Answer:
Ionizing radiation comes from these main sources:
Nuclear reactions in the Earth's sun and stars in space.
Radioactive decay in the body's tissues and in the soil.
Radioactive decay of unstable elements in rocks, especially rocks that contain radium and release radon gas.
Other examples of ionizing radiation include alpha, beta, and gamma rays from radioactive decay.
Answer:
Explanation:
The nucleus is surrounded by a membrane called the nuclear envelope, which protects the DNA and separates the nucleus from the rest of the cell.
Pulmonary surfactant is a mixture of lipids and proteins which is secreted into the alveolar space by epithelial type II cells. The main function of the surfactant is to lower the surface tension at the ir/liquid interface within the alveoli of the lung. In babies born prematurely, pulmonary surfactant may not be present in adequate amounts due to insufficient exocytosis in type II alveolar cells.
Answer:
The correct answer is B. The virus can infect the host.
Explanation:
- As the host and the virus both remain in the agar plate, the virus is capable of infecting the host cells.
- The host cell multiplies and grows by utilising the nutrient from the agar medium.
- After the virus particles infect the host, they replicate inside the host and produce new progeny virions which get released out of the host cell by killing it.
- The newly formed virions infect other host cells and the process continues.
- The killing of the host cells by the viruses result in the generation of clear zones on the agar plate which is also known as the zone of exclusion.
- In the zone of exclusion region, the host cells have been killed by the viruses.
