Exam 2 Flashcards
(124 cards)
1
Q
What is the C-Value Paradox
A
The direct relationship between the complexity of organisms and size of genome
2
Q
What is a genome
A
All DNA in a cell nuclues and organelles
3
Q
As genome size increases…
A
So does the number of non-coding sequences
4
Q
What is a telomere
A
A highly repetitive DNA sequence on the ends of linear chromosomes
5
Q
How many chromosomes do humans have?
A
46 chromosomes
(22 autosomes and 1 sex)
6
Q
What is a Karyotype
A
A complete set of chromosomes from an indivudual
7
Q
What does Ploidy mean?
A
Refers to the number of sets of chromosomes
8
Q
What’s the difference between haploid, diploid, triploid, and tetraploid?
A
Haploid: 1 set of chromosomes
Diploid: 2 sets of chromosomes
Triploid: 3 sets of chromosomes
Tetraploid: 4 sets of chromosomes
9
Q
What does homologs mean
A
Derived from one common ancestor
10
Q
What are the components of a chromosome?
A
Long DNA strands and packaging proteins
11
Q
What are the packaging proteins for eukaryotes and prokaryotes?
A
Eukaryotes: Histones
Prokaryotes: Histone-like
12
Q
Where are accessory proteins found?
A
In the Nucleus
13
Q
What do accessory proteins assist in?
A
-DNA replication
-DNA repair
-Gene Expression
14
Q
What is a centromere
A
A pinch in the center of a chromosome
15
Q
What are the three types of centromeres?
A
- Metacentric
- Acrocentric
- Telocentric
16
Q
Who started theorizing about DNA replication
A
Watson and Crick
17
Q
What type of replication does B-DNA follow?
A
Semi-conservative Replication
18
Q
What is a nucleosome
A
A structure composed of coiled DNA around a histone protein
19
Q
What is a histone composed of?
A
8 histones (core)
1 histone (clamp)
20
Q
True or False
Prokaryotes perform mitosis and meiosis
A
False, Binary fission
21
Q
Who are the main players in DNA replication?
A
Topoisomerase
Primase
DNA polymerase
DNA Helicase
Single-stranded binding proteins
DNA Ligase
22
Q
Correct the Statement
DNA polymerase synthesizes DNA from 3’-5’ and reads DNA 5’-3’
A
DNA Polymerase synthesizes DNA 5’-3’ and reads DNA 3’-5’
23
Q
True or False
DNA polymerase can only add to 3’ OH group
A
True
24
Q
What are the two types of mutations that occur in DNA?
A
Spontaneous
Induced
25
What are the types of spontaneous mutations?
1. Depurination
2. Deamination
3. Slippage
4. Mismatch
26
What are the types of induced mutations?
1. Radiant Energy
2. Ionizing/ Non-ionizing
3. Chemicals
4. Viruses
27
True or False
All DNA mutations are harmful
False, DNA mutations are either neutral, harmful, or beneficial
28
What is a Depurination mutation?
A loss of a Purine base
29
What is Deamination?
Removing an amino group from the amino acid
30
When and where does Slippage mutation occur?
During DNA replication at repeating sites
31
How does mismatch mutation happen?
When DNA polymerase and proof reading subunit don't catch the mistake
32
How do viruses affect DNA?
Bonus: What viruses do this?
By copying the genome and integrating themselves into the chromosome.
Bonus: HIV and HPV
33
What do chemicals do to DNA?
Cause deletion of DNA and Deamination
34
What's the difference between non-ionizing and ionizing energy?
Ionizing: X-ray and Gamma rays
-Breaks the DNA
Non-ionizing: UV, UVA, UVC, UVB
-causes covalent bonds to form with adjacent thymines
35
True or False
DNA Helicase requires ATP
True
36
What are the 3 types of DNA polymerase in Eukaryotes
Alpha, Delta, Epsilon
37
What 3 scientist reconfirmed Mendel's Work?
