exam 1 Flashcards

Question

ploidy

Answer 1

number of complete sets of chromosomes

Answer 2

count the number of centromeres

Answer 3

specific to a species * e.g. Homo sapiens N=23, 2N=46

Answer 4

**amount of nuclear DNA in a gamete (haploid)** - this is irrespective of ploidy *note: organismal complexity is not correlated with N, ploidy, or # genes*

Answer 5

organismal complexity is *not* correlated with **N, ploidy, or # of genes**

Answer 6

**region that contains condensed DNA/protein complexes** - attaches to inner membrane *note: this is characteristic of prokaryotes*

Answer 7

**nucleoid-associated proteins** - these _bind to repetitive sequences_ to _form loops of supercoiled DNA_ - ~10,000 bp/loop

Answer 8

help to condense bacterial chromosomes

Answer 9

supercoiling helps pack DNA into smaller spaces

Answer 10

enzymes (i.e. topoisomerases)

Answer 11

enzymes that overwind and underwind dsDNA

Answer 12

overwinds DNA

Answer 13

underwinds DNA

Answer 14

chemotherapeutic agent

Answer 15

**refers to a single histone/DNA complex** - the fundamental subunit of chromatin **eukaryotic histones in a nucleosome:** - composed of: **(1)** a core histone octomer & **(2)** a linker histone

Answer 16

petit - this is the short arm

Answer 17

queue - this is the long arm

Answer 18

ptel - this is on the short arm

Answer 19

qtel - this is on the long arm

Answer 20

**fluorescent in situ hybridization** - used to _visualize specific regions of a genome_ (typically when abnormalities are suspected) - a DNA or RNA probe complementary to a _specific region of the genome_ is hybridized to chromosomes - can also use lots of probes that are labeled with different colors to _"paint" chromosomes_

Answer 21

base-pair order

Answer 22

**within specific territories** - likely _allows for specific interactions_ between different chromosomes

Answer 23

**TRUE: genomes are dynamic** - sometimes our cells need to "see" the DNA in an uncondensed form (for DNA replication, gene expression, etc.)

Answer 24

1. DNA 2. proteins 3. RNAs 4. lipids 5. polysaccharides

Answer 25

1. # of each chromosme 2. total # of chromosomes 3. centromere position 4. chromosome length 5. chromosome shape (linear) 6. banding patterns

Answer 26

2% | the amount of non-coding DNA varies between species

Answer 27

1. introns 2. transposable elements 3. repetitive sequences 4. stuff we still don't understand (unique sequences)

Answer 28

parts of genes that are transcribed into mRNAs, and then removed before translation

Answer 29

**alternative splicing** - this might explain why humans only have 20% more genes than a single celled plasmodium

Answer 30

**members of the same species:** tend to have the same introns in the same positions **members of different species:** can gain or lose introns, but will maintain ancestral positons of introns more frequently than expected - suggests functionality

Answer 31

self-replicating, mobile DNA sequences - "jumping genes" - classified as "selfish" genetic elements or "genomic parasites"

Answer 32

not "junk", might provide genetic variation that is favored during evolution - can also contribute to regulatory changes (TE upstream of ISL1 alters gene expression) - novel proteins through changes in intron splicing ?????

Answer 33

can be: **1. short and sequential** - can consist of **(1)** simple repeats (SSRs), **(2)** simple tandem repeats (STRs), and **(3)** microsatellites **2. long and segmented** i.e. intrachromosomal vs. interchromosomal

Answer 34

cross an unknown to an individual with a known, recessive genotype - offspring will have predictive phenotypic ratios for the possible unknown genotypes

Answer 35

they should be selected against over evolutionary time

Answer 36

Gregor Mendel - created peas that were homozygous - showed that F1 and F2 offspring had predictable ratios of phenotypes

Answer 37

it will be maintained - the larger the non-coding sequence space, the more likely a TE will land in an unimportant region - this would make the non-coding sequences longer and allow for the expansion of more TEs

