Genetics Exam 2

Front 1

Aneuploidy

Back 1

gain or loss of one or more chromosomes form normal (2n) diploid set

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Nullisomy

Back 2

(2n-2) always lethal and so unkown among live births, because both copies of a particular chromosome types are lost, so all genes on that particular chromosome are completely absent

Front 3

Monosomy

Back 3

(2n-1)usually lehtal in animals unless chromosome involved is a: 1)very small autosome 2)sex chromosome [XO, but YO lethal]

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Tetrasomy

Back 4

(2n+2) usually lethal in animals unless chromosome involved is a sex chromosome (such as XXXX or XXXY)

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Trisomy

Back 5

(2n+1) usually lethal in animals unless chromosome involved is a: 1)sex chromosome 2)very small autosome

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Down Syndrome

Back 6

[trisomy 21 John L. Down] origin of third copy of chromo#21, non-disjunction of this chromosome type during meiosis in either male or female parents (usually female)

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Results of Down Syndrome

Back 7

reduction of IQ, general health and life expectancy. Poor motor control, cheerful personality, broad flat face, fold corner of eyes

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Monosomy 21

Back 8

[presence of only 1 copy of this chromosome type] is non-existnet even though the diagrams of primary and secondary non-disjunction show that meiotic non-disjunction always produces equal numbers of n+1 and n-1 gametes [maternal age effect= higher age: higher chance]

Front 9

Origin of Aneuploidy

Back 9

chromosomal nondisjunction (meiotic accidents: failure of chromosmoes to seperate normally)

Front 10

Polyploidy

Back 10

more than 2 multiples of haploid (n) chromosome set present

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a)Polyploidy in animals and plants

Back 11

rare in animals, common in plants (and important for agriculture)
diploid-2n
triploid-3n(sterile)
tetraploid-4n
pentaploid-5n(sterile)
hexaploid-6n

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b)Polylpoidy origin of extra sets

Back 12

1)autopolyploid
2)allopolyploidy

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1)Autopolyploid
2)Allopolyploidy

Back 13

1)ALL SETS FROM SAME SPECIES double fertilization [polyspermy] producing triploid offspring
2)MULTIPULE SETS FROM AT LEAST 2 SPECIES interspecific hybrization, as in commercial bread wheat, which is an allohexaploid (AABBDD)

Front 14

Variation in Chromosome structure

Back 14

a)Defective chromosome
b)Chromosome heterozygote
c)Balanced and Unbalanced
d)Chromosomes defects arise

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Chromosome Heterozygote

Back 15

is defined to be one normal and one defective

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Defective Chromosomes

Back 16

are heritable-often passed unchanged to offspring

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a)Balanced Chromosomal Mutation
b)Unbalanced Chromosmal Mutation

Back 17

a)no genetic information has been lost but location of certain genes has been altered
b)there is a gain or loss of genetic information compared to the normal situation

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Chromosome Defects

Back 18

arise as a spontaneous double-stranded break or a pair of breaks (broken ends are 'sticky' but don't always re-join properly

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Potential Consequences of a break

Back 19

a)loss of terminal piece(very bad)-unbalanced
b)abnormal reattachment(bad)-balanced
c)normal reattachment of broken pieces (best)-balanced

