Microtubules and microfilaments are elongated structures that cross the cell, giving support to the cell, and carries organelles and objects throughout the cell. Their supporting structure would be most like which system of a multicellular organism?

Their supporting structure would be most likely the MUSCULOSKELETAL SYSTEM of the multicellular organisms.

Explanation:

The musculoskeletal system found in multicellular organisms are made up of structures which provides support, protection and allows for various movements. These structures include:

--> Muscles

--> Cartilage

--> Ligaments

--> Tendons and

--> Joints

Furthermore, Microtubules and microfilaments are the major components of cytoskeleton. They are the structures that gives a cell it's shape and helps organise it's parts. As described in the question, they are elongated structures that cross the cell, giving SUPPORT to the cell, and carries organelles and objects throughout the cell.

Therefore, since the Microfilaments and Microtubules provides support and shape at the cellular level it can be most likened to the musculoskeletal system of multicellular organisms which performs the same functions.

osteogenesis imperfecta (oi) refers to a congenital ailment of bones. in the condition, the bones become brittle or fragile. this ailment is a general result of the defect or mutations in the genes (colia1 or colia2). this mutation results in imperfect collagen formation either in quantity or quality wise.  

there are eight kinds of oi defects, and each kind varies with certain distinctions in symptoms. the usual symptoms include frequent bone fractures, loss of hearing in infants, protruding eyes, discoloration of the white in the eyes, respiratory issues, loosening of the joints, short stature, and other symptoms.