Answer to Question 1
Ans:
A, B, C, D
Feedback:
Virtually all of the components of the immune system have the potential for eradicating cancer cells, including T lymphocytes, B lymphocytes, antibodies, macrophages, and natural killer (NK) cells. Although best known for their role in allergy and anaphylaxis, mast cells play an important protective role as well, being intimately involved in wound healing and defense against pathogens.
Answer to Question 2
Ans:
B, D
Feedback:
Sonic hedgehog signaling is involved in many key developmental events at multiple times during embryogenesis. It participates in such diverse developmental steps as establishment of the left-to-right axis responsible for the rostral-caudal orientation of the nervous system, the separation of the brain into two cerebral hemispheres, right and left eye orientation, and the separation and development of the correct number of fingers and toes. The PAX family of transcription factors is responsible for the development of the eye. Transfer RNA acts as a carrier system for delivering the appropriate amino acids to the ribosomes. Bone formation leading to macrocephaly is caused by fibroblast growth factors.