Cell Division/Cell Aging and Death Flashcards
What are the three stages of interphase?
G1, S, and G2
G1
growth and preparation for DNA replication
S phase (synthesis)
DNA replication
G2
growth and preparation for division of DNA
What are the phases of mitosis?
prophase, metaphase, anaphase, and telophase
Prophase
- nucleus breaks
- chromatin coils up into chromosome
- spindle fibers appear
Metaphase
- chromosomes line up in the middle of the cell
Anaphase
- chromatid begins moving apart towards the cell’s poles
Telophase
- Chromosomes begin to relax
- Cleavage is formed
- Nucleus is reformed
What does “pro-“ mean?
prepare
What does “meta-“ mean?
middle
What does “telo-“ mean?
end
Which to cell cycle phases overlap?
cytokinesis and telophase
DNA replication is also known as what?
DNA synthesis
DNA replication steps
- Parent DNA
- Parent strands unzipped
- Complementary strands synthesized
- 2 “sister” DNA copies
- Chromosome
What are the parts of a chromosome?
2 sister chromatids and centromere
Chromatids
each of the two threadlike strands into which a chromosome divides longitudinally during cell division.
What does each chromatid contain?
a double helix of DNA
Centromere
the region of a chromosome to which the microtubules of the spindle attach
What does DNA replication require?
regulatory proteins
What is an example of regulatory proteins?
DNA polymerase matches with 50 nucleotides
What do occasional mistakes in DNA replication?
mutations
Mutations
random changes in DNA
The cell cycle is typically what kind of process?
highly controlled
What is the result of disrupted cell regulation?
uncontrolled division
What is the result of uncontrolled division?
tumors
What are the two kinds of tumors?
benign and malignant
Benign tumors (noncancerous)
tend to grow slowly and do not spread
Malignant tumors (cancerous)
can grow rapidly, invade and destroy nearby normal tissues, and spread throughout the body
What are the two types of cell death?
necrosis and apoptosis
Necrosis
killed ny harmful agents/mechanical damage
What is the problem with necrosis?
with cellular lysis, the messy contents of the cell spills into the body
Cellular lysis causes what?
inflammation (swelling, redness, and pain)
Apoptosis
programmed cell death
What are the goals of apoptosis?
removal of damaged cells and normal development
What is an example of apoptosis’s role in normal development?
removing the tail of the human embryo
What are the steps involved in apoptosis?
- destruction of DNA/organelles
- breaking into vesicles so that the contents doe not spill
What happens to the contents in the vesicles formed in apoptosis?
it is recycled by macrophages
What does “-phage” mean?
eat
