radiation effect

Question 1

3 Principal observable effects that may result from irradiation of DNA

Answer 1

cell death, malignant disease,
genetic damage

Question 2

+ rejoining and healing of the broken ends of the chromosome
+ No damage to cell

Answer 2

restitution

Question 3

+ It is the joining of 2 chromatids without a centromere

Answer 3

Acentric chromosome

Question 4

joining of two chromatids with centromeres.

Answer 4

Dicentric chromosome

Question 5

+ It is the joining of an acentric
fragment from one chromosome to the fragment containing the centromere of the other chromosome. Normal appearing chromosome but there is a change in its gene sequence.

Answer 5

Translocation

Question 6

Chromosome appears normal, and
contains an original number of genes and DNA, however, the sequence of bases has been altered.

Answer 6

double break effect

Question 7

Process where the fragments between the breaks are deleted.
- Deleted fragments are lost during cell division
- The acentric fragment will join with the fragment with centromere to form a normal-looking chromosome but lacking in genetic material

Answer 7

deletion

Question 8

fragment with broken ends turns around and rejoins thereby reversing its position on the chromosome.

Answer 8

inversion

Question 9

• results when broken ends of the fragment with the centromere move about and twist before joining.

Answer 9

ring chromosome

Question 10

types of cell death

Answer 10

interphase death
mitotic (genetic) death
mitotic delay
reproductive failure
Interference with function

Question 11

Cell death before entering mitosis

Answer 11

interphase death

Question 12

programmed cell death

Answer 12

apoptosis

Question 13

Occurs when a cell dies after one or more divisions
- Even relatively small doses of radiation can cause this type of cell death.

Answer 13

mitotic death

Question 14

• failure of the cell to start dividing on time

Answer 14

mitotic delay

Question 15

results from exposure of cells to doses of ionizing radiation in the range of 1 to 10Gy.
- The cell does not die, it permanently loses its ability to procreate but continues to metabolize and also to synthesize nucleic acids and proteins.
- termination of the cell’s reproductive abilities does, however, prevent the transmission of damage to future generations of cells.

Answer 15

reproductive failure

Question 16

• Permanent or temporary interference with cellular function independent of the cell’s ability to divide can be brought about by exposure to ionizing radiation
• If repair enzymes are able to fix the damage, the cell can recover and continue to function

Answer 16

Interference with function

Question 17

INDIVIDUAL RADIATION EFFECTS

Answer 17

I. Short-Term SomaticEffects
II. LongTerm SomaticEffects
III. Stochastic (probabilistic) effects
IV. Non-Probabilistic (Deterministic) Effects
V. Genetic Effecfs

Question 18

referred to as the statistical response
- Increasing the dose increases the probability of damage, but the
severity of the effect is independent
of the dose

Answer 18

Stochastic (probabilistic) effects

Question 19

• It is formerly called non-stochastic effect
• It is thought to be a threshold, as there are doses below which the effect is not observed
• The examples are radiation burns, cataracts, erythema, fibrosis, and hematopoietic damage
• The increase in severity with dose, and thus are considered to be threshold

Answer 19

Non-Probabilistic (Deterministic) Effects

Question 20

effects of radiation on the embryo and fetus depend on the stage of development and the radiation dose.

Answer 20

genetic effects

Question 21

Of these 23 pairs, 22 pairs are nonsex chromosomes

Answer 21

autosomes

Question 22

male () or female ().

Answer 22

XY, XX

Question 23

Change in a number of individual
chromosomes but not in a complete set.

Answer 23

aneploid conditions

Question 24

also referred to as congenital ovarian
hypoplasia syndrome,
- was first described by ____, an
Oklahoma physician in 1938.

Answer 24

turner syndrome, henry turner

Question 25

(trisomy 21) - A genetic disorder caused by the presence of all or a portion of a third chromosome 21.

Answer 25

down syndrome

Question 26

● It means that a single copy of the mutated gene (from one parent) is enough to cause the disorder.

Answer 26

Dominant Gene mutations

Question 27

● It means that a single copy of the mutated gene (from one parent) is enough to cause the disorder.

Answer 27

Dominant Gene mutations

Question 28

abnormal (mutated) gene is located on one of the first 22 pairs of chromosomes(autosomes). You need only one copy of the abnormal gene to be affected by this type of disorder.

Answer 28

autosomal dominant disorder

Question 29

- condition that stops parts of the brain from working properly over time. It's passed on (inherited) from a person's parents. - It gets gradually worse over time and is usually fatal after a period of up to 20 years.

Answer 29

huntington’s disease

Question 30

- caused by a defect in the gene that enables your body to produce a protein that helps give connective tissue its elasticity and strength. - inherit the abnormal gene from a parent who has the disorder. Each child of an affected parent has a 50-50 chance of inheriting the defective gene. - Finger length - Typically have especially long fingers. It's common for their thumbs to extend far beyond the edge of their hands when they make a fist.

Answer 30

marfan disease

Question 31

- you inherit two changed genes (mutations), one from each parent. These disorders are usually passed on by two carriers. - Their health is rarely affected, but they have one changed gene (recessive gene) and one unaffected gene (dominant gene) for the condition.

Answer 31

RECESSIVE GENE MUTATIONS

Question 32

- as related to genetics, refers to characteristics(or traits) that are influenced by genes carried on the sex chromosomes. - In humans, the term often refers to traits or disorders influenced by genes on the X chromosome, as it contains many more genes than the smaller Y chromosome.

Answer 32

SEX-LINKED GENE MUTATIONS

Question 33

refers to when a gene controlling a characteristic is located on a sex chromosome (X or Y)

Answer 33

sex linkage

Question 34

Y chromosome is much _____ than the X chromosome and contains only a few genes

Answer 34

shorter, (50 million bp; 78 genes)

Question 35

X chromosome is ___ and contains many genes not present on the Y chromosomes

Answer 35

longer (153 million bp ;~ 2,000 genes)