Cadherin clusters of adherens junctions . 1) connect the external environment to the actin cytoskeleton 2) do NOT require calcium ions to perform their function 3) provide a pathway for signals to be transmitted from the cell exterior to the cytoplasm 4) connect the external environment to the vimentin cytoskeleton

Option-1 and 3

Explanation:

Cadherin is the protein complex present in the cell which is responsible for the sticking together of cell in tissue-like in the skin. The cadherin junctions allow the communication between the cells and the loss of the cadherin could cause cancer.

The cadherin junction is involved in the signalling pathway in the cells like in the Rho GTPase signalling, Ras signalling and many others which shows that they are responsible for the biological processes in an organism.

Thus, Option-1 and 3 are correct.

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.