Biology Chapter 6

Front 1

Structure of chromosomes

Back 1

made of DNA that is a long thin material that contains information needed to direct cell's activities

Front 2

Gene

Back 2

a little small part or section of the DNA that transmitts information from parent to offspring

Front 3

Chromosome

Back 3

A rod shaped structure that ciols up before cell division

Front 4

Chromatids

Back 4

Created when a chromosome copies itself, the coppies are called ex.

Front 5

centromere

Back 5

protien disc which the 2 chromatids are attached to

Front 6

Homologous chromosome

Back 6

the 2 copies of each chromosome one coming from each parent, similar in shape and size but not in genetic information

Front 7

Chromosomes in humans

Back 7

humans have 46 chromosomes in each cell of our bodie, except the hapliod # which is half the dipliod #

Front 8

dipliod

Back 8

the number of chromosomes when a cell contains 2 homologies of each chromosome

Front 9

Gemetes

Back 9

sex cell, the male is called sperm and the female is called the egg, they are hapliod or cells that contain 1 molecule of each our hapliod number is half our diplod

Front 10

Hapliod

Back 10

cell that contains only one homologue of each chromosome

Front 11

Zygote

Back 11

the one celled organism created when the sperm and the egg join- it will become an embryo

Front 12

minosomy

Back 12

when you are missing and entire embryo, the cell won’t develop any further

Front 13

trisomy

Back 13

when a cell has an extra chromosome It can cause down syndrome- if you have an extra copy of 21 chromosome it will duplicate itself over and over/ mild to serious retardation

Front 14

karyotype

Back 14

series of pictures of chromosomes/ helps scientists to look for defects in the chromosomes

Front 15

nondisjunction

Back 15

a mistake in chromosome separation/. Results when 1 new cell gets both chromosomes and the other doesn’t get any

Front 16

Parentsl testing

Back 16

- chromosome defects can be diagnosed early in pregnancy

Front 17

amniocentesis

Back 17

uses a needle and syringe removes amniotic fluid around the embryo and do this 14th and 16th weeks of pregnancy

Front 18

chrionic villi sampling

Back 18

Phisisian analizes a karotype made using cell grom from a sample of chronic villi

Front 19

mutation

Back 19

change in genetic material

Front 20

delection

Back 20

a fragment of a chromosome breaks off

Front 21

duplication

Back 21

the fragment that broke attaches to a homologous chromosome and now it has 2 sets of genes

Front 22

inversion

Back 22

the fragment that broke off reattaches to the chromosome in the opposite position

Front 23

translocation

Back 23

fragment breaks off and can join a non homologous chromosome
Chromosomes determine sex

Front 24

autosomes

Back 24

22 pairs of chromosome that are basically the same in male and female

Front 25

sex chromosomes

Back 25

- 23 pair of chromosome/ carry genes that determine the individuals sex

Front 26

girl/ boy

Back 26

girl-xx
boy- xy

Front 27

Binary fission

Back 27

simple cell fission that happens in a one cell organism/ no sex production/ produses identical offspring

Front 28

cell cycle

Back 28

repeating process that involves a cell being created and grows and matures and divides

Front 29

G1 phase
S phase
G2 phase
M phase
C phase

Back 29

-growth phase
-DNA is coppied
-cell is preparing for division of the nucleus
-mitosis- nucleus divides
-cytoplasm- splits in half- cytokinesious

Front 30

Mitosis

Back 30

process which the nucleus of an atom splits into 2 nuclei

Front 31

cytokinesis

Back 31

process which the cytoplasm divides

Front 32

interphase

Back 32

a normal no dividing cell cell does a great deal of growing

Front 33

spindle fiber

Back 33

made of microtubules and ae long hollow tubes of protien

Front 34

kinetochore

Back 34

disk of protien on a chromosome's centrmere in which microtubuals attach during miosis and miitosis

Front 35

meiosis

Back 35

form of cell division in which the nucleus of a cell completes 2 succesful divisions creating 4 nuclei each with a chromosome number that has been reduced by half

Front 36

spores

Back 36

hapliod cells that later lead to the production og gametes

Front 37

crossing- over

Back 37

the exachange of recipocal segments of DNA by chromosomes at the beginning of meiosis

Front 38

skipping replication

Back 38

because there are only 3 replication of DNA but 2 divisions, meiosis halves the number of chromosomes

Front 39

reduction division

Back 39

each cell produced contains half the number of chromosomes as the original cell. Meoisis I is an example

Front 40

genetic recombination

Back 40

the formation of a new combination of genes. Crossing over is an effective way to do this