MCB 2400 UCONN FINAL EXAM

SNP

single nucleotide polymorphism

SINGLE BASE CHANGE IN A REGION OF DNA

STR/VNTR

Short tandem repeat/ Variable number tandem repeat

there is a number of repeats in a row

restriction endonucleases

cut (digest) DNA at or near specific recognition sites

DNA probe

fragment of DNA that can be radioactively labeled

DNA fingerprinting

the idea of looking at a combination of all the different bands

Alec Jeffreys

father of DNA fingerprinting

Allele:

alternate sequence at a particular locus

locus/gene:

particular position or location on a chromosome

mitochondrial DNA

small circular DNA is resistant to damage

haplotype

combination of alleles on the same chromosome that tend to be inherited as a group

segregation and independent assortment

alleles segregate into separate gametes and sort independently of other alleles

recombination

information transfer between the chromosomes

how many chromosome pairs does a human have?

23 pairs

how many autosomes does a human have

22 pairs, 44 autosomes

what is the goal for mitosis

to make two genetically identical daughter cells (2N --> 2N)

what is the goal for meiosis

to make haploid gametes.

sexual reproduction.

germ cells specialized for reproduction.

have only one copy of the genome

2N--> N

homologous chromosomes

have the same genes at the same loci but could have different alleles

sister chromatids

one half of the duplicated chromosome

tetrad

4 chromatids that come in contact with another: two NON- sister chromatids recombine and "switch places"

pseudoautosomal region:

sequence similarity at the telomeres that allows for them to recognize one another during meiosis

barr bodies:

inactive X chromosome in a female somatic cell

How many barr bodies does a normal male have?

0

how many barr bodies would you expect to see in a normal female?

2

Turner's syndrome

female has a missing x chromosome

0 barr bodies

poor breast development, under-developed ovaries

What is klinefelter's syndrome

a male has an extra X chromosome

1 barr body

under developed testes

breast development

Translocations

movement of genetic material between non homologous chromosomes

difference between this and crossing over is crossing over is necessary for recombining alleles, translocation is a MUTATION

reciprocal translocations

equal exchange between genetic material

nonrepicprocal translocations:

"i give you something but you don't give me anything back"

unequal exchange between genetic material

robertsonian translocations:

break points associated with centromere and fusing of q arms of non homologous chromosomes

chromosome inversions

order of alleles changes (linkage group changes)

LIKE FLIPPING IT

cohesins

responsible for keeping the sister chromatids together

uniparental disomy

when a person receives two copies of a chromosome from one parent and no copies from the other parent

ex. Prader Willi and Angleman

penetrance

percentage of individuals with a particular genotype that express the expected phenotype

incomplete penetrance

genotype does not produce the expected phenotype

expressivity

degree to which a character is expressed

proband

a person serving as the starting point for the genetic study of a family

dominant mode of inheritance

affected child must have at least one affected parent

recessive mode of inheritance

affected child does not have to have affected parent

mitochondrial mode of inheritance

passed from mother to all her children

y-linked mode of inheritance

passed from father to all his sons

autosomal mode of inheritance

equal genders are affected

x-linked mode of inheritance

unequal genders are affected

hemizygous

only one copy of a chromosome is present

[copy of gene is deleted]

all genes on X chromosome of a male are hemizgyous

twin studies:

examine the concordance of a trait between members of a twin pair

heritability

genetic variance divided by phenotypic variance

estimate the proportion of the phenotypic variation in a population due to genetic differences

concordance

presence of the same trait in both members of a pair of twins

tumor supressor gene

inhibits the cell cycle from progressing

2 hits

proto-oncogenes

promotes the cell cycle from progression

oncogene:

gene that under certain circumstances will transform from a cell into a tumor cell

genomic integrity gene

normally functions in DNA damage repair

retinoblastoma

cancer of the retina

what are the tumor supressor genes?

