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.

answer: "circumcision is a common procedure in which the skin covering the tip of the penis is surgically removed."

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.