Biology-Course 2 Genetic Inheritance Flashcards
(242 cards)
1
Q
Define Genetics
A
the study of heredity
2
Q
Heredity
A
characteristics passed from parents to their offspring
3
Q
What hereditary material do all living organisms carry?
A
Deoxyribonucleic acid (DNA)
4
Q
What is considered the blueprint for how to build a living organism?
A
DNA
5
Q
How much DNA does each cell contain in humans (in length)?
A
6.6 ft for humans
6
Q
chromosomes
A
thread like structures of a single molecule of DNA (succession of the four nucleotides) to help make cell division & replication
7
Q
how many chromosomes/pairs do humans have
A
46 individual/23 pairs
8
Q
how many chromosomes/pairs do canines have?
A
78 individual/39 pairs
9
Q
how many chromosomes/pairs do cats have?
A
38 ind/19 pairs
10
Q
how many chromosomes/pairs do primates have?
A
48 ind/24 pairs
11
Q
how many chromosomes/pairs do equine have?
A
64 ind/32 pairs
12
Q
genes
A
stretches of DNA that are specific to a particular characteristic
13
Q
genome
A
all genes of an organism
14
Q
allele
A
versions of that gene that code for specific characteristics trait
(two diff copies of the same gene that lead to diff. phenotypes)
15
Q
how many alleles does each gene have?
A
two
ex. rough or smooth
16
Q
who mapped the structure of DNA in the mid 20th century?
A
Watson, Crick, and Franklin
17
Q
who received the nobel prize for discovery of DNA structure and when?
A
Watson, Crick, and Wilkins
1962
18
Q
Describe double helix
A
a twisted ladder shape of DNA, two complimentary strands of genetic information coiled into spirals
19
Q
who is considered the father of modern genetics?
A
Gregor Mendel
20
Q
refer to image in notes for double helix structure
A
:)
21
Q
What basis did Mendel discover and in what fashion was this done?
A
that genes exist & inherited in pairs, one from each parent
breeding pea plants
22
Q
define breeding
A
the mating & production of offspring of living organisms
23
Q
define True-breeding
A
in reference to plants which the offspring have exhibited the same traits in many generations
24
Q
crossbreeding
A
type of breeding in which diff. species or varieties are mated w/ eachother to produce a hybrid, contains features of both parents
25
pollination in reference to breeding
form of reproduction for plants which transfers pollen from male part of plant to female part of plant
26
What did Mendel's experiment entail?
cross-pollinating true-bred pea plants that posses particular traits & observed resulting trait in offspring
27
what are the parent plants called in Mendel's Experiment?
P-generation
28
What are the first generation of hybrid offspring in Mendel's Experiment called?
F1 Generation
29
What generation of Mendel's Experiment is identified as the dominant gene?
F1 generation
30
What generation in Mendel's Experiment starts showing effects of hybridization?
F2 generation
31
How many traits did Mendel observe in his experiment?
7
32
How many phenotypes in Mendel's experiment can each of the 7 traits result in?
one of two phenotypes
33
define phenotype
an organisms set of observable characteristic (physical traits)
34
what is the diff b/w an allele vs phenotype
an allele is the description of characteristic of an organism's gene (blue or brown eyes)
phenotype is the specific physical trait that can be observed (organism received blue eyes)
35
are true-bred strains homo or heterozygous?
homozygous
36
define homozygous individuals
organisms that has two copies of the same allele for a give trait (brown eye & brown eye)
37
which generation is homozygous referred to?
P-generation
38
Heterozygous individual
organism that has both dominant gene (A) and recessive gene (a)
39
which generation is referred to as heterozygous?
F1 generation
40
is the F2 generation homo or heterozygous?
