1
Q
How many chains of nucleotides in DNA
A
2
2
Q
Nitrogenous bases in DNA (4)
A
- Adenine (A)
- Thymine (T)
- Cytosine (C)
- Guanine (G)
3
Q
Found in all DNA (3)
A
- Deoxyribose sugar
- Nitrogenous bases
- Phosphate groups
4
Q
Components of a DNA backbone (2)
A
- Phosphate
- Sugar
5
Q
What ends of phosphates and sugars are in DNA (2)
A
- 5’ end with a phosphate
- 3’ end with a pentose
6
Q
DNA backbone is formed when nucleotides combine in a ___ reaction
A
Condensation
7
Q
Condensation reaction:
A
Molecule + molecule -> molecule = water
8
Q
monomer ___ combine to form the polymer ___
A
Nucleotides, DNA chain
9
Q
In the condensation reaction, the ___ group on one nucleotide forms a new ___ bond with the ___ group on the deoxyribose of the next nucleotide
A
5’ Phosphate, covalent, 3’ carbon
10
Q
DNA is built from __’ to __’
A
5’ to 3’
11
Q
What bond creates the double helix
A
Phosphodiester bond
12
Q
The two different strands of the DNA double helix run in the ___ direction
A
Opposite
13
Q
5’ - 3’ strand
A
Leading strand
14
Q
3’ to 5’ strand
A
Lagging strand
15
Q
weak chemical attractions between two polar molecules
A
Hydrogen bonds
16
Q
Adenine pairs with thymine with ___ hydrogen bonds
A
Two
17
Q
Guanine pairs with Cytosine with ___ hydrogen bonds
A
Three
18
Q
Which bonds are stronger: between A+T or G+C?
A
G+C (3 hydrogen bonds instead of 2 like A+T)
19
Q
Complementary base pairing has a vital role in allowing genetic information to be ___ and ___
A
Replicated and expressed
20
Q
What are DNA and RNA
A
Nucleic acids
21
Q
What kind of sugar is in DNA
A
Deoxyribose
22
Q
What kind of sugar is in RNA
A
Ribose
23
Q
Molecules that designate a nucleic acid as RNA
A
OH
24
Q
Molecules that designate a nucleic acid as DNA
A
H
25
Depending on the type of RNA, the molecule can twist and bind to ___
Itself
26
Function of DNA (2)
1. Passes heredity information between generations of cells
2. Codes for making RNA during transcription
27
Function of RNA (2)
1. Codes for making proteins during translation
2. mRNA, rRNA, and tRNA are the three main types of RNA involved in protein synthesis
28
Location of DNA
Nucleus
29
Location of RNA
Made in nucleus then moved to cytosol
30
A small amount of DNA can also be found in the ___ and ___
Mitochondria and chloroplasts
31
RNA that becomes part of 80s (eu) or 70s (pro) ribosome structure bound to the rough ER or are free floating in the cytoplasm
rRNA
32
RNA that is exported into the cytoplasm, where they are translated at ribosomes to produce proteins
mRNA
33
RNA that is found in the cytoplasm where they perform their function of delivering amino acids to growing polypeptide during translation
tRNA
34
Where is DNA found in a prokaryote (2)
1. Nucleoid
2. Plasmids
35
When A pairs up with T/U and G pairs up with C
complementary base pairing
36
During translation, the mRNA ___ will complementary base pair with the tRNA ___
Codon, anticodon
37
When the original DNA strand is halfway conserved, meaning each new DNA molecule is half old and half new
Semiconservative replication
38
The sequence of DNA nucleotides is the basis of a genetic code used for the production of ___ and ___
RNA and Proteins
39
The synthesis of RNA using a DNA template. The enzyme RNA polymerase builds an RNA strand by “reading” the DNA template and adding the complementary RNA nucleotide
Transcription
40
results in the RNA strand having the complementary sequence of bases as the DNA, thereby maintaining the information stored in the sequence of nucleotides of the code
Translation
41
RNA ___ transcribes DNA
Polymerase
42
The synthesis of a polypeptide from mRNA. The ribosome builds a polypeptide by reading the mRNA template and binding the coded amino acid to the polypeptide chain
Translation
43
The amino acids are brought to the ribosome by a tRNA. The tRNA forms a temporary bond to the mRNA using ___
Complementary Base Pairing
44
DNA stores ___ in the sequence of the ___
Information, Nitrogenous Bases
45
DNA is a double helix made of two ___ strands of nucleotides
Antiparallel
46
The Two functions of Information Stored in DNA
1. Passes information between generations
2. Codes for protein production
47
DNA is considered the molecule of ___ in all living organisms
Heredity
48
DNA has a ___ Capacity to Store Information
Limitless
49
The order in which the different types of nucleotides are arranged in DNA or RNA serves as a ___ for the making of a protein
Code
50
n the genetic code, a group of __ nucleic acid bases signifies for an amino acid
3
51
Do viruses use the same genetic code as living organisms?
