Unit 2 part 5 Flashcards
Cell Speacialization
Fertilization?
Fusion of gametes
- Leads to development of zygotes
Zygote?
Totipotent stem cell
Totipotent stem cell?
Can develop into all other cell types or into an embryo
- Can produce complete organisms
Blastocyst?
Contains embryonic stem cells
- Zygote develops into blastocyst
Embryonic stem cell?
Are pluripotent
Pluripotent?
Can differentiate into almost all other cell types in organisms but cant complete it
- Can’t produce complete organisms
Cell differentiation?
All cells from a multi cellular organism have some genome
- Stem cells differentiate into specialized cells by expressing some genes and not others
Adult stem cells?
Blastocyst develops into a foetus as embryonic stem cells differentiate into specialized cells
- Some adult stem cells remain to replenish dying cells and repair damaged tissue
- Most adult stem cells are multipotent
Hemotopoietic stem cells
Multipotent b/c they can differentiate into all types of blood cells but not all cells
Development of embryonic cells
They differentiate into specialized cells and tissues in a controlled manner through a group of gene regulating chemicals
Multi potent?
Able to form a range of closely related cells (limited)
Morphogens?
Gene regulating chemicals (transcription factors) that determine the specialized cell that develops according to their concentration
Traits of morphogens?
- produced + released from embryo cells and diffuse through tissues
- They spread, resulting in a concentration gradient across tissue
- Bird to receptors on cells resulting in activation or repression of genes
- Concentration of it determines which gene will be expressed, determining type of specialized cell
Stem cells
Undifferentiated cells that have a limited capacity to divide and can differentiate into specialized cells
- Are self renewal, differentiate, regulate hair growth, and main skin homeostasis
Stem cells niche
Locations in the body where stem cells can be maintained, promoted to proliferate ( rapid self removal), or differentiate
- Adult stem cells are in them
Example of stem cells niche
Bone marrow
- Niche for hemotopoietic stem cells that can differentiate into all types of blood cells
hair follicles
- Contains various pools of stem cells like epithelial, melanocyte, and mesenchymal
Sperm size
Smallest cells in body
- 50 MicroM
- Diameter of 3 MicroM
OVA (egg cells) size
Cells w/ largest volume
- Diameter of about 120 MicroM
Neurons size
350 MicroM in length
Red blood cells size
Diameter of 7.5 MicroM
- Allows them to move through capillaries
White blood cells size
12-15 MicroM depending on type of white blood cell
Skeleton muscle cells size
- 10-50 MicroM in width
- 40milliM in length
2 Factors that determine cell size?
- Basic process of cell psychology
- Need for materials to move in and out of cells, usually involves surface-area-to-volume - Cell division apparatus
- If cells are too large/ small the mitotic spindic will not function properly
Surface area
As cell grows, volume of cells increases at faster rate than surface area of cell and surface area to volume decreases as cell grows