Chapter 12-14 Biology Flashcards
(149 cards)
1
Q
What are the three parts of the Cell Theory?
A
- Cells are the basic unit of life
- Cells come from pre-existing cells
- All living organisms are composed of 1+ cells
2
Q
What steps are required for cellular replication
A
- Replicate DNA (2 copies)
- Separate cytoplasm, DNA, organelles
- Grow cell size
3
Q
Define chromosome
A
Bundles of DNA wrapped around histones
4
Q
Define sister chromatid
A
Chromatid copies attached at the centromere, both sister chromatids have the same DNA
5
Q
Define gene
A
Region that codes for RNA
6
Q
Chromatids are one strand of ___-stranded DNA
A
double
7
Q
Two ___ chromatids make up one chromosome.
A
sister
8
Q
Before mitosis, where is cohesion between sister chromatids?
A
All the way up. After mitosis, cohesion is at the centromere.
9
Q
I consist of a single, long DNA double helix wrapped around histones, what am I?
A
Unreplicated chromosome
10
Q
I consist of two copies of the same DNA helix, what am I?
A
Replicated chromosome
11
Q
I consist of condensed DNA wrapped around its histones and I am 10,000x shorter than my original length. What am I?
A
Condensed replicated chromosome
12
Q
Why do chromosomes condense?
A
In order to divide
13
Q
Why would you see an unraveled chromosome?
A
So it can be read, replicated, and proteins can be made
14
Q
Which of the following is the correct order for the phases of the cell cycle?
a) G1, G2, S, and M
b) S, G2, M, and G1
c) S, G1, M, and G2
d) S, G2, G1, and M
A
B
15
Q
Which 3 phases of the cell cycle make up interphase?
A
G1, S, G2
16
Q
What happens in G1 phase?
A
-Cell grows larger
-Organelles are copied
-Production of NEW proteins
17
Q
What happens in S-phase?
A
S for synthesis
-DNA is synthesized/replicated
18
Q
What happens in G2 phase?
A
-Cell grows more
-Duplication of organelles
-Cell begins to reorganize its contents in preparation for mitosis
19
Q
Interphase v.s. Mitosis
A
Interphase: cell is not dividing, it’s growing and PREPARING to divide
Mitosis: cell is dividing
20
Q
A certain species of animal has six pairs of chromosomes. How many sister chromatids do the nuclei of these animals have during G2 phase?
a) 48
b) 12
c) 6
d) 24
A
D
21
Q
When does G2 end?
A
When mitosis begins
22
Q
What is the difference between a chromosome and a chromatid?
A
A chromatid is one half of a replicated chromosome, whereas a chromosome consists of DNA wrapped around proteins in a highly organized manner.
23
Q
What are the 3 types of cell reproductions
A
- Binary fission (bacteria)
- Meiosis (gametes)
- Mitosis (somatic cells)
24
Q
Mitosis starts when ___ or body cells divide. When mitosis is completed ___ identical cells are produced
A
somatic, two
25
5 stages of Mitosis
1. Prophase
2. Prometaphase
3. Metaphase
4. Anaphase
5. Telophase
26
What is interphase?
-period between two consecutive mitoses
-uncoiled chromosomes
-cells growing/prepared to divide
MOST TIME SPENT FOR CELLS
27
Centromere v.s. Centrosome
Centromere: connects sister chromatids
Centrosome: where microtubules are made to move chromosomes
28
What happens in prophase?
-chromosomes condense
-spindle apparatus forms
29
Mitotic spindle fibers are composed of what cellular components?
a) kinetochores
b) microtubules
c) centrosomes
d) actin
B
30
What happens in prometaphase?
-nuclear envelope breaks down
-microtubules contact chromosomes at kinetochores
31
What happens in metaphase?
M for middle
-chromosomes line up in the middle
32
What happens in anaphase?
A for "Anna being separated from Elsa"
-sister chromatids separate
33
What is the metaphase plate?
The imaginary plane between two spindle poles
34
In metaphase each chromosome is held by ____ microtubules from ___ poles.
kinetochore, opposite
35
After which stage of mitosis are two identical sets of chromosomes created?
