TSH(thyrotropin)

Increased proteolysis of the thyroglobulin Increased activity of the iodide pump Increased iodination of tyrosine

Increased size and increased secretory activity of the thyroid cells

Increased number of thyroid cells

TLS Online TPP Program

#Id: 3855

#Unit 5. Developmental Biology

Dictyostelia (social amoebas)

solitary haploid amoebae live on decaying logs, eating bacteria and reproducing by binary fission.

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#Id: 3856

#Unit 5. Developmental Biology

Dictyostelium can utilize one of three survival strategies when food starvation-

(1) Microcyst formation, favoured in dark & wet conditions, or ammonia levels are high.
(2) Zygote formation, favoured in dark & wet conditions, & triggered by ethylene produced by the cells.
(3) Cell aggregation & differentiation

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#Id: 3857

#Unit 5. Developmental Biology

Phosphorylation of RegA is mediated by sensor histidine kinases/phosphatases which either phosphorylate or dephosphorylate themselves on a histidine residue when a signal molecule binds to their sensor domain.

TLS Online TPP Program

#Id: 3858

#Unit 5. Developmental Biology

Cell Aggregation & Differentiation is common to all Dictyostelids.
It consists of an interconnected programme of cell movement and cell differentiation.

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#Id: 3859

#Unit 5. Developmental Biology

The binding of ammonia to the sensor domain of DhkC leads to the activation of its histidine kinase activity and to the autophosphorylation of a DhkC histidine residue.

TLS Online TPP Program

#Id: 3860

#Unit 5. Developmental Biology

The phosphoryl group is transferred,

From histidine residue of DhkC  aspartate of DhkC histidine in phospho-transfer intermediate RdeA aspartate of RR of RegA