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Terminal Deletion

Back 20

(normal) ABCDEFoGHI and QRSTUoVWXYZ
(alter) BCDEFoGHI and QRSTUoVWXYZ

Front 21

Intercalary Deletion

Back 21

(normal) ABCDEFoGHI and QRSTUoVWXYZ
(alter) ABDEFoGHI and QRSTUoVWXYZ

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Tandem Direct Duplication

Back 22

(normal) ABCDEFoGHI and QRSTUoVWXYZ
(alter) ABABCDEFoGHI and QRSTUoVWXYZ

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Tandem Inverted Duplication

Back 23

(normal) ABCDEFoGHI and QRSTUoVWXYZ
(alter) ABBACDEFoGHI and QRSTUoVWXYZ

Front 24

Tandem Direct Duplication

Back 24

(normal)ABCDEFoGHI and QRSTUoVWXYZ
(altered)ABABCDEFoGHI and QRSTUoVWXYZ

Front 25

Tandem Indirect Duplication

Back 25

(normal)ABCDEFoGHIand QRSTUoVWXYZ
(altered)ABBACDEFoGHI and QRSTUoVWXYZ

Front 26

Dispersed Direct Duplication

Back 26

(normal)ABCDEFoGHI and QRSTUoVWXYZ
(altered)ABCDEFoGABHI and QRSTUoVWXYZ

Front 27

Dispersed Indirect Duplication

Back 27

(normal)ABCDEFoGHI and QRSTUoVWXYZ
(altered)ABCDEFoGBAHI and QRSTUoVWXYZ

Front 28

Paracentric Inversion

Back 28

(normal)ABCDEFoGHI and QRSTUoVWXYZ
(altered)AEDCBFoGHI and QRSTUoVWXYZ

Front 29

Pericentric Inversion

Back 29

(normal)ABCDEFoGHI and QRSTUoVWXYZ
(altered)ABHGoFEDCI and QRSTUoVWXYZ

Front 30

Reciprocal Translocation

Back 30

(normal)ABCDEFoGHI and QRSTUoVWXYZ
(altered)QRSTCDEFoGHI and ABUoVWYZ

Front 31

Non-reciprocal Traslocation

Back 31

(normal)ABCDEFoGHI and QRSTUoVWXYZ
(altered)QRABCDEFoGHI and STUoVWYZ or ABCDEFoGHI and STUoVWXYZQR

Front 32

(SPECIAL) pericentric inversion AND paracentric inversion

Back 32

a)change chromosome shape [para=parallel]
b)don't involve the centromere, will leave a submetacetric chromosome as submetacentric [peri=around]

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(classically) gene

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1)unit of heredity controls a particular trait
2)unit of transmission b/w generations
3)unit of pheno expression w/in an individual

Front 34

Particulate

Back 34

transmission b/w generations doesn't chnage the nature of the gene (EXCEPT GENE MUTATIONS)

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(Molecular) gene

Back 35

made of DNA but NOT ALL DNA is part of a gene [98% of human genome doesn't code for RNA transcript]

Front 36

Non-coded DNA

Back 36

1)structure element of chromosome [centromere and telomeres]

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EUKARYOTES chromosomes- special protiens

Back 37

histones [structural elements without carrying genetic information]

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DNA

Back 38

deoxyribonueleic acid

Front 39

RNA

Back 39

ribonucleic acid

Front 40

Construction of gene mapping

Back 40

small pieces to overall big piece [cuts down on chance of undetected double crosses]

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Non-coding DNA

Back 41

can't be called alleles because they do segregate during meiosis DON'T produce pheno differences

Front 42

1 map unit or 1% recombination

Back 42

approx equal to 1,000,000 bp of DNA

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haploid gneome contains

Back 43

3 Gb of DNA

Front 44

diploid genome contains

Back 44

6 Gb of DNA

Front 45

4 secrets of DNA sucess

Back 45

a)DNA can be copied for transmission thru a process= replication (during S period interphase)

Front 46

4 secrets of DNA sucess

Back 46

b)DNA carries genetic info and can store in a non-expressed form [a)barr bodies b)sperm cell nuclei c)gene dig enzymes

Front 47

4 secrets of DNA sucess

Back 47

c)Genetic info can change through process of mutatio= alteration, loss or gain of genetic info

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4 secrets of DNA sucess

Back 48

d)Expression of genetic info
[most genes control production of particular proteins through mRNA intermediate but some genes make tRNA or rRNA rather than mRNA

Front 49

3 stop codons

Back 49

UAA, UGA or UAG
[always written 5'-nnn-3']

Front 50

n

Back 50

any nucleotide (A,C,U,G)

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y

Back 51

either pyrimidine (C,U)

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r

Back 52

either purine (A,G)

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Overview of genetic code (9)

Back 53

1)code linear= read left to right (5'--3')

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Overview of genetic code (9)

Back 54

2)each 'word' in mRNA is 3 bases long ONE CODON (3 CONSECUTIVE BASES) SPECIFIES ONE AMINO ACID IN RESULTING POLYPEPTIDE)

Front 55

Overview of genetic code (9)

Back 55

3)with triplet code, there are 4x4x4=46 possible codons, each one with a)specific unambiguous meaning b)meaning maybe context-dependent

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Overview of genetic code (9)

Back 56

4)some amino acids(18 of 20 codons) are specified by more than one codon (degeneracy or redundancy)

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Overview of genetic code (9)

Back 57

5)NOT EVERY naturally occurring amino acid has a place in the genetic code [some BECAUSE OF POSTTRANSLATION MODIFICATION OF PROLINE)

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Overview of genetic code (9)

Back 58

6)NO PUNCTUATION between adjacent codons EVERY DNA OR RNA sequence can be translated according to any of three theoretical reading frames TRANSLATION MACHINERY recognizes the correct reading frame

Front 59

Overview of genetic code (9)

Back 59

7)certain codons specify beginnig (start) and end(stop) of message

Front 60

Overview of genetic code (9)

