Lec 12-2

Question 1

Traits and gene expression are affected by

Answer 1

Environment the organism develops and resides in

Question 2

Gene-environment interaction

Answer 2

Helps understand major challenges in genetics

Question 3

Useful tools for human genetics

Answer 3

Twin studies

Adoption studies

Question 4

Monozygotic twins

Answer 4

Identical twins

Results from a single egg fertilized by a single sperm

Embryo splits on into two, making two identical people

Genetically identical

Question 5

Dizygotic twins

Answer 5

Non-identical twins

Occurs when two separate eggs are fertilized by two different sperm

Produces two genetically distinct zygotes

Only share 50% of their genome

Question 6

Comparing dizygotic and monozygotic twins

Answer 6

Genes could be different but environment is the same

Comparing frequency of traits between these twins allows us to asses importance of genetics and environment

Question 7

Concordant

Answer 7

Both twins have a trait

Question 8

Discordant

Answer 8

Twins do not share a trait

Question 9

Traits strongly controlled by genes have higher concordance in

Answer 9

Monozygotic twins

Question 10

Environmentally influenced traits should have

Answer 10

Similar concordance between both types of twins

Question 11

Asthma twin study

Answer 11

Higher concordance in monozygotic twins therefore there is a genetic component

Question 12

Adoption studies

Answer 12

Finds environment effect on traits

If adopted child and parents have a similar trait, these similarities can be attributed to the environment

If adopted child and biological parents share a trait, these similarities can be attributed to genetics

Question 13

BMI adoption study

conclusion

Answer 13

Genetic factors influence BMI

Question 14

Genetic counseling

Answer 14

Provides info to patients
with genetic disorders and other concerned about hereditary conditions

Extensive testing is done before appropriate treatment is given

Question 15

Genetic testing allows people to

Answer 15

1. make informed choices about reproduction
2. intervene/prevent development of a condition
3. alleviate anxiety associated with uncertainty

Question 16

Testing is either done

Answer 16

Prenatal or postnatal

Question 17

Prenatal genetic testing

Answer 17

Currently includes procedures to diagnose hundreds of genetic disorders and disease

Allows family to make difficult decisions during pregnancy with afflicted child

Question 18

Ultrasonography

Answer 18

High frequency sound is beamed into uterus, bouncing back and indicating density of tissue

Non invasive

Question 19

Ultrasound can identify

Answer 19

• neural tube defects
• skeletal abnormalities
• developmental disorders

Question 20

Amniocentesis

Answer 20

Traditional prenatal testing required fetal tissue

Fetal cells cultured and then used for various tests

invasive

Question 21

Amniocentesis disadvantage

Answer 21

Cannot be done till later on in pregnancy (15-18th week)

Cell culturing takes more time

Question 22

Chorionic Villus Sampling (CVS)

Answer 22

Prenatal testing that can be done earlier (10th-12th week)

Collects larger amounts of fetal tissue

Chorion contains fetal cells but is not part of fetus

Question 23

Non-invasive screening

Answer 23

Uses only maternal blood

Also includes non-invasive prenatal screenings (NIPS)

Question 24

NIPS

Answer 24

Examine fetal DNA found in maternal blood

Performed 9-10 weeks into pregnancy

Question 25

How do you analyze the fetus’s DNA from the mother’s blood?

Answer 25

During pregnancy, a few fetal cells are released into the mother’s
circulatory system

Question 26

Newborn Screening

Answer 26

Postnatal testing for genetic disorders in newborn infants

Question 27

Pharmacogenetic testing

Answer 27

Postnatal genetic testing can help guide drug treatment

Question 28

Someone’s genotype can influence

Answer 28

Drug effectiveness

Chances of adverse drug reactions