Ch12 - 16 exam prep

The division of the genetic material in the nucleus. Cytokinesis is the division of the cytoplasm.

Mitosis and cytokinesis produce two identical cells which each have the genetic equivalent of the parent cell.

Cell division of sex cells.

Meiosis makes daughter cells with only one set of chromosomes, half as many chromosomes as the parent cell.

Fertilization produces one set of chromosomes from two haploid sets by fusing them together.

The cell cycle is the life of a cell from when its first formed during division until its own division into two daughter cells.

Mitotic phase (mitosis and cytokinesis), interphase (G1, S, G2)

Prophase, Prometaphase, Metaphase, Anaphase, and Telophase.

Centrosomes with centriole pairs make early mitotic spindles by moving away from each other (lengthening microtubules), each producing an aster of radial arrays of shorter microtubules. Chromatin fibers coil tightly and condensing into discrete chromosomes. Nucleoli disappear.

Chromosomes continue condensing. The nuclear envelope dissolves. Kinetochore (and non-) tubules form and attach to a kinetochore at each centromere of each chromatid. Nonkinetochore tubules will lengthen the cell.

Chromosomes align along a metaphase plate, centrosomes are at opposite poles of the cell. Each sister chromatid has two attached kinetochores on opposite poles of the cell.

Anaphase is the shortest phase of mitosis (maybe minutes). Begins when the cohesin proteins are cleaved, this allows the two sister chromatids of each pair to part suddenly. Kinetochores begin to shorten and pull each chromosome (now independent) toward opposite poles. The cell elongates more.

Two nuclei form in the cell around the chromosomes, Nuclear envelopes arise from fragments of parent cell's envelopes and endomembrane systems. Nucleoli reappear. Chromosomes become less condensed. Any spindle microtubules are depolymerized. Mitosis is complete.

Splitting of the cell membrane after mitosis. In animal cells this occurs by a process known as cleavage. The first sign is a cleavage furrow, a groove in the cell surface near the old metaphase plate. In plant cells, vesicles filled with cellulose form into a cell plate, to produce a new cell wall

Mitotic spindles attach to chromatids to separate them and elongate in other microtubules to stretch the cell for cytokinesis.

Mitotic spindles are made of fibers of microtubules and associated proteins. During mitosis, other cytoskeletal parts are used for material to construct the mitotic spindle

An enzyme that cleaves the two sister chromatids of each chromosome at the cohesins holding them together. This process is the beginning of anaphase.

A type of cell reproduction in which the cell grows to roughly double its size and then divides to form two cells. "division in half" This type of reproduction is asexual. This does not involve mitosis. Actin-like molecules move chromosomes and tubulin separate.

Prokaryotes, or bacteria and archaea

A specific place on a chromosome where the DNA of bacteria begins to replicate.

A cyclically operating set of molecules in the cell that both triggers and coordinates key events in the cell cycle. These regulatory molecules are mainly proteins made of two types: protein kinases and cyclins. Kinases activate or inactivate other proteins by phosphorylating them.

Cyclins are proteins that get their names from its cyclical fluctuation of concentration within the cell.

Kinases that must be attached to cyclin are called cyclin-dependent kinases, or Cdks.

The cell cycle phase where the cell exits the mitosis cycle by switching to a nondividing state. Most human cells are in the G0 phase.

A protein released by certain cells that stimulates other cells to divide.

Platelet-Derived growth factor (PDGF), When an injury occurs, platelets release PGDF in the vicinity. These are necessary for the division of cultured fibroblasts, a type of connective tissue cell.

The spread of cancer cells to locations distant from their original site.

Hereditary is the transmission of traits from one generation to another.

Variation refers to the differences between offspring from the same parents.

This study is called genetics.

Its specific place on the DNA molecule.

Reproduction of an organism that does not involve a second organism or sex cells. Individuals produced from asexual reproduction are referred to as clones.

two parents give rise to offspring that have unique combinations of genes inherited from the two parents. It provides more variation in genes which can provide more and better mutations to offspring.

The generation-to-generation sequence of stages in the reproductive history of an organism.

A display of the chromosome pairs of a cell arranged by size and shape.

A pair of chromosomes of the same length, centromere position, and staining pattern that possess genes for the same characters at corresponding loci. One homolog is inherited from each parent

A chromosome responsible for determining the sex of an individual.

A chromosome that is not directly involved in determining sex; not a sex chromosome.

A complete set of DNA from one parent. It should only be one or two unless there's a creature that can have 3 parents.

A modified type of cell division in sexually reproducing organisms consisting of two rounds of cell division but only one round of DNA replication. It results in cells with half the number of chromosome sets as the original cell.

A life cycle in which there is both a multicellular diploid form, the sporophyte, and a multicellular haploid form, the gametophyte; characteristic of plants and some algae.

The phase where two homologous chromosomes (one from each parent) are attached to each other

A zipper-like structure composed of proteins, which connects a chromosome to its homolog tightly along their lengths during part of prophase I of meiosis.

The X-shaped, microscopically visible region where crossing over has occurred earlier in prophase I between homologous nonsister chromatids. Chiasmata become visible after synapsis ends, with the two homologs remaining associated due to sister chromatid cohesion.

A chromosome created when crossing over combines DNA from two parents into a single chromosome.