Bio160 - Ch 8

Front 1

Cell Division

Back 1

The reproduction of a cell through duplication of the genome and division of the cytoplasm.

Front 2

Chromosome

Back 2

A gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis; the main gene-carrying structure of a prokaryotic cell. A _____ consists of one very long DNA molecule and associated proteins.

Front 3

Asexual Reproduction

Back 3

The creation of genetically identical offspring by a single parent, without the participation of sperm and egg.

Front 4

Clone

Back 4

As a verb, to produce genetically identical copies of a cell, organism, or DNA molecule. As a noun,the collection of cells, organisms, or molecules resulting from _____; colloquially, a single organism that is genetically identical to another because it arose from the _____ of a somatic cell.

Front 5

Sexual Reproduction

Back 5

The creation of genetically unique offspring by the fusion of two haploid sex cells (gametes), forming a diploid zygote.

Front 6

Binary Fission

Back 6

A means of asexual reproduction in which a parent organism, often a single cell, divides into two genetically identical individuals of about equal size.

Front 7

Chromatin

Back 7

The complex of DNA and proteins that make up eukaryotic chromosomes; often used to refer to the diffuse, very extended form taken by chromosomes when a cell is not dividing.

Front 8

Sister Chromatids

Back 8

One of two identical parts of a duplicated chromosome in a eukaryotic cell. Prior to mitosis, _____ remain attached to each other at the centromere.

Front 9

Centromere

Back 9

The region of a duplicated chromosome when two sister chromatids are joined (often appearing as a narrow "waist") and where spindle microtubules attach during mitosis and meiosis. The _____ divides at the onset of anaphase during mitosis and anaphase II during meiosis.

Front 10

Cell Cycle

Back 10

An ordered sequence of events (including interphase and the mitotic phase) that extends from the time a eukaryotic cell is first formed from a dividing parent cell

Front 11

Interphase

Back 11

The period in the eukaryotic cell cycle when the cell is not actually dividing. _____ constitutes the majority of the time spent in the cell cycle.

Front 12

Mitotic Phase (M Phase)

Back 12

The part of the cell cycle when the nucleus divides (via mitosis), its chromosomes are distributed to the daughter nuclei, and the cytoplasm divides (via cytokinesis),producing two daughter cells.

Front 13

Mitosis

Back 13

The division of a single nucleus into two genetically identical nuclei. _____ and cytokinesis make up the mitotic (M) phase of the cell cycle.

Front 14

Cytokinesis

Back 14

The division of the cytoplasm to form two separate daughter cells. _____ usually occurs in conjunction with telophase of mitosis. Mitosis and _____ make up the mitotic (M) phase of the cell cycle.

Front 15

Prophase

Back 15

The first stage of mitosis, during which the chromatin condenses to form structures (sister chromatids) visible with a light microscope and the mitotic spindle begins to form, but the nucleus is still intact.

Front 16

Prometaphase

Back 16

The second stage of mitosis, during which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the sister chromatids.

Front 17

Metaphase

Back 17

The third stage of mitosis, during which all the cell's duplicated chromosomes are lined up at an imaginary plane equidistant between the poles of the mitotic spindle.

Front 18

Anaphase

Back 18

The fourth stage of mitosis, beginning when sister chromatids seperate from each other and ending when a complete set of daughter chromosomes arrives at each of the two poles of the cell.

Front 19

Telophase

Back 19

The fifth and final stage of mitosis, during which daughter nuclei form at the two poles of a cell. _____ usually occurs together with cytokinesis.

Front 20

Mitotic Spindle

Back 20

A football-shaped structure formed of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis and meiosis.

Front 21

Centrosomes

Back 21

A structure found in animal cells from which microtubules originate and that is important during cell division. A _____ has two centrioles.

Front 22

Cleavage

Back 22

Cytokinesis in animal cells and in some protists, characterized by pinching in of the plasma membrane.

Front 23

Cleavage Furrow

Back 23

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

Front 24

Cell Plate

Back 24

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

Front 25

Anchorage Dependence

Back 25

The requirement that to divide, a cell must be attached to a solid surface.

