Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines to assist the immune response.
B. Scarcity of drinking water
Answer:
Option A
Option D
Option F
Explanation:
During the process of continuous starvation for a long period of time, the primary source of energy in body is hepatic gluconeogenesis which is responsible for producing endogenous glucose. Also lipolysis takes place in the adipose tissue to release fatty acid which is then converted into ketone bodies through though mitochondrial β oxidation and ketogenesis. The liver communicates with extrahepatic tissues, including adipose tissue and skeletal muscle and deliver glucose and ketone bodies to muscle and other extrahepatic tissues as fuels.
Hence, option A, D and F are true.
Answer:D. Water has a neutral pH.
Explanation: