Fish and amphibians commonly conduct fertilization externally. External fertilization occurs when the female releases the eggs into the environment and then the male releases sperm on top of the eggs.The eggs are then fertilized. Internal fertilization occurs when fertilization happens inside the female's body. After fertilization, the female either bears live young or lays eggs which hatch. Both of these processes take place after a period of incubation either internally or externally. Eggs which are externally fertilized do not have a hard external protective covering or shell.
Anaerobic respiration (without oxygen) would caused muscle cells to produce lactic acid. This causes the muscles to ache and in the long term, damages them. Also anaerobic respiration releases far less energy (ATP) than aerobic respiration. So it is best for muscle cells to respire aerobically as they need more energy.
Its a large nuclear pore
so pores :)
The answer is; To enhance desirable traits in an organism or switch off undesirable traits.
The transgenic organism has modified genome that alters its behavior. These organisms can be used in medical research in the laboratory or can be used for commercial purposes. An example of a transgenic organism is a GMO plant or bacteria that produce insulin.