Notes #3

Question 1

Miotic Recombination

Answer 1

the combination of parental genes not found in the parent organisms through mitosis (often as a result of radiation)

Question 2

Ionizing Radiation

Answer 2

(x-rays, radioactivity) ionize molecules at random throughout cells (severe damage breaks covalent bonds)

Question 3

U.V. Radiation

Answer 3

absorbed by specific molecules

Question 4

“Target”

Answer 4

cell components most sensititve to damage (DNA)

Question 5

Ionizing Radiation (Damage)

Answer 5

separates or breaks double-stranded structure of DNA (no replication)

Question 6

U.V. Radiation (Damage)

Answer 6

selectively absorbed by purine and pyrimidine bases (more concentrated radiation)

Question 7

U.V. rays form ______.

Answer 7

dimmers (T-T, C-C, T-C covalent bonds that prevent cell replication)

Question 8

Radiation repair

Answer 8

before too much O2 and O3 production —–> greater radiation

Question 9

Photoreactivation (repair)

Answer 9

when U.V. damaged cells are exposed to visible light. They use the energy to produce enzymes that reverse the formation of dimmers

Question 10

Excision Repair

Answer 10

sequence of events that remove damaged DNA, then resynthesize the missing portion (mutations often occur during messed up resynthesis of DNA)

Question 11

Lethal effects of radiation

Answer 11

DNA damaged not repaired before DNA replication (cell dies)

Question 12

Reproductive Death

Answer 12

When a cell can divide to form viable, but mutated offspring

Question 13

Metabolic Death

Answer 13

when cells are killed outright