Answer:
<em>The correct option is cell surface markers.</em>
Explanation:
The immune cells of our body detect foreign particles and generate responses so that our body can get rid of them. The foreign particles are often termed as antigens.
The immune cells such as antibodies possess cell surface receptors which detect the foreign objects or antigens. When the cell surface receptors detect any antigen they immediately recognize that a foreign particle has invaded the body and they then identify it and start to generate response.
The designation Rr for a pea-plant's peas shows that the plant is a <u>true-breeding plant</u>.
D= m/v
solve this formula to find v
by solving we get,
v = m/D
v = 13/19.3
v = 0.67 cm^3
Viruses are not made out of cells, they can't keep themselves in a stable state, they don't grow, and they can't make their own energy. Even though they definitely replicate and adapt to their environment, viruses are more like androids than real living organisms.
