<span>Desertification is the cancer of the earth,” Argentine geographer Elena Abraham told IPS. “It is a process of degradation that does not manifest itself in spectacular ways but furtively advances, and by the time it is visible there is nothing to be done, and people have to move away, in search of an alternative.”</span>
Answer:
Abierto es sin vasos y cerrado es con vasos.
Explicación:
El sistema circulatorio abierto es un tipo de sistema que se encuentra en los invertebrados. en el que la sangre fluye libremente a través de las cavidades en lugar de los vasos sanguíneos mientras que, por otro lado, el sistema circulatorio cerrado es un tipo de sistema en el que el corazón bombea sangre y la sangre fluye a través de los vasos y capilares. Este tipo de sistema circulatorio está presente en humanos y vertebrados.
one species using another as a food source, typically killing it
1. The energy left in the Quaternary consumer level is 0.06283 kcal.
2. 0.65 units of energy is still available at the tertiary consumer level.
<u>Explanation:</u>
Energy flow in an ecosystem obeys the ten percentage law According to which ten percentage of energy from a trophic level gets transferred to the next trophic level. In the given question plants belong to the trophic level , producers and it transfers 10 percentage of its energy to the primary consumer level.
In the question 1 the energy that the producers have is 628.3 kcal. Ten percentage of this i.e 62.83 kcal gets transferred to the primary consumer level. Ten percent of that which is 6.283 kcal gets transferred to the secondary consumer level. Ten percent of 6.283 kcal i.e 0.6283 kcal energy is transferred to the tertiary consumer level.
Thus the Quaternary consumer level gets ten percentage of 0.6283 kcal i.e 0.06283 kcal. In question B the initial energy at the primary level is 650 units. Ten percentage of 650 i.e 65 units reach the primary consumer level. Ten percentage of this 65 units then reaches the secondary consumer level. Thus the secondary consumer level has ten percent of 65 i.e 6.5 units of energy.
So the energy that reaches the tertiary consumer level is ten percentage of 6.5 i.e 0.65 units.
