Cell Division Flashcards
Chromosomes
In order for cells to carry out life functions they must have…
Copy of genetic instructions
Genome/complete copy of all of chromosomes included
Review characteristics of living things
Types of…
-
-
Reproduction
Asexual - does not not require the use of specialized sex cells
Sexual - require specialized sex cells but not of opposite sex always flowers
Chromosome structure Basic description: Chromosome composition Molecule of \_\_\_\_ which is, Proteins 1) 2)
Very compact rod shaped structure that is prepared for cell division
DNA; tightly wrapped
Histones
Non-Histones - involved in controlling the activity of specific regions of DNA
Chromosome numbers / specific for each species Classification of chromosomes 1)\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Combinations- 2)\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Ex.
Sex chromosomes; determine the sex of an organism also carries genes for other characteristics
Autosomes; all the other chromosomes besides sex chromosomes
Humans 22 pairs
Parts of a Chromosome
Chromatid: Half of the chromosome consists of…
-DNA is copied before…
Centromere: constricted area of chromosome which is the…
Chromatin:
A complete copy of DNA
Cell division so that each new cell has a complete copy
Point of attachment for the sister chromatids and is important in cell division
The uncoiled form of DNA between cell division so that info can be used to direct cell activity
Homologous chromosomes: (Homologues) pairs of chromosomes…
Similarities of pairs -
Karyotype:
Where one member of each pair is received from each parent
Same size shape type of gene like eye color and centromere position
Shows the complete diploid set of chromosomes group together in pairs arranged in order of decreasing size
Diploid Number/Cell
Type of cells include
Example
Cells having ……………..
both members of each homologous pairs of chromosomes.
Somatic/body cell
Skin cell EX human 46 fruit fly 8
Haploid Number/Cell:
Types of Cells included
Example
Cells having …………. only one member of each homologous pair.
sex cells
EX egg, sperm, gometes Ex humans 23
Cell division:
A. In Prokaryotic Organisms
1. Example organism
2. Type of ________ reproduction and includes -
Process by which cells produce new cells/offspring
- Bacteria
- Asexual;binary fission
In Eukaryotic Organisms
Ex organisms -
Two types of Cell division
Mitosis: process of…
Also occurs in…
Meiosis: process of…
Ex. animals, plants, fungus
Mitosis: nuclear division resulting in new cells with genetic information of the cell.
1. growth 2. replace old/dead cells 3. repair damaged cells
Meiosis: nuclear division in the production of sex cells or gamettes reproduction province , genetic variety.
The Cell Cycle:
Interphase:
Cell division:
a Mitosis
b Cytokinesis-
repeating set of events that make up the life of the cell
Time between cell divisions.
Cell division:
mitosis (mphase)
cytoknyseis - division of the cytoplasm
Interphase - represents …
- G1 Phase
- S Phase:
- G2 Phase:
- G o Phase
meet of the lifetime of a cell
G1 Phase: Cells grow to … their mature size; synthesize proteins & organg.
a. events between …. cell division and DNA is replicated.
b. “G” stands for … GAP
2. S phase - synthesis phase where DNA is replicated
- once entered the cell …complete the cell cycle.
3. G2 - gap between …DNA replication and cell division
- the cell prepares for mitosis.
4. G0 - cells that have matured and …carry outlife processes
a. These cells are not …copying or dividing DNA.
EX nerve cells , liver cells
Stages of Mitosis 1 2 3 4
PMAT Prophase Metaphase Anaphase Telophase
Stages of Mitosis 1. A B C -
- Prophase
a. genetic material ….. tightly coils fro its chromatin form to its chromosomes.
b. The nuclear envelope breaks down
c. Centrioles …… separate and a spindle deigns to form
- various types of fibers for various roles ex kinetichore
Stages of Mitosis
2.
- Metaphase - chromosomes line up across the midline and attach to the spindle fibers.
Stages of Mitosis
3.
- Anaphase - sister chromatids separate into individual chromosomes and move to opposite poles/sides/ or moved apart.
Stages of Mitosis 4. a b c
- also known as
a. chromosomes uncoil into the form of chromatid
b. The nuclear envelope reforms
c. Centrioles duplicate
Name just the four stages of mitosis
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
- Animal cells
- Plant cells
the split of the cytosol or cytoplasm.
- Animal cells - cell membrane pinches in creating cleavage furrow.
- Plant cells - formation of a cell plate to form new daughter cells
Rate of cell division
Different types of cells…
Ex.
Have different rates of cell division
- A balance of rate must exist to maintain homeostasis.
a. too slow-
b. too rapid-
Limited growth and development; aging
Cancer abnormal cells excess scar tissue keloidscars
Regulation of the Cell Cycle
a. cell to cell contact -
b. Cyclins:
1. _______________
2. _______________
Cells at the edge of a tissue are stimulated to divide until they contact other like cells
Proteins that regulate the timing of the cell cycle
- respond to events within the cell
- respond to events outside the cell
Ex. Growth factors
Reasons for research in controlling cell division. a. To ... Ex. b. To ... Ex.
Initiate or enhance cell growth
Ex spinal cord damage, skin grafts, cartilage repair
Halt undesired cell division
Ex cancer treatments
Meiosis:
Homologous pairs of chromosomes are…
Process that creates gometers
separated to achieve the haploid # in the gametes
Stages: Meiosis must begin with
the duplication of chromosomes during the S phase.
Meiosis 1 key result: Same set of phases occur in Meiosis as was present for... Pairing up of... Crossing over can result in... Anaphase separates
Homologues pairs of chromosomes are separated
Mitosis
Homologues chromosomes at the midline during meiosis 1
The exchange of genetic material between homologous chromosomes hc=leads to genetic diversity and variety
The homologous Pair therefore the haploid number is achieved
Genetic shuffling hc line up in many orders
Meiosis 2 key Result -
Same set of phases again occur…
End result:
sister chromatids into different cells
Prophase
4 gametes with the haploid number.