DeViries, Correns, and Tschermak
38
What 3 scientists identified the correlation between certain chromosomes and certain traits
Sutton, Stevens, and Hunt Morgan
39
What 4 scientist determined the structure of DNA
Watson, Crick, Franklin, and Wilkins
40
True or False
Watson and Crick used experimental models
False, only cardboard and models
41
What's the difference between unity and diversity
Unity: Having faithful copies of cells/organisms of information for making cells/organisms
Diversity: Differences that arise due to inherited information
42
What did Mendel's work identified?
He identified:
-There are 2 copies of traits that organisms inherit
-There are dominant and recessive traits
-The rule of independent assortment and rule of segregation
43
What are the base pairs in DNA
Cytosine and Guanine
Adenine and Thymine
44
How many hydrogen bonds can each base pair form?
Adenine and Thymine: 2
Guanine and Cytosine: 3
45
Fill in the blank
The DNA helix is ...-handed. For every one turn, there are... bases.
1. Right
2. 10
46
... + Sugar= Nucleotide
Base + ... + Phosphate group= Nucleotide Group
1. Base
2. Sugar
47
True or False
The sugar-phosphate backbone is positively charged.
False, Negatively
48
Who studied the way DNA replicates?
Messelson and Stahl
49
True or False
Eukaryotes synthesizes faster than prokaryotes
False
50
How many base pairs does RNA Primase lay down?
10-15
51
Why are Telomeres important?
It provides a complementary template for the linear chromosomes.
52
Does Telomere need a primer?
NO
53
What are the 3 reasons why neutral mutations happen?
1. When the mutation codes for the original amino acid
2. If it's a non-coding sequence
3. If the mutation codes for a amino acid with similar properties to the original
54
What happens when there's a harmful mutation in the coding sequence
When there's a mutation in the coding sequence causing a change in the amino acids making the protein not function
55
What happens when there's a harmful mutation in a regulatory sequence?
When there's a new amino acid but there's similar properties to the original
56
Promoters are on/off ...
Dimers
57
True or False
When comparing genome organization prokaryotic operons code for one mRNA that is controlled by multiple promoters and codes for one protein
False, the operons are controlled by 1 promoter and they code for multiple proteins
58
True or False
When comparing genome organization prokaryotes have no introns
True
59
True or False
When comparing genome organization eukaryotes each gene codes for one protein being controlled by their promoter
True
60
True or False
When comparing genome organization prokaryotes have modified mRNA while eukaryotes don't.
False, prokaryotes don't have modified mRNA while eukaryotes do
61
True or False
Exons code for different domains of proteins
True
62
What is the purpose of alternative splicing
Allows the same gene to produce different variations of proteins
63
What are the STOP codons?
UAG, UAA, UGA
64
What is the purpose of the anitcodon loop
-Used to be recognized by ribosomes that match it to complementary codons
65
What are the 3 sites on a ribosome?
A site: Acceptor charged tRNA match anticodon tRNA codon mRNA
P site: Peptidyl transferase covalent peptide bonds between adjacent amino acids
E site: Exit site
66
What is the effect of Tetracycline?
Blocks binding of aminoacyl-tRNA to the A-site of the ribosome
67
What is the effect of Streptomycin?
Prevents the transition from initiation complex to chain elongation
68
What is the effect of chloramphenicol?
Blocks the peptidyl transferase reaction on ribosomes
69
What is the effect of Erythromycin
Binds in the exit channel of the ribosome and inhibits elongation of the peptide chain
70
What is the effect of Rifamycin
Blocks initiation of transcription by binding to and inhibiting RNA polymerase
71
True or False
Prokaryotes have 5' caps
False
72
What is the intron sequence called when it's removed
lariat
73
True or False
Spliceosomes are snRNPs
True
74
Describe how different Poly A Tails lengths function
No Poly A Tail: It degraded after transcription
Short: Slightly more stable after transcription
Moderate: More stable for translation
Very long tail: Is usually stored
75
True or False
Very long Poly A Tails are stored after transcription
True
76
When is a Poly A tail added
After transcription termination
77
What type of bond is the 5' cap attached to the 5' end of mRNA
Covalent bond
78
What is the purpose of mRNA and snRNA?
