self study notes uni- to multicellular organisms Flashcards
what is the differentiation of cells that occurs in dictyoselium discoideum?
STALK or SPORE CELL: stalk cells help with mobility, help spores to be taken away by the wind or water; spores restart as single-celled organisms
what are the 3 essential things that illustrate evolution of multicellular organisms?
1) cell-cell signaling
2) cell differentiation
3) cell death/sacrifice/apoptosis
what is Volvox carteri and what are its characteristics?
Chlamydomonas = algae; they have a chloroplast where photosynthesis occurs; nucleus, eyespot to primitively detect light and flagella to swim
Volvox carteri look like a cluster of Chlamydomonas that are interacting with each other through an extracellular matrix. Their reproductive cells are called gonidia; they start cleaving and after an asymmetric cell division, smaller reproductive cells are generated with somatic cells
what is the differentiation of Volvox carteri cells?
reproductive cells, Chlamydomonas-like cells, cells that survive and generate a new organism (gonidia), cells that die
why is C.elegans suitable for genetic analysis?
relatively small number of cells, invariant lineage, transparent embryo, hermaphrodites
how are the AP axis and the DV axis specified in C. elegans?
AP axis - by how sperm enters the body: posterior part is where the sperm actually enters the body
DV axis - by cell-to-cell interactions
why do ducks have webbed feet?
they do not have apoptotic cells in between their digits, while chickens and mammals do
