

Answer 13

A change in the sequence of bases within a gene

Question 14

Gene mutations can lead to ____ ____ in cells

Answer 14

Malfunctioning protein

Question 15

What causes mutations? (3 causes)

Answer 15

1. Errors in replication
   - DNA polymerase “proofreads” new strands, error rare
2. Mutagens
   - Radiation, UV light, chemicals
   - Rate is low, DNA repair enzymes monitor and repair
3. Transposons
   - “jumping genes”
   - can move to new locations and disrupt sequences

Question 16

Who discovered the transposon, “jumping genes”?

Answer 16

Barbara McClintock

Question 17

Which one of the following was NOT one of the discoverers of DNA?

1. Francis Crick
2. Maurice Wilkins
3. James Watson
4. Barbara McClintock
5. Rosealind Franklin

Answer 17

Barbara McClintock

Question 18

Which one of the following is NOT one of the 4 bases in DNA?

1. Adenine (A)
2. Cytosine (C)
3. Guanine (G)
4. Thymine (T)
5. Uracil (U)

Answer 18

Uracil (U)

Question 19

______ is making a mRNA copy of DNA?

1. Transcription
2. Translation
3. Transfer
4. Transduction

Answer 19

Transcription

think, copy = transcribe

Question 20

____ are composed of 3 bases and code for a specific amino acid

1. Nucleotides
2. Codons
3. Exons
4. Introns

Answer 20

Codons

Question 21

Which type of RNA carries amino acids to the ribosome?

1. cRNA
2. mRNA
3. rRNA
4. tRNA

Answer 21

tRNA

Question 22

Which type of mutation moves all of the nucleotides after the mutation?

Answer 22

Frameshift

Question 23

According to the textbook, approximately when did the first cell evolve?

1. 4.6 Billion years
2. 3.5 Billion years
3. 2.1 Million years

Answer 23

3.5 Billion Years