LZHS Bio I Topic 7 Cell Differentiation

Interphase

Part of the cell cycle where chromosomes replicate, a cell spends the most time (most growth occurs ) in this phase; made up of the G1, S, & G2 phases. DNA is in chromatin form.

Prophase

The part of the cell cycle where the nuclear membrane disappears, chromosomes become thicker and darker

Metaphase

The part of the cell cycle where chromosomes line up in the middle of the cell

Anaphase

The part of the cell cycle where chromatids move to opposite ends of the cell

Telophase

The part of the cell cycle where spindle fibers and centrioles disappear, nuclear membrane reappears

Cytokinesis

Division of the cytoplasm. The cell membrane pinches at equator until it separates creating 2 daughter cells (cell plate forms in a plant cell)

Cell Cycle

A series of events a cell goes through as it grows and divides. Interphase, Mitosis (Prophase, Metaphase, Anaphase, Telophase), & Cytokinesis

Mitosis

Division of the nucleus: Prophase, Metaphase, Anaphase, Telophase

As a cell grows...

More demands are placed on the DNA, more waste is produced, & a cell has increasing trouble moving material across the membrane

Spindle fibers

Organelles that help move and separate the chromosomes during mitosis

Centrioles

Cell organelle that aids in cell division by attaching to spindle fibers in animal cells only

Centromere

the region of the chromosome that holds the two sister chromatids together during mitosis

Chromatin

loose strands (relaxed form) of DNA and protein found in the nucleus of a cell

Chromatid

one half of a duplicated chromosome

Chromosome

genetic material made of DNA and protein that is passed from generation to generation

Gamete

sex/reproductive cell; Examples include an egg OR a sperm cell

Somatic cells

Body cells; any cells in the body other than reproductive cells Examples include skin, liver, blood, muscle, nerve

Replication

process of copying DNA prior to cell division

Parent cell

original cell before cell division

Daughter cells

the two new cells that result from cell division (mitosis and cytokinesis)

Mutations

changes in DNA that control the production of proteins (including those that regulate the cell cycle)

Carcinogen

A cancer-causing substance

Malignant

A mass of abnormal cells resulting from uncontrolled cancer cell division. Cancerous.

Benign

An abnormal mass of cells that remains at its original site in the body. Not cancerous.

Histology

microscopic study of tissues

Oncology

study of cancer

Cell Differentiation

the process by which a cell becomes specialized for a specific structure or function.

Totipotent stem cells

Stem cells that can differentiate into any type of specialized cells found in organisms of that species.

Pluripotent stem cells

Stem cells that can become almost all types of tissues and cells in the body.

Multipotent stem cells

stem cells that can become a limited number of types of tissues and cells in the body

Unipotent stem cells

produce only one cell type but retain the property of self-renewal

Prokaryotic DNA

In the cytoplasm, in a single circular molecule called the chromosome (or nucleoid)

Eukaryotic DNA

Linear or stranded chromosomes within the nucleus

Cloning

Making a genetically identical copy of DNA or of an organism.

Called Binary Fission in bacteria

Diploid (2n)

2 sets of chromosomes

Haploid (n)

having a single set of unpaired chromosomes

Zygote

a diploid cell resulting from the fusion of two haploid gametes

Hayflick Limit

The number of times a human cell is capable of dividing into two new cells. The limit for most human cells is approximately 50 divisions