The best answer - dermal tissue.
Dermal tissue in plants forms the first line of defense against physical damage and infection from the outside world.
Dermal tissue covers the outside of the plant, except in woody shrubs and trees, which have bark. The most common cell type in dermal tissue is epidermal cell. Generally, a thin waxy layer called a cuticle covers the epidermal cells and protects them.
Other cells in the dermal tissue are guard cells that surround the stomata, which are openings in the leaves. Gases enter and leave the dermal tissue through the stomata.
Answer:
cAMP dependent pathway is important for processing of life.
Explanation:
cAMP pathway is also called as adenynyl cyclase pathway.
This mechanism requires different steps like-
- G protein coupled receptor is a integral protein that is activated by different external stimuli which binds with the specific ligand.
- Extracellular ligand causes activation of GPCR which in turn is responsible for conformational change in the receptor and allows it to bind with the intracellular heterotrimeric G protein complex.
- The Gα stimulate G protein complex to exchange GDP for GTP and then the complex is released.
- Activated Gα binds with adenylate cyclase and catalyzes ATP to form cyclic AMP.
- Activation of cAMP leads to the activation of nucleotide gated ion channel, and PKa(Protein kinase A) which is also called as cAMP dependent enzyme.
- Once, PKA is activated,it causes phospholylation of other proteins like AMPA receptor,transcription factors which regulate gene expression, and convert glycogen into glucose.
Polar.
Polar means that it has a negative pole and a positive pole
