Heredity & Gene Expression and Regulation (5+6) Flashcards
(123 cards)
1
Q
Polygenic Trait
A
Phenotypic characteristics that are affected by more than one allele
1
Q
Epiststasis
A
The expression of one gene effects the expression of another gene
2
Q
What did Morgan do?
A
Studied fruit flies, and determined X-Linked traits (SEX-LINKED TRAITS)
- Linked genes (on same chromosome = get inherited together)
3
Q
Cross over is a form of ___?
A
Genetic recombination and INCREASES diversity
4
Q
Cross over frequencies
A
Farther apart = greater chance of crossing over
5
Q
Null Hypothesis
A
No relationship between the variables
6
Q
Pleiotropy
A
1 gene has multiple effects on an organism
ex. Sickle Cell Anemia
7
Q
Co-Dominance
A
Two alleles are expressed equally
8
Q
Incomplete Dominance
A
Neither of the two alleles can concel the other
ex. Pink Flower (from red and white parents_
9
Q
True Breeding
A
Homozygous for all alleles being considered
10
Q
Test Cross
A
Homogenous recessive x unknown individual
11
Q
Non- Disjunction
A
Failure of a chromosome to fully separate during meiosis/gamete formation
12
Q
Non Nuclear Inheritance
A
Mitochondira and chloroplast
mitochondria are maternally inherited (egg not sperm)
13
Q
Mendels Law of Segregation
A
Diploid. -> meiosis (randomly segregates 1 copy of each gene into each gamete)
14
Q
Mendels Law of Dominance
A
Complete dominance
14
Q
Mendels Law of Indepedant Assortment
A
9:3:3:1
The two alleles of one gene segregates independantly (meiosis) of the alleles from another gene
- Genes are not linked
15
Q
DNA contains…
A
Instructions for making RNA, which contains instructions for making proteins, which carry out cell functions
16
Q
DNA is a long mass of strands called?
A
Chromatin
17
Q
During cellular division, DNA is reorganized and ___ into ____.
A
Condensed, chromosomes
18
Q
Histones
A
An organized arrangement of proteins that condense DNA into chromosomes
19
Q
Human somatic cells have __ chromosomes
A
46
22 pairs of homologus chromosomes
1 pair of sex chromosomes
20
Q
Homologous
A
Similar but not the same
ex. Blue eye and Green eye allele
21
Q
Allele
A
Different form of the same gene
22
Q
Diploid
A
A cell that contains pairs of homologous chromosomes
# in humans = 46
23
Haploid
Cell containing unpaired chromosomes (sperm and egg cells)
24
Polyploid
More than two sets of homologous chromosomes
25
What is the purpose of the cell cycle
To pass genetic information from parent to daughter cell, through cellular division
26
What are the four phases of the cell cycle
G1, S Phase, G2 Phase, Cytokinesis
27
Interphase includes
G1 phase, s phase, G2 phase
28
What happens during G1 Phase
Rapid growth and metabolic activity
29
What happens during S Phase?
Synthesis (DNA is replicated)
2 identical chromosomes are joined at the centromere
30
What happens during G2 Phase?
Cell rebuilds reserve energy and makes required proteins for cell division
31
What happens during prophase?
Centrioles migrate to opposite poles of the cell and the nuclear membrane fades
32
What are centrioles?
Small proteins that provide a site for spindle fibres to attach to
33
What happens during metaphase?
Sister chromatids move towards the center of the cell
34
What happens during anaphase?
Centromeres divide and sister chromatids (now chromosomes) move to opposite poles
35
What happens during telophase?
Chromosomes reach opposite poles of the cell
Spindle fibres dissolve
Nuclear membrane forms around each mass of chromatin
36
What happens during cytokinesis
Splitting of the cytoplasm
37
What happens during animal cell cytokinesis?
Furrow develops, pinching cell into 2 pairs
38
What happens during plant cell cytokinesis?
Cell plate develops = new cell wall
39
Are centrioles found in plants?
NO
40
What is the cell clock?
Regulates how many times a cell divides
41
Trisomy 21
Down Syndrom
42
Female with 1 X chromosome
Turners Syndrom
43
XXY
Klinefelters Syndrom
44
Trisomy 13
Patau's Syndrom
45
Trisomy 18
Edwards Syndrom
46
XYY
Jacobers Syndrom
47
When does crossing over occur?
Prophase 1 (meiosis)
48
Who discovered DNA structure and base pairing?
Watson and Crick
49
Who discovered DNA's helical shape
Franklin
50
DNA replication occurs during...?
The S phase of cell cycle in a semiconservative fashion and in a 5' to 3' direction
51
What are operons?
They act as on/off switches for transcription (allow for gene production to happen only when needed)
52
What is central dogma?
The flow of genetic information
DNA -> RNA -> Proteins
53
What does Helicase do?
Unzips DNA by breaking H bonds between nucleotides to produce a Replication Fork
54
What are primer sites?
They indicate where replication should begin
55
What does primase do?
Binds to the primers and to create the primer region
56
What does DNA polymerase do?
attaches to the primer region and adds nucleotides to a growing DNA strand in 5' -> 3' direction
57
Leading strand
The DNA strand that is copied continuously in the replication fork
58
Lagging strand
Consists of okazaki fragments
59
What does DNA lygase do?
Glues together okazaki fragments
60
What is excision repair?
A section of DNA containing an error is cut out and then filled in by DNA polymerase
61
What does topoisomerase do?
Helps in the unwinding and rewinding of DNA (relaxes supercoil at replication fork)
62
What does lygase do?
Connects two strands of DNA together by forming a bond between the phosphate group of one strand and the deoxyribose group of another
63
What are telomeres?
Short repetitative DNA sequences at the end of chromosomes that protect the ends of chromosomes
64
What does telomerase do?