50/50
41
Name Mendal's Laws
law of segregation
law of independent
assortment
law of dominance
42
define law of segregation (one of Mendel's laws
every organism acquires two alleles for each trait
43
when do alleles separate?
during reproduction
44
do alleles separate randomly or in organized fashion?
random
45
define the law of independent assortment (one of Mendel's laws)
states that the separation of alleles for a given gene occurs independently of any other gene
46
what is the exception to the law of independent assortment?
genes located on the same chromosome are called linked-genes and they tend to be inherited together
47
define The law of dominance (one of Mendel's laws)
establishes which genes manifest as traits in the new organism (dominant vs recessive)
48
define dominant gene
gene that will always be expressed if it's present in the organisms genetic code
49
define recessive gene
gene that is only completely expressed if both parents contribute recessive alleles
50
Why is the F1 generation all dominant phenotypes?
the offspring of that generation will have one dominant gene and one recessive gene from P-generation. That is why F2 generation starts showing variations of traits as their parents may be both recessive
51
refer to notes to see image of p-generation to F2 generational results
:)
52
define punnett square
organization method to determine the probability of offspring exhibiting certain characteristics
53
who was the punnett square named after?
Reginald Punnett
54
What is placed on the top row of the Punnett Square?
genotype of the recessive trait
55
what is placed along the first column of the Punnett Square?
Genotype for the dominant trait
56
if a dominant trait is present what is the diversity ration of the Punnett Square?
3:1 for dominant phenotype to recessive
57
define monohybrid crosses
involving only one gene determination (Aa, aa)
ex. blue or brown eyes
58
define Dihybrid crosses
"two factor crossbreeding" involving more than one gene determination
(RrYy, rryy)
ex. tall or short
and
rough or smooth
59
see notes for image of dihybrid punnett square
:)
60
How much more is the dominant trait expressed than the fully recessive phenotype?
9x more
61
what are the three exceptions to Mendel's principles?
incomplete dominance
codominance
enviromental factors
62
define incomplete dominance
one phenotype does not prevail over the other resulting in intermediate phenotype
63
what is an example of incomplete dominance?
a cream-colored horse & chestnut parent may result in a golden-blonde colored offspring (palomino)
64
codominance
traits that have phenotypes that show in both alleles
65
what is an example of codominance?
inheriting genes of two diff. colors resulting in a patterns, black and white parents of chicken result in offspring that are black with white speckles
66
environmental influences exception to Mendal's principles
the external world an organism lives/develops in affects it
67
what is an example of environmental influence?
organism w/ recessive gene may not survive environment & will not reproduce, making dominant trait predominant
68
who developed the chromosome theory of inheritance
Walter Sutton & Theodore Boveri
69
what is the chromosome theory of inheritance?
states genetic material passed down from parents to their children exists in the chromosome
70
who discovered the three components that make up a nucleotide?
Pheobus Levene
71
what are the three major components of a nucleotide?
phosphate group, a sugar (ribose in RNA/deoxyribose in DNA), and a base
72
What are the four bases of nucleotides?
RNA-guanine, uracil, adenine, cytosine
DNA-guanine, thymine, adenine, cytosine
73
What is Chargaff's rule?
states the amount of adenine is roughly equal to the amount of thymine, same with cytosine and guanine, indicating that bases must pair together in clarifying structure of DNA/RNA
74
What does mispairing of nucleotides result in?
genetic mutations
75
what is x-ray crystallography?
technique used to study the structure of organic mol in crystal form
76
what is Franklin's Photo 51?
photo taken using x-ray crystallography showing the diffraction pattern of DNA which developed the model structure of DNA
77
what is the double helix of DNA composed of?
two very long sugar-phosphate backbones (alternating b/w sugar/phosphate)
w/ base pairs attached to backbone which meet in the middle
78
which part of the helix in DNA carry genetic information?
base pairs
79
what does antiparallel refer to in the double helix strands of DNA?
the two helical strand run parallel to each other but in the opposite direction
80
What are the two strands of the double helix held together by?
hydrogen bonds b/w pairs of bases
81
Why is it important that it is hydrogen bonds b/w bases?
they are strong enough to hold form but weak enough to break when needed (reproduction)
82
define nucleoside
a nitrogenous base & the sugar without phosphate group
83
define DNA replication
process of copying DNA
84
what is DNA replication essential for?
cell growth, cell repair, reproduction
85
is DNA replication timed or a constant process?
constant process
86
when must DNA be replicated in relation to cell division?
beforehand
87
what are the components of a "cell cycle"
DNA replication, division of cytoplasm & organelles, produce two daughter cells)
88
what are the two main stages of the cell cycle in eukaryotic cells?
interphase, mitosis
89
what happens during interphase of the cell cycle?
cell grows, carries out cell processes, replicates DNA
90
what happens in mitosis of the cell cycle?
cell division
91
what are the steps of cell replication?
