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Flashcards in e x a m II Deck (48):
1

incomplete dominance

heterozygous allele is intermediate
Hh = pink. intermediate between red & white

2

codominance

expression of both alleles as heterozygote
both A & B are dominant in blood type

3

recessive lethal alleles

AyAy = lethal
AyA = yellow
AA = black
WOULD be 3:1 ratio, but is only 2:1 due to lethality.

4

pleiotropic traits

one gene affects many traits
-hormone binding receptors

5

polygenic traits

many genes affect a trait
- height in humans
9:3:3:1 ratio

6

complementation

two organisms have 2 dif mutations
occurs when they are on DIFFERENT genes
9:7 ratio

7

penetrance

% of individuals who exhibit the phenotype of that allele

how many people get breast cancer with a BRCA-1 gene mutation

8

expressivity

the degree to which phenotype is expressed (intensivity)

different shades of blue

percent of volume ejected from the heart w/ CHF

9

how can someone with an allele for a trait or disease not develop the disease?

there are many factors that contribute to expressivity & penetrance. having the allele doesn't necessarily guarantee it will be expressed

10

griffith & avery's experiments

s-strain bac transforms r-strain back into a-strain bac.
dna is transforming agent.

11

hershey-chase experiment

used sulfur first; no radioactive in bac (protein)
used phosphorus; radioactivity found in bac (DNA) concluding it's the agent necessary dot production of new phages

12

components of dna

deoxyribose sugar, phosphates, nitrogenous bases

13

purines

A & G

14

pyrimidines

T & C

15

how is a single strand of DNA formed?

phosphodiester bonds between adjacent nucleotides
aka sugar-phosphate backbone

16

dna shape

double helix with complimentary anti-parallel strands

17

base pairing

A-T
C-G

18

dna replication is...

semi conservative

19

meselson-stahl experiment

used different densities of N (14 & 15)
created an intermediate band between 14 & 15 in test tube after centrifuging

consistent with semiconservative hypothesis

20

how does dna replication begin?

DNA polymerase catalysis synthesis
starts at RNA primer

21

what direction is DNA synthesized in?

5'-->3' direction

leads to leading & lagging strand replication

22

DNA polymerase III

elongates RNA primers with new DNA

23

DNA polymerase I

removes RNA @ 5' end fragment; fills gap

24

primase

synthesizes a stretch of RNA complementary to that specific region of the chromosome

25

DNA ligase

joins the gap-filling dna to ogazaki fragment

26

telomerase

adds short repeats to 3' ends of DNA (overhang on end of DNA; telomere)

27

helicase

disrupt H bonds; unzips double helix

28

topoisomerase

removes super-coiled regions of dna allowing them to rotate

29

rna is...

the intermediate between DNA & protein

30

RNA polymerase is similar to...

DNA polymerase

31

differences between RNA & DNA:

RNA uses Uracil instead of Thymine
ribose is rna's sugar; deoxyribose is dna's sugar
dna is double stranded; rna is single stranded
dna does not have any catalytic activity

32

which direction does rna polymerase synthesize rna?

5'-->3'
dna is template

33

rna synthesis
intitiation:

rna binds to promoter

34

rna synthesis:
elongation-

rna polymerase synthesizes complementary strand of rna

35

rna synthesis:
termination-

terminators signal the end of the polymerase is done.
releases rna from rna polymerase

36

TATA box

site of first event in transcription- TATA-binding protein binding (lol)

37

TATA-binding protein

when bound, it attracts other GTFs to form pre-initiation complex

38

GTFs

general transcription factors; bind before RNA polymerase II to ATTRACT it to start transcription

39

RNA polymerase II

transcribes all protein-encoding genes
transcribes some snRNAs

40

carboxy tail domain

Allows other proteins to bind to RNA

41

is prokaryotic rna functional after transcription?

yes, immediately after transcription

42

is eukaryotic rna functional after transcription?

no, it requires further processing before it is translated into a protein

43

which end is capped?

5' by methylguanosine

44

what does splicing do?

remove introns, glues extrons together

45

where is the polyA tail added?

the 3' end

46

alternative splicing?

different proteins are made from the splicing together of different combinations of exons

47

snRNAs

small nuclear RNAs
Small protein localized in the nucleus
Bind to areas in the intron to recruit snRNPs

48

SnRNPs

Small nuclear ribonucleoproteins
Complexes of protein and one of 5 snRNAs
Help align splice sites at either end of an intron
Cleaves off the intron
Exon is ligased together