Anaphase
36
Which two forces pull chromosomes apart?
-kinetochore microtubules shrink
-motor proteins of polar microtubules push two poles of cell away from each other
37
When microtubules move chromosomes during anaphase, ___ subunits are lost from their (+) ends
tubulin
38
What happens in telophase?
-nuclear envelope begins to forms
-chromosomes begin to decondense
39
When mitosis is complete, two independent ___ have formed.
nuclei
40
Cytokinesis in animal cells is when ___-___ interactions pull the plasma membrane inward to divide the cell into two.
actin-myosin
41
After S phase, what makes up a single chromosome?
a) A single double-stranded DNA molecule
b) Two single-stranded DNA molecules
c) Two daughter chromosomes
d) Two sister chromatids
D
s=synthesis, DNA will have been replicated and sister chromatids will be conjoined
42
The structures on sister chromatids where microtubules attach.
Kinetochores
43
The material that makes up eukaryotic chromosomes and consists of DNA molecules with histones.
Chromatin
44
In what ways does fission differ from mitosis?
-no nucleus
-no packing of DNA
45
How is fission similar to mitosis?
-copying of DNA
-pinching as seen in cytokinesis
-two poles --> two daughter cells
46
True or false: Cell-cycle length varies
True
47
What is the function of the M-phase promoting factor (MPH)?
Tells the cell that it can divide
48
Present in different concentration throughout the cell cycle
Cyclin (think cycling, goes up and down)
49
Kinase that transfers phosphate group from ATP to target protein
Cyclin-dependent kinase (CDK)
50
CDK + Cyclin make up ___
MPF
51
When does cyclin peak? When does it start to decrease?
M-phase is when cyclin peaks, and decreases when the cell needs to stop cell division and come to a conclusion.
!!! you have to know that cyclin INCREASES in G1 and S phase
52
With the use of cyclin, the cell cycle is turned on in late ___ and turns off after ___.
G2, anaphase
53
3 Cell-cycle checkpoints
1. G1 checkpoint
2. G2 checkpoint
3. M checkpoint x2
54
Why do we have checkpoints in the cell-cycle?
-Make sure the cell is ready for the next phase
-No damaged DNA
55
What does the G1 checkpoint look for?
-Cell size is sufficient
-Nutrients are sufficient
-Social signals are present
-DNA is undamaged
56
What does the G2 checkpoint look for?
-If chromosomes have successfully replicated
-DNA is undamaged
-Activated MPF is present
57
What does the M-phase checkpoint look for? (part one)
-Chromosomes have attached to spindle apparatus
-Chromosomes have properly segregated and MPF is absent
58
What happens if a checkpoint fails?
-Cell can wait for prereqs to be fulfilled
-If DNA is damaged, P53 will pause cell cycle
-if damage is NOT repaired, apoptosis will occur (cell death)
59
WHAT PROTEIN IS IMPORTANT FOR PAUSING CELL CYCLE (!!!)
p53
60
M-phase checkpoint is between ____ and anaphase (part one) and then anaphase and ___ (part two).
metaphase, telophase
61
What does M-phase checkpoint look for? (part two)
-Chromosomes have fully separated
62
Which of the following conditions will most likely prevent a cell from passing the G2 checkpoint?
a) Chromosomes have replicated incorrectly
b) Nutrients are adequate
c) Cell has reached a certain minimum size
d) Activated MPF is present
A
63
Benign tumors
-Grow in one location
-Noncancerous and noninvasive
64
Cancer divides in an ___ fashion and ___nearby tissues and other parts of the body.
uncontrolled, invade
65
Malignant tumors
-Cancerous
-Can spread (metastasis)
66
True or false: Benign tumors cannot become malignant
False, they can
67
Cancer cells divide without ___ factors
growth
-they can tell themselves to divide
ex: cyclin overproduction
68
Why sexual reproduction and not mitosis?
Genetic variation and mitosis can pass on errors
69
When sperm and egg unite to form an individual
Fertilization
70
Gametes = ___ =____
reproductive cells = sex cells
71
Are gametes haploid or diploid?