Back 60

8)codons read in non-overlapping fashion *single base subsitution mutation might alter more than one consecutive amino acid in the plypeptide (DOESN'T HAPPEN)

Front 61

Overview of genetic code (9)

Back 61

9)genetic code is universal SINGLE CODING DICTIONARY used by most a)prokaryotic b)eukaryotic

Front 62

Consequences of synonymy (redundancy) of genetic code (2)

Back 62

1)many third position base subsitutions (mutations) don't alter the amino acid sequence
2)cell doesn't need 61 different tRNAs, each serving a different mRNA codon

Front 63

Synonymous (silent) substitution

Back 63

a mutation in the DNA that results in an altered mRNA swquence but NO CHANGE in the polypeptide sequence

Front 64

mRNA
tRNA
rRNA

Back 64

=messenger RNA
=transfer RNA
=reibosomal RNA

Front 65

mRNA gene
tRNA gene
rRNA gene

Back 65

=gene coding for messenger RNA
=gene coding for transfer RNA
=gene coding for ribosmal RNA

Front 66

ssDNA
ssRNA
dsRNA

Back 66

=single strand DNA
=single strand RNA
=double strand DNA

Front 67

Information flow (focus on protien-coding genes)

Back 67

dsDNA-(transc)-ss mRNA-(transl)-polypeptide
dsDNA-(transc)-ss rRNA (never translated)
dsDNA-(transc)-ss tRNA (never tranlated)

Front 68

Nucleic acids (DNA or RNA)

Back 68

long molecules(polymers) made of building blocks(nucleotides) that are themselves composed of three subunits

Front 69

DNA

Back 69

breaks into monomers-- breaks into--nucleotides--breaks into--deoxyribose (5 carbon sugar), phosphate (PO4) and nitrogenous base: C T A G

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RNA

Back 70

breaks into monomers-- breaks into--nucleotides--breaks into--ribose (5 carbon sugar), phosphate (PO4) and nitrogenous base: C U A G

Front 71

Nitrogen Bases: Pyrimdines

Back 71

Cytosine, Uracil and Thymine (single ring)

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Nitrogen Bases: Purines

Back 72

Adenine and Guanine (double ring)

Front 73

Sugar: Ribose (RNA)

Back 73

5 carbon sugar (has OH attached to 2,3 carbons)

Front 74

Sugar: (Deoxyribose)

Back 74

5 carbon sugar (has OH attached 3 and H attached 2 carbon)

Front 75

Nucleotide (3)

Back 75

nitrogenous base + sugar + phosphate group--(2 neg charges)

Front 76

Watson-Crick double helix model of DNA (source)

Back 76

Chargaff's rules, X-ray diffraction data (relative numbers= molar amounts of each base present in DNA from various species)

Front 77

Chargaff's Rule

Back 77

[A]=[T] or [A]/[T]=1
[C]=[G] or [C]/[G]=1
[A+G]=[C+T] or [purines]=[pyrimdines]
[A]=[T]=[C]=[G]=1/4

Front 78

Other possible ratios, like %GC

Back 78

%GC = {[G + C]/[G + C + A + T]} X 100
(OR ASYMMETRY RATIO)
[A + T]/[C + G]

Front 79

X-ray diffraction data

Back 79

suggesting that the DNA molecule is:
a)helical
b)long and narrow
c)has a repeating structure
d)is composed of >1 polynucleotide chain

Front 80

Details about DNA

Back 80

a)two chains have anti-parallel orientation
b)pairs of bases project from opposite sugar-phosphate strands meet in center of molecule (HYDROGEN BONDS]

Front 81

Two types of basepairs (bp) can form

Back 81

a) A=T (LESS DENSE)
b) C=G (MORE DENSE/SMALLER/ THERMOSTABILITY)

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Number of (bp) for every 360 degree twist of the molecule

Back 82

10 bp distance

Front 83

DNA molecule

Back 83

right-handed nature of DNA/ alternating major and minor grooves run along the right- hand fashion

Front 84

DNA Grooves

Back 84

sites for DNA-binding proteins

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Width of double helix

Back 85

2 nm (including phosphate backbone)

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Hydrogen bonds and hydrophobicity

Back 86

stability of genetic material (dissolve in water due to the neg charge of the phosphate groups on the outside of the molecule, whater cannot cause the two strands to seperate [NEED TO COLD, DRYNESS, HIGHT SALT]

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Conservative DNA replication

Back 87

new strands

Front 88

Semi-conservative DNA replication

Back 88

parental acts as a template with a new strand

Front 89

Dispersive DNA replication

Back 89

segmented replication in new strands