P could be meristematic tissues which possess the ability to grow and divide. Q could be phloem which contains only one type of dead cells i.e., phloem fibres, other types of cells of phloem are living. R could be parenchyma which is chiefly a storage tissue. S could be sderenchyma which is a dead mechanical tissue and possesses uniform lignified wall thickenings. Collenchyma possesses localised wall thickenings of cellulose or pectocellulose