Answer 38

1. there are "hereditary determinants of particulate nature" (genes) 2. genes come in pairs 3. alternate phenotypes of a single character are determined by different forms of these genes (dominant/recessive alleles) (Law of Dominance) 4. gametes contain one member of each gene pair (ploidy) 5. innheritance of alleles was random/random fertilization (Law of Segregation) 6. genes controlling different traits are inherited independently (Law of Independent Assortment)

Answer 39

1. Law of Dominance 2. Law of Segregation 3. Law of Independent Assortment

Answer 40

some alleles are dominant, others are recessive, a heterozygous individual will display the dominant form - this is one of Mendel's laws of heredity

Answer 41

only 1 allele is carried in a gamete - this is one of Mendel's laws of heredity

Answer 42

genes of different traits segregate independently to the gametes - this is one of Mendel's laws of heredity

Answer 43

1. interphase 2. meiosis I - prophase I - metaphase I - anaphase I - telophase I 3. meiosis II - prophase II - metaphase II - anaphase II - telophase II

Answer 44

- leptotene - zygotene - pachytene - diplotene - diakinesis

Answer 45

DNA replicates

Answer 46

homologous chromosomes find each other and recombine

Answer 47

chromosomes align on metaphase plate

Answer 48

chromosomes move to opposite poles

Answer 49

cell division

Answer 50

chromosome structures condense, no crossing over

Answer 51

chromosomes align to a central plane

Answer 52

chromosomes move to opposite poles

Answer 53

cell division

Answer 54

when both parents are heterozygous at 1 locus - e.g. Aa x Aa

Answer 55

when both parents are heterozygous at 2 loci - e.g. LlAa x LlAa

Answer 56

the entire process of going from one diploid germline cell to 4 haploid gametes

Answer 57

check notes and fill in

Answer 58

how close the loci is to the centromere - recombination doesn't happen at the centromere

Answer 59

always be the same

Answer 60

the relationship of the alleles

Answer 61

these regions are typically full of repetitive sequences - this may aid in compacting genome

Answer 62

1kb-400kb repeated sequences

Answer 63

transposable elements (TEs)

Answer 64

0.1% - variation is randomly distributed across the genome - not all variation is in coding sequences

Answer 65

FALSE - variation is randomly distributed across the genome - not all variation is found in the coding sequences

Answer 66

1. single nucleotide polymorphisms (SNPs) 2. copy number variants (CNVs) - trinucleotide repeats TNRs

Answer 67

this is a variation at a single position in a DNA sequence among individuals - between any 2 humans: ~ 1 SNP every 1000 bp - 3-5 million SNPs/genome

Answer 68

when the number of copies of a particular gene varies from one individual to the next - between any 2 humans: ~1500CNVs - avg. size of CNV=~20k bp examples: trinucleotide repeats (TNRs): TAGTAGTAGTAGTAG

Answer 69

coding and non-coding regions - they both can cause changes in phenotype but most of the time they have no phenotypic effect

Answer 70

3 nucleotides consecutively repeated within a region of DNA - this is a type of copy number variant (CNV)

Answer 71

1. when they occur within important genes (e.g. Huntington's Disease) 2. when they occur at structurally important regions of a chromosome (e.g. Fragile X syndrome) note: TNRs in non-coding regions that haave o phenotypic effecs are ofen used for identity analysis

Answer 72

FILL IN W NOTES

Answer 73

FILL IN W NOTES

Answer 74

when one copy of an allele overrules phenotypes conferred by a different allele - heterozygotes and homozygotes for completely dominant alleles show the same phenotype

Answer 75

heterozygotes for codominant alleles show both phenotypes - e.g. orange and black alleles in cats- both also happen to be X-linked

Answer 76

heterozygotes for incomplete dominant traits show a phenotype that is somewhere in between both homozygotes - e.g. piebald spotting in cats

Answer 77

1. interphase 2. prophase I 3. metaphase I 4. metaphase II

Answer 78

at the same locus

Answer 79

alter the phenotypic effects of other genes - e.g. modifier genes affect the hair length

Answer 80

major effect loci has more of an effect on allele than minor effect loci

Answer 81

AND = multiply - mutiply independent probabities - e.g. AaBb X AaBb, P(A_B_)= P(A_)*P(B)

