Exam 3 Flashcards
1
Q
Mitosis and binary fission generate
A
2 genetically identical copies from one cell
2
Q
lifespan of cell
A
varying life span is required for growth, repair, and development, as well as reproduction. Lifespan varies from days to years.
3
Q
meiosis
A
generates genetically unique cells from parent cells, occurs in just reproductive tissues, 1 cell to 4 cells
4
Q
apoptosis
A
programmed cell death, triggered by caspases, enzymes that trigger apoptosis
5
Q
cell cycle stages
A
interphase - preparation for division, long time
- G1 growth
- S Synthesis
- G2 growth 2
Mitosis - active division, less time
6
Q
interphase
A
involves G1, G0, S, G2, longest part of a cells life, cell performs normal functions and prepares for mitosis
7
Q
G0
A
cell functions normally but is not preparing for division, is at rest
ex) nerve cells
8
Q
G1
A
cell grows, produces new organelles, and materials to make DNA, communication also occurs between cells
9
Q
S
A
synthesis - all cells must replicate DNA before dividing
10
Q
G2
A
protein production required for cell division involves, centrioles and centrosomes
11
Q
mitosis
A
divides two eukaryotic copies of DNA are separated into two cells, occurs in all cells, 1 to 2 cells
12
Q
cytokinesis
A
actual physical splitting of a single cell into two daughter cells
13
Q
control of cell cycle factors
A
signal: an agent that influences the activities of the cell
growth factor: signaling proteins received at the plasma membrane secreted by one cell that INHIBITS or PROMOTES growth of another cell
14
Q
G1 checkpoint
A
- main checkpoint
- evaluates growth signals and size
- determines nutrient availability
–> CDK needs to be present to release E2F so it can bind to DNA - assesses DNA integrity
–> p53 proteins check quality control, if DNA is damaged, p53 phosphorylates and repairs DNA, or p53 is broken down
15
Q
G2 checkpoint
A
determines if S phase created undamaged copy of DNA
16
Q
M checkpoint
occurs near end of metaphase in mitosis
A
checks that 2 copies of DNA are lined up properly
make sure to know spindle fibers are attached to sister chromatids
17
Q
when is cell division prevented?
A
when cells are old, diseased, have a virus, metamorphosizing, or arresting at G0
18
Q
cancer
A
uncontrollable cell division
19
Q
benign
A
abnormal growth, noncancerous
20
Q
malignant
A
abnormal growth, is cancerous, and threatens life
21
Q
metastasis
A
spread of cancer from the place of origin throughout the body, invades tissue
22
Q
contact inhibition
A
the sense that normal cells have to stop replicating when in contact with one another
23
Q
angiogenesis
A
formation of new blood vessels to invade adjacent tissues
24
Q
cancer vs normal cells
A
cancer
- non differentiated
- abnormal nuclei
- do not undergo apoptosis
- no contact inhibition
- disorganized
- undergo metastasis
normal
- differentiated (specialized)
- normal nuclei
- contact inhibition
- one organized layer
- remain in original tissue
25
proto-oncogenes
- code for proteins that promote cell cycle and prevent apoptosis
- can become an oncogene if mutated, and will not be able to stop the cell cycle (continuing to press the gas pedal)
- M (dominant) - gain of function, only need one mutation to lead to complete loss of control of cell cycle
26
tumor suppressor genes
- code for proteins that inhibit the cell cycle and promote apoptosis (Rb, p53)
- can become mutated, preventing necessary checkpoint needed to regulate errors in DNA (brake failure - not being able to stop)
- m (recessive) - gain of function, need both mutations to lead to complete loss of control of cell cycle
27
causes of mutation
- hereditary
- environmental
- pesticides
- chemicals / toxins
- radiation
28
genome
all the cells genetic material
29
chromosome
individual molecules of DNA
30
how many chromosomes to humans have?
