genetics

Question 1

genetics link with disease

Answer 1

most diseases have both a genetic and environmental components, lots of evidence for genetics is found through studies on twins eg. monozygotic and dizygotic twins

purely genetic diseases are very rare except in marriages of close relatives (eg. pedigree dogs)

Question 2

genetic disease prevention

Answer 2

-more testing before birth (before having siblings)
-introduction of gene editing (lots of ethical moral and safety issues)

Question 3

trait

Answer 3

inhertible characteristic

Question 4

phenotype

Answer 4

variant of characteristic in individual (different hair colours)

Question 5

mutation

Answer 5

change in gene (mostly negative impact)

Question 6

allele

Answer 6

one of the different variants of gene

Question 7

polymorphisms (variants)

Answer 7

differences in the DNA between alleles (can be harmful on non harmful)

Question 8

genotype

Answer 8

combination of alleles in the DNA sequence on individual

Question 9

x linked

Answer 9

males only have one X chromosome the recessive alleles o the X chromosome effect them more often, x linked mutations have a sex bias (e.g colour blindness)

Question 10

autosomal chromosomal

Answer 10

non sex chromosome

Question 11

mitochondrial mutations

Answer 11

mitochondrial mutations are inherited from the mother only because the mitochondrial genomes are entirely inherited from your mother. mitochondria are frequently involved in drug metabolism. there is about 10-20 copies. some embryos have different variants as the mitochondrial genome is speared differently.

can add an unaffected persons mitochondrial DNA as resplacement off the mothers poorly effected DNAn (effectively a three parent baby)

Question 12

human genetics is not actually that clean cut…

Answer 12

-sometimes having gene variants make it more like but not certain you will have a disease

-most common diseases involve variants in multiple genes

-also different alleles in the same genes that causes diseases

Question 13

difference in gene variants in mitosis and meiosis

Answer 13

-gene variants on the same chromosome stay linked together in mitosis

-gene variants can be recombined, due to to crossing over and rearrangement

Question 14

how are genes mapped

Answer 14

genetic mapping is based on linkage that how close genes are on the same chromosome they will be more likely to be inherited together.

two genes are very close to each other on the chromosome, they are less likely to be separated by meiotic recombination

need family trees to study tis most modern families too small. so we need genome wide studies and sequencing entire population

Question 15

the genomic revolution

Answer 15

-massively spend up mapping genes

-can start predicting disease likelihood

-currently two bottle necks:

-obtaining enough DNA samples (with good clinical data and patient permissions. lots of ethical issues (can uses for non positive things like companies getting money)

-analyinsing the huge amount of data

Question 16

the human genome

Answer 16

it is diploid, we have 46 chromosomes, 44 are autosomal and 2 are sex chromosomes . (23 pairs of chromosomes)

-mitochondria have their own small genome.

• 25,000 protein coding genes
• mans have 6 billion base pairs in total, which are organized into 46 chromosomes (23 pairs).

-0.1 variable between humans (the rest is genetically the same)

Question 17

the empty genome

Answer 17

• question is why is a genome so big when we only have 25,000 protein coding genes 1.6% codes.

-most of our DNA is transcribed into RNA so the rest isn’t actually junk (although some are very unstable) also lots of DNA hasn’t correctly been identified so it has other roles eg. micro RNA that has regulatory roles

-also promoter or repressor elements that are not transcribed but have siqnificant role in regulation

Question 18

what is a pharmacogenetics variant

Answer 18

it is a polymorphism that is linked to the efficacy or toxicity of a drugs. how genetic make up influences response to drugs . this is influencing development of personalised medicines

can be inherited in a dominated recessive, x linked or mitochondrial fashion

Question 19

Example one polymorphism in the mitochondrial ribosomal RNA is linked to deafness after treatment with aminoglycoside antibiotics

Answer 19

mutations in the 12S ribosomal RNA genes are the mitochondrial ribosomes sensitive to ahminoglycosides meaning it effects the human ribosome.

-very high risk of deafness
-passed down maternal line
-or the mutation can just arise

germ line

Question 20

aminoglycoside antibiotics

Answer 20

are antibiotics that act on bacterial ribosomal RNA

Question 21

poor life style leads to…

Answer 21

more mutations.

Question 22

somatic cells

Answer 22

body cells not inherited by children, this is where most mutations happen .
the mostly cause cancer

Question 23

germline mutation

Answer 23

mutation of the gametes that can be passed down

Question 24

mutations in kinases link to cancer

Answer 24

mutations in kinases are strongly linked to cancer. Kinases are enzymes that play a crucial role in regulating various cellular processes, including growth, division, and survival. They work by transferring phosphate groups from ATP to other molecules, a process called phosphorylation, which helps activate or deactivate proteins involved

Question 25

the Philadelphia chromosome abnormality results from translocation in somatic cells

Answer 25

-if part of chromosome 9 moves on to chromosome 22 is generates a new fusion gene in a blood stem cell that generates a tyrosine kinase that causes leukaemia . dominate mutation its somatic and an example of cancer genetics can be treated with a tyrosine kinase inhibitor

Question 26

genetic testing

Answer 26

-developing very fast but our understanding is not developing fast enough so we not understand what the differences and polymorphisms mean. -no resources for genetic counselling -cant relay the info in a clear way for patients