Haploid, because they contain half the number of chromosomes
72
Cell division to produce gametes
Meiosis
73
Sperm and egg form a ___
zygote
74
Each organism has its own number of ___.
chromosomes
75
What is a karyotype?
Shows all the types chromosomes within an organism
76
Homologous chromosomes may contain different ___ of the same gene.
alleles
Gene is the same, allele is different (and gene is in the same location of the chromosome)
77
Two homologs of each chromosome/2 alleles of each gene
Diploid
78
How many copies of chromosomes 14 in your muscle cells?
2
79
In ploidy, n stands for what?
Distinct types of chromosomes
80
The goal of meiosis is to reduce ____ number
chromosome
81
Forming sperm and egg
Gametogenesis
82
Which meiosis am I?
Parent cell is diploid and contains a homologous pair of replicated chromosomes
Meiosis 1
83
Which meiosis am I?
Daughter cells are haploid and contain just one haploid
Meiosis 2
84
Meiosis starts with diploid parent cell, which contains __ chromosomes, divides into two sets of __ homolog(s)/chromosome(s), and lastly separates in to __ haploids/daughter cells
2, 1, 4
85
___ restores a diploid set of chromosomes.
Fertilization
86
How many copies of chromosome 14 do your egg or sperm cells contain?
1
87
When does ploidy change in an animal?
During the life cycle
88
What are the steps in meiosis 1?
1. Early prophase 1
2. Late prophase 1
3. Metaphase 1
4. Anaphase 1
5. Telophase 1
89
First division =
Meiosis 1
90
What happens in early prophase 1?
## Footnote
IMPORTANT S WORDDDD
-NUCLEAR ENVELOPE BREAKS DOWN
-Chromosomes condense
-Spindle apparatus forms
-SYNAPSIS (pairing) of homologous chromosomes
91
Bivalent
2 homologous pairs
92
Why does pairing of the homologous chromosomes occur in early prophase 1?
In order for the homologous chromosomes to stay together in the first division and for crossing over to happen
93
Chiasma is the site of ___ ___.
crossing over
94
What happens in late prophase 1?
-Chiasmata (crossover points) are visible
-Crossing over is happening
-Nuclear envelope is broken down
-Microtubules attach to kinetochore
95
Does crossing over occur in sister chromatids?
No, because they are identical. Crossing over occurs in homologous sister chromatids.
96
What does crossing over produce?
Chromosomes with a combination of sperm-derived and egg-derived alleles
97
What happens in metaphase 1?
-Paired homologs line up at the metaphase plate
-ALIGNMENT IS RANDOM
98
What is different between metaphase in mitosis and meiosis 1?
The alignment in meiosis 1 is RANDOM
99
Independent assortment
When the homologs line up independently and assort into genetically varied gametes
100
What happens in anaphase 1?
-When homologous chromosomes are separating, moving to opposite
-bivalence is separating
101
Difference between anaphase in mitosis and meiosis 1
In mitosis, the sister chromatids are separating and in meiosis 1, the homologous chromosomes are separating.
102
What happens in telophase 1?
-Spindle apparatus disassembles
-Cytokinesis: Cell divides
-Chromosomes number is reduced
103
What is the difference between telophase in mitosis and meiosis 1?
The nuclear envelope is not reforming in telophase 1 because it will go through another division.
104
4 phases in meiosis 2
1. Prophase 2
2. Metaphase 2
3. Anaphase 2
4. Telophase 2
105
What happens in prophase 2?
-Spindle apparatus forms
-Microtubules attach to kinetochores
106
What is different in prophase 2 compared to prophase 1 and prophase in mitosis?
-There is NO nuclear envelope to break down (both mitosis AND meiosis 1 have it)
107
What happens in metaphase 2?
Chromosomes line up at the metaphase plate
108
What happens in anaphase 2?
-Sister chromatids separate
-Moving to opposite poles
109
How many cells undergo anaphase 2?
2 daughter cells
110
What happens in telophase 2?
