General
What is one of the reasons cells divide?
to grow the organism
to repair/replace cells
to reproduce
What are the three stages of the cell cycle?
interphase, mitosis and cytokinesis
What is the main purpose of mitosis?
To produce two identical daughter cells for growth and repair.
What is the primary purpose of meiosis?
To produce gametes (sperm and eggs) for sexual reproduction.
How many rounds of division are in mitosis and meiosis?
Mitosis: 1 round, Meiosis: 2 rounds
What is the term for the process by which a cell's DNA is copies before it divides?
DNA replication
What happens during the G1 phase of interphase?
The cell grows
What happens to the chromosomes during metaphase?
Chromosomes line up along the equatorial plane of the cell.
How many chromosomes does a human gamete have after meiosis?
23 chromosomes.
_________ results in genetically identical daughter cells, whereas ________ results in genetically different daughter cells.
mitosis, meiosis
Uncontrolled cell division can lead to __________
cancer
What happens during the S phase of interphase?
What is cytokinesis?
The process that divides the cytoplasm of a parent cell into two daughter cells.
What is crossing over, and when does it occur?
The exchange of genetic material between homologous chromosomes during prophase I of meiosis.
What types of cells are produced by mitosis and meiosis?
Mitosis produces somatic cells; meiosis produces gametes
Body cells are also called _________ cells
somatic
What is the longest phase of the cell cycle?
Interphase
What structures are pulled apart during anaphase?
Sister chromatids
What structures are pulled apart during anaphase I?
Homologous chromosomes
What ploidy are the daughter cells of mitosis and meiosis?
Mitosis: diploid, Meiosis: haploid
What is another name for Down Syndrome, caused by nondisjunction?
Trisomy 21
What phase is considered the "resting phase" where cells go when they do not need/want to divide?
G0
The phase in which the nuclear envelope reforms and chromosomes start to decondense.
Telophase
Name 2 events that occur that lead to genetic variation.
Crossing over, independent assortment, random fertilization
What is a key difference between prophase in mitosis and prophase I in meiosis I?
Homologous pairs match up to form tetrads, crossing over occurs