Question

In cladistics
A. Data for cladogram is presented
B. Derived characters help to constant cladograms
C. A clade must contain the common ancestor plus all its descendants
D. All of the above

Answer 1

Hint: A system of biological classification that involves classification or categorization of organisms on the basis of traits or characters they possess in common is called as cladistics.

Complete Answer:
- In cladistics, organisms are arranged into groups called ‘cladees’. A clade represents a group that has a common ancestor and all descendants. The classification in which organisms are categorized on the basis of similar traits or characters is called cladistics.
- Cladistics is a modern method of taxonomy. The field of biology that is involved in the classification and arrangement of organisms in a phylogenetic tree of life is called cladistics. A phylogenetic tree is an evolutionary tree or branched structure that involves links between organisms on the basis of their phylogeny.
- The steps or differentiation or branching in a phylogenetic tree reflects how different species are involved from common ancestors. In ancient times where modern traits such as DNA analysis, fingerprint techniques were developed, organisms were classified on the basis of similarities and common traits.
- A cladogram is a representation used in the body of cladistics to show relation among organisms. A cladogram is different from evolutionary trees because it does not show common ancestors or descendants organizing the organisms into groups called clades.

Therefore, from the above explanation the correct option is (B) Secondary phloem.

Note: Cladistics can be differentiated from systematics as the classification of systematics involve the evolutionary relationship of species. Whereas cladistics involve classification on the basis of phylogenetic tree without considering divergence that shows common ancestry.