B2.3 Cell Specialisation Flashcards
What is differentiation?
transition of unspecialised cells into cells that have particular structure and function
What is stem cell niche?
locations that have stem cells and where stem cells regenerate and differentiate
What are totipotent stem cells?
can become any cell type in the body and embryonic tissues
What are pluripotent stem cells?
can become any cell type but only in adults
What are multipotent stem cells?
range of cells within a specific tissue or organ
What’s the surface area to volume ratio in smaller and in bigger cells?
- in smaller cells: SA:V is bigger
- in bigger cells: SA:V is smaller
What are the advantages of larger SA:V ratio?
- cell is more efficient at moving things in and out of the cell
- better at heat distribution
How cells can increase their SA:V ratio?
changing shape by making folds, flatening etc.
Why red blood cells are flat?
to increa SA:V ratio and move oxygen more effciently due to increased SA
What types of cells made up alveoli in lungs?
pneumocytes type I and type II
What are entrocyte?
absorb nutrients to bloodstream in small intestine
How small intestine increases it’s SA:V ratio?
- finger-like projections called villi
- microvilli
What’s the difference between I and II pneumocytes?
- I pneumocytes are thin and flattened
- II pneumocytes have cuboidal shape
What’s the function of type I pneumocyte?
they exchange gas
What’s the function of type II pneumocyte?
secrete surfactant, prevent alveoli from collapsing
What’s the percentage composition of pneumocytes type I and type II in lungs?
type I: 95%
type II: 5%
Which type of pneumocyte has larger SA:V?
type I
What are the features of muscle fibers (5)?
- long
- shorten to create force
- multiple nuclei
- need stimulation from nervous system
- made up of sacromeres - striated
What are the features of cardias muscle cells (6)?
- shorter
- made up of sacromeres - striated
- involuntary
- one nucleus
- branched for coordination
- connected by intercalated discs
List adaptations of sperm cell to its motile and energy-needing function (4)?
- small, so less energy is used to produce them
- many mitochondria for energy
- flagellum to move
- haploid nucleus in the head
- acrosome in the head with digestive enzymes to penetrate the egg cells’ zona pellucida
