1What is the cell cycle
A cell's cycle of life where it grows, develops, carries out its normal functions, and eventually divides
2What is mitosis
the division of eukaryotic cells
3What is Interphase?
cell grows and carries out its normal functions
4interphases are divided into stages. what are they?
3 stages: G1, S, G2
5what does G1 stand for
gap 1
6what does S phase stand for
synthesis
7a cell will spend most of its life in...
interphase
8interphase is __% of cell life
90
9why is it important for a cell to grow before it divides
so that each daughter cell is large enough to function
10why is it important for the DNA and organelles to replicate / copy before cell division occues?
so that each new daughter cell recieves a full copy of the DNA
11cell division is made up of two parts:
mitosis and cytokenisis
12what is cytokensis
division of he cell's cytoplasm
13what is the diff between Prokayotic DNA and Euk.?
Pro. DNA is one singlular, circular chromosome called a plasmid. In Euk. cell, DNA is organied into multiple pairs of linear chromosomes
14are pro. chormosomes accorciated with histones
no
15are euk. chormosomes accorciated with histones
yes
16hhow many copies of chromosomes in pro.
1
17hhow many copies of chromosomes in euk
2
18What type of molecule is DNA helicase
protein
19What type of molecule is topoisomerase
protein
20dna helicase
unwinds double heliz
21topoisomerase
relieves tension of supercoiling to stabilize function of helicase
22what does SSB proteins stand for
Single Stranded Binding Proteins
23Single Stranded binding proteins
dna does not like not being in a double helix. SSB proteins bind to the open strands to keep them open during replication
24molecule DNA Primase
protein
25molecule DNA polymerase II
protein
26dna ligase
seals the sugar phosphate backbone of new dna molecules
27dna helicase is an enzyme that unqinds the heliz, breaking the bonds between the nirtogenous bases in teh center. What bonds are in the middle of the double helix?
hydrogen bond
28dna helicase is an enzyme that unqinds the heliz, breaking the bonds between the nirtogenous bases in teh center. What bonds are in the middle of the double helix?
hydrogen bond
29SSB proteins stops the open DNA from re-annealing. what it means?
two strands of DNA reattach back into a double helix
30Why would these single stranded bindingproteins be so important to the replication procedure
double helix must remain open so that each strnd can be read for replication
31what enzyme eventually removes the RNA primer and replaces it with DNA nucleotides
DNA poly 1
32notice how 2 phosphates are removed from the free floating nucleotide-- this is just like removing a phosphate from ATP. what might this provide replication process with?
energy
33what is the leading strand
as the bubble/forks open more, the DNA poly III moving in the same direction as the DNA helicase is able to add nucleotides continously (without detaching) . only required one primer to be laid down
34lagging strand
dna polymerase III that works in the opposite directioof the replication fork is only able to replicate a small segment of DNA at a time, or it replicates discontinously (detaching and reattaching a lot). this creates small fragments of DNA called Okazaki fragments -- each segment needing a spereate DNA primer to b elaid down by DNA primase.
35okazaki fragment
small fragments of DNA
36DNA replication is
semiconservative
37why is dna replciation semiconservative
when a mlecule of DNA is replicated, each new molecule of DNA created will be half new nucleotide and half the original molecule
38condensed dna
chromosomes
39homologous chormosomes
chromosomes that are the same shape and size and carry the same genes
40sister chromatids
rpair of identical replcated chromosomes
41sister chromatids held together with a
centromere
42DNA condenses into chromosomes during...
cell division
43packages of dna
chromosomes
44chromosomes appear during
early stage of mitosis
45DNA replicates in..
S phase
46original or replicated chromosomes in mitosis?
replicated
47what is karyotupe
some to exmain someone's chromosomes.
48How do you create a karyotype
taking a sample of cells, freezing them, staining them, and indentifying them in mitosis, and then be cut up and arranged by size and shape
49are all chromosomes the same size/carry the same amt of dna
no
50which chromosomes carry the most dna
the longest/largest chromosomes
51what is the difference between these sets of chromosomes
different combinations of sex chromosomes
52when chromosomes are seen, how many different types of chormosomes are there in a human
23
53because there are 2 copies of each chromosome, how many total chromosomes are these in a human cell
46
54how many chromosomes did you recieve from each parent
23
55is the total number of chromosomes in all living things the same`
no
56what is used to find health conditions in chromosome pairs. how/why
karyotypes because you take a picture of it and if you have one extra chromosome (for example) you can see a health condition
57two X chromosomes means
girl
58one X and one Y means
boy
59karyotypes can...
oversimplify
60why does the physical expression of the genes controlled varies?
