Biology Key Terms Chap 8

Front 1

anaphrase

Back 1

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

Front 2

asexual reproduction

Back 2

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

Front 3

autosome

Back 3

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

Front 4

benign tumor

Back 4

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

Front 5

cell cycle

Back 5

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 until its own division into two cells.

Front 6

cell cycle control system

Back 6

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

Front 7

cell division

Back 7

the replication of a cell

Front 8

centromere

Back 8

The region of a duplicated chromosome where two sister chromatids are joined and where spindle microtubules attach during mitosis and meiosis. The centromere divides at the onset of anaphase during mitosis and anaphase II during meiosis.

Front 9

centrosome

Back 9

Material in the cytoplasm of a eukaryotic cell that gives rise to microtubules; important in mitosis and meiosis; also called microtubule-organizing center.

Front 10

chromatin

Back 10

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

Front 11

chromosome

Back 11

A threadlike, gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis; also, the main gene-carrying structure of a prokaryotic cell. Chromosomes consist of chromatin, a combination of DNA and protein.

Front 12

Crossing Over

Back 12

The exchange of DNA segments of chromatids during Prophase 1 of Meiosis, these are of Homologous Chromosomes

Front 13

Cytokinesis

Back 13

Cytoplasm division forming 2 daughter cells, Happens during telophase of Mitosis(part of M-phase)

Front 14

Deletion

Back 14

Loss of 1 0r more nucleotides by mutation, loss of f fragment of a gene

Front 15

Density Dependent Inhibition

Back 15

The stopping of cells that divide and touch when grown in a lab

Front 16

Diploid Cell

Back 16

Sexually reproduced cell, Has 2 sets of chromosomes, one from each parent, Homologous

Front 17

Down Syndrome

Back 17

Genetic disorder of the 21st chromosome; Characters include heart and respiratory defects and mental retardation

Front 18

Duplication

Back 18

Fragment of a homologous chromosome, a sister chromatid, that replicates and rejoins the chromatid

Front 19

Fertizilation

Back 19

The joining of nucleus' of both sex cells that produce a zygote(fertilized egg/dipliod)

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Gamete

Back 20

A sex cell, a haploid egg or sperm cell, 2 gametes make a zygote(fertilized egg/diploid)

Front 21

Genetic Recombination

Back 21

The production of a gene by crossing over chromosomes making different combinations of genes from the originals

Front 22

Haploid Cell

Back 22

Cell with 1 set of chromosomes, produced sexually

Front 23

Homologous Chromosome

Back 23

Matched pair, one from each parent with same length, same centromere, posses same genes for same characteristics at same loci(sites of specific genes)

Front 24

Interphase

Back 24

Not when cell is dividing, but when it is spent generating energy and DNA for division, Majority of time in cell cycle

Front 25

Inversion

Back 25

Reverse joining of chromosome fragment

Front 26

Malignant Tumor

Back 26

Cancerous tumor that continues to grow to other parts of the body

Front 27

Meiosis

Back 27

Division of 1 diploid cell into 4 daughter cells(haploids), has half as many chromosomes as parent cell, 2 stages -meiosis 1/chromosomes separate and meiosis 2/chromatids separate

Front 28

Metastasis

Back 28

Spreading of cancer from original site

Front 29

M Phase(m phase)

Back 29

Last part of cell cycle when chromosomes are divided making 2 daughter cells

Front 30

Miototic Spindle

Back 30

Structure of microtubules and proteins used to pull apart chromosomes

Front 31

Mitosis

Back 31

Division of a single cell into 2 daughter cells

Front 32

Nondisjunction

Back 32

Accident in which pair of chromosomes or chromatids fail to separate at anaphase

Front 33

Prometaphase

Back 33

Only in mitosis, when microtubules connect to kinetcores(protein motors) and poles form

Front 34

Prophase - Mitotis

Back 34

First stage - nuclear envelope breaks apart, hiways built for chromosomes(mitotic spindle)

Front 35

Sex Chromosome

Back 35

Determiner of male of female cell

Front 36

Sexual Reproduction

Back 36

Creation of offspring from 2 haploids(gametes) forming a diploid zygote

Front 37

Sister Chromatid

Back 37

Identical part of duplicated chromosome

Front 38

Somatic Cell

Back 38

Any other cell than sex cells

Front 39

Telophase - Mitosis

Back 39

Last stage, Chromosomes formed at poles, nuclear envelope forms around each group of nuclei

Front 40

Tetrad

Back 40

Set of homologous chromosomes, formed in prophase 1, has 2 sister chromatids

Front 41

Translocation

Back 41

attachment of fragment to non-homologous chromosome, can be associated w leukemia & congenital disorders

Front 42

Tumor

Back 42

Abnormal mass of cells

Front 43

Trisomy 21

Back 43

Down Syndrome

Front 44

Prophase 1 - Meiosis

Back 44

Chromatins coil, called synapsis(when chromatids exchange segments/crossing over); Structure formed is a tetrad(paired set of chromosomes)

Front 45

Prophase 2 - Meiosis

Back 45

Spindle forms and chromosomes move to middle of cell, meiosis 2

Front 46

Telophase 1 - Meiosis

Back 46

Last stage, w cytokenisis; Haploid daughter cells form, but DONT split

Front 47

Telophase 2 - Meiosis

Back 47

Last stage, w cytokenisis and 2 haploid cells form and split