8 Cell Division

Study.com College Biology 101

Haploid

Having one copy of each chromosome

Anaphase

Step 4 in mitosis Sister chromatids separate

Interphase

Precedes mitosis Chromosomes relaxed DNA duplicated

Sister Chromatids

Two identical DNA copies of a chromosome held together by a centromere

Nondisjunction

Occurs when homologous chromosomes or sister chromatids are not separated during anaphase I or II, leading to a cell with the incorrect number of chromosomes

Cytokinesis in Plant Cells

A cell plate is formed by vesicles formed from the Golgi apparatus, which divides the cell membrane in two and then makes new cell wall between the new cell membranes.

Trisomic

a diploid cell with three copies of one type of chromosome, caused by nondisjunction during meiosis

Diploid

Having two haploid copies of each chromosome

Cytokinesis in Animal Cells

This occurs when the contractile ring squeezes the cell together at the middle, forming two daughter cells and splitting cytoplasmic content when the two sides of the cell membrane join together.

Prophase

Step 1 in mitosis Chromosomes condense Spindles organize

Mitosis versus Meiosis I

Both occur after DNA replication Mitosis: sister chromatids separate, resulting in two identical diploid cells Meiosis I: homologous chromosomes separate, resulting in two haploid cells

Condensed Chromosomes

DNA that is tightly coiled before mitosis

Meiosis II

Sister chromatids separate, resulting in four haploid cells with one sister chromatid per chromosome

Meiosis I

Homologous chromosomes separate, resulting in two haploid cells with two sister chromatids per chromosome

Gametes

sex cells (in females: eggs, in males: sperm) which contain 23 chromosomes, half the number of chromosomes in the rest of the body's cells

Asexual Reproduction

Also known as vegetative reproduction, this is a process in which reproduction occurs via mitosis.

Telophase II

Last step of meiosis II in which chromosomes relax and the nucleus reforms, resulting in four cells that are haploid and have altered genetic content due to homologous recombination

Metaphase

Step 3 in mitosis where the chromosomes line up on metaphase plate