because we have two copies of each chromosome
61what is a homologous pair of chromosomes
a pair of chromosomes the same size and shape that carry the same genes (BUT could be different alleles)
62what is the word for location of a gene on a homologous pair
locus
63locus
location of a gene on a homologous pair
64alleles
certain segments of dna in your genes that has different forms
65example of allele
straight and curly hair are two different varieties or alleles of the hair type trait
66for each trait, how many alleles. from where
2; one allele from each parent found on homologous chromosomes
67when the 2 alleles that a person has for a trait are the same, the person is
homozygous
68when the 2 alleles that a person has for a trait are the diff, the person is
heterozygous
69what is hemoglobin
a quaternary protein made up of 4 separartely translated polypeptide chains. two of the 2 chains re called beta globin. there are 2 alleles that exist for the beta globin gene: HbA (normal) and HB5 (abnormal). the abnormal allele produces abnormal beta globin and therebfor abnormal, sticky hemoglobin preotein which changes the shape and function of red blood cells
70how many nucleotides are different in the HbA compared to the Hb5 allele
one different nucleotide pair
72shape size of normal blood cell
circle
73shape size of cickle cell anmenia blood cell
toenail
74what is mitosis
a series of steps that cells follow to ensure proper division of genetic information into two identical daughter cells
75stages of mitosis:
interphase, early prophase, late prophase, metaphase, anaphase, telophase, cytokensis
76what happens in prophase
nuclear envelope breaks down, spindle fibers form, dna condenses from chromatin to chromosomes, spindle fibers attach to chromosomes at the centromere
77what happens in metaphase
chormosomes align down the middle of the cell
78anaphase que pasa
sister chromatids are pulled apaart towards opposite sides of the cell
79what happens in telophase
nuclear envelope reforms, spindle fibers disappear, chromosomes relax back into chromatin
80what happens in cytokineiss
spitting of the elongated cell into two identical daughter cells
81cytokinesis in plant cells requires
formation of a cell plate to ensure that both daughter cells have a cell wall
82what is mitotic index
rate of cell division of a tissue that can be identified
83when is mitotic index higher
when tissues undergo more cell division
84what do you divide in mitotic index
cells undergoing mitosis divided by total cells
85what are cyclins
proteins that help regulate the progression of the cell cycle at various checkpoints
86what are functions of cyclin
check for cell size, check for replciated dna, check for chromosomes attachment to spindle; check for resources, growth factors, dna damages
87when cyclins or checkpoints are damaged...
unrestricted cell growth and division can occur
88tumors
masses of uncontrolled cells with irregular growth
89benign tumor
cell are not cancerous and won't spread
90malignant tumor
cells are cancerous and can spead to other tissues and organs
91difference between benign and malignant tumor
benign tumors are slower-growing and do not spread; malignant tumors are cancerous and can spread to other tissues
92carcinogens
carcinogens are things that can damage dna and cell cycle regulations resulting in malignant tumor growth
93example of carcinogens
smoking, radiation, sun exposure
94how can a mutation in a oncogenes can cause tumor formation
a mutation or change in an oncogenes can result in unrestricted cell growth (cancer)
95oncogene
a gene which in certain circumstances can transform a cell into a tumor cell.
96what is correlation
apparent trend or relationship in data
97example of correlation
smoking and cancer
98causation
one thing causes another
99some regions of dna do not code for the production of proteins. what are these regions of dna used as?
telomeres and coding for production of structural proteins
100Some regions of DNA act as telomeres or produce tRNA. State one other function of DNA sequences that do not code for protein
introns/telomere/ regular of gene expression / rRNA
101Gene expression in cells is regulated at various stages. During which stage does splicing of RNA occur?
Post transcription
102nucleosomes help to regulate transciption in eukaryotes. state the components of a nucleosome.
DNA and histone proteins
103state one role of nucleosomes in eukaryotics
a. help to supercoil/pack DNA in chromosomes
104explain the control of gene expression in eukaryotes
help to regulate transcription / gene expression
105explain the control of gene expression in eukaryotes
a. mRNA conveys genetic information from DNA to the ribosomes «where it guides polypeptide production»
b. gene expression requires the production of specific mRNA «through transcription»
c. most genes are turned off/not being transcribed at any one time/ regulated
10612. Meselson and Stahl conducted experiments using the isotopes 14N and 15N which showed that DNA replication is semi-conservative. What would they have observed about the distribution of isotopes in the DNA after one round of replication if DNA replication was conservative rather than semi-conservative?
Half the DNA with only 14N and half with only 15N
10714. What do DNA replication, transcription and translation have in common?
Complementary base pairing
108 15. Which are necessary to make DNA replication semi-conservative?
Complementary base pairing and Use of a pre-existing strand as a template
109For what purpose is a karyogram used?
to identify abnormal chromosomes in an individual
11019. What is a characteristic of the human Y chromosome?
It contains some genes that are not present on the X chromosome.
111What does eukaryotic DNA have that is missing from prokaryotic DNA?
introns
112What distinguishes an allele from a gene?
an allele is a variety of a gene
113DNA polymerase III uses what types of base pairing and adds what
uses complementary base pairing and only adds neclueoside triphosphate from 5' to 3'
114what did meselson and stahl do
performed an experiement using isotopes of nitrogen n-14 and n-15 to label the parental and daughter strand of dna to confirm that dna is replicated semi conservatively
115why cell division occurs?
to replce the dead or damaged cells
116binary fission
where prokaryotics cells replcates/divides (draw a diagram of this) (one prok cell into two)
117alleles
various specific forms of a gene
118how are new alleles are formed
mutation
119mitotic index
number of cells in mitosis/ total number of cells
120telomere
regionsat ends of the chromosomes