Gyrase, a type II topoisomerase, provides a swivel that allows one DNA strand to rotate around the other.

TLS Online TPP Program

#Id: 7462

#Unit 5. Developmental Biology

Histidine phosphatase activity of DhkA causes inactivation of RegA, the accumulation of cAMP and PKA activation, causes spore maturation.

TLS Online TPP Program

#Id: 10291

#Unit 4. Cell Communication and Cell Signaling

The second phase of T-cell development

1.Positive selection: Selection for those cells whose T-cell receptors engage self-MHC.

2.Negative selection: Selection against those cells whose T-cell receptors bind too strongly to self-peptide/MHC combinations.

3.Lineage commitment: Commitment of thymocytes to effector cell lineages, including CD4 helper or CD8 cytotoxic populations

TLS Online TPP Program

#Id: 7533

#Unit 6. System Physiology – Plant

Dense plastids serve as gravity sensors

Gravity does not form gradient.

The only way of sensing gravity is through the motion of a sedimenting body.

In plants intracellular gravity sensors are large, dense amyloplast.

Statoliths –amyloplasts that function as gravity sensors.

Statocytes-specialized gravity sensing cells in which statoliths are present.

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#Id: 4894

#Unit 13. Methods in Biology

Comparison Between Correlation and Regression

TLS Online TPP Program

#Id: 3225

#Unit 4. Cell Communication and Cell Signaling

Benzo(a)pyrene, found in cigarette smoke as well as in coal tar, undergoes metabolic activation by cytochrome P-450 in the lungs to form a potent mutagen.