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TLS Online TPP Program

#Id: 8978

Proportion of base pairs that differ between sequences(D) 

D= 2rt

r  = rate of divergence per base pair per million  

T = time

#Unit 11. Evolution and Behavior #Rate of change in gene frequency through natural selection #Part B Pointers
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TLS Online TPP Program

#Id: 943

#Unit 5. Developmental Biology

Chemotaxis 
sperms are attracted toward eggs of their species by following a gradient of a chemical secreted by the egg.
TLS Online TPP Program

#Id: 944

#Unit 5. Developmental Biology

In Sea urchin,
Sperm-activating peptides provide direction to sperm during chemotaxis.
TLS Online TPP Program

#Id: 945

#Unit 5. Developmental Biology

SAP in the egg jelly of the sea urchin Arbacia punctulata 
Resact (14-amino acid chemotactic peptide)
TLS Online TPP Program

#Id: 946

#Unit 5. Developmental Biology

SAP in the egg jelly of, Strongylocentrotus purpuratus
Speract
TLS Online TPP Program

#Id: 947

#Unit 5. Developmental Biology

Resact from Arbacia egg jelly binds to its receptor on the sperm, activates the receptor’s guanylyl cyclase (RGC) activity.
TLS Online TPP Program

#Id: 948

#Unit 5. Developmental Biology

Active guanylyl cyclase causes the sperm cell to produce more cGMP, that activates a calcium channel in the cell membrane of the sperm tail.