Which of the following are only in plant cells?

a. gap junctions

b. desmosomes

c. plasmodesmata

d. tight junctions

Gap junctions are channels in animal cells that allow ions, nutrients, and other substances to flow between them, allowing them to interact. So, option a is wrong.

Desmosomes are found in animal cells which form a continuous strip of epithelial tissue or contact points that binds cells together. They are also used to provide structural support. Option b is incorrect too.

Plasmodesmata are channels present in only plant cells that allow ions, nutrients, and other substances to flow between them, allowing them to interact. Thus, option c is correct

Tight junctions connect cells and are made up of linked parts of the plasma membrane. They are also found in animals. Hence, option d is incorrect as well.

Plasmodesmata are channel between plant cells which allows them to communicate.