-Daughter chromosomes are at opposite poles (sister chromosomes are separated)
-Spindle apparatus disassembles
-Cytokinesis (cell division)
111
Does the chromosome number change in telophase 2?
No
112
Meiosis of one diploid cell results in the production of
a) 2 diploid cells
b) 2 haploid cells
c) 4 diploid cells
d) 4 haploid cells
D
113
Mitosis produces 2 ___.
diploid
114
Meiosis or mitosis
The spindle fiber attachments goes on each side of the chromosome.
The spindle fiber attachments go on the entirety of the homologous chromosome
Mitosis, Meiosis (specifically division 1)
115
When do we see unreplicated chromosomes?
G1
116
When does bivalence exist (paired homologous chromosomes)?
Prophase 1 and metaphase 1
117
3 ways for genetic variation
1. Crossing over
2. Independent assortment
3. Fertilization
118
Crossing over contributes genetic variability between
a) sex chromosomes
b) homologous chromosomes
c) nonhomologous chromosomes
d) sister chromatids
B
this is because we need to switch out the same gene (eye for eye)
another correct answer is non-sister chromatids
119
Independent assortment occurs during
a) fertilization
b) prophase 2
c) prophase 1
d) metaphase 1
D, chromosomes have to be lined up
120
Nondisjunction
Chromosomes are not separating correctly
121
When can nondisjunction occur?
Anaphase 1/when homologous chromosomes separate
Anaphase 2/when sister chromatids separate
122
Nondisjunction leads to errors in chromosome ___
number
123
Why can errors/nondisjunction happen?
-Random
-Mother's age
124
Which of these statements is incorrect concerning homologous chromosomes?
a) Homologous chromosomes separate during anaphase 1
b) Homologous chromosomes undergo crossing over in prophase 1
c) Homologous chromosomes have identical alleles before crossing over
d) 4 sister chromatids are present for each set of homologous chromosomes at prophase 1
C
125
Alternative versions of individual genes
Alleles
126
Location of gene on chromosome
Loci
127
Why did Mendel use peas?
-Quick reproduction
-Cheap
-Simple genes
128
Transmission of traits from parent to offspring
Hereditary
129
Polymorphic traits have __ or more forms
two
130
Self-fertilization creates __
pure breds
131
Inheritance of any genes NOT on a sex chromosome
Autosomal inheritance
132
Phenotype v.s. Genotype
Phenotype = visible traits
Genotype = listing of alleles
133
Offspring of the OG cross
F1 generation
134
Offspring of the crossing F1s
F2 generation
135
Simple dominance ratios crossing two heterozygous
3 (dominant) :1 (recessive)
136
Dihybrid cross ratio crossing two heterozygous (RrYy x RrYy)
9:3:3:1
137
Meiosis explains the principles of ___.
segregation
when homologous chromosomes separate in meiosis 1/ when independent assortment happens
138
If an individual is heterozygous for both hair color (Hh) and eye color (Ee), which of the following statements is true about the gametes produced by this individual?
a) The individuals somatic cells will contain HE or he
b) The individual can make gametes that contain only HE or he
c) The individual can make gametes that contain only H, E, e, or h
d) The individual can make gametes that contain HE, He, hE, or he
D
139
Two important terms applying to drosophilas
1) Wild type
2) Mutants
1) Most common phenotype
2) Organism with traits caused by mutation
140
Red eyes are __ and white eyes are __
wild-type, mutant
141
Two crosses to determine if it's sex-linked and change the phenotype of each sex
Reciprocal cross
142
Reciprocal cross confirms that eye color in drosophilas are ___
X-linked
143
Linkages genes are located on the same ___.
chromosome
144
True or false: Crossing over occurs more often between genes that are far apart
True
145
Recombination is produced by ___.
crossing over
146
Incomplete dominance v.s Codominance
Incomplete = blending
Codominance = both traits show up
147
Pleiotropy is when one ___ affects many traits.
gene
148
___ is when one trait is influenced by alleles of two or more different genes. The expression of one gene can influence the expression of another.
Epistasis
GENE INTERACTION
149
___ traits often have a normal distribution (bell curve)
Quantitative
