Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

My Packs: UWO (BIO 1001) > Cycle 4 (Workshop + Study Session) > Flashcards

Cycle 4 (Workshop + Study Session) Flashcards

(72 cards)

Start Studying
1
Q

Define and state the types of DNA damage

A

Exogenous: Coming from outside the cell (e.x. UV, IR, chemicals)
Endogenous: Coming from inside the cell (e.x. Cell Metabolism (ROS), replication errors)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the difference between mutations and DNA Damage?

A

Mutations are changes in the double stranded DNA sequence, while DNA damage is any change to DNA that is not double stranded

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

True or False:
Genetic variation refers to DNA damage

A

False, genetic variation refers to mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Can DNA damage lead to mutations?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are ROS?

A

Reactive Oxygen Species
Very electronegative and unstable, will take electrons away from any sort of molecule nearby to regain stability (Targets DNA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What can taking electrons away from DNA lead to?

A

Double-stranded breaks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the Oxygen Paradox?

A

While oxygen is crucial to many cell functions, too much of it can ultimately lead to cell death

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Too much oxygen causes _________ ______

A

Oxidative Stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What helps our cells combat the effects of ROS?

A

Antioxidants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

True or False:
DNA Polymerase can proofread during replication

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does DNA polymerase recognize that a mistake has been made?

A

Detection of distortion in the DNA backbone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does DNA polymerase remove incorrect bases?

A

Moves backwards and removes the incorrect base through 3’-5’ exonuclease

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

True or False:
3’-5’ exonuclease can remove several bases at a time from the end of the chain

A

False, 3’-5’ exonuclease can remove bases one at a time from the end of the chain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Describe the _ steps in mismatch excision repair

A

4

Repair enzymes detect the distortion

Mismatch/repair enzymes bind to the damaged region and excise (cleave) the backbone through endonuclease activity

DNA polymerase fills in the gap

Ligase seals the nick

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Define:
Mismatch repair

A

When the mistake is brought upon by mistakes by DNA polymerase III that are not fixed by proofreading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define:
Excision repair

A

Used when there are exogenous sources of DNA damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

True or False:
Repair enzymes that have endonuclease activity can make cuts at the ends of the backbone

A

False, repair enzymes that have endonuclease activity can make cuts that are within the backbone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Define:
Thymine Dimers

A

A type of damage that occurs when adjacent thymines are exposed to UV light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How are thymine dimers repaired?

A

Photolyase + white light
Excision repair

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Describe a thymine dimer

A

Formed under UV light, when two T bases to covalently bond together (forming a dimer)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Define:
Non-Homologous End Joining (NHEJ)

A

Repairs double-stranded breaks by joining blunt ends without using a template

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

True or False:
NHEJ is relatively precise

A

False, NHEJ is very sloppy as it grabs floating nucleotides and puts them back in random orders and numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What mutations can NHEJ result in?

A

Insertion, deletion, or inversion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

True or False:
Only 90% of your DNA is essential coding

A

False, only 10% of your DNA is essential coding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does 2% in the 10% of essential coding account for?
Protein coding
26
What types of mutations are there?
Substitution, deletion, insertion, and inversion
27
Define: Substitution mutation
Also known as point mutation, when one base changes
28
Define: Deletion mutation
When a base pair is removed
29
Define: Insertion mutation
Base pair is added
30
Define: Inversion mutation
When a sequence is flipped
31
What are the _ types of point mutations?
3 Silent Nonsense Missense
32
Define: Silent point mutation
The base change will result in a change in the mRNA, but still codes for the same amino acid
33
Define: Nonsense point mutation
The base change will result in a change in the mRNA and code for a premature stop codon, potentially leading to a nonfunctioning protein
34
Define: Missense point mutation
Base change will result in a change in the mRNA and will change the amino acid it codes for; may cause an issue
35
Define: Single Nucleotide Polymorphisms (SNPs)
Single nucleotide changes "in pairs"
36
True or False: SNPs are the most common type of genetic variation between individuals
True
37
True or False: SNPs will cause individuals to develop certain diseases
Not exactly. Majority of SNPs have no effect on health and development
38
Backward slippage occurs in the ___________ strand
Synthesized strand
39
Backwards slippage will cause _________, causing the copied DNA to be ______
Insertion Longer
40
Where is backward slippage more common?
More common in regions where the DNA sequence is repetitive
41
In backwards slippage, a strand slips during replication and creates a ____
Loop
42
Why is the loop created in backwards slippage not repaired?
It is very stable and not recognized by DNA polymerase III or other repair enzymes
43
What kind of slippage occurs in the template strand?
Forward slippage
44
Forwards slippage will cause _________, causing the copied DNA to be ______
Deletion Shorter
45
When does forward slippage happen?
Can happen when the DNA polymerase is going too fast
46
True or False: Tautomeric shifts are NOT spontaneous events
False, tautomeric shifts are SPONTANEOUS events
47
True or False: Tautomeric shifts DO NOT result in a mismatch
True
48
If a tautomeric shift is not recognized by the cell as a mismatch, what is it?
A shift in preferential base pairing
49
Thymine and Guanine are mainly in ____ form, but can shift to ____ form
KETO ENOL
50
Adenine and Cytosine are mainly in _____ form, but can shift to _____ form
AMINO IMINO
51
What does ENOL T pair with?
Guanine
52
What does IMINE A pair with?
Cytosine
53
Define: Mutagens
Things that increases the rate of mutations in cells
54
True or False: DNA polymerase has perfect specificity
False, DNA polymerase does not have perfect specificity
55
What is an example of analogous molecule to thymine?
5-bromouracil
56
What can analogous molecules do to DNA replication?
Analogs are much more unstable in most cases and thus more likely to undergo tautomerization and cause mutation through tautomeric shifts
57
Define: Analogous
Similar in structure
58
Define: Transition Mutation
Purine to purine OR Pyrimidine to pyrimidine
59
Define: Transversion Mutation
Purine to pyrimidine OR Pyrimidine to purine
60
Give an example of a transition mutation:
AT to GC
61
Give an example of a transversion mutation
AT to CG
62
What are transposable elements?
Short regions of DNA that are able to move ("jump") around the genome
63
Where can we generally find transposable elements?
TEs are generally found in between genes - in the "safe havens"
64
True or False: Transposable Elements generally appear in between genes, which affects gene function
False, TEs generally appear in between genes in the "safe havens" so they don't interfere with the function of genes
65
Genome size does not necessarily reflect the ______ of _____ an organism has
Number Genes
66
How many TEs can a genome have?
Many, depending on the organism.
67
___ are the reason that genomes can be so _____
TEs Large
68
True or False: Most transposable elements are dead
True, most are silenced/deactivated by the host and longer undergo transposition (jumping around)
69
Can transposable elements still be active?
Yes, few can be active and fewer still can transpose
70
If a TE lands on a gene, what can it cause?
Can cause disease-causing mutations OR gene shuffling
71
Define and give an example of a: Multifactorial Disease
A disease that can be caused by a variety of factors, both environmental (exercise, diet, lifestyle) and genetics (SNPs) E.x. Heart disease
72
True or False: TEs can take a piece of genome and add it to another section
True, it can do this under a different promoter

My Packs: UWO (BIO 1001) (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions