Chapter 16 - The Genetic Code

Question 1

Aneuploidy

Answer 1

An abnormal number of chromosomes

Question 2

Polyploidy

Answer 2

More than 2 homologues of one or more chromosome (ex. triploidy)

Question 3

Euploidy

Answer 3

Normal number of homologues

Question 4

What is the euploidy for humans?

Answer 4

2 sets of 23 for 46 chromosomes

Question 5

What does DNA Methylation do?

Answer 5

Gene Expression - DNA more available

Question 6

How many stop codons are there?

Answer 6

Three!

Question 7

What does RNA become?

Answer 7

mRNA and regulatory RNA

Question 8

Reverse Transcriptase

Answer 8

Synthesize DNA strand from RNA template - some bacteria can do this!

Question 9

What direction are codons written?

Answer 9

5’ to 3’

Question 10

Which strand of DNA is used to make RNA?

Answer 10

The template strands (3’ to 5’)

Question 11

Missense Mutations

Answer 11

Replacement mutation - new codon codes for different amino acid.

Question 12

Chromosome Inversion

Answer 12

Chromosome parts break and rotate before rejoining to rest of chromosome

Question 13

Chromosome Translocation

Answer 13

Broken section of one chromosome attaches to another

Question 14

What are the main reasons for Chromosome Mutations?

Answer 14

Cohesions and/or codensions malfunction. Problem in Crossing over

Question 15

What is the most common number of codons that specifies a single amino acid?

Answer 15

Two

Question 16

Translation

Answer 16

The coding from mRNA to proteins

Question 17

One-gene, one enzyme hypothesis

Answer 17

Bases on N. crassa knock-out mutants that lacked the ability to synthesise certain compounds. Mutations in single genes eliminated the production of the corresponding enzyme.

Question 18

How many amino acids are represented in the genetic code by just one codon?

Answer 18

Two

Question 19

What charge does DNA have?

Answer 19

Negative

Question 20

What charge do histones have?

Answer 20

Positive

Question 21

Epigenetics

Answer 21

Changing gene expression without altering the DNA base sequence

Question 22

What does DNA methylation do?

Answer 22

Silences gene expression

Question 23

What does histone acetylation do?

Answer 23

Increases gene expression by making the histones less positive and less attractive to DNA.