Ch. 6 Reproduction at the Cellular Level - OpenStax Concepts of Biology

Genome

The sum of all of the genetic material in an organism

Diploid

When an organism has matched sets (pairs) of chromosomes; the "double" number of chromosomes

Haploid

When a cell or organism has one set of chromosomes, ex. eggs or sperm; the "half" number of chromosomes

Homologous chromosomes

Chromosomes in a pair that have the same types of genes, but are not necessarily identical

Genes

Determine specific characteristics by coding for specific proteins (traits).

Cell cycle

An ordered series of events involving cell growth and cell division that produces two new daugther/ offspring cells.

Interphase

The phase during which the cell grows and DNA is replicated.

G1, S, G2

The phases of Interphase

G1 Phase

The first gap phase during which the cell grows and prepares itself for upcoming stages.

S Phase

DNA Synthesis phase in which all of the DNA of the cell is replicated (= the chromosomes are doubled).

G2 Phase

The second gap phase or growth phase during which the cell makes any last preparations needed before mitosis begins.

Mitosis

Nuclear division

Cytokinesis

Separation of the cytoplasm; cell division

Prophase

Chromosomes condense, the nuclear envelope breaks down, and spindle fibers make contact with the chromosomes.

Metaphase

The spindle fibers move the chromosomes to line up in the middle of the cell.

Anaphase

The spindle fibers pull the doubled chromosomes apart from each other.

Telophase

The spindle fibers pull the separated chromosomes into two separate piles at opposite ends of the cells, the chromosomes decondense, and a new nuclear envelope forms around each set of chromosomes.

Animal cell cytokinesis

A contractile ring forms a cleavage furrow and pinches one big cell into two.

Plant cell cytokinesis

A cell plate is formed to divide one big cell into two.

G0 Phase

Phase in which cells are not actively preparing to divide.

Heart and nerve cells

Cells that stay permanently in the G0 phase.

G1 Checkpoint

The cell checks to make sure it's big enough to continue to divide and checks for damage to the genomic DNA.

G2 Checkpoint

Ensures that all of the chromosomes have been replicated and that the replicated DNA is not damaged.

M Checkpoint

Determines if all of the sister chromatids (individual chromosomes that were pulled apart from each other) are correctly attached to the spindle fibers.

Cancer

Uncontrolled cell division

Many accumulated mutations

What causes a cell to become a cancer cell

Tumor suppressor genes

Code for regulator proteins that can prevent a cell from undergoing uncontrolled division

p53

Example of a tumor suppressor gene/protein

Binary fission

A simple process that prokaryotes undergo in which the cell gets bigger, the chromosome is duplicated, and the cell divides into two.

No

Do prokaryotes do mitosis?

Prophase picture

Metaphase picture

Anaphase picture

Telophase picture