Front 26

Density-Dependent Inhibition

Back 26

The ceasing of cell division that occurs when cells touch one another.

Front 27

Growth Factor

Back 27

A protein secreted by certain body cells that stimulates other cells to divide.

Front 28

Cell Cycle Control System

Back 28

A cyclically operating set of proteins that triggers and coordinates events in the eukaryotic cell cycle.

Front 29

Tumor

Back 29

An abnormal mass of rapidly growing cells that forms within otherwise normal tissue.

Front 30

Benign Tumor

Back 30

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

Front 31

Malignant Tumor

Back 31

An abnormal tissue mass that can spread into neighboring tissue and to other parts of the body; a cancerous tumor.

Front 32

Cancer

Back 32

A disease characterized by the presence of malignant tumors (rapidly growing and spreading masses of abnormal body cells) in the body.

Front 33

Metastasis

Back 33

The spread of cancer cells beyond their original site.

Front 34

Somatic Cell

Back 34

Any cell in a multicellular organism except a sperm or egg cell or a cell that develops into a sperm or egg.

Front 35

Homologous Chromosomes

Back 35

The two chromosomes that make up a matched pair in a diploid cell. _____ are the same length, centromere position, and staining pattern and possess genes for the same characters at corresponding loci. One _____ is inherited from the organism's father, the other from the mother.

Front 36

Locus

Back 36

The particular site where a gene is found on a chromosome. Homologous chromosomes corresponding gene _____.

Front 37

Sex Chromosomes

Back 37

A chromosome that determines whether an individual is male or female.

Front 38

Autosomes

Back 38

A chromosome not directly involved in determining the sex of an organism; on mammals, for example, any chromosome other than X or Y.

Front 39

Diploid

Back 39

In an organism that produces sexually, a cell containing two homologous sets of chromosomes, one set inherited from each parent; a 2n cell.

Front 40

Gametes

Back 40

A sex cell; a haploid egg or sperm. The union of two _____ of opposite sex (fertilization) produces a zygote.

Front 41

Haploid

Back 41

In the life cycle of an organism that reproduces sexually, a cell containing a single set of chromosomes; an n cell.

Front 42

Fertilization

Back 42

The union of the nucleus of a sperm cell with the nucleus of an egg cell, producing a zygote.

Front 43

Zygote

Back 43

The diploid fertilized egg, which results from the union of a sperm cell nucleus and an egg cell nucleus.

Front 44

Crossing Over

Back 44

The exchange of segments between chromatids of homologous chromosomes during synapsis in prophase I of meiosis; also, the exchange of segments between DNA molecules in prokaryotes.

Front 45

Chiasma

Back 45

The microscopically visible site where crossing over has occurred between chromatids of homologous chromosomes during prophase I of meiosis.

Front 46

Recombinant Chromosomes

Back 46

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

Front 47

Nondisjunction

Back 47

An accident of meiosis or mitosis in which a pair of homologous chromosomes or a pair of sister chromatids fail to seperate at anaphase.

Front 48

Karyotype

Back 48

A display of micrographs of the metaphase chromosomes of a cell, arranged by size and centromere position. _____ may be used to identify certain chromosomal abnormalities.

Front 49

Trisomy 21

Back 49

A human genetic disorder resulting from the presence of an extra chromosome 21; characterized by heart and respiratory defects and varying degrees of mental retardation. Also known as Down's syndrome.

Front 50

Deletion

Back 50

The loss of one or more nucleotides from a gene by mutation; the loss of a fragment of a chromosome.

Front 51

Duplication

Back 51

Repetition of part of a chromosome resulting from fusion with a fragment from a homologous chromosome; can result from an error in meiosis or from mutagenesis.

Front 52

Inversion

Back 52

A change in a chromosome resulting from reattachment of a chromosome fragment to the original chromosome, but in the reverse direction. Mutagens and errors during meiosis can cause these.

Front 53

Translocation

Back 53

A change in a chromosome resulting from a chromosomal fragment attaching to a nonhomologous chromosome; can occur as a result of an error in meiosis or from mutagenesis.