Produces protective DNA sequences (telomeres)
65
Which bases are purines?
A, G (pure sliver)
66
Which bases are pyrimidines?
C, T
67
Gregor Mendel determined...?
Factors called genes are inherited in a particular manner
68
Erwin Chargaff proposed...?
A 1:1 ratio of purines and pyrimidines
69
Watson and Crick ..?
A model showing an anti-parallel double helix
70
Rosalind Franklin...?
used x-rays to show a helical structure of DNA
71
Thomas Hunt Morgan...?
Studied fruit flies and proposed the chromosomal theory of inheritance
72
What is DNA Replication?
Creating an exact copy of a DNA molecule (its genome), during S phase
73
What does semi conservative replication mean?
Each new molecule of DNA contains one parent strand of the original complimentary DNA molecule and one new strand
74
What happens during initiation?
DNA replication 1
Helicase enzyme bonds to the replication origin on the DNA, the double strand opens creating s replication fork (free bases are exposed)
75
What is the replication fork?
Two unwound DNA strands that branch out into two complimentary single strands (templates for making new DNA strands)
76
What happens during elongation?
DNA replication 2
RNA primers attach to free nitrogen bases to act as starting blocks with the help of primase enzyme.
Then, DNA polymerase adds complimentary base pairs to both original strands from 5' to 3'
Then, DNA lygase enzyme glues the two new growing strands together
77
What direction is DNA built in?
5' -> 3' (nucleotides are added to 3' end (free OH)
78
What are the conditions for elogation to occur?
1. Can only occur in the 5' to 3' direction
2. A short strand of RNA (primer) must serve as starting point for the attachment for new nucleotides
79
What happens during termination?
DNA replication 3
80
Where does transcription occur?
In the nucleus
81
What happens during transcription?
Sections of one DNA strand is copied into a messenger RNA (mRNA) molecule
82
Where does translation occur?
In the cytoplasm
83
What happens during translation?
mRNA is translated into a chain of amino acids using transfer RNA (tRNA) molecules and ribosomes
84
What is the sense strand?
The one strand of the DNA molecule that is transcripted
85
What is the anti-sense strand?
The not transcripted DNA strand
86
What does mRNA do?
Carries info from the DNA in the nucleus to protein synthesis machinery in the cytoplasm
87
What does RNA polymerase do?
Creates a complimentary strand of codons to the sense strand of DNA (during transcription)
88
What are the three characteristics of the genetic codea/
1. Redundant
2. Continuous
3. Universal
89
How is genetic code interpreted?
mRNA codon (not DNA codon)
90
What are codons?
DNA triplets
91
What is the mRNA codons the same as?
Complimentary to the sense strand
Excatly the same as the anti-sense strand
92
What funky shape does anti-codons have?
Hairpin loop (because of attractive forces)
93
RNA polymerase copies the gene by base pairing with what strand?
Non coding strand
94
How is a mutation inherited?
If it happens in the gametes (germ cells)
95
What mutation are not inherited/
Mutations that occur in the somatic cells
96
What is a silent mutation?
An incorrect nucleotide is subsituted, but still codes for the same amino acid = no effect on protein function
97
What is a mis-sense mutation?
An incorrect nucleotide is subsituted, changing the amino acid.
98
What is a conservative mis-sense mutation?
An amino acid change but the amino acid has the same properties (hydrophilic/phobic)
- Usually not deleterious
99
What is a non - conservative mis-sense mutation?
Amino acid change with a deleterious loss of function
100
What is a heterozygous advantage?
Explains why some deleterious mutations are maintained in a population
101
What is a non-sense mutation?
An insertation or deletion of a base.
Causes the protein to be non functional
102
What is a frame shift mutation?
The codons are shifted one base forward or backward because of the insertion or deletion of a base)
103
What is a point gene mutation?
Lead to evolution (can be beneficial or harmful)
ex. Cystic Fibrosis, Sickle Cell Anemia
104
What is recombinant DNA?
DNA that includes genetic material from different sources
105
What is Restriction Endonucleases (RE)
Enzymes that catalyze the cleavage of DNA at specific nucleotide sequences
106
What is DNA's charge?
Negative (PO4-, OH-)
107
What is bacterial transformation?
Gene alteration of a cell from the direct uptake and incorporation of exergonic (foreign) material
108
What are intercoms?
Sequences of mRNA that do not code for amino acids
109
What are inducers?
Molecules that can bind to the regulatory protein and cause it to change shape
110
What is alternative splicing?
The process of splicing internos and connecting exons in mature mRNA
Exons can be retained in different variations which leads to different proteins
111
What is an operen?
Closely linked genes that produce 1 mRNA molecule during transcription.
It is under control of the same regulatory sequence and the operator
112
What is an operator?
A sequence that inhibits or promotes transcription by binding with regulatory proteins
113
What does a GTP Cap do?
It protects the mRNA transcript and helps ribosomes attach to mRNA
114
What is the poly-A tail?
100-200 adenine bases that increase the stability of the mRNA and helps in exporting from nucleus
115
What are promoters?
DNA sequences that are upstream from the transcription start where RNA polymerase and transcription factors bind to initiate transcription
116
What is horizontal transfer of genetic information?
The exchange of genetic information between different genomes or between unrelated organisms
117
What is transformation?
A type of horizontal transfer
The uptake of naked DNA from an external environmental source
118
What is naked DNA?
DNA not protected by proteins or other molecules
119
What is transduction?
A type of horizontal transfer
Transmission of foriegn DNA into a cell when a viral genome integrates with the host
120
What is conjugation?
A type of horizontal transfer
Cell to cell transfer if DNA through external extension
121
What is transposition?
The movement of DNA segments without n and between DNA molecules
