Final Flashcards

Question

Euchromatin

Answer 1

Chromatin that exhibits normal packing and unpacking in cell cycle Contains genes that are actively being transcribed (loosely packed) Typically devoid of repetitive sequences

Answer 2

Packed tightly | Not being actively transcribed

Answer 3

A change in phenotype that doesn't result from a change in the sequence of a gene Change is heritable Caused by switching on or off parts of genome in response to environment

Answer 4

DNA replication proceeds in both directions due to the presence of 2 replication forks

Answer 5

Parent strand is used as template and joins with new strand | Correct model of replication

Answer 6

Lagging strand of DNA is synthesized this way as a series of short fragments

Answer 7

Place on DNA where replication begins

Answer 8

Spot on DNA where replication is occurring | DNA strands are denatured, so DNA is temporarily single-stranded

Answer 9

Structure created during DNA replication | Consists of 2 denatured strands that can be synthesized off of

Answer 10

Strand of DNA that is synthesized off of in the 5' to 3' direction

Answer 11

Strand of DNA that is synthesized off of in the 3' to 5' direction

Answer 12

Sections of newly synthesized DNA | Formed on lagging strand

Answer 13

Enzyme that breaks H-bonds between nucleotide bases in DNA replication

Answer 14

Protein that binds to single strands of DNA in replication, holding them apart

Answer 15

Enzyme that makes RNA primer in DNA replication

Answer 16

Enzyme that catalyzes phosphodiester bond formation between nitrogenous bases (dNTPs) in DNA replication

Answer 17

Enzyme that connects DNA strands in DNA replication

Answer 18

Enzyme that unwinds DNA in DNA replication

Answer 19

Process of turning DNA into mRNA

Answer 20

Strand to which RNA pol makes complementary RNA strand | Strand of DNA that is site of transcription

Answer 21

Constitutive heterochromatin Packed tightly: constricts chromosome Mitotic spindle attaches to centromere in order to pull chromosomes apart during cell division

Answer 22

Tandemly repeated DNA at the ends of linear chromosomes | Protects integrity of DNA from exonucleases (chew up ends of DNA: defense against foreign DNA)

Answer 23

Enzyme that transcribes RNA by linking together NTPs

Answer 24

Sequences that are expressed | Transcribed and translated

Answer 25

Euk genes only Long insertions of non-coding sequences Intervening sequences: transcribed, but not translated Buffer against mutation and contain enhancer sequences

Answer 26

Methylated guanine nucleotide (5' methyl G-cap) is added to 5' end of mRNA Protects RNA from exonucleases and ensures correct positioning of ribosome during translation

