Unit C Topic 1 - Mitosis Flashcards
Schleiden & Schwann Cell theory (2)
1) all living organisms are composed of one or more cells
2) The cell is the most basic unit of life
Virchow Cell theory
All cells arise only from existing cells
Somatic Cells
Body cells that undergo the cell cycle in different ways, depending on cell type
Partent cell
Original cell
Daughter cell
New cell
Prokaryotic Cell and chromosomes
Bacteria cells with short and circular chromosomes that are not contained in a nucleus
Eukaryotic Cells and chromosomes
membrane-bound cells with Long and linear chromosomes contained in a nucleus
Histones
Proteins that DNA is wrapped around in a chromosome
Chromatin
(spaghetti) Form of DNA in a mass of entangles strands that condense into chromosomes
Centromere
The middle of a chromosome
homologous chromosomes
Two chromosomes with the same genes (we have 22 pairs)
The two sex chromosomes
XX and XY
Alleles
Different versions of the same gene
Diploid
Somatic cells with two of each chromosome (2n=46)
Haploid
Gamete cells with one of each chromosome (n=23)
Polyploid
more than two sets of chromosomes (ex: sturgeon Fish are octoploid or 8n)
Karyotype
Sets of chromosomes possessed by an individual
Stages of the cell cycle (2)
- Interphase (growth phase)
- Mitosis & Cytokinesis (division phase)
GSG
Stages of interphase
- G1 (Gap or Growth 1) phase
- S ( Synthesis) Phase
- G2 (Gap or Growth 2) phase
G1 Phase
Rapid growth, metabolic function, normal activity
S phase
each chromosome duplicates
G2 phase
Preparing for division
Mitosis
Division of genetic material into two identical sets
Cytokinesis
Division of the cell contents
PMAT
Stages of mitosis
Prophase, Metaphase, Anaphase, Telophase
CNCS
Prophase steps (4)
- Chromosomes condense
- nuclear membrane dissolves
- centrioles move to opposite poles
- Spindle fibers attach to chromosomes
Metaphase
Chromosomes lined up in the middle of the cell
Anaphase
Centromeres divide and are pulled to opposite poles (Each end of the cell has a complete set of DNA)
D-R-D
Telophase (3 steps)
Reverses Prophase
1. Chromosomes decondense
2. Nuclear membrane and nucleolus reforms
3. Spindle fibres desolve
Cytokinesis
contents of parnt cell are divided into two daughter cells
“cell movment”
Cleavage
Animal cell membrane pinches at equator and splits cell into two
Cell Plate
Plant cells use it to divide the cell in two, acting as a new cell wall
Telomeres
Ends of chromatin that shorten during DNA Replication
Cell Cycle Checkpoints
What are they and what’s the three major ones
Certain signals are used to determine when to divide and when to stop dividing cells
- G1 to S (is the DNA ok for replication?)
- G2 to mitosis (has the DNA been replicated right?)
- Metaphase to anaphase (Are chromosomes aligned properly in the middle?)
Cause of Cancer
when cells stop oberving checkpoints due to faulty mutations, and begin quickly and uncontrollably multiplying
Tumor
A mass of cancer cells
Angiogenesis
When a tumor tricks the body into growing blood vessels to bring nutrients to the tumor
Carcinogens
Agents that cause cancer
Ex: radiation, tobacco smoke, pesticides
Metastatis
Cancer cells ability to reproduce all over the body
Benign Tumors
Non-cancerout tumons that grow slowly and remain at original site
Can be removed surgically or killed by radiation
Malignant Tumors
Cancerous tumors that can spread through lymphatic and blood vessels
Removed by surgery folowed by radiation and chemotherapy
Asexual reproduction
Reproduction involving one parent producing genetically identical offspring
Sexual Reproduction
Reproduction incluting two parents and a genetically unique offspring
Binary Fission
Cell divison of prokaryotes to produce identical offspring
Conjugation
prokaryotes exchanging genetic information
Budding
A miniature version of the parent grows out of the parents body
Vegetative reproduction
Stem of a parent plant grows out and a new plant grows from it
Fragmentation
Creation of a new organism from the fragment of a parent organism
Parthenogenesis
When an unfertilized egg developes into an adult
Ex: Honey bee unfertilized eggs grow into male drones, while fertilized ones turn into female worker ants
Spores
a structure of genetic material formed by mitosis that is spread by the elements
Cloning
When identical offspring are fromed by a parent cell
Topipotent cell
A cell that can mature from an egg to an adult
In humans this makes the extra-embryonic layers
Pluripotent cell
A cell that can mature into any tissue in the body
AKA it can make the whole body (not the extra-embryonic layers)
Multipotent cell
a cell that can mature into multiple specialized cell types in a tissue or organ
Ex: adult stem cells
Why are human cells dificult to clone?
2 reasons
- lose totipotency when they mature
- many cells are too specalized to activly divide