Yes
52
The explanation for genetic universality is that the genetic code was the one carried by the ___ and it has been passed over time to all of its descendents
Last Universal Common Ancestor (LUCA)
53
All of an organism's DNA
Genome
54
Pathway of DNA
DNA -> gene -> chromosome -> genome -> cell
55
How much of your total genome is in each cell?
All of them
56
The space between genes that arranges chromosomes in the nucleus
Intergenic region
57
How many chromosomes in a person
(23 pairs)
58
Chromosome types (2)
1. Autosomes
2. Sex chromosomes
59
Chromosomes that go together
Homologous pairs
60
Picture that shows all the chromosomes in a person
Karyograph/karyotype
61
Molecules of DNA wrapped around proteins where genes are located
Chromosomes
62
A sequence of DNA bases that codes for functional RNA or protein product. Also referred to as a trait
Gene
63
The basic functional unit of inheritance
Gene
64
Genes can be a few ___ base pairs long to a few ___
Hundred, million
65
Where on the chromosome a gene is located
Gene locus
66
Plural of locus
Loci
67
Chromosome number is ___ within a species
Conserved
68
___ sequences can be genes or not
Copied
69
___ sequences can have implications for height, health, disease and more
Duplicate
70
any biological system that functions as an individual life form
Organism
71
a group of organisms of the same species in the same area
Population
72
the populations of two or more different species occupying the same geographical area at the same time
Community
73
differences between members of a group. Can be discrete or continuous
Variation
74
traits that can be put into distinct qualitative categories. Usually influenced by only one or a few genes and can be influenced by environment, although usually not significantly
Discrete variation
75
traits that vary along a quantitative continuum. Most types of biological variation are this. Result from complex interaction between many different genes, often with the environment playing a significant part in the expression of the phenotype
Continuous variation
76
many different genes
Polygenic
77
Variations exist at these levels (4)
1. Molecules
2. Cells
3. Organisms
4. Ecosystems
78
Variation within a species
Intraspecies variation
79
Genetic variation within a species is ___, meaning transmitted from parents to offspring
Inheritable
80
Genetic variation within a species can result from these (4)
1. Mutation
2. gene flow
3. Meiosis
4. Sexual reproduction
81
the changes in the sequences of genes in DNA
Mutation
82
the movement of genes between different populations of organisms
Gene flow
83
the formation of egg and sperm which leads to the creation of new combinations of alleles
Meiosis
84
random fertilization between egg and sperm
Sexual reproduction
85
One of two or more versions of DNA sequence at a given locus (aa, AA, aA, Aa)
Allele
86
The genetic makeup of an organism for a particular trait
Genotype
87
The observable characteristic from the genotype for a particular trait
Phenotype
88
The main force that drives evolution
Natural Selection
89
he clearly distinguishable shapes and forms of organisms
Morphology
90
Dear King Philip Came Over For Good Soup
1. Domain
2. Kingdom
3. Phylum
4. Class
5. Order
6. Family
7. Genus
8. Species
91
"A species is a group of actually or potentially interbreeding populations which are reproductively isolated from other such groups"
Biological species concept
92
the offspring resulting from the sexual reproduction between two closely related, but separate species
Hybrid
93
Method of asexual reproduction wherein part of the parent body is ‘pinched off’ to produce a small individual exactly like the parent
Budding
94
Method of asexual reproduction wherein the single parent cell divides into two daughter cells
Binary Fission
95
different stages in the same evolving lineage that existed at different points in time without splitting or branching
Chronospecies
96
the formation of new and distinct species in the course of evolution
Speciation
97
Does the number of chromosomes correlate to the number of genes?