Answer 27

``` End of transcription Steps: 1. mRNA is cleaved at poly A site 2. mRNA is released 3. 50 to 250 adenine nucleotides are added to 3' end by poly A polymerase ```

Answer 28

Set of cis-acting (next to) sequence elements bound by trans-acting (from someplace else) factors Contains core promoter, proximal elements (close to core promoter; enhancers or silencers), and distal elements (far away from core promoter; may be on other chromosome; enhancers or silencers)

Answer 29

Region of DNA that initiates transcription of a particular gene

Answer 30

Bind to core promoter, recruiting polymerase and causing basal transcription

Answer 31

Sequences of DNA that are bound by proteins called activators When bound, transcription of gene is increased Located further downstream or upstream from +1 site

Answer 32

Proteins that bind to enhancers, causing increased transcription of genes 2 major domains: DNA binding domain and transcription activation domain Change shape, allow for binding to DNA

Answer 33

Proteins that bind to silencers, causing decreased transcription of genes

Answer 34

Sequences of DNA that are bound by proteins called repressors When bound, transcription of gene is decreased Located further downstream or upstream from +1 site

Answer 35

Modification of RNA in which introns are removed from exons

Answer 36

One gene can encode more than 1 protein because different combinations of exons are spliced together to create different proteins

Answer 37

Removes introns from mRNA

Answer 38

Ribosomal RNA

Answer 39

Small nuclear RNA | Non-coding

Answer 40

Process of turning mRNA into proteins

Answer 41

Polymers of amino acids that are connected by peptide bonds

Answer 42

Combination of polypeptides folded in a 3-D structure

Answer 43

Building blocks of proteins | Each different amino acid (20 in total) has a different R group that provide it different functions

Answer 44

Set of 3 mRNA nucleotides that code for an amino acid

Answer 45

tRNA loaded with an amino acid | Ribosome can transfer amino acid from tRNA to growing peptide strand

Answer 46

Triplet nucleotide sequence of tRNA that is complementary to that of mRNA

Answer 47

Set of rules by which information encoded within genetic material (DNA or mRNA sequences) is translated into proteins by living cells

Answer 48

More than 1 codon occurs for each amino acid (3rd nucleotide might be different) Allows for protection against mutation Same as redundancy

Answer 49

Base pairing between tRNA anticodon and mRNA codon doesn't necessarily follow complementary base pairing rules at the 3rd nucleotide Reason: energetic favorability

Answer 50

The codons of an mRNA that are read sequentially to specify amino acids

Answer 51

Site of translation

Answer 52

Multiple ribosomes translating same RNA concurrently

Answer 53

Change in nucleotide sequence

Answer 54

Substance that induces mutation in DNA | Examples: radiation, intercalating agents, some drugs

Answer 55

Change from functional codon to stop codon | Often severe phenotypic effect, but effect depends on where mutation is and what amino acid is changed

Answer 56

A change in a codon so that a different amino acid is added to the polypeptide Phenotypic change depends on amount of difference from original

Answer 57

Addition or deletion of 1 or more base pairs changes open reading frame Missense or stop results

Answer 58

Loss of nucleotide(s) from sequence

Answer 59

Change amino acid to another amino acid with similar chemical properties Mild or no phenotypic effect

Answer 60

Change 1 codon for 1 amino acid to a different codon for the same amino acid

Answer 61

Single base pair substitution

Answer 62

Causes gene product to have more activity

Answer 63

Results in partially or fully nonfunctional gene product

Answer 64

Fully nonfunctional allele

Answer 65

Segments of DNA that have the capacity to move in the genome

Answer 66

Histone core is moved so that the gene is accessible: allows transcription of genes blocked by histone

Answer 67

CpG island is methylated, causing gene to be silenced Methyl groups physically block transcriptional machinery Can sometimes recruit histone deacetylases to modify histone tails

Answer 68

``` Histone acetyltransferases (HATs) cause masking of positive charge on histone tails, making DNA accessible Heritable change Process is reversible by histone deacetylases (HDACs), recruited by DNA methylation ```

Answer 69

1. miRNA is transcribed 2. miRNA is processed into shRNA (short hairpin RNA) 3. RISC (RNA interference silencing complex) recognizes shRNA and picks it up 4. RISC complex binds to mRNA 5. RISC complex cuts off mRNA's poly A tail 6. mRNA is degraded

Answer 70

RNA that makes a sharp hairpin turn | Can be used to silence gene expression through RNA interference

Answer 71

Point in time at which half of RNA is degraded | Depends on structure, proteins bound, and poly A tail length (too short, degraded)

Answer 72

Number of chromosomes in individual's cells isn't a multiple of the normal haploid set 1 or more extra or missing chromosomes

Answer 73

Addition of a base pair

Answer 74

Doubling of part of chromosome

Answer 75

Piece of 1 chromosome is placed onto another chromosome

Answer 76

Segment of chromosome is taken out and re-inserted backwards

Answer 77

Narrow sites of some chromosomes | Prone to breakage

Answer 78

Identical copy of a chromosome

Answer 79

Chromosomes that aren't identical, but code for the same genes

Answer 80

Cross between two individuals whose alleles differ for one gene

Answer 81

Cross between two individuals whose alleles differ for two genes

Answer 82

In meiosis I, homologous chromosomes end up at one pole or the other at random

Answer 83

In meiosis I, chromosomes don't influence each other's segregation

Answer 84

Cross of unknown genotype (homozygous dominant or heterozygous) with homozygous recessive individual Allows for determination of unknown genotype

Answer 85

Heterozygote shows the phenotypes of both homozygotes simultaneously Ex- roan horses (both red and white hairs)

Answer 86

Phenotype of heterozygote is intermediate to homozygotes | Ex- palomino horses (intermediate to chestnut and cremello)

