<u>Answer</u>: Cystic fibrosis is a genetic disorder that causes thick mucus secretions.
<u>Explanation</u>:
- <em>Cystic fibrosis</em> is a genetic disorder caused by mutations in a gene that makes a protein called CFTR (cystic fibrosis transmembrane regulator).
- The CFTR protein normally functions as a channel for transport of chloride ions in cells responsible for mucus production.
- A person suffering from cystic fibrosis produces abnormal CFTR protein or no CFTR protein at all.
- This is the reason that thick, sticky mucus is produced instead of the thin, watery kind.
Answer:
Most food webs have between 4 and 5 trophic levels
Explanation:
Energy flow: From the whole quantity of energy that reaches the earth's surface, autotroph organisms or producers only absorb 0.1 or 1%.
From the input of solar energy begins a unidirectional energy flow. It passes through all the organisms in the ecosystem, from autotrophs to heterotrophs, until it is eventually dissipated in the environment.
There is an energy transfer from each trophic level to the next, and each level only uses 10% of this energy. This assessment is called "The 10% rule". As a general rule, only about 10% of the energy stored as biomass at one trophic level, per unit time, ends up as biomass at the next trophic level, in the same unit of time. The rest of the energy is used by the organisms in their own metabolism or dissipated as heat to the environment.
The progressive reduction of energy determines the number of trophic levels, which, in general, turns to be between 4 and 5.
The correct answer is D. None of the above
Explanation:
Urban sprawl or the expansion of human settlements such as cities has multiple negative consequences on the ecosystems. This includes deforestation because trees are usually cut to build houses and other human structures. Indeed, most threes and plants are removed for human construction. This also implies a loss of natural resources that include a wide variety of plants, animals, and even water as nearby bodies of water might be polluted. Besides, this general pollution increases in the area this includes noise pollution, water pollution and air pollution that result from human activities. Thus, all are possible consequences of urban sprawl; therefore, the correct answer is none of the above.
