The question is incomplete as it does not have the options-
a. superfluous organ
b. extra appendage
c. vestigial structure
d. living fossil
e. chromosomal aberration.
Answer:
The correct answer will be option-vestigial structure
Explanation:
Vestigial structure are the structures which do not play any role in the organisms but still are inherited from the ancestors to maintain the fitness of the organisms.
Vestigial organs are found in many organisms including humans in which the presence of vermiform appendix do not play any role but it used to play roles in the ancestors of humans as they carried the cellulose-degrading bacteria.
Thus, a vestigial structure is the correct answer.
Bone marrow plays an important role in our circulatory system because Bone marrow contains hematopoietic stem cells which is the major producer of red blood cells or erythrocytes,white blood cells also know as leukocytes and also platelets( thrombocytes) which is the major components of our blood,the only liquid that is very essential in our circulatory system.
Cell biologists photograph cells in mitosis, then cut out the chromosomes from the photographs and group them together in pairs to form a karyotype.