Permanentt tissue

A) Simple Permanent Tissue

i) Parenchyma Cells

ii) Collenchyma Cells

iii) Sclerenchyma Cells

B) Complex permanent tissue

i) Xylem ( Hydrome)

ii) Phloem

TLS Online TPP Program

#Id: 8925

#XL - T Zoology

The protein kinases DNA-PK, ATM, and ATR are activated at sites of damaged DNA

TLS Online TPP Program

#Id: 8926

#XL - T Zoology

ATR activated by single-stranded DNA breaks.

TLS Online TPP Program

#Id: 8927

#XL - T Zoology

ATM and DNA-PK are specifically activated by double-strand breaks

TLS Online TPP Program

#Id: 8928

#XL - T Zoology

ATM and ATR, activate a triad of related protein kinases: Chk1, Chk2, and MK2

TLS Online TPP Program

#Id: 8929

#XL - T Zoology

Chk1, Chk2, and MK2

cause cell cycle arrest by inhibiting Cdc25

stabilizing the transcription factor p53, which induces the transcription of CKI p21 

TLS Online TPP Program

#Id: 8930

#XL - T Zoology

If the DNA damage is severe, p21 can cause the cells to senesce or p53 can induce apoptosis.