Cell Cycle
What are the four phases of the cell cycle?
Gap or growth one, synthesis, gap or growth two, and mitosis
Apoptosis is a ____________ cell death that is a normal function designed to work in two parts of the life of an organism.
Programmed
In experiment 4.1, what process did the yeast go through to form a new organism?
Budding
This is the division of the cytoplasm which results in two cells where there was only one before.
Cytokinesis
What are the five stages of mitosis?
Interphase, prophase, metaphase, anaphase, telophase
For most organisms, most of life activities of a cell occur in this phase.
G1 phase
The molecules in this type of food are capable of activating apoptosis in cells that need to die before they become cancerous.
Spicy
True or False: budding only occurs in single-celled eukaryotic organisms like yeast.
False; it is common in prokaryotes as well as multi-celled eukaryotes
What is the first part of binary fission?
DNA replication
In which phase do cells spend most of their time in the cell cycle.
Interphase
In the S phase, ___________ of DNA occurs here to make a complete copy of the genome.
Synthesis
Name one of the two most important proteins involved in apoptosis.
Caspase and p53
Prokaryotes use budding in this common form of reproduction.
Asexual
What is the origin of replication?
The point were copying DNA begins and it continues in two directions because the DNA is circular.
True or False: mitosis is only found among single-celled organisms in which case it is a form of asexual reproduction.
False; it is also found among multi-celled organisms, but in that case, the purpose is to produce more cells, for either growth or for the replacement of cells that have died
In the G2 phase, the cell grows and produces many ___________ in preparation for cell division.
Proteins
Explain one instance when apoptosis occurs.
During development in a multi-celled organism, what usually happens is that there are more cells produced than are needed. When the point comes where the overall structure is in place, cells die to remove the extras.
-or-
During the cell cycle, if there’s a cell in which a problem cannot be solved, signaling in the cell turns on apoptosis which enables a cell to commit suicide or remove itself from the organism.
Name a multi-celled organism that undergoes budding.
Sponges, worms, plants
Binary fission is similar to mitosis, but has two important differences; what are they?
The copying of the DNA occurs during binary fission whereas the copying of the DNA in the cell cycle occurs during the S phase, which is before mitosis. Second, the process by which the copies of DNA are moved into the new cells is different.
Is interphase a part of mitosis? Why or Why not?
No; it is actually the G1 phase, the S phase, and G2 phase. It’s included in the discussion since the overall perspective is how a cell reproduces
The actual division of the cell into two new cells, called daughter cells, occurs in this phase.
Mitosis
Give the other instance when apoptosis occurs.
During development in a multi-celled organism, what usually happens is that there are more cells produced than are needed. When the point comes where the overall structure is in place, cells die to remove the extras.
-or-
During the cell cycle, if there’s a cell in which a problem cannot be solved, signaling in the cell turns on apoptosis which enables a cell to commit suicide or remove itself from the organism.
Explain the process of budding.
A small portion of the parent cell begins to form a bulge, or a bud, that continues to extend outward. A copy of the genome moves from the nucleus of the original cell into the bud. Eventually, this new daughter Cell contains a complete genome and the cytoplasmic components that are needed to become a new organism. Then the plasma membrane completes the process by pinching off the bud resulting in a new cell.
Explain the process of cytokinesis.
The cell elongates, the DNA moves toward the two ends that are becoming further apart from each other. FtsZ proteins move to the center to form a ring which acts as a scaffold upon which a membrane can be assembled. Eventually, a complete barrier exist between the two new cells. Finally, the cytoskeleton of the two cells constricts, pinching off the two cells. The result is two daughter cells that have exact copies of the original DNA.
What are the first 2 signs of prophase?
The nuclear membrane begins to break down; chromosomes appear