The Cell Cycle - Quiz 3

Cell Cycle

Includes everything the cell does from the time that it is formed to the time that it undergoes cell division.

Cell Division

The production of two identical cells from one cell.

Interphase (90% of cell cycle)

The first stage of the cell cycle where the cell is growing, performing its functions and accumulating nutrients. The cell will eventually start copying its DNA and make other preparations for cell division.

Mitosis (10% of cell cycle)

The second stage of the cell cycle that involves the division of the nuclear contents.

Cytokinesis

Division of the cell itself.

Genome

All of the DNA contained within the nucleus. Mitochondrial genome refers to all the DNA contained within the mitochondrion and the chloroplast genome is all circular DNA in the chloroplasts.

Chromosome

DNA (and its associated proteins) that moves as a single unit.

Gene

An informational unit of DNA; typically codes for proteins, but can code for rRNA, tRNA, and any of the other types of RNA.

Somatic Cells

Body cells. Usually contain the full set of DNA. Said to be diploid because these cells contain two copies of every chromosome.

Homologous Chromosomes

Pairs of chromosomes in human somatic cells (46 chromosomes or 23 pairs of chromosomes, homologs)

Diploid number

Abbreviated 2n, for humans is 46.

Gametes

Sex cells; sperm and egg. Contain half as many chromosomes as somatic cells. Haploid with only one copy of every chromosome. Human gametes contain 23 chromosomes, haploid number = n.

Cohesins

Proteins that join each DNA molecule to its duplicate.

Centromeres

Region on the DNA where the cohesins join duplicate pieces of DNA to one another.

Sister chromatids

Identical DNA molecules that are joined to one another by the centromere.

Before and After DNA Replication

Before: Each chromosome is made up of one DNA (douvle-helix molecule)

After: Each chromosome is made up of two identical DNA molecules.

During cell division: Sister chromatids are separated from one another and partitioned into separate cells.