Answer:
Option B, It was made in stars that lived before the solar system formed.
Explanation:
Almost all the carbon that exists today with in the living organisms was produced in the stars. When these stars exploded during the big bang theory all the carbon within hem was introduced in the environment of earth some billions of years ago. Hence , though carbon introduced in earth’s environment was due to big bang, its origin is from the stars. Hence option B is the correct answer
Cyanobacteria is responsible for generation of oxygen on planet earth and thus option D is in correct.
The presence of vertebral column or notochord at any stage of life in any organism is the characteristic of vertebrate.
Explanation:
An animal is vertebrate if it fulfils the following criteria:
Presence of vertebral column or notochord.
Presence of endoskeleton or backbone.
The spinal cord runs above the vertebral column.
Humans embryo has notochord which becomes a vertebral column.
The alimentary canals end in the anus.
Mouth is present ta the anterior side of the vertebrate.
Have legs, fins or wings for movement.
Presence of a nervous system and sensory organs.
Presence of skin, lungs or gills.
Presence of a circulatory system.
Vertebrates include fish, amphibians, reptiles, birds and mammals.
