In fetal life, the lungs are not expanded, so most of the blood from the right ventricle is shunted from the pulmonary artery to the aorta through the patent ductus arteriosus. With a few breaths the lungs expand, and blood flows from right ventricle to pulmonary artery into the lungs. Withdrawal of circulating prostaglandin from the mother plus bradykinins released from the expanding lung of the infant cause the ductus to close over a few minutes to hours. The closed ductus remains as the ligamentum arteriosum.
In the coding region, natural selection tends to eliminate all of the mutations because of the high importance these regions have. The coding region contains genes that synthesize proteins and the changes in the DNA sequence can have devastating effects on the cell. Therefore, there are very few differences in the sequences of coding regions that can help us trace the lineage.
On the other hand, in the non-coding regions, the mutations often accumulate because they have little effect on the cell and the adaptive value of the organism. This enables us to trace up the lineage by comparing the sequences and seeing the differences in the sequences.
The animal cell will swell and then eventually burst when placed in a Hypotonic Solution.
Answer:
An Ecosystem is a community of Living Organisms and Non living components of their Environment
OPTION A IS YOUR ANSWER!!!
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.