1.helicase (enzyme) separates the DNA strands into a lagging strand & a leading strand which "unzips the double helix"
2. RNA primer is added to the strand leading strand
3.DNA polymerase (enzyme) adds/binds the appropriate base pairs to reconstruct the ladder
4.RNA primer attaches to lagging strand
5. DNA polymerase adds Okazaki fragments
6. a third enzyme removes the RNA primers, the sugars along the sugar-phosphate backbone are bonded to make two identical DNA strands
92
Why is the leading strand easily replicated?
it runs in the same direction as the original DNA, replicated continuously
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why is the lagging strand in cell replication not easily replicated?
it must be replicated in reverse
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define okazaki fragments
small groups of base pairs that are added to replication of lagging strand in cell replication
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what percentage of mistakes made in pairing bases are fixed before cell replication starts?
99%
96
what do altered (mutated) nucleotides result in?
change function of DNA sequencing or render it unusable
97
define the Semi-Conservative model of replication
the parent DNA separates & a newly synthesized strand is added to each parent strand (basis of cell replication)
98
what are the three main steps of DNA replication?
initiation
elongation
termination
99
what are the steps o of initiation in DNA replication
1. a location on DNA double helix is targeted for unwinding
2.helicases break the hydrogen bonds b/w base pairs
3.proteins keep the single strands of DNA from joining again
4.topoisomerases (enzyme) surround the unzipped strands and relax the twisting of the helices
5.DNA develops "forked structure"(DNA replication fork)
6. primase (enzyme) builds short stretches of RNA called RNA primers that are required to start elongation
100
what is the leading stands directionality?
5' to 3'
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what is the lagging strands directionality?
3' to 5'
102
what are the steps of the elongation phase of DNA replication?
1.DNA polymerase travels down DNA strand starting where primase has added RNA primers, works in the 5' to 3' direction
2. DNA polymerase adds new nucleotides to each ot eh two DNA strands (continuous is leading strand, discontinuous is lagging)
3. ligase (enzyme)that helps "glue" the fragments together to form a complete daughter DNA molecule
103
define termination of DNA replication
the end of replication at the finish of elongation phase, two double helices have replaced the original helix
104
what is the Meselson-Stahl experiment?
exp that demonstrates that DNA replicates in a semi-conservative manner
105
what is the prokaryotic genome?
a single DNA molecule that floats freely in the cells cytoplasm
106
define the process of binary fission
a type of asexual reproduction in prokaryotic cells in which replicated chromosome makes two copies that associate with opposite ends of the cell membrane,
cell then pulls apart to create two identical cells each containing a copy of the prokaryotic genome
107
is RNA or DNA a shorter polymer?
RNA
108
Define gene expression
the order of bases along a given DNA strand serving as a code for making RNA which in turn makes proteins
109
what are the types of proteins?
antibodies
enzymes
protein messengers/structural proteins
110
see image in notes for gene expression
:)
111
what are the two main steps of gene expression?
transcription & translation
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what is the main idea of transcription?
DNA is converted to RNA
113
what is the main idea for translation?
cellular machinery reads the RNA to form polypeptides (building blocks for proteins)
114
define the Central Dogma
a framework for translation & transcription that states DNA encoded RNA, and RNA encodes proteins
115
describe the process of the central dogma
Helicase (enzyme) opens DNA strand,
then the coding strand synthesizes the RNA using RNA polymerase during the transcription process,
DNA is rewritten as a single strand of RNA, in translation the codes that have been written as RNA are three-letter combinations of bases occurring at the ribosome
116
What types of RNA are used in transcription?
