Exam 1 Flashcards
(94 cards)
1
Q
unwinds and hold apart the replicating DNA.
A
helicase
2
Q
stop the separated strands from rejoining
A
Binding protein
3
Q
adds short primers to separate strands of DNA
A
primase
4
Q
serve as anchors for construction of the new chains of DNA
A
primers
5
Q
brings in nucleotides to bind to the exposed DNA strands, and it corrects errors made during replication
A
DNA polymerase
6
Q
are also removed and replaced with the proper DNA bases
A
short primers
7
Q
seals the sugar phosphate backbone of the DNA
A
ligase
8
Q
The two strands of DNA are considered to be antiparallel
A
DNA directionality
9
Q
what is the direction for DNA ?
A
5’ to 3’
10
Q
a portion of the DNA code, a gene is a template for the synthesis of a complementary chunk of mRNA. mRNA carries codes specifying particular amino acids and directs protein synthesis.
A
transcription
11
Q
What is being constructed in transcription?
A
mRNA
12
Q
structure that is single stranded and instead of deoxyribose, has a slightly different sugar, called ribose
A
RNA
13
Q
In RNA, the nitrogenous bases are what?
A
U instead of T
14
Q
building blocks of proteins
A
amino acids
15
Q
process of producing proteins is known as? usually makes ribosomes
A
translation
16
Q
- initiate gene transcription at those regions
- ontain special sequences that signify the start point of particular gene
A
promoters
17
Q
are non-protein- encoding fragments of genetic code
A
introns
18
Q
are the portions of genetic code that ultimately get translated
A
exons
19
Q
a change in the nitrogenous base sequence of a gene’s DNA
A
gene mutation
20
Q
make up tissues and organs of the body ( 23 pairs of chromosome)
A
somatic cells
21
Q
occurs in somatic cells typically during DNA replication so its very localized of the mutation
A
somatic mutations
22
Q
any detectable and heritable variation in the lineage of germ cells
A
germline mutations
23
Q
a change in a single DNA base
A
point mutation
24
Q
- point mutation that changes a codon that normally specifies a particular amino acid into on that encodes for a different amino acid
- If the structured is changed results may be signs or symptoms of a disease or another observably different phenotype
A
missense mutation
25
point mutations that change a codon specifying an amino acid to “stop” codon. A stop shortens the protein product and can profoundly change its function
nonsense mutation
26
type of mutation that is responsible for addition or deletion of bases
formation shift mutation
27
What are the two types of formation shift mutation?
1. insertion
| 2. deletion
28
areas that the sequence is repeated and the DNA may actually double up on itself
mutation hotspots
29
mutations that are caused by toxic exposures
induced mutations
30
an agent that induces a mutation
mutagens
31
wavelengths can damage DNA by causing an extra bond to form between pyrimidine bases located next to each other in a strand of DNA
UV radiation
32
a specific version of a gene; same from both parents homozygous and different heterozygous for that gene
alleles
33
the degree to which survival is helped or hindered by possession of a particular allele and its associated phenotype will determine the frequency of that allele within a population
natural selection
34
DNA is what type of material?
hereditary material
35
helical ladder shaped molecule that htas the capability of unraveling and making copies of itsel
DNA
36
DNA coils around proteins called what?
histones
37
the building blocks of DNA consist of nitrogenous bases that are bound to one sugar group and on phosphate groups
nucleotides
38
what are the 4 nitrogenous bases?
adenine (A), Guanine (G), thymine (T), and cytosine (C)
39
adenine and guanine are classified as what?
purines
40
thymine and cytosine are classified as what?
pyrimidines
41
what is the backbone of DNA?
sugar phosphate
42
what are the 4 types of changes in chromosome structure?
