chapter 2.6 binary fission and mitotic cell division Flashcards
Cells arise from pre-existing cells, and cell division leads to an increase in cell number. Cell division in somatic cells is different from the cell division that produces gametes from germ-line cells. Continuity of life requires the replication of genetic material and its transfer to the next generation through processes including binary fission, mitosis, meiosis, and fertilisation. Explain why the amount of DNA in a cell doubles before division. The products of mitotic division or binary f
What type of cells are involved in cell division?
Cell division involves the reproduction of somatic or asexual cells.
What is semi conservative DNA replication?
Before a cell divides it needs to make a copy
of its DNA through semi-conservative
replication
One strand of DNA is conserved
Each strand serves as a template for making
the new complementary strand by nucleotide
base pairing
What types of cell division do prokaryotic cells use?
Prokaryotic cells use binary fission.
What is binary fission?
Steps of binary fission:
prior binary fission DNA replicates through semi-consverative DNA replication making a copy of the chromosome
- The cells DNA condesnes to form two identical circular chromosomes.
- Each chromosomes attaches to the inside of the cell membrane .
- The size of the cell increases length way (elongates), seperating the chromosomes
- The seperated chromosomes move to the opposite ends of the cell.
- A new cell wall and membrane form and the cell divides into two.** Creating two daughter cells each with thier own circular chromosome**.
Is there a cytoskleteon used throughout binary fission?
Prokaryotic cells don’t have a cytoskeleton to move things around.
What type of cell division do eukaryotic cells use?
Eukaryotic cells use mitosis.
What are the 4 stages of mitosis?
The four stages of mitosis include: Prophase, Metaphase, Anaphase and Telaphase.
What occurs during the prophase stage?
Prophase is the first stage of mitosis:
- Chromatid fibers become tightly coiled
- Two identical sister chromatids are joined at the centromere
- Nucleus disappears and chromosomes move into the cytoplasm
- Microtubules appear as spindle fibers
Centrioles move towards either side of the cell
What occurs during the metaphase stage?
**Metaphase is the second stage of mitosis: **
- Spindle fibers radiate from each side of the cell (poles)
- Chromosomes align in the middle (metaphase plate)
- Microtubules attach to the centromeres
What occurs during the anaphase stage?
**Anaphase is the third stage of mitosis:
- Centromeres of the chromosomes divide
- Sister chromatids are pulled apart (daughter chromosome)
- Microtubules contract and pull the daughter chromosomes towards each pole
What occurs during the telaphase stage?
** Telaphase is the fourth stage of mitosis-
- Nuclei begin to reappear
- Chromosomes uncoil to form chromatin
- Cytokinesis occurs - Division of the cytoplasm and the formation of two new cells
Are the amount of chromosomes in the parent cell prior cell divsion the same as in the daughter cells produced?
The products of mitotic division or binary fission have the same number and type of chromosomes as the parent
What is one factor which can lead to different DNA in prokarotic cells throughout binary fission?
If cells are exposed to radiation its possible mutations can occur producing different DNA in the cells.
Can mitosis lead to cancer?
Cells replicate through a process called mitosis, making perfect copies of themselves. Sometimes, a cell’s DNA can mutate during replication. Most mutations are harmless, but some can cause cells to grow uncontrollably, leading to cancer.
