Theory:

Biological Classification:
1024px-Simple_Phylogenetic_Tree_of_LIfe.png
Phylogenetic tree of life
 
1024px-Tree_of_Living_Organisms_2 (1).png
Phylogenetic tree of life
 
1024px-Simplified_tree.png
Classification of organisms
  
13536385423_be9d1e55c9_c.jpg
Kingdom Plantae
 
Plant_phylogeny (1).png
Classification of plants
  
13536384133_d872c7072f_c.jpg
Animals classification - Kingdom Animalia
  
Taxonomic_ranking (1).svg
Hierarchy of different animals
 
Taxonomic_Rank_Graph.svg
Hierarchy of Red fox - Vulpes vulpes
 
Figure_20_01_04ab.jpg
Canus lupus familiaris - Hierarchy of dog
Reference:
https://www.flickr.com/photos/121935927@N06/13536385423/in/photostream/
https://www.flickr.com/photos/121935927@N06/13536384133/in/photostream/
https://upload.wikimedia.org/wikipedia/commons/thumb/b/ba/Tree_of_Living_Organisms_2.png/1024px-Tree_of_Living_Organisms_2.png
https://upload.wikimedia.org/wikipedia/commons/thumb/2/29/Simple_Phylogenetic_Tree_of_LIfe.png/1024px-Simple_Phylogenetic_Tree_of_LIfe.png
https://upload.wikimedia.org/wikipedia/commons/thumb/e/e6/Simplified_tree.png/1024px-Simplified_tree.png
https://upload.wikimedia.org/wikipedia/commons/3/36/Plant_phylogeny.png
https://upload.wikimedia.org/wikipedia/commons/f/fd/Taxonomic_ranking.svg
https://upload.wikimedia.org/wikipedia/commons/7/71/Taxonomic_Rank_Graph.svg
https://commons.wikimedia.org/wiki/File:Figure_20_01_04ab.jpg