Genetics Flashcards
1
Q
The units of inheritance
A
Genes
2
Q
Diseases caused by a mutation in a single gene
A
Mendelian
3
Q
XY code a
A
Man
4
Q
XX code a
A
Female
5
Q
Cystic fibrosis is an example of a
A
Mendelian Disease
6
Q
The central dogma of molecular biology
A
DNA>RNA>Protein
7
Q
The study of sets of genes in one or more species
A
Genomics
8
Q
On average 50% of children are affected with the disease and 50% are unaffected
A
Autosomal Dominant
9
Q
On average 25% of children are normal, 50% are carriers and 25% are affected with the disease
A
Autosomal Recessive
10
Q
On average 50% of male children from a carrier female will have the disease & 50% of female children will be carriers
A
X-linked
11
Q
Huntington’s disease is an example of
A
Autosomal Dominant
12
Q
What type of mendelian disorder is cystic fybrosis?
A
Autosomal recessive
13
Q
Haemophilia is an example of
A
X-linked recessive
14
Q
What diseases are treated by by suppression of
expression of the mutant gene?
A
Dominant diseases
15
Q
What diseases are treated by introducing a normal copy of the gene?
A
Recessive diseases
16
Q
Two genes that occupy the same position on
homologous chromosomes.
A
Allele
17
Q
The entire set of genes in an organism.
A
Genome
18
Q
A fixed location on a strand of DNA where a gene or one of its alleles is located.
A
Locus
19
Q
Having identical genes (one from each parent) for a particular characteristic.
A
Homozygous
20
Q
Having two different genes for a particular characteristic.
A
Heterozygous
21
Q
The allele of a gene that masks or suppresses the expression of an alternate allele
A
Dominant
22
Q
An allele that is masked by a dominant allele
A
Recessive
23
Q
The physical appearance of an organism
A
Phenotype
24
Q
A genetic cross involving a single pair of genes
A
Monohybrid Cross
25
Predicted that genes occur in pairs
Mendel
26
Mendel's Principles
1. Principle of Dominance
2. Principle of Segregation
3. Law of dominance
27
Mendel's Law of Dominance
One factor in a pair of traits dominates the other in inheritance unless both factors in the pair are recessive.
28
An organism with two identical alleles for a character
Homozygote
29
An organism with two different alleles for a gene
Heterozygote
30
Matings that involve parents that differ in two genes
Dihybrid Cross
31
The tendency of genes from the same chromosome to remain together when they enter the gamete.
Linkage
32
The appearance of new combinations of alleles.
Recombination
33
____ dominance occurs when phenotypes of the heterozygote and dominant homozygote are identical.
Complete
34
____ dominance, the phenotype of F1 hybrids is somewhere between the phenotypes of the two parental varieties.
Incomplete
35
____ dominance, two dominant alleles affect the phenotype in separate, distinguishable ways.
Co
36
Pleiotropy
The concept that most genes have multiple phenotype effects.
37
Cell division involving somatic cells
Mitosis
38
Cell division involving gametes
Meiosis
39
One pair of homologous chromosomes
A diploid cell
40
Each cell receives only one of the homologues
| (Half a chromosome)
Meiosis I
41
Each cell receives only one sister chromatid
Meiosis II
42
9:3:3:1 inheritance pattern
Dihybrid Cross
43
How many chromosomes are there?
23
44
Thomas Hunt Morgan worked with
Drosophila flies
45
Offspring with a phenotype matching one of the parental (P) phenotypes are called
Parental Type
46
Offspring with nonparental phenotypes are called
Recombinants
47
A protein structure that forms between homologous
chromosomes (two pairs of sister chromatids) during meiosis
The synaptonemal complex
48
The farther apart two genes are, the ____ the probability that a crossover will occur between them
higher
49
Griffith's Experiment
Insert different forms of strep into mice
| Demonstrated bacterial transformation
50
The movement of genetic material between unicellular and/or multicellular organisms other than by the vertical transmission of DNA from reproduction.
Horizontal Gene Transfer
51
The uptake of short fragments of naked DNA by naturally transformable bacteria.
Transformation
52
The transfer of DNA from one bacterium into another via bacteriophages.
Transduction
53
The transfer of DNA via sexual pilus and requires cell-to-cell contact.