No
98
Breaking of a chromosome into two smaller chromosomes
Chromosome splitting
99
When two different chromosomes grab onto each other fusing to become a single one
Chromosome fusion
100
Which human chromosome was formed by the fusion of two ancestral chromosomes that remained separate in other primates
Chromosome 2
101
Evidence that the primate chromosomes 12 and 13 fused to form the human chromosome 2 (2?)
1. The genes are in the same order when 12 and 13 are aligned with 2
2. The centromere in one of the original chromosomes lines up with chromosome 2's centromere
102
an image of chromosomes arranged in a standard format
Karyogram
103
the description of the chromosomes as seen in the karyogram
Karyotype
104
the process of determining the karyotype by creating a karyogram
Karyotyping
105
Benefits of karyotyping (3)
1. Can reveal changes in chromosome number, such as trisomy 21 (Down syndrome)
2. Can indicate chromosomal sex
3. Can provide information for specific birth defects, genetic disorders, and cancers
106
Steps of karyotyping (6)
1. Sample collection and cell culture
2. Inhibition of mitosis with drugs
3. Separate the chromosomes
4. Staining
5. Photography
6. Karyogram preparation
107
What chemical is used to stop mitosis in metaphase
Colchicine
108
A small sample of cells (called chorionic villi) is taken from the placenta
Chorionic Villus Sampling
109
Amniotic fluid is removed from the uterus
Amniocentesis
110
The fluid that surrounds and protects a baby during pregnancy
Amniotic fluid
111
This solution is added to the cultured cells which causes the cells to take in water and in effect swell up and burst
Hypotonic salt solution
112
How to tell if a person had Down syndrome based on their karyogram
There will be 3 "chromosome 21"s instead of 2
113
How can genomes vary between species (3)
1. Composition of nucleotides
2. Size
3. Number of genes
114
Characteristics shared across individuals of the same species (2?)
1. Chromosome number
2. Gene number
115
What causes variation between members of the same species
Alleles (differences in the gene sequence)
116
A difference in a single nucleotide. The most common type of genetic variation among members of a species
Single Nucleotide Polymorphisms (SNPs)
117
The possible SNPs that can occur in a gene
Allele
118
A change in a single nucleotide base
Point mutation
119
Types of point mutations (3)
1. Insertion
2. Deletion
3. Substitution
120
Mutation where a nucleotide base is removed from the sequence (ex: AT GC GC -> AT GC)
Deletion mutation
121
Mutation where a nucleotide base is added to the sequence (ex: AT GC GC -> AT GC GC AT)
Insertion mutation
122
Mutation where a nucleotide base is swapped for a different base (ex: AT GC GC -> AT AT GC)
Substitution mutation
123
How does point mutation affect protein structures
The mutation can cause the structures to lose their function, have a different function, or change their level of functioning
124
Relationship between SNPs and mutations
SNPs are a type of mutation that are much more common, occurring in at least 1% of the species population
125
Factors that can cause mutations (3)
1. Errors in DNA replication
2. Radiation
3. DNA breaks down
126
The fact that every organism uses almost the exact same code. Evidence for universal common ancestry
DNA Universality
127
Impact of DNA's antiparallel backbones on DNA replication
The leading backbone strand (5' to 3') of the replication fork can synthesize new nucleotides continuously, while the lagging strand (3' to 5') must synthesize nucleotides in bursts
128
DNA strand that uses polymerase to continuously synthesize new nucleotides on the replication fork
Leading strand
129
DNA strand that uses polymerase to synthesize new nucleotides on the replication fork in short pieces called okazaki fragments
Lagging strand
130
What kind of bonds hold together the nucleotides of a double helix
Hydrogen bonds
131
What kind of bonds hold together the sugar and phosphates of a double helix
Phosphodiester bonds
132
This system allows DNA to accurately replicate itself and its genetic code
Complementary base pairing
133
Impact of hydrogen bonding on DNA replication
The hydrogen bonds between complementary nucleotides are strong enough to be stable and directional but weak enough to be broken apart for replication/transcription
