The cramps can be caused due to anaerobic respiration in the muscles and lactic acid formation.
During intense physical activity the muscles become deprived of oxygen, in this condition, anaerobic respiration takes place in the muscle cells causes the formation of the lactic acid.
The physical training increases the strength of the muscles, which can help the muscles not to get tired easily. that is why, physical training is required before any marathon.
the picture print is not good enough to be readable please delete the question and post a new question wth a good print
Because the dark box is blending in with the shadows, however the white box is bright and easier to see
Answer:
Explanation:
A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host’s genome by an integrase enzyme. The virus thereafter replicates as part of the host cell’s DNA. Retroviruses are enveloped viruses that belong to the viral family Retroviridae. A special variant of retroviruses are endogenous retroviruses, which are integrated into the genome of the host and inherited across generations. Endogenous retroviruses are a type of transposon.
