Biology Test- Chapter 8

Front 1

centromere

Back 1

a region of the chromosome where the 2 sister chromatids are held together & which is the site of attachment of the chromosome to the spindle fibers during mitosis

Front 2

diploid

Back 2

a cell that contains both chromosomes of a homologus pair

Front 3

histone

Back 3

a protein molecule that DNA wraps around during chromosome formation

Front 4

karotype

Back 4

a picture of an individulas chromosomes

Front 5

anapahse

Back 5

a phase of mitosis & meiosis in which the chromosomes seperate

Front 6

cell cycle

Back 6

the events of cell division; includes interphase, mitosis, and cytokenisis

Front 7

centriole

Back 7

a structure that appears during mitosis in animal cells

Front 8

cleavage furrow

Back 8

the area of the cell membrane that pinches in and eventually seperates the dividing cell

Front 9

Go phase

Back 9

a phase of the cell cycle in which the cell is not dividing & its DNA is not replicating

Front 10

G2 phase

Back 10

the final period of interphase, in which the cell undergoes rapid growth and prepares mitosis

Front 11

kintochore

Back 11

a disk-shape protein found in the centromere region of a chromosome and attaches the cchromosomes to the mitotic spindle fiber

Front 12

metaphase

Back 12

the 2nd phase of mitosis during which all the chromosomes move toward the cells equator

Front 13

mitotic spindle

Back 13

the array of spindle fibers that serve to divide the chromatids during nuclear division

Front 14

prophase

Back 14

the 1st stage of mitosis & meiosis characterized by condensation of chromosomes

Front 15

spindle fiber

Back 15

one of the microtubules that extend across a dividing eukaroytic cell; assists in the movement of chromosomes

Front 16

asexual reproduction

Back 16

the production of offspring that does not involve the union of gametes

Front 17

gamete

Back 17

a reproductive cell

Front 18

oogenesis

Back 18

the production of mature egg cells

Front 19

sexual reproduction

Back 19

the production of offspring from the combination of genetic material from two parent organisims

Front 20

autosome

Back 20

a chromosome that is not a sex chromosome

Front 21

sex chromosomes

Back 21

a chromosome that determines sex

Front 22

binary fission

Back 22

an asexual cell division of prokaroyes that produces identical offspring

Front 23

homologus chromosome

Back 23

one of a pair of morphologically similar chromosomes

Front 24

chromatid

Back 24

1 or 2 identical pairs of a chromosome

Front 25

haploid

Back 25

having only one chromosome of each homologus pair

Front 26

m phase

Back 26

mitosis; the phase of cell division in which the nucleus divides

Front 27

s-phase

Back 27

the second period of interphase during which the replication of DNA occurs

Front 28

meiosis

Back 28

the process of nuclear division that reduces the number of chromosomes in a cell by 1/2

Front 29

G1 phase

Back 29

the 1st period of interphase, in which the cell doubles its size

Front 30

centrosome

Back 30

a dark body containing a centriole in animal cells bunt not in plant cells; spindle fibers radiate from the centrosome in preparation for mitosis

Front 31

cell plate

Back 31

a membrane that divides newly forming plant cells following mitosis

Front 32

cytokenisis

Back 32

the division of the cyptoplasm of 1 cell into 2 new cells

Front 33

interphase

Back 33

a period of cell growth & development that procedes eukaryotic cell division

Front 34

mitosis

Back 34

eukaryotic nuclear division

Front 35

telophase

Back 35

the final stage of mitosis during which a nuclear membrane forms around each set of new chromosomes

Front 36

crossing-over

Back 36

the exchange of genes by preciprocal segments of homologous chromosomes during meiosis

Front 37

spermatogenesis

Back 37

the production of sperm cells

Front 38

independent assortment

Back 38

during meiosis, the random distribution of genes from different chromosomes to the gametes

Front 39

polar body

Back 39

one of the two small cells produced and discarded during each of the two meiotic divisions that yield the haploid egg

Front 40

tetrad

Back 40

a group of two homologous chromosomes during meiosis

Front 41

spermatid

Back 41

in meiosis, a haploid cell that develops into a mature sperm cell

Front 42

synapsis

Back 42

the paring of homologous chromosomes during meiosis

Front 43

kinotochore fiber

Back 43

a spindle fiber that extends from the centrosome at one pole of the cell to a chromatid during mitosis