Chapter 11

Question 1

What is a mutation?

Answer 1

Any change in the genetic information in DNA. Mutations are RANDOM and cannot be controlled or manipulated

Question 2

Mutation in somatic vs germ cell

Answer 2

Mutations in somatic cells are passed on to daughter cells through cell division but are NOT transmitted to future generations

Mutations in germ cells ARE passed on to future generations

Question 3

Two main groups of mutations

Answer 3

Spontaneous: are caused by internal factors (ex. Errors in DNA replication)

Induced: are caused by external factors (ex. Radiation or chemicals)

Question 4

Missense mutation

Answer 4

Occurs when a single base pair in the DNA is changed, resulting in a different amino acid being produced

Question 5

Nonsense mutation

Answer 5

Occurs when there is a change in a single base that changes a codon for an amino acid into a stop codon (normally creating a shorter polypeptide chain)

Question 6

Silent mutation

Answer 6

Occurs from a change in a single base that leads to the mRNA codon being different but not the amino acid produced. This is due to redundancy (multiple codons code for a single amino acid)

Question 7

Frameshift mutation

Answer 7

Insertion or deletion of one or more bases that changes the reading frame of the codons and therefore the amino acids produced (changes the sequence and the # of bases)

Question 8

What is a de novo mutation?

Answer 8

A change in the DNA that has arisen for the first time ever because of a mutation in a germ cell (it was not inherited from the parent)

Question 9

Deleterious mutation

Answer 9

Any mutation that decreases fitness (it makes it harder for the organism to survive or is just entirely lethal)

Question 10

Does mutations increase or decrease genetic variance?

Answer 10

Increase

Question 11

DNA endonuclease vs DNA exonuclease

Answer 11

Endonuclease removes bases on the inside of a damaged strand for DNA polymerase to go back and add the correct bases. Exonuclease removes bases from the ends or “outside” of the strand

Question 12

Homologous recombination repair

Answer 12

Uses the undamaged DNA of a homologous strand as the template for a repair

Question 13

Nucleotide excision repair

Answer 13

Repair process that removes DNA damage caused by radiation, chemicals, and other mutagens

Question 14

Base excision repair

Answer 14

Repair process that removes DNA damage caused by induced mutations

Question 15

Non-homologous end joining

Answer 15

An error prone repair process that ligates two broken DNA ends together regardless of homology

Question 16

DNA mismatch repair

Answer 16

Process that repairs incorrectly or “mismatched” bases