The answer is an embryonic stage. This is the period of gestation right after the implantation, this is when the major organs of a baby are formed.
In the embryonic stage, <span>ectoderm is the outer layer that develops to a hair, teeth, brain and spinal cord. </span>
Answer:
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:
Griffith concluded that the R-strain bacteria must have taken up what he called a "transforming principle" from the heat-killed S bacteria, which allowed them to "transform" into smooth-coated bacteria and become virulent.
Explanation:
The genotypic ratio of their offspring is 100% Ee.
Hope this helps! God bless
-vf