Neurogenetics

Question 1

what is a pecometre?

Answer 1

trillionths of a metre

Question 2

how many pairs of nucleotides are in one’s genetic code?

Answer 2

3 billion

Question 3

what is a genome?

Answer 3

someone’s genetic code

Question 4

what are the building blocks of proteins?

Answer 4

methionine?

Question 5

what are the building blocks of genetic code?

Answer 5

nucleotides or bases

Question 6

what are the 4 different bases in DNA?

Answer 6

adenine, cytosine, guanine, and thymine

Question 7

what are amino acids/what do they do?

Answer 7

they are the building blocks of proteins

Question 8

what happens to proteins?

Answer 8

they are encoded by one’s genetic code

Question 9

what constitutes the genetic code for a particular amino acid?

Answer 9

a specific sequence of 3 building blocks

Question 10

what is gene transcription?

Answer 10

the gene is read out into a protein

Question 11

how many bases are in the whole human genome?

Answer 11

3 billion

Question 12

how many genes in a human code for proteins?

Answer 12

20-25 thousand

Question 13

how do genes always pair?

Answer 13

cytosine always with guanine C-G

adenine always with thymine A-T

Question 14

t or f, the dna helix is double stranded ?

Answer 14

true

Question 15

What is dna bundled into in cells?

Answer 15

chromosomes

Question 16

how many chromosomes does the human karyotype consist of? what is the make up?

Answer 16

46
22 pairs of autosomal chromosomes
two sex chromosomes

Question 17

XX sex chromosomes are….

Answer 17

female

Question 18

what determines how proteins interact with other proteins in the body?

Answer 18

how the proteins are folded

Question 19

the function of a protein is determined by what?

Answer 19

its structure

Question 20

what is the structure of a protein determined by?

Answer 20

its sequence of amino acids

Question 21

an amino acid is represented in the genetic code by what?

Answer 21

a sequence of three bases

Question 22

what is a sequence of 3 bases called?

Answer 22

a codon

Question 23

true of false, each amino acid has only one codon that can represent it

Answer 23

false

Question 24

t or f, a change to a single base in a codon cannot change an amino acid

Answer 24

false

Question 25

what codons represent alanine, name 4

Answer 25

GCT, GCC, GCA and GCG

Question 26

t or f, changing the amino acid cannot change the structure and function of the protein

Answer 26

false

Question 27

what is a single nucleotide polymorphism

Answer 27

a position on the genome where the base differs between individuals or between chromosomes within same individuals

Question 28

what are the alternative bases of an SNP called?

Answer 28

alleles

Question 29

what is an individual's genotype at a SNP determined by?

Answer 29

the two alleles on the two copies of the chromosome

Question 30

what is a phenotype

Answer 30

the presence, absence or value of a trait of interest

Question 31

what are the 4 types of structural genetic variants?

Answer 31

insertion - deletion - block substitution - inversion - copy number

Question 32

what happens to bases in an insertion deletion variant?

Answer 32

bases are added or are missing

Question 33

what happens to bases in an block-substitution variant?

Answer 33

multiple bases are substituted

Question 34

what happens to bases in an inversion variant?

Answer 34

bases are replaced with the reversed sequence from the other stand

Question 35

what happens to bases in a copy number variant?

Answer 35

sequence of bases are repeated one or more times

Question 36

what is a mutation?

Answer 36

something that is rare (less than 1% of alleles in pop)

Question 37

what is a polymorphism?

Answer 37

something that is common (more than 1% of alleles in pop)

Question 38

where does the gene XIST live

Answer 38

on the X chromosome

Question 39

to avoid excess dosage of x chromosome proteins in females, what happens?

Answer 39

one copy of the x chromosome in each cell is silenced or inactivated

Question 40

in many mammals, the process of silencing one x chromosome in each cell is random, true or false

Answer 40

true

Question 41

what is an RNA transcript?

Answer 41

an intermediate step in the process of converting a gene encoded in DNA to a protein

Question 42

what functionally happens when two x chromosomes are in one cell?

Answer 42

XIST gene produces RNA transcript that coats one chromosome, which is then inactivated

Question 43

what is a barr body?

Answer 43

an inactive chromosome

Question 44

what does TSIX do ?

Answer 44

produces RNA transcript that suppresses transcription of XIST

Question 45

what are antisense partners?

Answer 45

encoded by same stretch of DNA but transcribed in opposite directions

Question 46

what is the classical equation in heritability? | what do all terms refer to?

Answer 46

``` P = G + E p = phenotypic variance G = variance from Genes E = variance from environment ```

Question 47

what is missing from classical heritability equation?

Answer 47

variance from gene and environment interaction | and covariance between genes and environment

Question 48

what is covariance between genes and environment?

Answer 48

how some genetic variance are more likely to exist in certain environments

Question 49

what is heritability?

Answer 49

it is the proportion of phenotypic variability that can be attributed to variance from genes

Question 50

what are two key things about heritability?

Answer 50

that it is an estimate of a specific population at a specific time

Question 51

before molecular genetics, how did we measure heritability?

Answer 51

genetic epidemiology

Question 52

what does genetic epidemiology rely on?

Answer 52

the fact that related individuals share a predictable amount of genetic material

Question 53

what are concordance rates?

Answer 53

if one twin has a trait, does the other twin possess it?

Question 54

what are MZ twins, what are DZ twins? | how much genetic inheritance is shared ?

Answer 54

``` MZ = monozygotic = 100% DZ = dizygotic = about 50% ```

Question 55

what do dominant traits require for expression of the phenotype?

Answer 55

mutation on one copy of the chromosome

Question 56

what do recessive traits require for expression of the phenotype?

Answer 56

mutation on both copies of the chromosome | exception, male sex chromosome as there is only one

Question 57

what can be inferred from a pedigree chart?

Answer 57

modes of inheritance

Question 58

how are males v females and affected v unaffected represented in pedigrees?

Answer 58

filled in circle = affected female outlined circle = unaffected female filled in square = affected male outlined square = unaffected male

Question 59

what bases repeat in the FMRI protein?

Answer 59

CCG

Question 60

what triggers a process of methylation?

Answer 60

the large increase of the CCG repeat in the FMRI protein

Question 61

what is FMRI essential to?

Answer 61

the strength and capabilities of synapse | also its plasticity

Question 62

what is fragile x syndrome?

Answer 62

a monogenic disorder that results from a copy number variant in the 5 untranslated region of the FMRI gene

Question 63

what is a monogenic disorder?

Answer 63

a disorder that can be trace to a single gene

Question 64

what does the 5 untranslated region of a gene contain?

Answer 64

the promoter region where chemicals bind to start the process of transcribing a gene into a protein

Question 65

what are the 4 quadrants of modes inheritance using pedigree maps?

Answer 65

dominant - recessive | autosomal - x linked

Question 66

what can dominant traits not do?

Answer 66

cannot skip generations

Question 67

in recessive traits, two affected parents cannot have unaffected offspring, t or f?

Answer 67

True

Question 68

true or false, autosomal disorders are equally common in both sexes

Answer 68

true

Question 69

do sons ever receive the x chromosome from their father?

Answer 69

no they can only receive the y chromosome

Question 70

if daughter of an affected father has to be affected, what sort of trait is this? and why is this the case?

Answer 70

x linked | because a daughter has to get her fathers X chromosome

Question 71

what is a must of an x linked recessive trait?

Answer 71

father of affected daughter must be affected

Question 72

x linked recessive disorders are more common in males or females?

Answer 72

males

Question 73

what are some monogenic disorders

Answer 73

huntington's and fragile x syndrome

Question 74

what are polygenic disorders?

Answer 74

where there is no single gene that causes a certain disorder or influences cog outcomes

Question 75

what do genome wide association studies examine?

Answer 75

the statistical association between a phenotype and many SNP markers throughout a genome

Question 76

how many markers do GWAS typically look at

Answer 76

500,000 to 2,000,000 markers

Question 77

what does linkage disequilibrium allow?

Answer 77

allows us to observe indirect associations, allowing us to sample common variation sparsely