Antigens are proteins that are found on the surface of the pathogen and are viruses, fungi, or bacteria. Nonliving substances such as toxins, chemicals, drugs, and foreign particles. Antigens are usually carried by proteins and polysaccharides, and less frequently, lipids but it also needs to be attached to a large carrier molecule which is usually a protein. When an antigen enters the body, the immune system produces antibodies against it. The Antigen stimulates the immune system to produce antibodies. YOUR WELCOME ;)
Eukaryotic cells contain several organelles it has: Mitochondria, chloroplasts, the endoplasmic reticulum, the golgi apparatus, and lysosomes. These organelles performs specific function critical to the cell's survival. <span />
Natrual variations i think
Answer:
circulatory and respiratory
Explanation:
The body system of Birds possesses a higher arrangement of organs to perform a particular function. The organs form a system which includes the organs and associated structures.
When the biologist observed the shortage of the dissolved oxygen and increase in the level of dissolved carbon dioxide, this could be the result of the failure of the circulatory system which supplies these gases on the body and the associated respiratory system which helps in the exchange of these gases with the atmosphere.
Thus, circulatory and respiratory is the correct answer.
