Cells Flashcards
Mitosis
When one cell becomes 2 cells
St 1 of mitosis
Interphase
G1: Growth 1, growth of the cell-> get big & gather resources
S: Synthesis, replicating of DNA
G2: Growth 2, create extra organelles
Interphase is the longest stage
St 2 of mitosis
Prophase
-DNA winds up into chromosomes
-Nucleus begins to break down
-centrioles go to the poles
-chromosome forms
St 3 of mitosis
Metaphase
-centrioles are at the poles
-chromosomes line up along the middle
-centrioles send spindle fibres to connect chromosomes before getting pulled apart
St 4 of mitosis
Anaphase
-centrioles pull apart the chromosomes into their sister chromatids
-everything needed for a full cell is in each half of the current cell
St 5 of mitosis
Telophase
-chromatids unwind back into DNA strands
-centrioles are done their job
-nucleus begins to form again
-cell begins to pinch at the middle (necking)
St 5 mitosis pt 2
-telophase part 2 called citokynesis
-nucleus is fully formed
-DNA unravels
-cellular membrane cleaves apart
-plant cells build a wall in the middle
-plant cells have no centrioles
-mitosis is now complete
Type 1 of cell reproduction
Asexual reproduction
-single parent cell becomes 2 identical daughter cells
Type 2 for cell reproduction
Sexual reproduction
-two parent cells (gametes) coming together to create a new cell (zygote)
Reason 2 for production
Repair:
Ex. Skin cells are constantly exposed and need to be replaced
Reason 3 for reproduction
Growth:
A cell grows by taking nutrients in, moving them to where they’re needed and building itself out of them. The movement is called diffusion
Diffusion
The natural movement of particles through a fluid as the particles go from an area of high concentration to low concentration. A cell will spit into two smaller parts to allow the travel of nutrients to be faster since diffusion is slow. The smaller the cell, the more efficient and quick things can move inside it.
Nuclear control
Cells do not have language but instead signals called messenger compounds
The nucleus is signalled when a development checkpoint has been reached and will not divide until all checkpoints are reached
If a cell is not dividing correctly the nucleus has the power to destroy the cell
Apoptosis
Self destruction of a cell
When a cell is found to be faulty by the nucleus will undergo apoptosis
Cancer
-When fast replicating cells develop copying errors
-apoptosis can be faulty and this causes faulty cells to stop self destructing
-they replicate rapidly and create clusters called tumours
Benign tumours
Cluster of cells that doesn’t cause harm and exists without harm in the body
Malignant tumours
The cluster of cells is negatively affecting organs, tissues and other cells around it
-Tumours break move and spread
Cellular differentiation
When a cells form or function changes to become a more specific type of cell to preform one task
Ex. White blood cell-> Neutrophil
How does specialization occur?
A stem cell can become many cells
An embryo thats 1-4 days old has totipotent stem cells
They can turn into the embryonic cells & the cells of the placenta
After day 4 the cells are either placenta or fetus
The embryonic are pluripotent meaning they can become any kind of cell in the human body
Levels of organization
- Organelles
2.cells
3.tissues
4.organs
5.organ system
6.organism (life)
