BIOL 207 Lab Final

Chromosome

A molecule of DNA wrapped around and associated with various proteins.

Telomeres

The ends of eukaryotic chromosomes.

Centromere

The single region between telomeres containing DNA packaged tightly into a constriction point on the metaphase chromosome.

Metacentric chromosomes

The centromere is in the center of the telomeres.

Acrocentric chromosomes

The centromere is closer to one telomere.

Telocentric chromosomes

The centromere is very close to one telomere.

Gametes

Haploid (n) cells with 23 chromosomes and c-value (measurement of the amount of DNA in a genome) of 1.

Somatic cells

Diploid (2n) cells with 46 chromosomes (homologous pairs) and a c-value of 2.

Karyogram

A display of chromosomes from a cell displayed in order from 1-22 and X/Y.

Cell cycle

The process where cells alternate between a growth phase (interphase) and dividing phase (mitosis and cytokinesis) to produce 2 new daughter cells.

Interphase

The time in the cycle where cells perform designated functions, maintain structural and metabolic functions, and prepare to divide.

Gap 1 (G1) phase (substage of interphase)

Begins when the previous round of cell division ends. Cells perform cell-specific duties and build new cellular components.

S phase (substage of interphase)

Starts when DNA (packaged as chromosomes) begins to replicate. Each chromosome consists of a single piece of DNA at the beginning of S phase, each chromosome becomes replicated and consists of 2 identical DNA molecules termed sister chromatids in the end. Sister chromatids are held together by proteins in the centromere throughout interphase and most of cell division.

Gap 2 (G2) phase (substage of interphase)

The cell carries on with its cell-specific duties and the building of new cellular components, while also preparing for cell division.

Mitosis

Division of the nucleus.

Cytokinesis

Division of the cytoplasm.

Prophase

Progressive condensation of replicated chromosomes into highly compact structures and the dismantling of the nuclear envolope.

Metaphase

Microtubules connect to each replicated chromosome at the centromere and move those chromosomes to the center of the cell. The movement of each replicated chromosome happens independently and ends when all of them are on the equatorial plate.

Anaphase

Microtubules contract and pull the sister chromatids of each replicated chromosome to opposite poles. Chromatids gain the status of chromosomes as soon as they segregate from their sister.

Telophase

A nuclear membrane forms around the chromosomes at each pole and those chromosomes become less condensed. The result is 2 genetically equal nuclei that become a part of their own new cells at the end of cytokinesis.