Answer 87

1 gene masks the expression of another gene | Polygenic phenomenon

Answer 88

``` 1 dose of gene product supports life Autosomal recessive Homozygous wt= healthy Heterozygous= healthy Homozygous mutant= sick or dead ```

Answer 89

Trait carried on the X chromosome | More commonly seen in males than females

Answer 90

Having unpaired genes | Ex- guys are this in respect to X-linked traits

Answer 91

Becomes active at 6-8 weeks during development Encodes Testes Determining Factor (TDF), which controls the development of testes (absence of this causes gonads to develop into ovaries)

Answer 92

Silencing of 1 X chromosome in females allows for the same level of expression for genes on the X chromosome in males and females Entire chromosome isn't completely inactivated- some parts are a little bit active

Answer 93

The amount of gene product present in an individual

Answer 94

1 gene is responsible for multiple phenotypes

Answer 95

The % of individuals with a particular genotype who show the expected phenotype

Answer 96

Degree to which a phenotype is expressed | Severity of phenotype

Answer 97

Differences in phenotype between individuals

Answer 98

Mitochondria and mtDNA in egg cytoplasm are inherited in offspring Phenotype of the offspring is determined by the genotype of the mother

Answer 99

DNA found in mitochondria

Answer 100

Trait that results from action by multiple genes | Most traits are these

Answer 101

Influence from many genes along with environment

Answer 102

Clearly defined by 1 or a few genes No degrees of severity Only a few traits follow this mode of expression

Answer 103

Measurable in numeric terms Controlled by multiple genes and environmental factors Have continuous variation

Answer 104

Phenotypes are distributed along a continuum | Series of intermediate phenotypes that fall between 2 extremes

Answer 105

How much of the phenotypic differences are due to genetic factors Expressed in a number ranging between 0-1 (0- none, 1- all)

Answer 106

Loci that influence quantitative traits

Answer 107

Changes in allele frequencies due to random sampling Reduces genetic diversity Ex- settlers killing off millions of bison on the Great Plains

Answer 108

Population is drastically reduced in number, reducing genetic diversity Not due to anything that would reduce selectively, like certain diseases

Answer 109

Population is established from a small number of breeding individuals Reduced genetic diversity

Answer 110

Frequency of alleles that confer survival and reproduction increases in the population

Answer 111

All of the alleles in a population

Answer 112

Flow of alleles into and out of a population

Answer 113

An individual migrates and contributes its alleles to the gene pool of the new population

Answer 114

Mating of organisms in a non-random manner

Answer 115

Study of an entire genome(s)

Answer 116

Global analysis of function of sequences in a genome

Answer 117

Comparison of entire genomes from different species, individuals, or groups

Answer 118

Combination of biology and computer science

Answer 119

Study of complete set of transcripts that are produced by a genome under a specific condition

Answer 120

Enzyme that synthesizes DNA from RNA

Answer 121

2 or more different genes in 2 different organisms that have the same or similar function Result of speciation

Answer 122

2 or more genes in an organism that have similar or identical function Result of duplication

Answer 123

Paralogs and homologs

Answer 124

Study of role of genetics in a drug response

Answer 125

Amplify millions of copies of DNA molecule from very small starting portion of DNA Many cycles of 3 steps: denature DNA using heat, anneal primers to DNA, extend strand using Taq polymerase

Answer 126

Complementary DNA: complementary to RNA

Answer 127

Measure increase in amount of PCR product during thermal cycling reactions Measure specific cDNA as it's being amplified: use reporter probe

Answer 128

Contains fluorescent marker and quencher When quencher is close to fluorescent marker, no light is emitted As polymerase makes strand, quencher is displaced from fluorescent marker, causing light to be emitted

Answer 129

Method that provides sequences of all transcripts in a sample Steps: 1. Extract RNA from cells of interest 2. Reverse transcribe into cDNA 3. Sequence cDNA using Next Gen technology

Answer 130

Human manipulation of an organism's DNA

Answer 131

Getting a host (ex- E. coli) to take up a cloning vector to make clones of the sequence of interest

Answer 132

Identical copy

Answer 133

Specific region of DNA that varies among individuals | Used to create a detailed map of the individual's genome

Answer 134

Changes in DNA sequence between individuals

Answer 135

Changes in DNA sequence at a specific nucleotide

Answer 136

Number of copies of genes present in a person's genome | Cause changes between people

Answer 137

Method of identifying SNPs | SNP changes restriction enzyme site: different number of fragments observed in gel electrophoresis

Answer 138

1. Extract DNA from human cells 2. Cut DNA into small, overlapping fragments (contigs) using restriction enzymes (reaction is performed at suboptimal conditions- enzymes don't cut at every site) 3. Clone contigs to make genomic library 4. Sequence each clone using Sanger sequencing 5. Use computers to reassemble sequences of contigs by puzzling together overlapping sequences 6. Deposit sequences into database, NCBI GenBank

Answer 139

Project in 1990s that focused on sequencing whole human genome (hadn't been done yet)

Answer 140

1. Cloning vector containing DNA of interest is amplified by PCR 2. When polymerase randomly adds ddNTP with attached fluorescent probe, sequencing reaction stops 3. Different sized segments of DNA are created 4. Segments are separated by size using capillary gel electrophoresis (electrophoresis in a capillary tube) 5. Detector identifies ddNTPs based on their unique fluorescence 6. Sequence is recreated by reading ascending order of ddNTPs

Answer 141

1. Extract DNA 2. Cut into contigs 3. Affix DNA to solid support (bead, chip, etc.) 4. One by one, wash dNTPs across the DNA 5. If known dNTP is incorporated by polymerase, then light is emitted 6. Reassemble overlapping sequences

Answer 142

Identification and description of genes and their important sequences Can be done using computer algorithms to predict open reading frames: look for promoters, start sites, and polyadenylation sites

Answer 143

Set of SNPs that are close together on a chromosome | SNPs are inherited together: low recombination rates

Answer 144