46, 23 pairs, 22 autosomal pairs, 1 sex pair
31
diploid
represented by 2n
2 copies of each type of chromosome are present
32
How is DNA organized in interphase?
loosely packed to make genetic information easily accessible for protein generation
33
How is DNA organized once replicated?
| sphase
DNA is condensed into manageable packages to be transported into daughter cells
34
histones
proteins that wind DNA up into chromosome structure from double helix structure
35
nucleosome
a stretch of DNA coiled around 8 histone proteins
36
chromatin
DNA and proteins combined together, there are 2 types
37
euchromatin
loosely coiled, site of active gene transcription
38
heterochromatin
densely packed, inactive gene transcription
39
centromere
where sister chromatids are attached
40
asexual cell division
genetically identical offspring, requires only one parent
41
sexual cell division
genetically different offspring, requires 2 parents
42
generation time
time it takes for a bacterial population to double
43
binary fission
divides prokaryotic cell into two identical cells over and over again
44
prokaryotic cell division types
asexual or sexual
45
eukaryotic cell division
| for somatic cells
mitosis - divides eukaryotic cells genetic info into two identical cells, just one time
46
homologous chromosomes
- one comes from mother and one from father
- same gene, same location
- DIFFERENT ALLELES
47
sister chromatids
only present right before cell is ready to divide, a COPY of DNA from homologous pairs
48
mitosis stages
prophase, metaphase, anaphase, telophase
- genetic info is copied once, cell divides once
49
centrosome
microtubule organizing center, organizes centrioles
50
centriole
set of 2 microtubules involved in assembly of mitotic spindles
51
mitotic spindles
set of microtubule proteins that coordinate movement of chromosomes during mitosis
52
astral microtubule
not directly attached to sister chromatids
53
kinetochore microtubule
attach to sister chromatids directly
54
interpolar microtubule
pull apart cells only attach to one another
55
prophase
- chromosomes condense
- spindles form as centrosome moves to opposite poles
- chromosomes are visible (under a microscope)
- DNA is same on both sides of chromosome
56
metaphase
- spindles align chromosomes down equator of cell, the metaphase plate
- alignment ensures that each cell will receive 1 copy of each chromosome type
- *M checkpoint ensures this*
57
anaphase
- sister chromatids split, and chromosomes are pulled to opposite ends of cell
- microtubules lengthen and move poles apart, stretching and dividing cell
58
telophase
- spindle disassembles and chromosomes begin to unwind
- nuclear envelope forms at each end of stretched cell
- cytokinesis occurs
59
plants vs animals in mitosis
animals
- lot more spindle fibers
- form cleavage furrow during telophase
plants
- no centrioles
- have spindle fibers but no aster spindle fibers
- form cell plate during cytokinesis
60
cytokinesis for plants vs animals
animals
- cell membrane
- form cleavage furrow via actin and myocin
- creates contractile ring which is then stretched and separated
plants
- cell wall and cell membrane
- building new wall
- vesicles establish cell plate with cellulose
61
kinetochore
protein that allows for attachment of centromere between homologous pairs
62
sexual reproduction
genetic makeup comes from two parents, mixes and recombines traits so offspring are different from each other and parents
63
meiosis
- produces haploid (n) gamete cells used during sexual reproduction
- genetic info is copied ONCE
- cell divides TWICE
64
bivalents
2 homologous chromosomes that are close together
65
types of genetic variation in sexual reproduction
crossing over
independent assortment
random fertilization
66
crossing over
exchange of genetic material between non identical sister chromatids during meiosis 1
- occurs through bivalent and nucleoprotein lattice, causing chiasmata of sister chromatids (non identical)[don't necessarily need to worry about all these terms]
- specifically during prophase 1 of meiosis
67
independent assortment
when homologues align at the metaphase plate, the maternal or paternal homologue may be oriented toward either pole.
