7th Grade Life Sci DNA and cell cycle

Interphase

Longest part of the cell cycle
Chromosomes
copied
, appear as
threadlike
coils at the start, then each chromosome and its copy
change to sister chromatids
at the end of phase

Prophase

Nucleus begins to break down
, chromosomes finish condensing

Prophase

Mitosis begins
; centrioles begin to move to opposite ends of cell; Nucleus starts to disappear

Metaphase

Shortest phase of mitosis.
Chromatids attach to
spindle fibers
; chromosomes line in
middle
of cell

Anaphase

Chromatids separate
, begin to move to opposite ends, pulled by the spindle fibers

Telophase

Cell
membrane moves inward
to create two daughter cells - each with own nucleus with identical chromosomes.

Cytokinesis

Cell membrane pinches in center (cleavage furrow) & leaves the cell into two daughter cells

Centromere

Most
condensed
region of a chromosome; where
spindle fiber attached
during mitosis

Mitosis

Cell division when nucleus divides into two nuclei containing the
same number
of chromosomes ending in
2 identical cells

Spindle Fibers

Special fibers made of proteins - connect to centromeres and pull apart chromosomes

Sister chromatids

two identical strands of the same chromosomes

Chromosome (replicated)

During prophase and metaphase, the DNA in a eukaryotic cell is tightly packed and coiled into structures called...

Centriole

Where the spindle fibers come from during mitosis in both plant and animal cells.

G1 Phase

The cell grows and is just being a cell.

G2 Phase

The cell prepares to divide by copying all organelles & condensing all DNA into chromosomes.

S Phase

The cell replicates/duplicates DNA.

Checkpoints

Happen at G1 and G2 of cell cycle to determine if the cell should divide.
VERY
important to ensure no mutations.

Centromere

Region of a chromosome where the two sister chromatids attach.

Autosomes

Chromosomes
not involved
in determining an individual's sex ie eye color, height, hair texture

Sex chromosomes

Chromosomes that contain genes that will determine the sex and corresponding characteristics

Karyotypes:

Photo of chromosomes in a dividing cell organized by size

Binary fission

Process that bacteria cell uses to divide.

Deletion

Removes a chromosomal segment

Duplication

Repeats a chromosomal segment

Inversion

Reverses a segment within a chromosome

Translocation

Moves a segment from one chromosome to another non-homologous one.