The correct answer is option a. true.
The fossil fuels, including coal and oil are present very deep inside the earth. In the carbon cycle, only fixation of atmospheric carbon dioxide in the organic material takes place. This cycle does not involve the recycling of the fossil fuels.
The burning of the fossil fuels directly release carbon dioxide and other carbon compound in the atmosphere, which was not involved in the cycle when it was present deep beneath the earth and ocean. Hence, the burning of fossil fuels increases the amount of carbon in the carbon cycle.
Answer:
Protein
Explanation:
Protein is made up of amino acids that help to grow, maintain and repair different tissues in the body- including muscle.
Answer: Lack of energy
Explanation:
Oxygen is needed in a process known as Respiration where it is used to produce energy from glucose. This energy is what the cell uses to continue whatever functions that it carries out which are needed for the body to survive. If the cells don't get oxygen, they can't make energy and if they can't make energy, they die.
Some cells are more important than others and so will need a constant supply of oxygen. The brain for instance requires 20% of the oxygen used in the body. If the body suffers from a lack of oxygen for whatever reason, brain cells begin to die within about 4 minutes.
The brain is extremely important as it directs the body. If the cells there begin to die, the body deteriorates and the body stops engaging in certain processes due to a lack of direction from the brain. This coupled with the other cells dying around the body will lead to even more deterioration till the body dies.
Answer:
The correct answer is option c, that is, variation.
Explanation:
In the given case, the gravel mix is to be selected on the basis of the size of pebbles, which is analogous to the organism selected in nature. In the given question, the sorting machine is analogous to the environment, that is, a selective force.
Like a specific environment permits the organisms exhibiting specific traits. For example, in a desert where the environment is hot and dry, only the species exhibiting the tendency to conserve water can thrive, similarly sorting machine will permit to distinguish gravel on the basis of the pebble size. Thus, different size of pebble resembles variation.