p53 and RB1

what is the function of the p53 gene

important in apoptosis

what is the function of the RB1 gene

functions at the G1 to S checkpoint,

halters cell growth

Li Fraumeni Syndrome

germline mutations in p53

Half of the p53 will be functional half be not be functional

Spontaneous cancers

requires two independent mutations

hereditary cancers

germline mutation in a tumor supressor gene > inherited and affects all cells

requires a second mutation

Human papillomavirus (HPV)

-can cause cancer (cervical, vuluar, vaginal, penile, and anal)

-type of strain determines whether you get warts or cancer

-it is transmitted through skin contact (sexually)

helicobacter pylori

bacteria responsible for causing ulcers

causes general inflammatory stress

passenger mutation

found within cancer genomes

not contributed to cancer development

driver mutations

casually implicated in oncogenesis

growth advantage on the cancer cell

genetic linkage

when genes are located close to each other on the same chromosome and crossing-over during meiosis is needed to generate different allele combinations

recombination frequency

tells us how far apart two loci are on a chromosome

what is the equation for recombination frequency

# of recombinants

-----------------------

total offspring

what does recombination frequency also provide us with

genetic distance measured in centiMorgans or mapunits

Genome wide Association Studies (GWAS)

way to scan the entire genome for mutations

uncover differences between patients and controls

recombinant DNA

DNA that has formed artificially from such thing as cloning

Gene Therapy

correction of genetic disease by transfer of normal version of the gene into patient's somatic cells

dideoxy/sanger sequencing

has dNTPs and colored ddNTPs to determine the identity/ order of the bases in a DNA molecule

read bottom to top (smallest to largest)

only one primer

Next generation sequecing

determines the bases in a DNA molecule by using synthesis

RNA sequencing:

(aka shotgun sequencing)

uses next-generation sequencing (NGS) to reveal the presence and quantity of RNA in a biological sample at a given moment in time. RNA-Seq is used to analyze the continually changing cellular transcriptome

transcriptome: the sum total of all the messenger RNA molecules expressed from the genes of an organism

Exome sequencing:

sequencing all expressed genes in a genome(aka all the genes in the exome which is all the exons since introns are removed) [you can focus only on protein coding regions]

What three general characteristics must the genetic material possess?

capacity for change (mutation)

storage for a lot of information(code for all traits)

chemical/genetic stability(faithful copies)

What are the pyrimidines?

cytosine and Thymine

what are the purines?

adenine and guanine

how many rings do pyrimidines have?

1

how many rings do purines have?

2

what do hyrdrogen bonds link?

nitrogenous bases

what do covalent bonds link?

nucleotides to nucleotides

how many hydrogen bonds does A&T have

2

how many hydrogen bonds does G&C have

3

when does replication occur?

S phase

Denaturation

heating up to break the hydrogen bonds

annealing

cooling down so the primers can be added

elongation

heating back up so taq polymerase can be recruited and add nucleotide bases

when does transcription occur?

all throughout interphase

what is another name for a transcription unit?

a gene

2 ways the structure of an RNA molecule differs from a DNA molecule

ribose vs deoxyribose

single stranded vs double stranded

is the promotor incorporated into the mRNA transcript?

no

is the sequencing primer incorporated into the synthesized fragment?

yes

what modifications would the mRNA strand need for transcription to occur?

5'cap (recruit ribosome for translation)

remove introns

3 poly a tail (stability)

what does TBP stand for

TATA binding protein

What are the two categories for the molecular change mutation?

point mutation/base substitution

insertion/deletion

what are the classes of point mutation/base substitution

transition or transversion

what occurs in a transition

a purine changes for another purine

a pyrimidine changes for another pyrimidine

what occurs in a transversion

a purine changes for a pyrimidine and vice versa

what is a missense point mutation

change in the entire amino acid

what is a nonsense point mutation

a premature stop occurs

what is a silent point mutation

there is no change in the amino acid

what happens when there is an insertion/deletion of a multiple of 3

an amino acid gets either inserted or deleted