10.1 Study Guide Flashcards
Why do multi-celled organisms divide? There are three main reasons.
- Growth and Development
- Repair and Renewal
- Reproduction
Why do single-celled organisms divide? There is one main reason.
Reproduction
What are totipotent embryonic stem cells?
Stem cells that can form all cell types of the body, including those that make up the embryo and the extra-embryonic tissues (like the placenta).
What are pluripotent embryonic stem cells?
Stem Cells derived from the inner cell mass of a pre-implantation embryo.
They can differentiate into any cell type in the body,
They can divide indefinitely in a lab setting while maintaining their ability to develop into various cell types.
What are multipotent embryonic stem cells?
Stem cell that can differentiate into multiple, but not all, cell types within a specific tissue or organ.
Why would cells in an organism need to divide to be replaced or renewed?
Cells can die from normal wear and tear or injury
Somatic stem cells divide to make more stem cells or specialized cells
Are all cell types renewed at the same rate?
No
Cell division in reproduction happens in two major ways. What are they? What is an example of each?
- asexual ; hydras
- sexual; mammals
What are the three things that can happen to a cell formed from mitotic division?
- Divide - the cell continues to grow in preparation for dividing again
- Differentiate - the cell specializes and matures and will never divide again
- Die
What is an example of a cell type that would grow and divide again?
Stem Cell
What is an example of a cell type that would differentiate?
Nerve Cell
Muscle Cell
What is apoptosis?
How does apoptosis help an organism?
Cell Death
This process eliminates unnecessary cells during development and removes unhealthy or damaged cells in the mature organism.
If a cell has unfixable DNA damage what are the two things that could happen?
- Apoptosis - cell death
- Cancer - uncontrolled cell division
What is the cell cycle?
The cell cycle is a series of events that a cell undergoes as it grows and divides.
What are the main phases of the cell cycle?
- Interphase
-G1 (Gap 1)
-S (Synthesis)
-G2 (Gap 2) - M phase
-mitosis
-cytokinesis - G0
What happens to a cell in Interphase?
This is the period between cell divisions where the cell grows, replicates its DNA, and prepares for division.
What three steps are included in Interphase?
- G1 (Gap 1)
- S (Synthesis)
- G2 (Gap 2)
What happens in the G1 (Gap 1) stage?
The cell grows, carries out its normal functions, and prepares for DNA replication.
What happens in the S (Synthesis) stage?
DNA replication occurs, creating two identical copies of each chromosome.
What happens in the G2 (Gap 2) stage?
The cell continues to grow and prepares for mitosis, ensuring DNA replication is complete and that the cell is ready to divide.
What happens to a cell in M Phase?
The cell divides into two daughter cells.
What two steps are included in the M Phase?
Mitosis and Cytokinesis
What happens in the Mitosis stage?
Division of the cell into two daughter cells each with the same number of chromosomes.
What happens in the Cytokinesis stage?
Division of the cells cytoplasm and formation of two separate cells.