SI exam 3 notes Flashcards
(100 cards)
1
Q
cytokinesis
A
after cleavage furrow appears in telophase, actin filaments form a contractile ring that eventually breaks the cells apart
2
Q
mitosis phases
A
interphase, prophase, metaphase, anaphase and telophase
3
Q
G1,S, G2
not a part of mitosis
cell does its normal job and grows
DNA is not condensed in the nucleus
A
interphase
4
Q
cell grows and reproduces, if DNA is damaged, apoptosis occurs
A
G1
5
Q
DNA synthesis occurs
A
S phase
6
Q
if DNA replicated correctly, mitosis will occur, if not apoptosis will occur
A
G2 phase
7
Q
- 4 genetically diverse
daughter cells - creates sex cells
- two cell divisions
- daughter cells are haploid
cells - occurs at certain points in
an organism life cycle - Homologous chromosomes
line up in metaphase I
A
meiosis
8
Q
2 genetically identical
daughter cells
* creates body or stem cells
* one cell division
* daughter cells are diploid
* occurs almost continuously
in life cycle
* No paired chromosomes line
up
A
mitosis
9
Q
- include prophase,
metaphase, anaphase, and
telophase - create new cells
- start with one parent cell
A
similarities between meiosis and mitosis
10
Q
the complete set of chromosomes
A
diploid (2n)
11
Q
half the chromosomes
A
haploid (1n)
12
Q
pair of identical chromosomes connected by centromere
A
sister chromatids
13
Q
chromosomes of the same length, gene placement, and centromere height
A
homologous chromosomes
14
Q
homologous chromosomes line up as pair (synapsis), crossing over
A
prophase I
15
Q
non-sister chromatids exchange information, which creates genetic diversity
A
crossing over
16
Q
homologous chromosomes line up in tetrads next to each other at the cell equator, independent assortment
A
metaphase I
17
Q
homologous chromosomes can be pulled apart in any assortment, created genetic diversity
A
independent assortment
18
Q
homologous chromosomes are pulled apart to opposite poles of the cell
A
anaphase I
19
Q
two daughter cells are formed
each have one chromosome from a homologous parent
A
telophase I
20
Q
the two new daughter cells are ready to divide
chromosomes attach to the spindle
A
prophase II
21
Q
sister chromatids line up at the cell equator
A
metaphase II
22
Q
sister chromatids are pulled apart to separate sides of the cell
A
anaphase II
23
Q
the spindle disappears
nuclear envelope reforms
cytokinesis will occur
A
telophase II
24
Q
what is the biggest advantage of meiosis?
A
form gametes for sexual reproduction causing genetic diversity through independent assortment and crossing over
25
if the diploid chromosome number is 16, the chromosome number of each gamete will be ____.
8
26
During what stage of meiosis do sister chromatids separate from each other?
anaphase II
27
What lines up at the metaphase plate during both metaphase I of meiosis and metaphase of mitosis?
homologous chromosomes for meiosis, each chromosome is composed of two sister chromatids for mitosis
28
the nuclear membrane reappears in mitosis during ___?
telophase
29
Meiosis results in a change in chromosome number indicated by ___?
2n to n
30
During which stage of the cell cycle do the chromosomes duplicate?
interphase
31
What is the correct sequence for the cell cycle?
S-G2-M-G1
32
a double helix structure
made up of monomers called nucleotides
made up of a nitrogen-containing base and a phosphate-sugar backbone
A,T,C,G
DNA structure
33
double-stranded
T
deoxyribose sugar
DNA
34
single stranded
U
ribose sugar
RNA
35
made up of nucleotides ( N-containing bases and phosphate-sugar backbone)
A, C and G
similarities between DNA and RNA
36
what are the steps of DNA replication?
1. DNA helicase unzips the double helix
2. DNA polymerase using base pairing
3. DNA ligase connects Okazaki fragments and breaks in the backbone
4. Two new DNA strands are formed
37
why is DNA replication semiconservative?
each new strand is synthesized on an existing strand, and the new double helixes are made up of one old strand and one new strand
38
the process of reading gens to synthesis a protein
gene expression
39
what ate the two processes of gene expression?
transcription
translation
40
occurs in the nucleus
DNA serves as template for mRNA formation
transcription
41
occurs in the cytoplasm on the ribosomes
protein created from RNA
uses mRNA, tRNA and rRNA
translation
42
what are the three steps of translation?
initiation
elongation
termination
43
codons
sets of three nucleotides that are translated to a specific amino acid or start/stop
44
which of the classes of RNA molecules carries the amino acids that are added to the growing polypeptide chain?
transfer RNA
45
during the process of transcription, the information in ____.
