cell reproduction Flashcards
process by which a cell divides to form two new cells( daughter cells)
cell division
three types of cell division/ cell reproduction
binary fission
mitosis
meiosis
Is a form of cell division in prokaryotic organisms that produces identical offspring
binary fission
cell or organism growth… replacement or repair of damaged cells
mitosis
formation of sex cells or gametes
meiosis
why do cells divide
DNA overloud
reproduction
Exchange of materials
tissue repair
growth
replication of genetic materials
if cells grow without limit, an “information crisis” would develop
DNA cannot serve the needs of the increasing size of cell
DNA overload
food and oxygen have to cross membrane very quickly
waste must go out
if cells is too large this occurs too slowly and cell will die
exchange of materials
prokaryotic cell division
binary fission
eukaryotic cell division
meiosis
mitosis
3 main steps of binary fission
DNA replication
Chromosome segregation
Cytokinesis
DNA is copied resulting in 2 identical chromosomes
DNA replication
2 chromosomes separate, move towards ends(poles) of cell
chromosome segregation
cytoplasm divides forming 2 cells
cytokinesis
each new daughter cell is_____ to parent cell
genetically identical
The cell Cycle has 3 phases
G1 Phase, S phase, G2 phase
G1 phase is
Cell growth
S phade is
DNA REPLICATION
G2 phase is
Preparation for replication
Cell increases in size
G1 phase
Replication of chromosomes
S phase
Organelles double
New cytoplasm forms
All other structures needed for mitosis form
G2 phase
DNA containing cells genetic code
Chromosomes
Each chromosomes has a matching pair
Homologous pair
During interphase each chromosomes _____
Copies itself
DNA found on chromosomes located in____
Nucleus of cell
Cell cycle continues process
Cells grow
DNA replicated
Organelles duplicated
Divide to form daughter cells
2 main steps kf eukaryotic cell division
Mitosis
Cytokinesis
4 steps of mitosis
Prophase
Metaphase
Anaphase
Telophase
Cytoplasm divide forming 2 cells
Cytokinesis
Nuclear division
Mitosis
Mitosis is followed by____
Cytokinesis
Process that divides cell nucleus to produce two new nuclei each with a complete set of chromosomes (continues process)
Mitosis
Chromosomes visible(sister chromatids)
Nuclear membrane disappears
Spindle forms
Prophase
Centrioles migrate to the poles
In animals
Chromosomes line up on the equator of the cell
Spindles attach to centromeres
Metaphase
Sister chromatids separate
Centromeres divide
Sister chromatids move to opposite poles
Anaphase
Chromosomes uncoil chromatin
Nuclear membrane reform
Spindle disappears
Telphase
Occurs at end of mitosis
Division of cytoplasm to form 2 new daughter cells
Organelles are divided
Cytokinesis
Control the cell cycle at checkpoints
Cyclins
Decides whether or not cell will divide
G1 checkpoint
Determines if DNA has been properly replicated
S checkpoint
Ensures chromosomes are aligned at mitotic plate
Mitotic spindle checkpoint
Result of uncontrolled cell division of cells that has lost ability to regulate cell cycle
Cancer cell
Reproduce more rapidly than normal cells
Cancer cells
MAsses formed called
Tumors
5 phases of cell cycle
First growth phase (G1)
Synthesis phase (S)
Second growth phase (G2)
Mitosis
Cytokinesis
Division of the cytoplasm
Cytokinesis
Cell cycle is controlled through
Feedback mechanism
Chromosomes contain
Genetic information
Cells must divide for
Growth
Repair of tissue
Asexual reproduction
Mitosis occurs in____
Somatic or body cells
Examples of mitosis occur in somatic
Liver
Heart
Skin
Stomach
How many chromosomes does human have
46
Haploid of chromosomes
23
Diploid means
2 sets or 2N
XX
Female
XY
Male
Meiosis occurs in
Sex organs
Males sex organs are the
Testes
Females sex organs are the…
Ovaries
Meiosis in male produces
4 sperm
Meiosi n female….
Produces 4 egg cells but 1 is viable the other 3 are polar bodies
They gave up their cytoplasm to nourish the 1 good egg
Polar bodies
Egg and sperm are called
Gametes
Other name of body cells
Somatic
Meiosis occurs in male..
Beginning at puberty
When meiosis occurs in female
Before birth and the egg mature in puberty
Fertilized eggs
Zygote
Zygote develops in
Embryo and form into an adult by mitosis
Process by which an egg and sperm unite
Fertilization
Organism in early stage of development
Embryo
Homologous chromosomes pair up
Before 1st cell division
Homologous chromosomes
Look alike
Code for same traits
Receive one from each parent
Homologous chromosomes exchange genes during…
Crossing over
Homologous chromosomes separate during
2nd division of meiosis
Crossing over increases
Genetic variation
No crossing over cause…
Daughter cells are identical to parent cells
Crossing over occurs cause….
Genetic variation
What kind of cells? Of meiosis and mitosis
Mitosis: Somatic cells (body cells)
Meiosis: sex cells or gametes
When does this occur? Meiosis mitosis
Mito: any time
Mei: male puberty
Female before birth but mature in puberty
Number# of division of mito and meio
Mito: 1
Meio: 2
of daughter cells in mito meio
Mito: 2
Meio: 4 male
1 viable in female
of chromosomes mito meio
Mito: same as parent cell diploid 46
Meio: half pf parent cell haploid 23
Type of reproduction of mito meio
Mito: Asexual
Meio: Sexual
Genetic composition of mito meio
Mito: daughter cells identical
Meio: daughter cell not identical
Pairing of homologous chromosomes mito and meio
Mito: no pairing
Meio: yes crossing over of genes
Function or importance mito and meio
Mito: growth repair
Meio: reproduction of sex cells