3.1 Cell Cycle, Mitosis, and Meiosis

Interphase

Phase in cell cycle of normal cell activity

Mitosis/Mitotic Phase

Phase in cell cycle of cell divison

Reproduction, growth and devlopment, and tissue renewal

Functions of the cell cycle

Chromatin

The protein wrapped around DNA that condenses during cell division

Histone

The protein that DNA wraps around to form the nucleosome

Heterochromatin

Highly coiled regions where genes aren’t used or expressed

Euchromatin

Loosely coiled regions where genes can be used or expressed

2n = 46

The amount of chromosomes humans have

Homologous Chromosomes

Chromosomes that look the same, control the same traits, but may code for different forms of it and had an independent origin. Sister chromatids.

Centromere

The center piece that holds chromatids together.

Kinetichore Microtubules (spindle things)

The thing that pulls the chromosomes apart

Diploid

A cell that has two copies of each chromosome

Haploid

A cell that has a single copy of each chromosome

G1

Interphase stage where cells go through the majority of growth

Synthesis Phase

Interphase stage where each chromosome replicates to make sister chromatids

G2

Interphase stage where chromosomes begin to condense.

Prophase

First stage of mitosis where the nuclear envelope begins to disappear, the mitotic spindle begins to form, and chromosomes condense.

Metaphase

Second stage of mitosis where chromosomes begin to line up in the middle and the centrosomes of the spindle are at opposite sides of the cell.

Anaphase

Third stage of mitosis where microtubules attach to the chromatids and pull them apart, resulting in equal chromosomes on each side of the cell

Telophase

Fourth stage of mitosis where the nuclear envelope returns and the cells return to packaging.

Cytokinesis

The complete division to make two new cells. Cellular cleavage forms.

Meiosis

Process of cell division that only occurs for organisms that sexually reproduce. Ends in brand new cells rather than duplicates and divides twice resulting in 4 haploids.

Prophase 1

Stage of meiosis where chromosomes condense and form a tetrad to begin swapping or crossing over.

Metaphase 1

Stage of meiosis where the tetrad of chromatids align in the middle

Anaphase 1

Stage of meiosis where the pairs of homologous chromosomses split

Telophase 1

Stage of meiosis where two haploids are formed.

Metaphase II

Stage of meiosis where sister chromatids align at the middle of the cell, but are no longer genetically identical

Telophase II

Stage of meiosis where the cells divide into 4 haploid cells with completely new genetic material.