DNA is converted in RNA information
46
which is the process by which a protein is constructed in the cytoplasm of the eukaryotic cells?
translation
47
a permanent change in DNA
can be silent or produce an abnormal or incomplete protein
gene mutations
48
gene mutation causes
errors in replication
mutagens
transposons
viruses
49
If the normal nucleotide sequence was TACGGCATG, what type of gene mutation is present if the resulting sequence becomes TAGGCATG?
deletion mutation
50
mutations in DNA
occur at random sites
51
law of segregation
the two alleles for a trait separate at the formation of gametes, each gamete carries one factor/allele from each pair
52
law of independent assortment
factors separate independently, so the gamete can receive any combination of alleles
53
chart that shows family history regarding a specific trait
pedigree
54
in a pedigree females are
circles
55
in a pedigree males are
squared
56
in a pedigree shaded shaped are
affect individuals
57
in a pedigree unshaded shaped are
unaffected individuals
58
when the top shapes aren't shaded but the bottom one is in a pedigree
autosomal recessive
59
when the top shaped are shaded but the bottom one is not in a pedigree
autosomal dominant
60
genetic disorders
Tay-Sachs disease, Cystic Fibrosis, Sickle Cell disease and Huntington's disease
61
- Autosomal Recessive
* Build up of lysosomes in
the cells
* Primary build-up in the
brain
* Child development slows
between 4 and 8 months
* Child becomes blind and
this eventually leads to
paralyzation
Tay-Sachs disease
62
* Autosomal Recessive
* Chloride ions fail to pass
through the membrane
* Sodium and water are
supposed to follow Cl,
but they cannot
* Leads to a build up of
mucus
cystic fibrosis
63
* Autosomal Recessive
* Cell is abnormally
shaped (sickle shaped)
* Hemoglobin stacks up in
cell
* can clog vessels and
lead to poor circulation,
anemia, and low disease
resistance
* Does provide some
protection from malaria
sickle cell disease
64
* Autosomal Dominant
* Progressive degeneration
of brain cells
* Normally does not
become apparent until
middle age
* Death comes 10-15 years
after symptom onset
* No effective treatment
Huntington's disease
65
two traits are equally expressed in heterozygotes
codominance
ex. red and white flower
66
phenotype is a blend between the two traits in a heterozygote
incomplete dominance
ex. red and white flower make a pink flower
67
polygenic inheritance
trains are determined by more than one gene
ex. eye color, skin color and height
68
which one represents the physical characteristics of the individual?
phenotype
69
what are alleles?
alternative forms of a gene for a single trait, such as blue eyes or brown eyes
70
Mendel's law of segregation implies that the two members of an allele pair are ____.
distributed to separate gametes
71
a women who can roll her tongue ( presumably dominant) is married to a man who cannot. two of their four children can roll their tongues and two cannot, if A=rolls and a= cannot roll, then what is the genotype of the parents?
women Aa, man aa
72
a pheasant breeder starts with two birds in the P generation, one of which is AA and the other is aa, if he takes two of the birds from the F1 generation and breeds them together, what can he expect in his F2 offspring?
AA, Aa, and aa
73
linked to the x and y chromosomes (most are x-linked)
sex linked traits
74
x linked recessive traits
hemophilia, colorblindness and Duchenne muscular dystrophy
75
homologous chromosomes or sister chromatids fail to separate in meiosis I or II
nondisjunction
76
only one chromosome of a pair
monosomy
77
three chromosomes instead of a pair
trisomy
78
what are the chromosome number disorders?
down syndrome, turner syndrome, poly x females and kleinfelter syndrome
79
a trisomy in chromosome pair 21
trisomy that is most likely to survive birth
down syndrome
80
one x chromosome
1 in 2000 girls born
turner syndrome
81
more than two x chromosomes
poly x females
82
xxy chromosomes
Klinefelter syndrome
83
considering that males can have Klinefelter syndrome, XYY, and normal XY chromosomal combinations and females can have Turner syndrome (XO), poly x (XXX,XXXX), and normal XX combinations, it is obvious that ____.
maleness results from the minimal presence of one y chromosome
84
color-blindness in inherited as an X-linked recessive trait, a male who is color-blind marries a heterozygous woman, what percent of their total children will be color-blind?
50%
85
evolution
a change in a population over time
86
Lamarck theory
giraffes keep stretching their necks so their offspring have longer necks
87
Darwin theory
giraffes with longer necks reach food, so they survive to have offsprings
88
a species form the fossil record that shows an intermediate between two different species
transitional forms
89
structure with a function in one group of organisms but no function in a related group
vestigial structures
90
similar structures in different species resulting from common ancestry
homologous structure
91
what are the mechanisms of evolution?
mutations, genetic drift, gene flow, founder effect and bottleneck effect
92
changes in genetic makeup introduce new alleles
mutations
93
chance event changes the frequency
genetic drift
94
alleles are shared between separate populationss
gene flow
95
a few organisms move to an isolated place
founder effect
96
a disaster that drastically decreases population
bottleneck effect
97
what is the ratio of two double heterozygote dihybrid crosses?
9:3:3:1
98
Hardy- Weinberg Equilibrium, evolution will not occur if there are:
no mutations
no genetic drift
no gene flow
nonrandom mating
no natural selection
99
two populations evolve into two different species and required isolation of species
speciation
100
what are the isolating mechanisms?
habitat, temporal, behavioral, mechanical and gametic
