Lecture 24: the human genome & disease

Question 1

mutations are…

Answer 1

permanent changes to the DNA sequence

Question 2

mutations can be…

Answer 2

inherited or acquired

Question 3

mutations that are inherited are called…

Answer 3

germline mutations

Question 4

germline mutations are passed on via…

Answer 4

the gametes (sperm/eggs)

Question 5

mutations xan also be acquired by somatic cells if DNA gets…

Answer 5

damaged or copied incorrectly

Question 6

somatic mutations are ….. passed to the next generation

Answer 6

not

Question 7

genetic variation/mutations are a driving force for…

Answer 7

evolution

Question 8

mutations can have 1 of 3 effects on an organism they are:

Answer 8

• beneficial
• no effect
• deleterious (damageing/harmful) effect on the organism

Question 9

the effect of most mutations is…

Answer 9

no effect

Question 10

outcome of a mutation can also depend on:

Answer 10

• environmental factors

- other genes

Question 11

example of an environmental factor that mutations can depend on:

Answer 11

• diet

- exposure to toxins

Question 12

humans are diploid which means they have…

Answer 12

two copies of each of their genes (one maternal/paternal)

Question 13

a mutation can either be…

Answer 13

heterozygous or homozygous

Question 14

dominant mutation causes…

Answer 14

a phenotype when heterozygous

Question 15

recessive mutation causes…

Answer 15

a phenotype when only homozygous

Question 16

for a mutation to have a phenotype it must…

Answer 16

affect the function of a gene

Question 17

a mutation might break a gene causing it too…

Answer 17

not work as well as normal/or might not work at all

Question 18

mutation that causes a gene not to work as well/work at all is called…

Answer 18

a “loss of function” mutation

Question 19

loss of function mutations are often…

Answer 19

recessive

Question 20

loss of function mutations are usually recessive because…

Answer 20

the second chromosome can replace the loss of function on the defected one

Question 21

a mutation that causes a gene to work too well, or do something unexpected is Called…

Answer 21

a “gain if function” mutation

Question 22

gain of function mutations are often….

Answer 22

dominant

Question 23

gain of function mutations are often dominant because…

Answer 23

they will not be replaced by the normal copy of the gene

Question 24

example of an autosomal recessive mutation

Answer 24

• inability to taste PTC

- cystic fibrosis

Question 25

example of an autosomal dominant mutation

Answer 25

• widows peak

- Huntington’s disease

Question 26

example of an w-linked recessive mutation

Answer 26

haemophilia A/B

Question 27

polygenic disorders involve…

Answer 27

several genes acting together or environmental factors interacting with genes

Question 28

example of polygenic disorders include:

Answer 28

• diabetes

- obesity

Question 29

most genetic disorders are ….. not deterministic

Answer 29

probabilistic