mRNA: Codes for protein structure
snRNA: Assist with transcription
79
True or False
snoRNA modifies tRNA and mRNA
True
80
What is the purpose of snoRNA and microRNA
snoRNA: Modifies tRNA and mRNA
microRNA: Regulates translation
81
True or False
siRNA regulates transcription
False, Targets exogenous RNA
82
What is the purpose of tRNA and rRNA
tRNA: Assist with Translation
rRNA: Assist with translation
83
What are the 3 stages of translation
Initiation
Elongation
Termination
84
What is the START codon and what amino acid does it code for?
AUG codes for Methionine
85
What is a branchpoint
An adenosine base which is used as a site to create a lariat structure `
86
During intron formation, snRNP U1 binds at ... end and U2 binds at...
1. 5'
2. 3'
87
True or False
Exons don't code for different domains of proteins
False, they do
88
Why does protein degradation happen?
1. Misfolded protein
2. Malfunctioning
3. Has a brief function
89
What is a proteosome?
Chamber for protein degradation
90
What is a polyubiquitin Tag?
A tag that is recognized to be degraded and or recycled
91
True or False
All cells in the body have the same DNA
True
92
What is an example of X inactivation?
Barr Body
93
Compare and Contrast Heterochromatin & Euchromatin
Heterochromatin:
1. More condensed
2. Genes are turned off
3. Telomeres and Centromeres
Euchromatin
1. Less condensed
2. Genes are more accessible and can be turned on
94
What does Facultative heterochromatin mean?
Sometimes the genes are condensed
95
What are the types of chemical modifications of histones?
1. Acetylation
2. Methylation
3. Phosphorylation
96
What are the cis elements
Enhancers, silencers, and promoters
97
What are the trans elements
Activators, inhibitors, RNA polymerase, and initiation factors
98
What is the level called when there are low levels of gene expression?
Basal Levels
99
What increases levels of expression?
Activators and regulators
100
What does Drosha do?
Processes microRNA and exports from the nucleus
101
What is RISC
RNA induced silencer complex
102
What does DICER do?
Cuts the microRNA into 20-24 double-stranded RNA
103
What happens to the protein when RISC 100% matches with the RNA
Degrades the protein
104
What happens to the protein when RISC matches only 1-2 base pairs?
Prevents translation
105
True or False
Proteins act as activators
True
106
True or False
Histone subunits are negatively charged
False, positive
107
Acetylation adds a... group
Acetyl
108
Acetylation makes the the chromatin...
Loose
109
Phosphorylation adds... to add a phosphate group
Kinase
110
How many base pairs are wrapped around the histone?
Around 150
111
What does RNA polymerase 1 code for?
Most tRNA genes
112
What does RNA polymerase II code for?
All protein-coding genes, miRNA genes, and genes for other noncoding RNA
113
What does RNA polymerase III code for?
tRNA genes, 5sRNA genes, and genes for other small RNAs
114
In eukaryotes what removes primer?
Endonuclease, RNAase, DNA polymerase Delta
115
What is a TATA box
A promoter region where transcription begins
116
What are the 3 types of histone modification?
Methylation
Phosphorylation
Acetylation
117
What is prokaryotic cell production called?
Binary fission
118
What is Ori C
The origin of replication in Prokaryotes
119
What is the origin of replication in eukaryotes called?
Autonomously Replicating Sequence (ARS)
120
Where does DNA replication occur in eukaryotes
In the nucleus
121
When does DNA replication happen?
During Interphase
122
True or False
The replication fork is bi-directional
True
123
True or False
In prokaryotes DNA Polymerase 1 removes the primer but doesn't fill in the gap
False, it does fill in the gap and remove the primer
124
