<span>The smell of Danger.
Researchers have discovered a single compound found in high concentrations in the urine of carnivores that triggers an instinctual avoidance response in mice and rats. This is the first time that scientists have identified a chemical tag that would let rodents sense carnivores in general from a safe distance.</span>
Answer:
A virus attaches to a specific receptor site on the host cell membrane through attachment proteins in the capsid or via glycoproteins embedded in the viral envelope. The specificity of this interaction determines the host (and the cells within the host) that can be infected by a particular virus.
Explanation:
Answer:
The neutrophil forms multiple lamellipodia extensions
Explanation:
Neutrophils are white blood cells (granulocytes) which comprise the first line of defense in the innate immune system. The lamellipodium (in plural, lamellipodia) is a cytoskeletal actin extension found in mobile cells, whose main functions are cell motility and migration. Rac1 is a member of the Rho GTPase protein family which is involved in actin-myosin cytoskeletal reorganization of neutrophil cells in response to microorganism infections. In this regard, it has been shown that Rac1 controls the initial uncapping of actin ends in order to regulate cytoskeleton dynamics, thus regulating lamellipodia formation. By using mice as models, researchers observed that Rac1 constitutive activation may lead to the formation of multiple lamellipodia in neutrophils.
I believe the answer is B.2
