AP Bio - Cell Cycle

First of the 3 basic processes associated with cell reproduction and division

Replication of the DNA within the parent cell. This occurs in the "S" phase. Each cell must have a complete copy of the DNA and the DNA is identical.

Second of the 3 basic processes associated with cell reproduction and division

Replication of any items that are in the cytoplasm, such as ribosomes and organelles (only in eukaryotic cells).

Third of the 3 basic processes associated with cell reproduction and division

Division of the cytoplasm and cell membrane (cytokinesis)

Division of \_____ is referred to as \_____ and only occurs in eukaryotic organisms

nucleus ; Mitosis

Process of Reproduction/Replication in prokaryotes

Binary Fission

Binary fission is a type of \_______ reproduction

asexual

Binary Fission does not create

any genetic diversity

DNA replication starts

at a single origin of replication

DNA replication works

around the entire, single circular chromosome

DNA replication results in

two identical circular chromosomes in the nucleoid region

DNA replication is followed by the production of

a cleavage furrow

The formation of a cleavage furrow is called

cytokineses

Cytokineses produces \___________ called \_________

2 new cells ; clones

They are called clones because they possess

100% identical DNA strands

The life cycle of the cell ; includes times in which the cell grows and carries out its designated function(s) and times in which it replicates its DNA and divides. A HIGHLY REGULATED SERIES OF EVENTS FOR THE GROWTH AND DEVELOPMENT OF CELLS.

cell cycle

the original that begins to divide

parent (mother) cell

the two identical cells that result from the division of the mother cell; these cells are genetically identical clones

daughter cells

the entire genetic material (DNA) for an organism or cell

genome

DNA in its loose, non chromosome formation; in this state DNA can be replicated and transcribed

Chromatin

DNA in its tightly coiled state; these are only present in a cell just before and during the process of cell division

Chromosomes

normal body cells

somatic cells

somatic cells make up

the majority of an organism

chromosomal content for somatic cells

2n or diploid

cells that have 2 copies of each type of chromosome (half from mother, half from father)

diploid (2n)

humans have \____ chromosomes ; \____ in egg and \____ in sperm

46 ; 23 ; 23

only cells in the human body capable of going through meiosis

germ cells

the proteins that help DNA condense (coil up) to form chromosomes during cell division

histones

the whole combined structure of DNA wrapped around a histone

nucleosome

a portion of the whole "duplicated" chromosome

sister chromatids

duplicated or bivalent chromosomes look like

an X

the two halves are held together at the

centromere

a group of proteins in a constricted portion of the chromosome

centromere

two chromosomes are of the same type and control the same traits

homologous

ordinary cell division

mitosis

a mother cell forms two identical daughter cells after

mitosis and cytokinesis

functions of mitosis

repair tissue damage, replacement of old/worn out cells, growth, and asexual reproduction

forming haploid gametes from diploid germ cells

meiosis

one germ cell forms \____ haploid gametes after meiosis

four

the four gametes are

genetically different from each other

Meiosis is important for

genetic variation

cells spend up to 90% of their existence in

Interphase

interphase is NOT

a part of mitosis

the part of cell division where the cell caries out ordinary, everyday growth

Interphase

three parts of interphase

G1, S, G2

the phase in which ordinary , everyday growth , activity , and/or repair of the cell takes place

G1

in this phase organelles begin replicating

G1

the first checkpoint of the cell cycle occurs

at the end of G1

the cell only passes through the G1 phase if

it is an appropriate size and has adequate energy reserves

At the first checkpoint the cell also

checks for DNA damage

the cell can halt the cycle and attempt to

remedy the problematic condition

the cell can advance into G0 (inactive) phase to

await further signals when conditions improve

During this phase DNA replication occurs

S phase

46 single chromatid chromosomes are replicated to form

46 bivalent chromosomes

during this phase the organelles enlarge and are replicated

G2

newly synthesized DNA is

checked for errors

the second checkpoint is at the end of

G2

the G2 checkpoint

bars entry into the mitotic phase if certain conditions are not met

most important frole of the G2 checkpoint is to

ensure that all of the chromosomes have been accurately replaced without mistakes or damage

mitosis ensures the transfer of a complete genome from \______ to two genetically \_______

a parent cell ; identical daughter cells

mitosis is a form of

nuclear division

mitosis is followed by \_______ which \_______ \___ \____ __ \_________

cytokinesis ; divides the cell or cytoplasm

During prophase

the nuclear envelope is broken down and the centrosomes construct the spindle apparatus

during prophase, chromatin condenses to form

"X" shaped bivalent chromosomes

during prophase, centrioles move

toward the poles

during prophase, spindle fibers begin

to attach to each chromosome at a point on the chromosome called the kinetochore

during prophase, centrioles act as

anchorage points for the spindle fibers in animal cells

In plant cells the \_____ \_____ is used as an anchor point for the spindle fibers

cell wall

"meta" means

middle

during metaphase, the chromosomes are

pulled toward the middle of the cell and line up on the metaphase plate (middle of the cell)

the M checkpoint is also known as

the spindle checkpoint

the spindle checkpoint determines

whether the sister chromatids are all correctly attached to the spindle microtubules

the cell cycle will not proceed until the

kinetochores of each pair of sister chromatids are firmly anchored to atleast two spindle fibers

as the chromosomes' kinetochores connect with the spindle apparatus,

enzymes are "turned on"

when the concentration levels of APC reach the checkpoint level,

Anaphase begins

"ana" means

"separate"

during anaphase, each of the bivalent chromosomes are

pulled apart

during anaphase, the two chromatids from each bivalent chromosome are

pulled towards opposite poles of the cell

during anaphase, the spindle apparatus is

broken down

during anaphase, the two sister chromosomes are \______ toward the poles by \_____ \________ which use \___ as an energy source

walked ; motor proteins ; ATP

"telo" means

"last"

during telophase, a new nuclear envelope is

built around each of the two sets of DNA

during telophase, the chromosomes begin to

decondence back into their chromatin state

during telophase, a \________ \______ begins to for using \_____ and \______ microfilaments

cleavage furrow ; actin ; myosin

during telophase, can be though of as the opposite of

prophase

cytokinesis is the

division of the cytoplasm

the cytoplasm and cell organelles are separated to produce

two genetically identical daughter cells

when plant cells divide,

NEW cell wall "plate" develops

when a new cell wall develops,

small segments of cellulose are used

when plant cells divide, to form a new cell wall

no cleavage furrow is formed

a period in the cell cycle in which cells exist in a non-dividing state

G0

G0 can be viewed as (1)

an extended G1 phase, where the cell is neither dividing nor preparing to divide

G0 can be viewed as (2)

a distinct quiescent stage that occurs outside of the cell cycle

G0 is sometimes reffered to as \_________________ since the cells in G0 are in a \________ \____________ phase outside of the cell cycle

a "post-mitotic" state ; non-dividing

nerve and muscle cells

become post mitotic when they reach maturity

Some types of cells enter G0 when they reach maturity but

continue to perform their main functions for the rest of the organisms life

Cells in G0 stage will

never re-enter the normal cell cycle

in some cases cells in the G0 phase will reenter the normal cell cycle in response to

certain environmental cues

the spindle apparatus is composed of

a network of protein filaments (mostly microtubules)

the construction begins at the \________ and works towards the \_________

centrosome ; chromosomes

spindle fibers attach at the \________ in the centromere of the \________ \____________

kinetochore ; replicated chromosomes