A. is your correct answer
Answer:
A. anaerobic respiration in muscle cells, forming lactic acid
Explanation:
Running marathon is a vigorous exercise, which often leads to excessive use of oxygen in the cells of the athlete. This causes the cells to switch from the aerobic (with oxygen) to the anaerobic (without oxygen) mode of respiration. This anaerobic respiration produces a product called LACTATE OR LACTIC ACID.
The lactic acid becomes excessive and gets stored in the muscle cells of the athlete. This often leads to cramps, muscle pulls etc. during the marathon. Therefore, an individual running a marathon may experience periods of oxygen deprivation that can lead to anaerobic respiration in muscle cells, forming lactic acid.
Carbon dioxide is essential to plant life and is a key part of the global carbon cycle. An important component of this cycle takes place when plants take in CO2 and break it down into carbon and oxygen through the process of photosynthesis. The carbon is stored in the plant and the oxygen is released to the atmosphere.
Chemical (mutagens)
usually either mimic the structure of nucleotides and are inserted in DNA or either cause
chemical changes (such as alkylation) in nucleotides hence causing mismatching during replication.
Radiation, on the other hand, (due to its high energy) causes double-strand breaks in DNA causing an
increased likelihood of mutations during the repair of the DNA by cell
mechanisms.
Answer:
Option (4)
Explanation:
Carbon forms the basin element for the existence of life. It is present in the atmosphere in the form of CO₂, which is one of the major green house gas. It plays an important role in the carbon cycle.
The increase in the concentration of carbon in the atmosphere can lead to the global rise in the temperature. It can lead to global warming. The amount of carbon in the atmosphere has been rising continuously, right after the industrial revolution.
The carbon is mainly emitted from the heavy industries and factories, vehicles, burning up of fossil fuels. It also increased due to the increasing absorption of solar radiation.
This emission of carbon if not controlled by the humans, then the concentration of carbon in the atmosphere will abruptly increase after some decades.
Thus, the correct answer is option (4).
