The diagram sh An oak tree provides food for many animals. The oak tree is found at which level of the energy pyramid?
A) 2
B
1
D) 3

Some substances but not other can cross the (blank) membrane of a cell

Do the following statements describe actin, myosin, both of the proteins or neither of the proteins? (a) contains a binding site for calcium (b) found in the i band (c) exists in a globular (g) form and a filamentous (f) form (d) contains a binding site for atp (e) is a component of the thin filament (f) is a component of the thick filament

Explain what is meant by a river’s load, and describe how the load is carried.