Biology (Day 21; Mitosis) Flashcards
Understand the Lesson
Cell Cycle
the series of growth and development steps a cell undergoes between its formation and reproduction
Interphase
the phase of the cell cycle where the cell grows and makes a copy of its DNA
Mitosis
the phase of the cell cycle where the cell separates its DNA into two sets and divides, forming two new cells
Cancer
A disease of uncontrolled cell growth
What happens in the G1 phase of interphase?
the cell grows larger and the organelles are copied
What happens in the S phase of interphase?
the cell synthesizes a complete copy of the DNA in its nucleus
What happens in the G2 phase of interphase?
the cell grows more, makes proteins and organelles, and begins to reorganize its contents in preparation for mitosis
What happens to cells that divide slowly or not at all that are currently in the G1 phase?
these cells can escape the G1 phase and enter a non-dividing state called G0; some cells may stay in this state permanently, while other re-enter the division
What happens during prophase?
the mitotic spindle forms, chromosomes condense, and nuclear envelope breaks down
What happens during metaphase?
chromosomes line up at metaphase plate
What happens during anaphase?
microtubules push poles apart, and the chromosomes are pulled toward opposite sides of the cell
What happens during telophase?
Chromosomes start to decondense, spindle disappears, and nuclear membrane reforms
What happens during cytokinesis?
the cell divides into two identical daughter cells
What are positive regulators?
encourage cell growth, but they may become hyperactivated
Negative regulators
prevent the formation of tumors, but they may become inactivated