RNA, mRNA (messenger)
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what types of RNA are used in translation?
rRNA (ribosomal), tRNA (tansfer)
118
what is the role of rRNA?
part of ribosome in organizing & synthesizing proteins
119
what is the role of tRNA?
physically brings the specific amino acids to add to the growing polypeptide chain
120
what would be the complementary DNA strand for a single strand of DNA sequenced as AATTAAT?
TTATTA
121
What sequence of RNA would be transcribed for a DNA strand of AATTAAT and a complementary strand of TTATTA?
RNA AAUAAU
122
what base pairs of tRNA pair w/ DNA?
RNA, A with DNA, T
RNA, U with DNA, A
123
define codon
a three letter sequence of DNA/mRNA that contains info
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what does each codon contain instructions for?
a specific amino acid
125
define polypeptides
chains of amino acids
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define genes
segment of DNA
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what does cellular machinery in gene expression do
reads each codon of RNA & adds the corresponding amino acids together to produce chains of amino acids
128
circular codon wheel
interprets a DNA sequence & understand what amino acids they're coding
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in which direction is the circular codon wheel read?
starts w/ center base then middle base then third base (smallest letters, furthest out)
130
What happens when the polypeptide is completed?
fold into its correct structure
then may need to be further processed/ moved to specific location/
added to other polypeptides
before it functions as protein in the cell
131
which strand of DNA is mRNA produced from
antisense (antiparallel)
132
Which direction does the leading strand of DNA and RNA run in?
5' to 3'
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what direction does the lagging (antiparallel) strand run in?
3' to 5'
134
mRNA is identical to the original coding strand except for what?
U assumed the role of T and bonds w/ A
135
is the life cycle of mRNA in eukaryotic cells long or short lived?
short
136
where is mRNA located?
located in the nucleus in transcription and then transported to cytoplasm to translate into proteins
137
what happens to mRNA after translation?
degraded
138
what does mature mRNA include?
start codon
139
define start codon
instructions to the ribosome to start assembling amino acids as laid out in RNA
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what end of the mRNA is the start codon located?
5' end
141
define stop codon
located at end of coding sequence & tells ribosome to stop assembling amino acids
142
what dictates the directionality of a mol of DNA/RNA?
the sugar-phosphate backbone
143
Why is only one strand of DNA the coding strand?
because the antisense strand is in "reverse" order the code is backwards and does not make sense to code
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what molecules are included in translation?
mRNA, tRNA, ribosome, and rRNA
145
can different codons, code for the same amino acid?
yes
146
how many codons can code for how many amino acids?
64 codons can code for 20 diff amino acids
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define tRNA
gathers appropriate amino acids in the cytoplasm and delivers them to the ribosome as three letter codes to drop off in ribosome
148
define rRNA
used to produce proteins in ribosome, based on the mRNA sequence
149
what are framwork mutations?
poorly defined start & stop locations for translation, drastically alter the protein being made
150
where are framework mutations more likely
in regions of repeated sequences such as colorectal, prostate, ovarian, breast
151
what is RNA's primary purpose
serve as intermediary b/w the genetic code of DNA & the creation of protein molecules
152
list the main functions of RNA
-convert genetic code from DNA to protein
-regulates the process of gene expression
-facilitates biological reactions
-senses & communicates responses to cellular signals
-exists as the genetic material found in some viruses
153
what are the three main types of RNA
tRNA , mRNA, rRNA
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what is the main function of mRNA
messenger, carries info transcribed from DNA to cytoplasm
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what is the main function of tRNA
transfer, during translation gathers appropriate amino acids & delivers them to ribosomes
156
what is the main function of rRNA
ribosomal, carries out protein synthesis in the ribosome
157
how many subunits are ribosomes made up of?