134
Enzyme that catalyzes the breaking of hydrogen bonds between nucleotides and unwinds the double helix into the replication fork ("unzips" the DNA)
Helicase
135
Enzyme that relaxes the supercoiled DNA so the double helix doesn't get too tightly wound from the tension. Does this by making little nicks in the helix to release the tension
Topoisomerase
136
Enzyme that reads the nucleotides on one strand of the replication fork and adds the corresponding nucleotides on the new strand
DNA Polymerase
137
Enzyme that synthesizes short RNA primers that DNA Polymerase can build nucleotides upon (starting point for the polymerase)
Primase
138
Enzyme that synthesizes a phosphodiester bond between the two backbones of DNA, thus finalizing the DNA replication process
Ligase
139
Areas of the genome that are more likely to mutate
Highly repetitive sequences (ex: trinucleotide repeats)
140
When more than one codon is translated into the same amino acid. Provides some protection against mutations
Degeneracy
141
The sequence of nucleotides that actually codes for protein and is “read” by the ribosome
mRNA reading frame
142
mRNA strands frequently have ___ reading frames
Multiple
143
Proteins that do not work will cause a change in the ___
Phenotype
144
Mutations that are usually a change in 1 to 3 nucleotides and only affect one gene
Point mutations
145
When do point mutations occur
DNA synthesis
146
Mutations that affect big sections of chromosomes and affect many genes
Chromosomal mutations
147
When do chromosomal mutations occur
Meiosis
148
Types of point mutations (2)
1. Substitution mutations
2. frameshift mutations
149
A type of point mutation where the original nucleotide is replaced by a different nucleotide
Substitution mutation
150
Types of substitution mutations (3)
1. Silent mutations
2. Missense mutations
3. Nonsense mutations
151
A change in a single nucleotide that doesn’t result in a change in amino acid sequence.
No effect on protein structure or function and thus no change in the phenotype
Silent mutation
152
A change in a single nucleotide that results in a change in a single amino acid in the sequence. Variable effect on protein function and phenotype
Missense mutation
153
Possible effects of missense mutations (3)
1. protein stops working entirely: amino acids with completely different chemical properties are incorporated into the activate site of a protein
2. Protein has decreased functionality: amino acids with similar chemical properties are incorporated into the active site of the protein
3. New/Increased protein function: a change in amino acid sequence that allows the protein to be more functional and/or gain a completely new function leading to a new phenotype. Very rare
154
A change in a single nucleotide that results in a premature stop-codon in the mRNA sequence, so the codons after the stop codon will not be translated. This means the protein will not have all its amino acids, so it will not fold/function properly
Nonsense mutation
155
A type of mutation where addition or removal of a single nucleotide changes the reading frame for the protein. Always has a negative effect on protein structure and phenotype
Frameshift mutation
156
Types of frameshift mutations (2)
1. Insertion mutation
2 Deletion mutation
157
Insertion of a single nucleotide into the DNA sequence. This changes the reading frame which also changes the entire amino acid sequence after the insertion, so the protein will not fold or function correctly
Insertion mutation
158
Deletion of a single nucleotide into the DNA sequence. This changes the reading frame which also changes the entire amino acid sequence after the deletion, so the protein will not fold or function correctly
Deletion mutation
159
Mutations can sometimes ___ genetic variation in a population. This only occurs if the mutation causes a change in the protein that alters the ___ of the mutant organism
Increase, phenotype
160
A change in allele frequency in a population over time
Evolution
161
Current uses of genome sequencing (3)
1. Better understanding genetics, aka how DNA is replicated and what this means for an organism
2. Better understanding diseases and how to treat/cure them (CRISPR)
3. Better understand evolution
162
Are all of an organism's genes expressed in all of their cells all of the time?
