Some embodiments include an integrated structure having a conductive material, a select device gate material over the conductive material, and vertically-stacked conductive levels over the select device gate material. Vertically-extending monolithic channel material is adjacent the select device gate material and the conductive levels. The monolithic channel material contains a lower segment adjacent the select device gate material and an upper segment adjacent the conductive levels. A first vertically-extending region is between the lower segment of the monolithic channel material and the select device gate material. The first vertically-extending region contains a first material. A second vertically-extending region is between the upper segment of the monolithic channel material and the conductive levels. The second vertically-extending region contains a material which is different in composition from the first material.