Lesson 8: Cell Specialisation Flashcards
What is cell differentiation?
The process where unspecialized cells become specialized following fertilization.
What are the two properties of stem cells?
self renewal and potency
What is self-renewal?
continuously divide and replicate
What is potency?
The ability to differentiate into specialised cell types.
what are the four different types of stem cells?
totipotent, pluripotent, multipotent, unipotent
What are totipotent stem cells?
Stem cells with the potential to differentiate into any type of cell.
What are pluripotent stem cells?
differentiate into all body structures but cannot form whole organisms.
What are multipotent stem cells?
Differentiate into a few closely related body cells
What are unipotent stem cells?
Can only become one type of cell
What is an example of a totipotent stem cell?
Zygote
What is an example of a pluripotent stem cell?
Embryonic stem cells
What are some examples of multipotent cells?
Umbilical cord stem cells
bone marrow stem cells
What is an example of an unipotent stem cell?
liver stem cells
How are RBCs adapted for oxygen transport?
Biconcave shape increases SA, no nucleus maximises space for haemoglobin.
How does the alveoli increase their SA:V ratio?
small
numerous
sphere shaped.
How do cells become specialised?
Special cells release morphogens (signaling molecules).
Morphogens spread out, creating a gradient (high concentration near the source, lower further away).
Embryo cells detect morphogen levels with their receptors.
Cells react based on the amount of morphogen they detect.
How does the intestinal microvilli increase their SA:V ratio?
numerous microvilli
folds on the surface of epithelial cells
microvilli projections
how are squamous type 1 pneumyocytes specialized?
one cell thick
Covers ~95% of alveolar surface - large SA
how are the cardiac muscles specialized?
branched shape for contractions to spread quickly
many mitochondria and nuclei.
How are skeletal muscle cells specialised?
multi-nucleated, many mitochondrias
How are sperm cells adapted for fertilisation?
Flagellum for movement, acrosome with enzymes to penetrate egg, many mitochondria for energy.
How is an egg cell adapted for development?
Large cytoplasm with nutrient reserves, and a zona pellucida to prevent polyspermy.
What is the function of the type 1 pneumocyte?
gas exchange
What do type II pneumocytes secrete and why?
Pulmonary surfactant, reduces surface tension to prevent alveolar collapse and improve gas diffusion.
