Why must some hormones bind to a membrane receptor on a target cell's membrane in order to activate it? to stimulate endocytosis to internalize the hormone because they cannot cross cell membranes because they are not water-soluble for activation by ATP

a and b

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]

1. b.

2. d.

3. a.

5. d.

6. c.

these are the only ones that i know, i hope this , and good luck.