Factors Determining the Fates of the Blastomeres

Question 1

it is a factor determining the fates of the blastomere, which states that: differentiation of cells are not traced to differences in nuclear components of each cell but difference inside the cytoplasmic component

• within the cell (from the cytoplasm of the cell)

Answer 1

Intrinsic Factors

Question 2

it is a factor in differentiation which states that what the blastomeres become may be dictated by surrounding blastomeres

• Centrifugation experiment: ang gin centrifuge nga oocyte, when fertilized, still cleaves — zygote will not progress
• cytoplasm needs to be in very specific places

-Cytoplasm is the source of morphogenetic determinants

• Transcripts that are strategically located in the oocyte

-Once zygote is fertilized, translated protein will become the morphogenetic determinants

Answer 2

Extrinsic Factors

Question 3

In extrinsic factors, ______ is the source of morphogenetic determinants

Answer 3

Cytoplasm

Question 4

In extrinsic factors,

Once zygote is fertilized, _____ will become the morphogenetic determinants

Answer 4

translated proteins

Question 5

what are the four supports for intrinsic factors in differentiation?

Answer 5

1. Spemann’s experiment of egg constriction
2. Dentalium Zygote: only blastomere D with clear cytoplasm from veg pole develop mesoderm
3. Styela Partita
4. Germ plasm observations
   - only certain parts of the vegetal pole that will become the PGCs
   - gives rise to PGCs

Question 6

it gives rise to the dorsal lip of the blastopore which will become the primary organizer

Answer 6

gray crescent

Question 7

what supports extrinsic factors

Answer 7

1. experiments on future ICM and trophoblast cell
   
   • at early stage, if future ICM (inner cell mass) and trophoblast cells are mixed, whatever locates inside becomes embryo, whatever is outside becomes the trophoblast
2. concept of regulatory/ indeterminate cleavage
   - sea urchin and vertebrates

Question 8

this concept can be applied in sea urchin invertebrates (under extrinsic factors)

Answer 8

concept of regulatory/ indeterminate cleavage

Question 9

this concept can be applied in sea urchin invertebrates (under extrinsic factors)

Answer 9

concept of regulatory/ indeterminate cleavage

Question 10

only blastomere D with clear cytoplasm from veg pole develop mesoderm

Answer 10

Dentalium Zygote