- happening with gametes
- knowing the number of homologous chromosomes can determine the number of potential combinations
2^n
68
random fertilization
any of the genetically unique sperm created by a male may fertilize any of the genetically unique egg cells
2n^2
69
prophase 1
- spindle forms as centrosomes migrate away from one another
- nuclear envelop fragments
- crossing over occurs between non sister chormatids
70
metaphase 1
- sister chromatids align along the metaphase plate
- independent assortment occurs and either maternal or paternal sister chromatid may be oriented
71
anaphase 1
- homologous chromosomes are pulled apart
- sister chromatids remain bound together at centromere
- paternal and maternal chromosomes are associated with one centrosome at random
72
telophase 1
- spindles are broken down
- nuclear envelope is reformed
- cells are haploid and only contain one version of each type of chromosome
73
interkinesis
short rest period between meiosis 1 and 2, similar to interphase, but no DNA replication occurs
74
meiosis 2
second division of genetic material to get 4 total haploid daughter cells from 1 diploid parent cell
75
prophase 2
- cells have 1 chromosome from each homologous pair
- nuclear mem break down
- spindle fibers attach to kinetochores
76
metaphase 2
- sister chromatids align along the metaphase plate
77
anaphase 2
- sister chromatids split and daughter chromosomes move to poles
78
telophase 2
- spindles are broken down
- nuclear envelope reforms
- cytokinesis
79
mitosis and meiosis similarities
have the same order, and same general processes
80
nondisjunction
when chromosomes do not split up correctly during meiosis
81
primary nondisjunction
occurs in meiosis ONE, pair goes into single cell rather than splitting into two cells
82
secondary nondisjunction
occurs in meiosis TWO, pair goes into a single cell, but leads to less overall damaged cells than primary
83
aneuploidy
zygotes have too many or too few chromosomes
84
trisomy
2n + 1 (3 chromosomes) --> more survivable aneuploidy, leads to down syndrome
85
monosomy
2n - 1 (1 chromosome) --> more deadly aneuploidy, rare chance of survival
86
asexual reproduction
| what are the benefits?
- don't need energy or resources to find mate
- numerous offspring can be produced because energy requirement is low
- can colonize ideal habitat quickly
87
cross pollination
anther --> produces pollen (sperm)
stigma --> contains ovules (eggs)
cut anthers, brush on pollen from another plant
88
self fertilization
cross pollination of pollen from same plant onto a parent plant
89
true breeding
all the same
90
hybrid
different, a mix of genetics
91
monohybrid cross
1 trait is the focus of breeding
92
homozygous
the same -- dominant (AA) or recessive (aa)
93
heterozygous
different -- will be dominant (Aa)
94
law of segregation
- each individual has two factors for each trait
-->factors separate during gamete formation
- each gamete has 1 factor from each pair
- fertilization gives a new individual 2 allele for each trait
explained by meiosis
| basically the process from being diploid, to haploid, to diploid again
95
mendels conclusion
organisms must contain alternative versions of genes
96
allele
variation of gene
97
locus
location of gene
98
law of independent assortment
each homologous pair segregates independently of the other pairs
- all possible combinations can occur in metaphase 1 and are reflected in possible combinations of chromosomes in gametes
99
test cross
used to determine genotype of unknown individual expressing a dominant trait by mating with a homozygous recessive individual
100
dihybrid cross
2 traits are being focused on (ex plant height and pod color)
101
phenotype
physical representation
102
genotype
genetic representation
103
determining genotypes for gametes of dihybrid cross
1&3, 1&4, 2&3, 2&4
104
incomplete dominance
heterozygote has phenotype that is in between (mixed), occurs with intermediate phenotype
--> correlates with theory of blending from before mendel
--> ex: pink flower
105
co-dominance
heterozygote has phenotype where both dominant alleles are fully expressed
--> ex: flower is red and white
106
polygenic
many genes interact to control a phenotype or trait
Ex:
- eye color
- human height
- skin color
107
pleiotropy
one gene effects many phenotypic characteristics
108
product rule
chance that two independent events will occur = product of chance that individual events will occur, meaning you multiply the probability of each individual event together to get the overall probability
109
phenotypic plasticity
individual genotypes produce different traits when exposed to different environmental conditions
--> Ex: shells of snails being thinner when in more exposed intertidal region, because crabs can not predate as much as in land, where shells are thicker
110
sex linked traits
will be present on a sex chromosome, most commonly the X chromosome
Remember
Female: XX
Male: XY
with a recessive x linked disorder, males would only need one x linked allele whereas females would need 2.
