The calcium ions released into the cytosol during excitation of skeletal muscle bind to

Bind to the protein complex troponin.

Explanation:

Excitation of skeletal muscle caused by the calcium ions. During excitation of skeletal muscle, after calcium ions released into the cytosol, they bind to the protein complex known as troponin and causing substitutions in the protein complex.

These alterations permit protein to push out from the myosin-binding sites on the actin filament.

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.

c. orbital shape i hope this is correct