2, large & small subunit
158
are prokaryotic or eukaryotic ribosomes smaller?
prokaryotes are small with less # of proteins and rRNA
159
what is the major difference in
gene expression (translation & transcription) in prokaryotic cells
prokaryotic cells DNA & ribosomes are in the cytoplasm so mRNA is not needed and transcription and translation can happen simultaneously
160
what percent of the mass of ribosomes in prokaryotic and eukaryotic cells
60% in prokaryotic, 50% in eukaryotic
161
what are the other types of RNA that are used in gene expression besides the main three
small nuclear RNA (snRNA)
small cytoplasmic
(scRNA)
micro RNA
(miRNA)
small interfering
(siRNA)
RNAI
162
where is the snRNA located
localized to cell's nucleus
163
what function does snRNA hold
splicing & processing of mRNA in the nucleus
164
where is scRNA located
cytoplasm
165
what is the function of miRNA
small highly-conserved segments of non-coding RNA that are involved in the regulation of gene expression (evade degredation)
166
what is the function of siRNA
regulates gene expression through RNA interference or RNAI
167
define RNAI
type of RNA to silence genes by specifically targeting & degrading their mRNA
168
define retrovirus
type of virus that uses RNA as its genetic material
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how does a retrovirus work
after it infects the cell, it uses an enzyme called reverse transcriptase to convert it's RNA to DNA, this is how a retrovirus can integrate its DNA into the DNA of the host so it can continue to replicate
170
what is the structure of mRNA
each strand contains three codons
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what is the ribosomes role in gene expression
read the mRNA & link the appropriate amino acids together to create polypeptide chain
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what are the two categories of gene expression mutations
small-scale and large-scale mutations
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when do large scale mutations happen during
meiosis
174
examples on what causes large scale mutation
radiation, exposure to teratogens during developmental phase
175
what do large scale mutations result in
often lethal but may lead to changes in phenotypes
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what are the four main large-scale mutations in genetic code
1.deletion-segment of DNA is lost
2.duplication-segment is duplicated & inserted back into the original DNA
3.inversion-segment of DNA is reversed
4.translocation-segment of DNA is moved to another homologous chromosome
177
what do small-scale mutations in gene expression affect
affect protein synthesis
178
why are small-scale mutations important
source of diversity among organisms because they're the source of new genes
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what are small-scale mutations considered if they change phenotype?
"genetic disorder" or "hereditary disease"
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define small-scale mutations
single nucleotide pair mutation that involves substitution, insertion or deletion
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what is the result of single nucleotide mutation
can encode for a different protein or cause a stop codon to terminate translation
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what are the two main types of genetic mutation
germline mutations
somatic mutation
183
define germline mutation
hereditary mutations inherited from parent, located in parents egg/sperm cell
184
define somatic mutation
"aquired" occur at some point in persons life caused by environmental exposure (mutagens)
185
define silent mutation
occurs when one DNA base in protein-coding region is substituted for another that encoded for the same amino acid
186
define genetic polymorphisms
genetic variation
187
what are the four steps in cell development in a multicellular organism
1.cell proliferation
2.cell specialization & differentiation
3.cell-cell interactions
4.cell movements
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define cell proliferation in cell development
process of growth & division of cells that produce many cells from original through mitosis
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what is the end goal of cell proliferation
create exact copies of given cell & enough diff cells for each type of tissue
190
what does uncontrolled proliferation lead to
contribute to conditions such as cancer, undergo mutations
191
define cell differentiation
develops features that enable cells (after proliferation) to fulfill specific roles
192
define cell specialization
differ genes turned on & expressed at different times in the cell result in genetic programming
193
how much does each cell express the organisms genome
a fraction of the entire genome
194
what are iPSC's (induced pluripotent stem cells)
adult stem cells that have been reprogrammed to cebome like embryonic stem cells
195
define cell-cell interaction
cell interaction by chemical or electrical means
196
what are the types of chemical signaling in cell to cell interaction
direct contact
paracrine
synaptic
autocrine
endocrine
197
what is direct contact signaling in cell-cell interaction
cells located next to each other & channels b/w cells allow molecules to diffuse from one cell to another
198
what is paracrine signaling in cell-cell interaction
production of chemical then diffused over a short distance to reach nearby cells
199
what synaptic signaling in cell-cell interaction
occurs b/w cells separated by synapsis (gap) which neurotransmitters send messengers
200
what is autocrine singaling in cell-cell interactions
cell signaling to itself, releases receptors on its surface
201
what is endocrine signaling in cell-cell interaction
conducted by hormones & travels via circulatory system
202
define cell movement in cellular development
process in cell receiving signals from other cells & extracellular molecules that direct cell movement
203
changes in a organisms genotype can also cause change in .....
