Biology 1A03 Test 3 Final Exam
Questions With Correct Solutions.
cell division in prokaryotes - Answer binary fission, also reproduction, identical genetic
material distributed among daughter cells. DNA replication begins when DNA is attached by
proteins to the inside of the plasma membrane. as chromosomes replicate, cells elongate and
new DNA attaches to opposite plasma membrane, cell forms new cell membrane and cell wall
and splits in 2
Eukaryotic cell division - Answer allows a unicellular fertilized egg to become a multi cellular
organism
Stem cells - Answer unspecalized cells that can reproduce indefinitely and differentiate into
specialized cells. In adults, stem cells can only replace non-reproducing specialized cells
Satellite stem cells - Answer activated when muscle tissue is damaged. satellite stem cell
activity leads to proliferation (differentiation and fusion of muscle precursor cells called
myoblasts) which become committed to forming mature muscle cells (myofiber). Once myofiber
is formed, it can no longer divide.
Eukaryotic cell cycle - Answer Interphase (cells prep for division), S phase (DNA synthesis
occurs, DNA replication), G1&G2 phase (G1 prep fro synthesis, G2 prep for mitosis), M phase
(where mitosis and cytokinesis occur), G0 phase (is somewhere between M and S phase, pause
in cell growth and division). Some cells can enter a permanent G0 phase
Define quiescent - Answer a period of no cell division
What are the 5 stages of mitosis? - Answer prophase, prometaphase, metaphase, anaphase,
telophase- stages are based on chromosomal changes
What happens prior to mitosis? - Answer chromosomes must be duplicated and condensed,
produce sister chromatids that will eventually separate and move to 2 different cells
Describe prophase - Answer chromosomes condense, centrosomes radiate microtubules and
migrate to opposite poles
, Describe metaphase - Answer chromosomes align in the center of the cell at the metaphase
plate
Describe anaphase - Answer sister chromatids (which become individual chromosomes when
the centromere splits) separate and travel to opposite poles
Describe telophase - Answer nuclear envelope reforms and chromosomes decondense
Describe cytokinesis - Answer division of the parent cell into 2 daughter cells, division of the
cytoplasm and therefore the cell, form contractile ring which displays cleavage furrow
Tim Hunt and mitosis promoting factor from G2 to M phase - Answer Tim hunt measured
protein level changes of dividing sea urchin embryos. added radioactive methionine to eggs,
took samples every 10 min and used gel electrophoresis to see protein changes. most protein
bands came back darker each time, one band oscillated intensity with each division- named the
protein cyclin
Cyclin proteins - Answer mitosis promoting factor between phases G2 and M consists of cyclin
proteins and cyclin-dependent kinases.
What are kinases? - Answer Kinases are enzymes that activate or inactivate other proteins by
phosphorylating key amino acids on the target protein
G1/S cyclin-CDK complex - Answer transition from G1 to S phase and preps DNA for replication
S-cyclin-CDK complex - Answer initiates DNA synthesis
M cyclin-CDK complex - Answer Initiates process of mitosis
cell cycle checkpoints - Answer G1, G2, M. cell surveillance and can block cyclin CDK
At end of G2, is all DNA replicated?
Before S phase, is DNA damaged?
Before anaphase, all chromosomes attached to spindles?
Questions With Correct Solutions.
cell division in prokaryotes - Answer binary fission, also reproduction, identical genetic
material distributed among daughter cells. DNA replication begins when DNA is attached by
proteins to the inside of the plasma membrane. as chromosomes replicate, cells elongate and
new DNA attaches to opposite plasma membrane, cell forms new cell membrane and cell wall
and splits in 2
Eukaryotic cell division - Answer allows a unicellular fertilized egg to become a multi cellular
organism
Stem cells - Answer unspecalized cells that can reproduce indefinitely and differentiate into
specialized cells. In adults, stem cells can only replace non-reproducing specialized cells
Satellite stem cells - Answer activated when muscle tissue is damaged. satellite stem cell
activity leads to proliferation (differentiation and fusion of muscle precursor cells called
myoblasts) which become committed to forming mature muscle cells (myofiber). Once myofiber
is formed, it can no longer divide.
Eukaryotic cell cycle - Answer Interphase (cells prep for division), S phase (DNA synthesis
occurs, DNA replication), G1&G2 phase (G1 prep fro synthesis, G2 prep for mitosis), M phase
(where mitosis and cytokinesis occur), G0 phase (is somewhere between M and S phase, pause
in cell growth and division). Some cells can enter a permanent G0 phase
Define quiescent - Answer a period of no cell division
What are the 5 stages of mitosis? - Answer prophase, prometaphase, metaphase, anaphase,
telophase- stages are based on chromosomal changes
What happens prior to mitosis? - Answer chromosomes must be duplicated and condensed,
produce sister chromatids that will eventually separate and move to 2 different cells
Describe prophase - Answer chromosomes condense, centrosomes radiate microtubules and
migrate to opposite poles
, Describe metaphase - Answer chromosomes align in the center of the cell at the metaphase
plate
Describe anaphase - Answer sister chromatids (which become individual chromosomes when
the centromere splits) separate and travel to opposite poles
Describe telophase - Answer nuclear envelope reforms and chromosomes decondense
Describe cytokinesis - Answer division of the parent cell into 2 daughter cells, division of the
cytoplasm and therefore the cell, form contractile ring which displays cleavage furrow
Tim Hunt and mitosis promoting factor from G2 to M phase - Answer Tim hunt measured
protein level changes of dividing sea urchin embryos. added radioactive methionine to eggs,
took samples every 10 min and used gel electrophoresis to see protein changes. most protein
bands came back darker each time, one band oscillated intensity with each division- named the
protein cyclin
Cyclin proteins - Answer mitosis promoting factor between phases G2 and M consists of cyclin
proteins and cyclin-dependent kinases.
What are kinases? - Answer Kinases are enzymes that activate or inactivate other proteins by
phosphorylating key amino acids on the target protein
G1/S cyclin-CDK complex - Answer transition from G1 to S phase and preps DNA for replication
S-cyclin-CDK complex - Answer initiates DNA synthesis
M cyclin-CDK complex - Answer Initiates process of mitosis
cell cycle checkpoints - Answer G1, G2, M. cell surveillance and can block cyclin CDK
At end of G2, is all DNA replicated?
Before S phase, is DNA damaged?
Before anaphase, all chromosomes attached to spindles?