``` Plasmid used in cloning Contains Ori (origin of replication), MCS (multiple cloning site), and gene for antibiotic resistance ```

Answer 145

Enzyme that re-seals phosphodiester bonds between sequence and cloning vector

Answer 146

1. Isolate DNA from organism of interest 2. Cut DNA into small pieces using restriction enzymes 3. Separate DNA fragments using gel electrophoresis 4. Transfer DNA from gel to membrane/blot (DNA is in same position on blot as on gel) 5. Incubate blot with labeled probe that is complementary to DNA of interest 6. Visualize probe: see band on blot where DNA of interest is located

Answer 147

Cuts DNA at specific site, creating sticky ends | Used to create space in MCS for sequence of interest to be inserted

Answer 148

Cleaves sequence at its end

Answer 149

Cleaves sequence in its middle

Answer 150

Gene transplanted from one organism to another

Answer 151

Using restriction enzymes that cleave at known sequences to obtain structural information about a piece of DNA (find out how large it is and the sizes of fragments making it up)

Answer 152

Region of the genome with increased recombination rates

Answer 153

Region of the genome with decreased recombination rates

Answer 154

Less than 0.05: fail to reject null hypothesis Greater than or equal to 0.05: reject null hypothesis Null hypothesis: statistical difference between observed numbers and expected numbers

Answer 155

DNA is transcribed into RNA which is translated into amino acids

Answer 156

1. Solution of labeled probes is added to DNA sample in question while it is being denatured 2. Sample is allowed to hybridize 3. Probe will hybridize to the sample DNA if the specific sequence is present Used in detection of genetic disorders that result from copy number changes

Answer 157

Human karyotype is labeled with 24 uniquely labeled chromosome paints Used to detect complex rearrangements, small translocations, and unknown chromosomes

Answer 158

Patient's DNA and normal DNA are differently labeled and co-hybridized to arrays of DNA clones which span the entire genome (comparison is expected to yield ratio of 1:1, indicating equal DNA copy numbers in both samples) If yellow, normal copy number If red, deletion in patient's DNA If green, duplication in patient's DNA

Answer 159

Analysis of the exons (coding regions) of thousands of genes simultaneously

Answer 160

p= frequency of dominant allele (B) q= frequency of recessive allele (b) p+q=1

Answer 161

p^2 + 2pq + q^2 = 1 p^2= f(AA) 2pq= f(Aa) q^2= f(aa)

Answer 162

Map units=% recombination | Map units= (number of recombinants/total number of progeny)*100

Answer 163

Double crossover

Answer 164

DCO tells which gene is in middle: only one that isn't switched (odd one out)

Answer 165

No linkage of genes

Answer 166

Odd trait out assorts independently and other two are linked

Answer 167

Odd trait out is in middle and all traits are linked