Lab 1 Flashcards
What are the three divisions of interphase?
G1, S, G2
G1: The cell does what it normally does and increases in size. S: DNA in nucleus copied. G2: Centrosomes move to opposite sides of nucleus.
What occurs during the G1 phase of interphase?
The cell does what it normally does and increases in size
This phase prepares the cell for DNA replication.
What happens during the S phase of interphase?
DNA in nucleus is copied
Chromosomes originally have 1 chromatid and turn into 2 held together at the center by centromere.
What is the genetic information in the two chromatids after the S phase?
Identical
This ensures that each daughter cell receives the same genetic information.
What occurs during the G2 phase of interphase?
Centrosomes move to opposite sides of the nucleus
This phase prepares the cell for mitosis.
How many phases are there in mitosis?
4 phases
The phases are Prophase, Prometaphase, Anaphase, and Telophase.
What happens during prophase?
Chromosomes condense and mitotic spindle forms
This marks the start of mitosis.
What occurs during prometaphase?
Nuclear membrane breaks down and some spindle fibers connect to chromosomes
Chromosomes are locked at the equator.
What happens during anaphase?
Two chromatids are pulled apart by motor proteins toward newly forming nuclei
This ensures that each nucleus will receive an identical set of chromosomes.
What occurs during telophase?
Nuclear membrane forms around two groups of single-chromatid chromosomes and spindle disappears
This phase concludes mitosis.
What is cytokinesis?
Division of cytoplasm, resulting in two daughter cells
This process typically occurs after telophase.
What is the chromosome composition during G1?
2n
This represents the diploid state of chromosomes.
What is the chromosome composition during S and G2?
4n
This indicates that the DNA has been replicated.
What is the chromosome composition after cytokinesis?
2n
Each daughter cell returns to the diploid state.
What is a kinetochore?
Structure on the centromere where spindle fibers attach
This is essential for the movement of chromosomes during cell division.
