Chapter 8Chapter 8

Cell ReproductionCell Reproduction

In a eukaryotic cell, one of the structures in the nucleus that is made up of DNA and

protein; in a prokaryotic cell, the

main ring of DNA

Chromosome

A type of protein molecule found in the chromosomes of eukaryotic cells

but not prokaryotic cells

Histone

One of the two strands of a

chromosome that become visible

during meiosis or mitosis

Chromatid

The region of the chromosome that

holds the two sister chromatids together during

mitosis

Centromere

The material that makes up both mitotic

and interphase chromosomes; a

complex of proteins and DNA strands that are loosely coiled such

that translation and transcription can occur

Chromatin

One of the pair of chromosomes that

determines the sex of an individual

XX = FemaleXY = Male

Sex chromosome

Any chromosome that is not a sex

chromosome

Autosome

Chromosomes that have the same

sequence of genes, that have

the same structure, and that

pair during meiosis Homologous

chromosome

A micrograph of the array of chromosomes visible in a cell during

metaphase; a graphical display that shows an individual’s

chromosomes arranged in

homologous pairs and in order of diminishing

sizeKaryotype

A cell that contains two

haploid sets of chromosomes

Diploid

Describes a cell, nucleus, or

organism that has only one set of

unpaired chromosomes

Haploid

A form of asexual reproduction in

single-celled organisms by which one cell divides into

two cells of the same size

Binary Fission

In eukaryotic cells, the cell organelle that is surrounded by two membranes and that is the site

of cellular respiration, which

produces ATP

Mitosis

Reproduction that does not involve the

union of games and in which a single parent

produces offspring that are genetically

identical to the parent

Asexual Reproduction

A process in cell division during which the number

of chromosomes decreases to half the

original number by two divisions of the nucleus,

which results in the production of sex cells (gametes or spores)

Meiosis

A haploid reproductive cell that unites with another haploid reproductive cell to form a zygote

Gamete

A period between two mitotic or

meiotic divisions during which the cell grows, copies

its DNA, and synthesizes

proteinsInterphase

The division of the cytoplasm of a

cell; cytokinesis follows the

division of the cell’s nucleus by

mitosis or meiosisCytokinesis

The first stage of mitosis and meiosis in

cell division; characterized by the condensation of the

chromosomes and the dissolution of the nuclear envelope

Prophase

One of the microtubules that extend across a

dividing eukaryotic cell; assists in the

movement of chromosomes

Spindle fiber

One of the stages of mitosis and

meiosis, during which all of the chromosomes

move to the cell’s equator

Metaphase

A phase of mitosis and meiosis in

which the chromosomes

separate

Anaphase

The final stage of mitosis or meiosis,

during which a nuclear membrane forms around each

set of new chromosomes

Telophase

The precursor of a new plant cell wall that forms during cell division and

divides a cell into two

Cell Plate

The pairing of homologous

chromosomes during meiosis

Synapsis

The four chromatids in a pair of

homologous chromosomes that come together as a result of synapsis

during meiosis

Tetrad

The exchange of genetic material

between homologous

chromosomes during meiosis;

can result in genetic

recombinationCrossing-over

The regrouping of genes in an

offspring that results in a

genetic makeup that is different from that of the

parentsGenetic Recombination

The random distribution of the pairs of genes on

different chromosomes to

the gametes

Independent Assortment

The process by which male

gametes form

Spermatogenesis

The production, growth, and

maturation of an egg, or ovum

Oogenesis

Describes a molecule with

opposite charges on opposite ends

Polar body

Reproduction in which gametes

from two parents unite

Sexual Reproduction