The Thymus is a unique gland which protects the body against autoimmunity when the immune system act against itself.Hence the Thymus plays a significant role the dual systems i.e.,the lymphatic system (body’s defensive mechanism) and the endocrine system
Explanation:
The Thymus is special gland located anteriorly to the chest directly behind the sternum and in between the lungs. Active until puberty and gradually shrinks to become fat after puberty.
Function: Prior to birth and during childhood thymus engage in producing and maturation of T-lymphocytes or T-cells a particular type of white blood cells which defence the body against infectious disease germs.Though the organ does not function throughout the life span but it plays a significant role protecting the body against autoimmunity refers to an immune system works against itself .Therefore the thymus plays a key role in lymphatic system and an endocrine system.
Secretion:Thymus secretes Thymosin a hormone it instigates the development of T-Cells ( disease resisting cells) Thymosin stimulates the development of T-Cells until a human attains its puberty.
At the age of 75 thymus becomes a fatty tissue.
ANSWER: C, the continents were at one time joined together.
REASONING: Alfred Wegener was the first person to propose the scientific theory of Continental Drift. Continental Drift is a theory that supposes all the continents were at one time joined together as one large land mass. The mechanisms of continental drift can be explained by Plate Tectonics.
it explains how eukaryotes came from ancestral prokaryotes.
it theorizes that some organelles (mitochondria and chloroplasts), evolved from free-living prokaryotes that were overtaken and subsequently became obligate endosymbionants.
