Answer: c. The Earth’s surface is responsible for a small fraction of heat radiation to space.
Explanation:
In later ages the large amount of sun's energy is reflected back by the terrestrial surface back to the space. But now due to the abundance of large concentration of greenhouse gases in the atmosphere is responsible for the absorption of thermal energy from sunlight by these gases causing the atmosphere to be hot. This is the reason of global warming. Now only small fraction of heat is radiated back to the space.
Answer:
Photon radiation
A high-energy photon beam is by far the most common form of radiation used for cancer treatment. It is the same type of radiation that is used in x-ray machines, and comes from a radioactive source such as cobalt, cesium, or a machine called a linear accelerator (linac, for short).
The speed of radioactive particles is also an important factor in medical use. Beta particles travel very fast. This, combined with their small size, gives them significant penetrating power. In cancer treatment, for example, beams of beta particles can be created outside the patient's body and directed at tumors.
Answer:
They are thick, strong and made up of thousands of tubulin which are spiral in shape.
Explanation:
In eukaryotic cells, they have microtubules which are fibres serving as tracks for cell to cell transport and regulate the shape of a cell.
Microtubules are different from other cytoskeletal filaments because they possesses a cylindrical shape with the tube having a larger diameter of 20-25 nm as compared to microfilament that have a diameter of 3-6 nm.
Microtubules are made of subunits of proteins called tubulin named alpha and beta that is not present in other cytoskeletal filaments.