<span>In the past, human populations were controlled by </span>Disease and Famine
A mushroom or a mold commonly reproduces asexually by the formation of spores. Spores are produced in the sporangium through mitosis involving only one parent. They are released from the parent and germinate into new a mushroom or a mold. The offspring are genetically identical to that parent because their formation do not involve meiosis and fertilization. Spores allow fungi to expand their distribution and colonize new environments.
b. 10% of energy is transferred from the first to the second trophic level.
Explanation:
In trophic level flow of energy is one way, only a small amount of energy get transferred with the organism. A large amount of energy gets dissipated in life processes like respiration, reproduction and digestion. The energy is also released as waste product. Thus, only ten per-cent of the total energy is present in the organism.
The energy transfer does not depend on the number of trophic levels.
Each trophic level receives the 10% energy from the previous trophic level as when algae is eaten by flagship.
Answer:
substances can move from areas of low concentration to areas of high concentration
Explanation:
usually substances move across their concentration gradient which is from high concentration to low concentration. Active transport can allow substances to move against their concentration gradient.
Answer:
carbon dioxide- burning of fossil fuels
fluorinated gases- industrial processes
methane- production and transport of oil and natural
gas
nitrous oxide- agricultural and industrial activities
Explanation:
Greenhouse gases are gaseous components that induces greenhouse effect. This means that due to their structural ability to trap heat energy in the atmosphere, they contribute to the global warming effect on the Earth. However, this greenhouse gases are produced in large amounts as a result of the day-to-day anthropogenic activities. The following are the greenhouse gases and how they are produced.
Carbondioxide (CO2)- Carbondioxide is the most common and important greenhouse gas. It is generated via natural processes like respiration but also produced when fossil fuels e.g coal, petroleum etc. are burned.
Fluorinated gases- This is another greenhouse gas caused by activities of man. Fluorinated gases are produced in industries during the production of certain products.
Methane- Methane is a gaseous hydrocarbon and the principal constituent of natural gas. Therefore, the production and transportation of oil and natural gases can lead to the escape of methane into the atmosphere.
Nitrous oxide- Nitrous oxide is an oxide of nitrogen. It is mainly produced via agricultural processes such as nitrification and denitrification or use of fertilizers etc. and also industrial actions.