Conjugation
54
A polymer of nucleotides, each consisting of a nitrogenous base, a sugar, and a phosphate group
DNA
55
The nitrogenous bases of DNA
* Adenine,
* Thymine,
* Guanine,
* Cytosine
56
1. The base composition of DNA varies between species
2. In any species the number of A and T bases is equal and the number of G and C bases is equal
Chargaff's Rules
57
To pack chromatin, DNA are wrapped around
Histones
58
Euchromatin
Loosely packed chromatin
59
Heterochromatin
Densely packed chromatin
60
Required properties of DNA
1. It must contain the Information required to construct and maintain life forms
3. Must be Inherited Intact through Generations
2. It must be Replicated with High Precision
61
A nucleotide is made up of
Phosphate + Sugar + Base
62
Purines
* Adenine
* Guanine
63
Pyrimidines
* Thymine
* Cytosine
* Uracil (RNA)
64
* dAMP
* dGMP
* dCMP
* dTMP
The 4 types of nucleotides
65
The only linkage allowed between nucleotides
Phosphodiester bond
66
The directionality of DNA is
5' to 3'
67
Replication of DNA is
semi-conservative
68
DNA synthesis occurs via
primer extension
69
DNA polymerase can only add nucleotides to the ____ end of a replicating strand.
3’
70
The ____ strand copies continuously in the direction of unwinding
Leading
71
The ____ strand copies in segments
Lagging
| Through Okazaki Fragments
72
Okazaki fragments are joined by
Ligase
73
Uracil replaces ____ in RNA
Thymine
74
* This is the RNA transcribed from ‘protein-coding’ genes
* encode the information for specific proteins
mRNA
75
* Is a structural & functional component of Ribosomes
* is very stable
* is a non-coding RNA
rRNA
76
* Very abundant and very stable
* A non-coding RNA
* 'Clover-leaf’ secondary structure
tRNA
77
The synthesis of RNA based on a DNA template
Transcription
78
DNA sequences that guide RNAP to the beginning of a gene to start transcription
Promoters
79
DNA sequences that specify the termination of RNA synthesis, and the release of RNAP from the DNA
Terminators
80
Roles of RNAP
| RNA Polymerase
* Initiates transcription
* Elongates the mRNA chain
* Terminates transcription
81
The process of making an mRNA copy of the DNA sequence via RNAP
Elongation
82
RNAP I - makes
rRNA
83
RNAP II - makes
mRNA
84
RNAP III - makes
tRNA
85
____ remove introns from pre-mRNA
Spliceosomes
86
Gene regulation dictates
1. When
2. Where
3. How much
87
The fundamental unit of gene organization and regulation of gene expression in Prokaryotes
Operons
88
A set of genes encoding enzymes each of which is required in the same metabolic pathway
Operons
89
Genes that encode Regulatory Proteins that control the expression of other genes
Regulatory Genes
90
That may function either as Repressors
(or Activators) of gene expression
Regulatory Proteins
91
DNA + Histones =
Nucleosome
92
* Chromatin is compacted
* Histone tails have methyl groups
* DNA is inaccessible
Heterochromatin
93
* Chromatin is ‘open’ or ‘loose’
* Histone tails have acetyl groups
* DNA is accessible
Euchromatin
94
Amino acids linked together via peptide bonds
Polypeptide
95
A polymer with a sequence of 20 different amino acids
Protein
96
The mRNA sequence is decoded _ bases at a time
3
| A codon
97
One codon specifies ____ amino acid
one
98
The decoding machinery disengages from the mRNA when it encounters a
STOP Codon
99
The Anticodon region recognizes and binds to a codon in _RNA by base pairing
m
100
How does a given tRNA acquire its specific amino acid?
Aminoacylation
101
What do ribosomes do?
Make protein
102
When a ____ enters the A site of the ribosome, a protein called Release Factor is recruited
STOP codon
103
* many ribosomes translating a single mRNA
* A protein production line
Polysomes
104
Individuals with different forms (alleles) of the same gene
Variants
105
Variants are typically referred to as ____, if they have
been deliberately produced in the laboratory
mutants
106
Somatic mutations
Not inherited
107
Germline mutations
Inherited
108
What is a mutation caused by external factors?
Induced
109
What is a mutation caused by errors in DNA replication?
Spontaneous
110
Chemical mutagens that cause cancers.
Carcinogens
111
Example of a missense mutation
Sickle Cell Disease
