The answer is natural killer cells.
Natural killer cells are a type of lymphocytes and they are important for the innate immune system. They recognise stressed cells much faster than other immune cells. Their response is rapid and usually only a few days after a viral infection. They also respond to <span>cancer cell </span>formation. While other immune cells can detect only those harmful cells that have specific markers on the surface of the cell membrane, natural killer cells can even detect those cells that miss markers for apoptosis.
The answer would be D. The definition of a homologous structure is an organ or body part that appears in different animals and is similar in structure and location, but doesn't necessarily share the same purpose. The birds and rabbits have similar bones in their forelimbs, but one uses them to run and other uses them to fly.
Answer:
A crayfish
Explanation:
everything else is an insect
