cell differentiation

Question 1

what do differentiated cells express?

Answer 1

genes coding for cell-type specific proteins

Question 2

what does transcriptonal activity of gene depend on?

Answer 2

extrinsic signals (non-autonomous) , intrinsic signals (autonomous). accessibility of chromatin and regulatory binding sites

Question 3

what develops from somites?

Answer 3

muscle dermis and cartilidge

Question 4

what are somites?

Answer 4

segmented blocks of tissue that contain undifferentiated mesodermal progenitor cells.

Question 5

what is MyoD?

Answer 5

transcription factor produced only in muscle or muscle precursor cells

Question 6

is myoD essential for muslce development?

Answer 6

it is sufficient but not essential for muscle development

MYF5 acts without MYoD

Question 7

what is a stem cell?

Answer 7

type on undifferentited cell that is both self renewing and can also give rise to differentiated cell types

Question 8

what cells can replace muscle cells in adult?

Answer 8

satellite cells

Question 9

where are satellite cells situated?

Answer 9

between basal lamina and cell membrane of mature muscle fibres

Question 10

what do satellite cells express?

Answer 10

specific marker proteins - PAX7 (transcription facotr)