1. deletion
2. duplication
3. inversion
4. translocation
43
removes a chromosomal segment
deletion
44
repeats a segment
duplication
45
reverses a segment within a chromosome
inversion
46
moves a segment from one chromosome to another
translocation
47
- homologous pairs of chromosomes orient randomly at metaphase I meiosis
- each pair of chromosomes sorts maternal and paternal homologues into daughter cells independently of the other pairs
independent assortment of chromosomes
48
crossing over produces_____ which combine genes inherited from each parent
recombinant chromosomes
49
adds to genetic variation because any sperm can fuse with any ovum
random fertilization
50
what are the three mechanisms for genetic variation
1. independent assortment of chromosomes
2. crossing over
3. random fertilization
51
results in accumulation of genetic variations favored by the environment
natural selection
52
large-scale chromosomal alterations leads to what?
spontaneous abortions or miscarriages or cause a variety of developmental orders
53
pairs of homologous chromosomes do not separate normally during meiosis
nondisjunction
54
results from fertilization of gametes in which nondisjunction occured
aneuploidy
55
a zygote has only one copy of a particular chromosome
monosomic
56
zygote has three copies of a particular chromosome
trisomic
57
a condition in which an organism has more than two complete sets of chromosomes
polyploidy
58
is polyploidy common in plants or animals?
plants
59
are polyploidy more normal in appearance than aneuploidy?
yes
60
an aneuploid condition that results from three copies of chromosome 21
down syndrome
61
the result of an extra chromosome in a MALE, producing XXY individuals
Klinefelter syndrome
62
produces X0 females, who are sterile; it is the only known viable monosomy in humans
Turner syndrome
63
- results from a specific deletion in chromosome 5
- delayed development
- small head size
- low birth weight
- weak muscle tone in infancy
cri du chat
64
type of allele that determines the organism's appearance
dominant allele
65
type of allele that has no noticeable effect on appearance
recessive allele
66
states that 2 alleles for a heritable character separate (segregate) during gamete formation and end up in different gametes
law of segregation
67
diagram for predicting the results of a genetic cross between individuals of known genetic makeup
Punnett square
68
what are the 3 degrees of dominance?
- complete dominance
- incomplete dominance
- codominance
69
occurs when phenotypes of the heterozygote and dominant homozygote are IDENTICAL
complete dominance
70
the phenotype of hybrids is SOMEWHERE BETWEEN the phenotypes of the two parental varieties
incomplete dominance
71
2 dominant alleles afeect the phenotype in separate, distinguishable ways
codominance
72
the property that most genes have multiple PHENOTYPIC effects
pleiotrophy
73
gene at one locus alters the phenotypic expression of a gene at a second locus
epistasis
74
characters that vary in the population along a continuum
quantitative character
75
an additive effect of 2 or more genes on a single phenotype
polygenic inheritance
76
what is an example of a polygenic inheritance?
skin color in humans
77
the phenotypic range of a genotype influenced by the environment
norm of reaction
78
term that describes genetic and environmental factors as something that influences phenotype
multifactoral
79
what are examples of multifactorial disorders?
- CVD
| - cancer
80
a family tree that describes the interrelationships of parents and children across generation
pedigree
81
true or false. many genetic disorders are inherited in a recessive manner
true
82
are HETEROZYGOUS individuals who carry the recessive allele but are phenotypically normal
carriers
83
a recessive condition characterized by a lack of pigmentation of skin and hair
albinism
84
a form of dwarfism caused by a rare DOMINANT allele
achondroplasia
85
gene located on either sex chromosome
sex-linked gene
86
sex linked recessive disorders are more common in males or females?
males
87
phenotype depends on which PARENT passed along the alleles for mammalian traits
genomic imprinting
88
the liquid that bathes the fetus is removed and tested
amniocentesis
89
sample of placenta is removed and tested
chorionic villus sampling (CVS)
90
the process of helping people understand and adapt to the medical, psychological and familial implications of genetic contributions to disease
genetic counseling
91
the process by which DNA directs protein synthesis, includes two stages
transcription and translation
92
who developed the one gene to one enzyme hypothesis that states that each gene dictates production of a specific enzyme?
Beadle and Tatum
93
the synthesis of RNA under the direction of DNA?
transcription
94
transcription produces what?
mRNA
