Summary
Summary Review of developmental biology LS/BML10
- Module
- Institution
Complete review of the developmental biology classes given for BMLS10 which will be in the theme test of C.elegans
[Show more]
Seller
Follow
kelly-lan
Content preview
LS10 Developmental biology reviewLesson 1 How is it possible that a complete
organism is generated from a single cell?
Preformism theory states: sperm cells are cells that
could caary the preformed offspring
★ So organisms develop from miniature
versions of themselves (homunculi)
★ It was believed that the form of living things
existed prior to their development
Epigenesis (William Harvey)
★ Showed that life came from eggs
★ Development through differentiation
Theory of recapitulation (Johann Friedrich Meckel)
★ The development of the embryo goes
through stages that represent evolution of ancestors
★ ‘’Ontogeny recapitulates phylogeny’’
★ Ontogeny = embryonic development represents
★ Phylogeny = history of evolution
★ Each species seems to recapitulate ancestral morphologies during its own development,
so they have common genetic developmental plans!
Development begins with a single cell-the fertilized egg/zygote (undifferentiated), which divides
mitotically to produce all the cells of the body into fully differentiated cells
★ Development does not stop at birth, or even at adulthood e.g. bone marrow generates
million of new red blood cells every minute, regeneration of severed parts,
metamorphosis etc.
★ Developmental biology is the discipline that studies embryonic development and other
processes related to organisms’ development
Cell polarization
★ Can happen due to external niche which keeps contact with one daughter cell =
extrinsic regulation
★ Only one daughter cell can maintain contact with the niche
★ Intrinsic regulation = regulators of self-renewal within a cell is localized asymmetrically
→ they are inherited by only one of the two daughter cells
, The two sides of a zygote differ → assymetrical
★ This happens after fertilization and determines the assymetry of the zygote
★ Myosin (in the cytoskeleton) rearranges to one side which determines the anterior and
posterior side
★ There are mechanisms which maintain the polarity before mitosis
PAR proteins: an internal cellular signal for
polarisation
★ PAR = partitioning defective genes
★ They are well conserved and create
domains which have a distinct
composition for different functions
★ A domain is created by proteins
interacting with each other and
aggregating
★ PAR proteins localize in a mutually exclusive matter → the loss of PAR proteins
(mutant) effects the localization on the other side
★ So posterior PARs are required to prevent anterior PAR proteins from lozaling at the
posterior side and vise versa!
Cellular polarization → asymmetric cell division
★ The anterior side is bigger than the posterior side
★ There is a relationship between PAR proteins and asymmetry in order for the two
daughter cells to dissociate
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller kelly-lan. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £5.56. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
78600 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now