Answer:
Feudalism
Explanation:
Feudalism was the leading way of political and economic life in the Medieval era. Monarchs, like kings and queens, maintained control and power by the support of other powerful people called lords. Lords were always men who owned extravagant homes, called manors, and estates in the country
Answer:
The correct answer is b. Immunogens
Explanation:
Immunogens are the antigens that can trigger the immune response in the body once gets inside the body. Any antigen having capacity to excite a immune response against them is called immunogens but not every antigen is immunogen.
An antigen is called immunogen when it has some characteristic features like foreignness, high molecular weight and chemical complexity. An immunogen can initiate both innate and adaptive immune response. Adaptive immune response is memory based and very specific for any particular immunogen.
Some common immunogens are: bacteria, virus, drugs, chemicals, dust, toxins.
Answer:
Option A, Release of chemical signals by keratinocytes that have been damaged by UV light will increase the production of melanin.
Explanation:
Negtaive feedback mechanism of homeostasis maintains the stability of any internal condition or function through lessening of output of a system or through slow down of a functional system.
Here in this case the keratinocytes function is reduced by damaging them on exposure to UV light which further triggers the release of chemicals that enhance the production of melanin.
Hence, option A is correct