Answer 82

OR = add - add dependent probabilities - e.g. P(A_) or P(B_) = P(A_) + P(B_)

Answer 83

the production by a single gene of two or more apparently unrelated effects pleiotriopic alleles lead to many different phenotypes (hair color, deaf, eye color) - 1 gene, many phenotypes

Answer 84

masks the effects of alleles at other genes - if one allele prevents you from being able to predict the genotype at annother locus, the you have epistasis

Answer 85

must define your variables - e.g. a = probability of having a child with normal RBC, b = probability of having sickled RBC - use Pascal's triangle

Answer 86

(a+b)^3 = a^3+3a^2b+3ab^2+b^3

Answer 87

(a+b)^5 = a^5+5a^4b+10a^3b^2+10a^2b^3+5ab^4+b^5

Answer 88

refers to the aatomy of an individual's reproductive system and secodnary sex characteristics

Answer 89

refers to social roles or internal awareness based on the sex of a person

Answer 90

using pseudoautosomal regions 1. primary pseudoautosomal region found on the short arm 2. secondary pasudosomal region found on the long arm found on both X and Y chromosome

Answer 91

perform a reciprocal cross - a pair of crosses between the male of one strain and the female of another, and vice versa - if sex linked, phenotypic ratios will be different in a reciprocal cross

Answer 92

1. presnent the assumed genotypes of cross you are testig 2. present the observed and expected data in a table 3. state an explicit null hypothesis pertaining to defined cross 4. calculate the X^2 statistic 5. state the degrees of freedom (and show its calculation) 6. determine the X^2crit for the appropriate alpha value (P value) to test for significance 7. compare the X^2crit to your X^2 value, and state whether or not the H0 is rejected 8. state the overall conclusion

Answer 93

1. sickle cell anemia 2. is more common among people with African ancestry 3. not all people with sickled red blood cells have anemia 4. not all sickle cell anemia cases are fatal

Answer 94

non-blood relatives are not carriers - however if you know mode of inheritance, can deduce that someone entering a pedigree must be a carrier dominant traits - the first person in a pedigree to show the trait is most likely heterozygous

Answer 95

1. appear equally in males and females 2. doesn't skip generations 3. affected children have an affected parent 4. unaffected people do not transmit the trait

Answer 96

1. appear equally in males and females 2. skip generations 3. more to appear among progeny of related parents

Answer 97

1. does not skip generations 2. affected males pass trait to all daughters and no sons 3. affected heterozygous females pass trait to half of sons and half of daughters

Answer 98

1. affected males produce carrier daughters 2. no sons of affected males are affected 3. males more likely to be affected than females 4. half of the sons from an unaffected carrier will be affected

Answer 99

1. traits appear only in males 2. all sons of affected males will be affected

Answer 100

1. affected females pass the trait to all children 2. affected males never pass down the trait 3. mtDNA traits often show incomplete penetrance

Answer 101

when not every individual that must be a particular genotype shows the expected phenotype

Answer 102

the coexistence of multiple mtDNA variants in a single cell or among cells within an individual - mtDNA heteroplasmy is common in humans - cells have many copies of mtDNA

Answer 103

NO - random segregation of mtDNA during meiosis annd mitosis leads to unequal inheritance of mtDNAs

Answer 104

if it reaches a certain threshold, disease symptoms arise

Answer 105

1. autosomal dominannt 2. autosomal recessive 3. X-linked dominant 4. X-linked recessive 5. Y-linked 6. mitochondrial

Answer 106

autosomal recessive traits can look like autosomal dominant when alleles are common in the population - if an allele is common, we can't assume that people entering the pedigrees are NOT carriers

Answer 107

1. what is the mode of inheritance of the trait? 2. what are the genotypes (or possible genotypes) of the parents? 3. what are the possible crosses that could produce an affected child? 4. what are the individual probabilities of each cross? 5. what are the total probabilities?

Answer 108

p(A|B) is the probability of event A occurring, given that event B occurs

Answer 109

look at notes