AP Bio: Unit 4 Cell Signaling and Cell Cycle Diagram | Quizlet

Chromosome

A threadlike, gene-carrying structure found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins.

Gene

A segment of DNA on a chromosome that codes for a specific trait

Mutation

change in a DNA sequence that affects genetic information

Chromatin

Substance found in eukaryotic chromosomes that consists of DNA tightly coiled around histones

Chromatid

one of two identical "sister" parts of a duplicated chromosome

Centromere

Region of a chromosome where the two sister chromatids attach

Autosome

Any chromosome that is not a sex chromosome

Gamete

specialized cell involved in sexual reproduction

Cell cycle

The regular sequence of growth and division that cells undergo

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.

S phase

The synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated.

G2 phase

The second growth phase of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

M phase

mitosis and cytokinesis

G0 phase

A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.

Checkpoint

A control point in the cell cycle where stop and go-ahead signals can regulate the cycle.

Cyclin

one of a family of closely related proteins that regulate the cell cycle in eukaryotic cells

Cancer

any malignant growth or tumor caused by abnormal and uncontrolled cell division

Contact inhibition

a process that stops additional cell growth when cells become crowded; cancer cells are immune to contact inhibition

Angiogenesis

formation of new blood vessels

Metastasize

the process by which cancer spreads from one place in the body to another

Benign tumor

An abnormal mass of cells that remains at its original site in the body.

Cytokinesis

Division of the cytoplasm during cell division

Interphase

period of the cell cycle between cell divisions (G1, S, and G2 phase)

Mitosis

a type of eukaryotic cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

TERM

Prophase

DEFINITION

Chromosomes become visable, nuclear envelop dissolves, spindle forms

TERM

Metaphase

DEFINITION

Chromosomes line up in the middle of the cell

Metaphase plate

Plane midway between the two poles of the cell where chromosomes line up during metaphase.

TERM

Anaphase

DEFINITION

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

TERM

Telophase

DEFINITION

After the chromosome seperates, the cell seals off, Final phase of mitosis.

Centrosome

A structure in animal cells containing centrioles from which the spindle fibers develop.

Spindle fibers

help pull apart the cell during replication and are made up of microtubules

Microtubules

Spiral strands of protein molecules that form a tubelike structure; part of the cytoskeleton

Cleavage furrow

The first sign of cleavage in an animal cell; a shallow groove in the cell surface near the old metaphase plate.

Cell plate

A double membrane across the midline of a dividing plant cell, between which the new cell wall forms during cytokinesis.

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

Meiosis I

The first division of a two-stage process of cell division in sexually reproducing organisms that results in cells with half the number of chromosome sets as the original cell.

Meiosis II

The second phase of meiosis consisting of chromatids separating, along with the two diploid cells splitting in two

Gametes

reproductive cells, such as sperms and eggs

homologous chromosomes

Chromosomes that have the same sequence of genes and the same structure

Bivalent

a pair of homologous chromosomes

Crossing over

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

Tetrad

structure containing 4 chromatids that forms during meiosis

Independent assortment

Independent segregation of genes during the formation of gametes during meiosis

Zygote

A fertilized egg

Diploid

containing two complete sets of chromosomes, one from each parent.

Haploid

having a single set of unpaired chromosomes

Synapsis

the pairing of homologous chromosomes during meiosis

Chiasma

the site of crossing over during meiosis

Spermatogenesis

production of sperm

Oogenesis

the production, growth, and maturation of an egg, or ovum

Polar body

a small cell containing little cytoplasm that is produced along with the oocyte and later discarded

Nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

Aneuploidy

Abnormal number of chromosomes.

Trisomy

3 copies of a chromosome

Down syndrome

Trisomy 21

Barr body

Inactivated X chromosome

Cell signaling

The process of cell-to-cell communication mediated by signaling molecules and membrane receptors. Composed of three steps:

1) reception

2) transduciton

3) response

reception

The target cell's detection of a signal molecule coming from outside the cell.

receptor

protein that detects a signal molecule and performs an action in response

ligand

A molecule that binds specifically to a receptor site of another molecule.

transduction

the signaling molecules binds to the receptor and changes it shape, causing the receptor to change its function

cAMP

a second messenger produced in GPCR signaling

response

In cellular communication, the change in a specific cellular activity brought about by a transduced signal from outside the cell.

phosphorylation

The transfer of a phosphate group, usually from ATP, to a molecule.

G protein-coupled receptors (GPCRs)

a large family of proteins that function as receptors; they provide a mechanism for molecules outside a cell to influence the inner workings of the cell.

Fun fact: these are Dr. Hathaway's favorite proteins :)

Signaling cascade

Series of events, starting with the binding of a ligand to a receptor. This sequence of events ultimately results in a change in cellular behavior

second messenger

a molecule that is generated when a specific substance attaches to a receptor on the outside of a cell membrane, which produces a change in cellular function

ligand-gated ion channel

Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape. When the receptors are activated they open and allow ions to cross the cell membrane.

apoptosis

programmed cell death involving a cascade of specific cellular events leading to death and destruction of the cell

gene expression

process by which certain genes are turned "on" or "off"