phenotype
204
define autosomal alleles
follows law of dominance in which dominant traits will be expressed over recessive ones
205
when is an autosomal recessive allele expressed
if individual is homozygous for recessive allele
206
do autosomal dominant or autosomal recessive skip generations?
dominant present in each generation, recessive skips generations
207
define sex-linked alleles
characteristic pattern of inheritance exhibited by genes located on a sex chromosome
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are females sex linked alleles homo or heterozygous?
since females have two x chromosomes, either can be homo or hetero
209
can males sex-linked alleles be homo or heterzygous?
because males have one x chromosome, they express alleles on that chromosome and recessive and dominant do no apply to make sex chromosomes
210
what are non -mendelian inheritance patterns?
give way to complex or multifactorial traits, giving rise to variety of phenotypes
211
how many chromosomes/pairs do humans have
46 chromosomes/22 pairs
212
how many sex chromosomes do humans have
1 pair
213
what is karyotope
organized profile of an organism's chromosome in the nucleus that shows # of, relative size, shape and appearance
214
see image of common canine karyotypes in notes
:)
215
define karyograms
image of chromosomes in a cell arranged by size & other characteristics
216
what can karyograms identify
if organism has too many or few chromosomes
217
define euploid
organism w/ the appropriate # of chromosomes
218
define aneuploid
organism w/ more or less than appropriate chromosomes
219
define x-inactivation
an x chromosome in a female is inactivated due to preventing twice as many gene products in a cell
220
define barr bodies
the name for the inactivated x chromosomes
221
is x-inactivating selective or random
random
222
please see image in notes for pedigree family symbols
:)
223
what is autosomal dominant disorder pedigree
if one or both the alleles of a gene carry a disorder, will exhibit in the individual
224
what percentage of heterozygous individuals with a disorder have of passing the disorder to each child
50%
225
what percent of children will homozygous individuals for a mutated allele with pass the mutated allele?
to every child
226
define sex-linked recessive disorder pedigree
the only people that exhibit the disorder have one or two copies of the recessive allele
227
if a mother exhibits a sex linged recessive disorder (indicating both x are affected) how many of her sons will inherit a mutated x chromosome and exhibit the disorder?
100%
228
if a mother is a carrier to sex-linked recessive disorder how many of her songs will be affected and how many will just inherit (carry)
50/50%
229
because daughters receive both x chromosomes from each parent, when will they exhibit sex-linked recessive disorder?
if they receive the mutated alleles from both parents
230
how are recessive disorders easily identified on predigree charts?
they skip generation
231
what is shotgun sequencing?
a genome sequence method used to determine the genetic sequencing of long strands of DNA by randomly breaking up DNA into many small fragments, computer program then reassembling the DNA fragments
232
define bioinformatics
science of collecting and analyzing complex biological data (by way of computer program)
233
define genetic recombination
the rearrangement & exchange of genetic info from different sources (by way of different chromosomes or diff segments of the same chromosome)
234
what is genetic recombination essential for
help create new genetic types forming evolution
235
what percent of the human (and mice) and canines genome originally came from viruses passed from generation to generation
8%, 1%
236
what is artificial recombination used for
-modify organisms for research
-create modified crops
-genetic testing
-testing for diseases
-uses bacteria to manufacture medications
237
define selective breeding
breeding organisms w/ desired characteristics that will result in that offspring
238
define inbreeding
type of selective breeding that occurs when ind. w/ similar characteristics continue to be bred to keep those traits
239
what is the result of inbreeding
high potential for mutated alleles
240
define transgenic organisms
have both their original DNA and the genes of another organisms
241
define cloning
the use of a single cell to produce new cells, tissues, or full organisms by removing a nucleus from that cell and fusing w/a donor nucleus
242
