Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

MBCHB - PRINCIPLES 1 Summary > Genetics Summary > Flashcards

Genetics Summary Flashcards

1
Q

What contributes to disease?

A

Genes and environment

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

In what fashion do DNA strands pair up?

A

Antiparallel

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

What direction is DNA replicated and read?

A

5’ to 3’ direction

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

What type of backbone does DNA have?

A

Sugar-phosphate backbone

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

How are DNA strands wound?

A

By associating with proteins including Histones

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

What is the wound DNA structure called?

A

Chromosome

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

When does disease occur in relation to DNA replication?

A

DNA can be damaged during replication, disease occurs when repair mechanisms are defective

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

What joins Okazaki fragments together?

A

DNA ligase

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

What unzips DNA?

A

DNA helicase

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

What does Mitosis produce?

A

One diploid parent cell becomes two identical diploid daughter cells

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

What does Meiosis produce?

A

One diploid parent cell becomes 4 varying haploid daughter cells

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

What process produces genetic variation between cells produced via meiosis?

A

Crossing over

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

When is meiosis used?

A

Formation of gametes

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

What type of back bone does RNA have?

A

Ribose sugar backbone

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

What is central dogma?

A

DNA is transcribed into preRNA
PreRNA is spliced into mRNA
mRNA is translated into protein

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

How many bases encode 1 amino acid or stop codon?

A

3 bases

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

What are the possible sequence variations within a gene?

A

Changes in promoter sequence (marks where gene begins)
Changes in exon sequence

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

What are the possible sequence changes possible in DNA between genes?

A

SNPs (Single Nucleotide Polymorphisms)
Larger deletions or duplications

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

What are polymorphisms?

A

Any variation in human genome which has a population frequency of greater than 1%

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

Do polymorphisms cause disease?

A

Not in their own right but can predispose to common disease

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

What is a mutation?

A

Any heritable change in the human genome
Gene change that causes a genetic disorder

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

What is classical genetic disease?

A

One mutation sufficient to cause disease

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

What is multifactorial disease?

A

Multiple polymorphisms cause risk of disease

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

What is the chromosomal nomenclature of a normal female?

A

46 XX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the chromosomal nomenclature of a normal male?
46 XY
26
What is a balanced chromosomal rearrangement?
All chromosomal material is present
27
What is unbalanced chromosomal arrangement?
Extra or missing chromosomal material
28
What is aneuploidy?
Whole extra or whole missing chromosome
29
What is translocation?
Rearrangement of chromosomes
30
What condition is 47 XY +21?
Down's syndrome Trisomy 21
31
What condition is 47 XY +14?
Miscarriage Trisomy 14
32
What condition is 47 XY +18?
Edward syndrome Trisomy 18
33
What condition is 45 X?
Turner syndrome
34
What condition is 47 XXY?
Klinefelter syndrome
35
What is Robertsonian translocation?
Long ends of two acrocentric chromosomes are stuck together end to end Short ends are lost
36
What does Microarray CGH detect?
Missing or duplicated chromosome
37
What is PCR?
A small piece of human genome is amplified and sequenced to find mutations
38
What is FISH?
Used to light up a specific sequence of chromosome
39
Mutation Promotor and splice site sequence changes causes
Stopping of transcription Abnormal splicing
40
Mutation Base changing causing amino acid change causes
Change in protein sequence May or may not reduce protein function
41
Mutation Premature stop codon causes
Shortened protein May or may not reduce protein function
42
Mutation Insertion or deletion of bases
May or may not change protein produced
43
What is a Mendelian disorder?
A disease that is caused by a change in a single gene
44
Autosomal Dominant How many generations are affected?
All generations
45
Autosomal Dominant What is the risk of affected child if parent affected?
50%
46
Autosomal Dominant How severe is disease?
Variable severity
47
Autosomal Dominant Is a particular sex more affected?
Both males and females are equally likely to be affected
48
Autosomal Dominant How many copies of gene are required to cause disease?
Only 1 copy of faulty required to cause disease
49
Autosomal Recessive How many copies of gene required to cause disease?
2 copies faulty gene are required to cause disease
50
Autosomal Recessive How many generations are affected?
Often only one generation is affected
51
Autosomal Recessive How likely is it that a child is affected if parents are carriers?
25%
52
Autosomal Recessive What increases likelihood of being affected by this disorder?
Consanguineous (incestuous) families
53
Autosomal Recessive What does this type of disorder cause?
Usually loss of function
54
X-linked Is this type of disorder dominant or recessive?
Recessive
55
X-linked What role does the Y chromosome play in this type of disorder?
Almost irrelevant
56
X-linked If a mother is a carrier, what is the chance of daughter being a carrier or son being affected?
50% chance of daughter being a carrier 50% chance of son being affected
57
X-linked If a father is affected, what is the chance of daughter being a carrier or son being affected?
50% chance daughter is affected 0% chance son is affected
58
What is X-inactivation?
In females one of X chromosomes within each cell is randomly inactivated
59
Why does X-inactivation occur?
Cell only required one working copy of the X chromosome
60
Mitochondrial Disorders Where is mitochondrial DNA inherited from?
Almost exclusively maternally
61
Mitochondrial Disorders What does mitochondrial DNA contain?
Genes for mitochondrial metabolic pathways and ribosomal RNAs
62
Mitochondrial Disorders Symptoms of this type of disorder
Myopathy - disease of muscle tissue Diabetes Deafness Optic atrophy - damage to optic nerve Stroke like episodes Encephalitis - inflammation of brain
63
What is haploinsufficiency?
Having only one copy of working gene is not enough
64
What is a dominant negative?
Abnormal protein interferes with normal protein
65
What is a Gain of function mutation?
A mutation activated gene
66
Mendelian Disorders What extent does environment contribute to disease?
Small environmental contribution
67
Mendelian Disorders What level is penetrance of this type of disorder?
High penetrance
68
Multifactorial Disease What role does genetic change play in risk of disease?
Just another risk factor
69
Multifactorial Disease What is the penetrance of one mutation in this type of disorder?
Low for any one mutation
70
What does DNA methylation cause?
Modification of histones which represses transcription
71
What does imprinting cause?
Differences in gene expression depending on whether the gene was maternally or paternally inherited
72
What is Heteroplasmy?
Different daughter cells contain different proportions of mutant mitochondrial
73
What characteristics are gained by cells on progression to cancer?
Proliferation Evasion of immune system Aquire vascular supply Avoid apoptosis Metastasis - development of secondary growths
74
What genes are involved in cancer?
Oncogenes Tumour suppressors DNA repair genes Drug metabolism
75
Cancer What is oncogenes role?
Switch on for cell division
76
Cancer What are tumour suppressors role?
Switch on to stop cell division
77
Cancer What is the role of Drug metabolism?
Genes that metabolise carcinogens
78
What are mechanisms of gene activation?
Duplication of gene Activation of gene promotor Change in amino acid sequence

MBCHB - PRINCIPLES 1 Summary (5 decks)

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