BIOL 351/ BIOL351 Module 1: (Latest 2026/ 2027 Update)
100% Verified Questions & Answers | Grade A
BIO 351 Module 1
What do solid vs empty exons represent?
Solid = protein-coding exons; empty = non-coding exons.
What do intron lines represent?
Introns separating exons.
Where is the TATA box located?
~30 bp upstream of the transcription start site.
What do enhancers do?
Bind TFs, loop to promoters, regulate tissue-specific transcription.
Purpose of RNA splicing
Remove introns and increase protein diversity.
How do myostatin mutations cause muscle excess?
New splice sites → nonfunctional myostatin → loss of inhibition of muscle growth.
Define specification
Reversible fate commitment in a neutral environment.
Define determination
Irreversible fate commitment even in non-supportive environments.
, What defines a stem cell?
Potency + asymmetric division.
Potency and differentiation relationship
Potency decreases as differentiation increases.
PAR/aPKC pathway outcome
Activates Yap/TAZ → Tead → Cdx2 → trophectoderm fate.
E-cadherin/Hippo pathway outcome
Represses Yap/TAZ → no Cdx2 → Oct4 ON → ICM pluripotency.
Yamanaka factors
Oct4, Sox2, Klf4, c-Myc.
Autonomous specification example
Trochoblast cells in snails forming cilia via maternal determinants.
Conditional specification example
Sea urchin blastomeres form full larvae when separated.
Perivascular niche main signal
CXCL12/SDF1 promotes HSC quiescence.
Endosteal niche signals
Jagged1/Notch, Tie2/Ang1, Wnt → maintain self-renewal.
100% Verified Questions & Answers | Grade A
BIO 351 Module 1
What do solid vs empty exons represent?
Solid = protein-coding exons; empty = non-coding exons.
What do intron lines represent?
Introns separating exons.
Where is the TATA box located?
~30 bp upstream of the transcription start site.
What do enhancers do?
Bind TFs, loop to promoters, regulate tissue-specific transcription.
Purpose of RNA splicing
Remove introns and increase protein diversity.
How do myostatin mutations cause muscle excess?
New splice sites → nonfunctional myostatin → loss of inhibition of muscle growth.
Define specification
Reversible fate commitment in a neutral environment.
Define determination
Irreversible fate commitment even in non-supportive environments.
, What defines a stem cell?
Potency + asymmetric division.
Potency and differentiation relationship
Potency decreases as differentiation increases.
PAR/aPKC pathway outcome
Activates Yap/TAZ → Tead → Cdx2 → trophectoderm fate.
E-cadherin/Hippo pathway outcome
Represses Yap/TAZ → no Cdx2 → Oct4 ON → ICM pluripotency.
Yamanaka factors
Oct4, Sox2, Klf4, c-Myc.
Autonomous specification example
Trochoblast cells in snails forming cilia via maternal determinants.
Conditional specification example
Sea urchin blastomeres form full larvae when separated.
Perivascular niche main signal
CXCL12/SDF1 promotes HSC quiescence.
Endosteal niche signals
Jagged1/Notch, Tie2/Ang1, Wnt → maintain self-renewal.
