Show:
The Cell Cycle
Mitosis and Cytokinesis
Regulation of the Cell Cycle
Asexual Reproduction
Section 5
100
What is the cell cycle?
The regular pattern of growth, DNA duplication and cell division that occurs in eukaryotic cells.
100
What is cancer?
The common name for a class of diseases characterized by uncontrolled cell division.
100
True or false: it is possible to reproduce through mitosis
True
100
What are stem cells?
A unique type of body cell that has the ability to 1) divide and renew itself for long periods of time 2) remain undifferentiated in form 3) develop into a variety of specialized cell types
200
Why is cell size limited?
If the cell is too large, its volume will get too large, making it difficult for materials to transport throughout the cell.
200
How does cytokinesis differ from animal cells to plant cells?
In animal cells, the membrane forms a furrow that is pulled inward by tiny filaments. Membranes pinch closed. In plant cells, a cell plate forms between the two nuclei, forming a new cell well that evenly divides the cell.
200
What is the difference between a benign and a malignant tumor?
In a benign tumor, cancer cells typically remain clustered together. When a tumor is malignant, some of the cancer cells have metastasized, making it more dangerous.
200
What is asexual reproduction?
The creation of offspring from a single parents and does not involve the joining of gametes.
200
What is cell differentiation?
The process by which unspecialized cells develop into their mature forms and functions
300
How do cell division rates vary?
Some cells (like skin cells) divide very quickly, living for about 2 weeks, whereas some cells (like neurons) live for ages and replicate fairly rarely.
300
What are the phases of mitosis?
Prophase, metaphase, anaphase, telophase
300
What are some external factors that control cell growth?
Physical cell-to-cell contact and growth factors (broad group of proteins that stimulate cell division)
300
What is binary fission?
The asexual reproduction of a single-celled organism by division into two roughly equal parts.
300
What are the complex structures that cells can create?
Groups of cells create tissues Groups of tissues create organs Groups of organs create organ systems
400
How are mitosis and cytokinesis related?
Mitosis duplicates the cell's nucleus and its contents; cytokinesis splits the cell in two.
400
What happens during each phase of mitosis?
Prophase- Chromosomes are formed, nuclear envelopes break, centrioles move to opposite poles, spindle fibers form Metaphase- spindle fibers attach, chromosomes align along the cell equator Anaphase- chromatids separate to opposite ends of the cell Telophase- nuclear membranes form, chromosomes uncoil, spindle fibers fall apart
400
What are some internal factors that control cell growth?
Kinases (enzymes that transfer a phosphate group from one molecule to a specific target molecule) increase the energy of the target molecule/changes its shape. Cyclins activate those kinases, and cyclins are made and destroyed at certain points in the cell cycle.
400
How does binary fission work?
Bacterial chromosomes are copied, the cell grows and chromosomes move away from each other, and cytokinesis splits it in two.
400
What are some possible future uses for stem cells?
It may be used to cure diabetes, repair damaged organs, help with spinal problems, etc.
500
What are the four states of the cell cycle and what occurs during each?
Gap 1- the cell acts normally, gaining size and nutrients while checking to make sure it is okay to proceed with division Synthesis- nuclear DNA is duplicated Gap 2- the cell acts normally, checking to make sure it is okay to proceed with division Mitosis- the cell divides its nucleus and contents, dividing the cell into two
500
How are chromosomes formed?
DNA wraps around histones, forming chromatin. Chromatin condenses around organizing proteins, forming chromosomes.
500
What is apoptosis and how does it work?
It is programmed cell death. It occurs when cell signals activate genes that help produce self-destructive enzymes.
500
What are some advantages and disadvantages of asexual reproduction?
Asexual reproduction is more efficient, and on occasion genetic variation could be more harmful than helpful. However, if conditions change, genetically identical offspring that lack the same traits may end up dying off.
500
How does cell differentiation occur differently in plant and animal cells?
In plant cells, the first division of a fertilized egg is unequal, producing two cells that make up the embryo and its nutrients. In animals, an egg undergoes divisions until there are plenty of cells to migrate to specific areas.