No. While all cells have all the genes in the organism, they only express ("turn on") the genes needed for their specific function
163
Process of DNA replication (10)
1. Helicase breaks the hydrogen bonds between nucleotides
2. Topoisomerase relaxes the supercoiled DNA molecule so that it can form the replication fork
3. On the leading strand: DNA primase synthesizes RNA primers on the strand for DNA polymerase to build nucleotides upon
4. DNA polymerase reads the nucleotides on one strand and adds the corresponding nucleotides on the new one
5. Lagging strand: DNA primase synthesizes multiple short RNA primers
6. DNA polymerase adds corresponding nucleotides in short bursts called okazaki fragments
7. Both: Ligase creates phosphodiester bonds between the strands to make the two separate DNA molecules (mainly stitches together okazaki fragments)
8. Exonuclease removes the RNA primers
9. Telomerase (type of DNA polymerase) synthesizes telomere sequences at the ends of the DNA so the final chromosomes don't fuse
10. Topoisomerase supercoils the relaxed DNA molecules back into their double helix shape
164
Process of DNA transcription (4)
1. Initiation: In the nucleus, RNA polymerase binds to a sequence of DNA called the promoter at the beginning of the gene and separates the DNA strands
2. Elongation: The RNA polymerase "reads" the template strand and builds an RNA molecule out of complementary nucleotides from 5' to 3'
3. Termination: Sequences called terminators signal that the process is complete, and the transcript is released from the RNA polymerase
4. RNA creation is complete
165
Impact of complementary base pairing on transcription
It ensures that DNA is accurately transcribed into RNA, with every nucleotide being in the same sequence
166
Impact of hydrogen bonding on transcription
Ensures that nucleotides are firmly held together when needed but easily broken when RNA is transcribed
167
Process of DNA translation (6)
1. Initiation: tRNA carrying the first amino acid attaches to the small subunit of the ribosome and binds to the 5' end of the mRNA on the ribosome
2. The subunit and tRNA move along the mRNA until they get to the "start" codon (AUG)
3. The big subunit joins the codon, tRNA, and small subunit to create the initiation complex (P site)
4. Elongation: The codon A site next to the P site is exposed and a tRNA with the right anticodon is connected to it with a peptide bond
5. The mRNA is pulled onward by one codon, which exposes a new codon in the A site so the cycle can repeat
6. Termination: A stop codon in the mRNA enters the A site, and proteins called release factors in the P site recognize the stop and mess with the peptide bond (adds a water molecule to the last amino acid) so the chain breaks off the tRNA to form a new protein
168
What kinds of RNA are involved in translation
All of them
169
Role of rRNA in translation
Forms most of the ribosome subunits and helps bind tRNA to mRNA
170
Codon vs. Anticodon
Codons are a sequence of three nucleotides in mRNA, while anticodons are this in tRNA. Anticodons bind to complementary codons and deliver the correct amino acid
171
Method to compare DNA sequences of different species
PCR (polymerase chain reaction) and gel electrophoresis
172
A technique used to separate DNA fragments based on size and charge by pulling them through a gel using an electric current
Gel electrophoresis
173
DNA fragments are __ charged, so they move towards the ___ electrode in gel electrophoresis
negatively, positively
174
Because all DNA fragments have the same amount of charge per mass, ___ fragments move through gel faster than ___ ones
Small, large
175
Enzyme used in the extension stage of PCR to amplify the amount of short DNA segments (also heat resistant)
Taq polymerase
176
A sequence in DNA where two or more sequential base pairs are repeated. Useful for DNA profiling
Tandem repeats
177
Uses of DNA profiling (2)
1. Paternity tests
2. Evidence of innocence or guilt in a crime
178
Features of DNA fragments used to separate them during gel electrophoresis (2)
1. Size
2. Charge
179
The binding site that the tRNA molecule detaches from to leave the ribosome
E site
180
Where are the EPA sites
The ribosome
181
The complete set of proteins that an organism can make
Proteome
182
Always the start codon
AUG (Methionine)
183
Why are the ratios of ATCG in DNA more consistent than the ratios of AUCG in RNA?
DNA is a double helix, so complementary base pairing ensures that the % of A is equal to the % of T etc. RNA does not have this and thus is more varied in its %s
184
The agent capable of permanently changing the base sequence of DNA
Mutagen
185
What type of cells can pass on their mutations to the organism's offspring
Germ cells (eggs and sperm)
186
Causes of variation in a species (3)
1. Meiosis
2. Mutation
3. Random fertilization
IB Bio
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