Answer:
B) is characterized by four different zones
Explanation:
edge 2020
Organelles exist within cells, which exist within tissues. Communities exist within ecosystems, which exist in the biosphere.
Answer:
B: volcanic activity
D: fossil fuel consumption
Explanation:
Fossil fuel consumption and volcanic activity are the two factors that has a great influenced on the global temperatures. Fossil fuel consumption is a human activity and volcanic activity both releases carbondioxide gas while burning. This carbondioxide gas is a greenhouse gas which block the reflected solar radiation and leads to increase in the surface temperature of the earth.
Answer:
sorry im not in that level
Explanation:
Answer:
The correct answer is b. must be present in a population before natural selection can act upon the population
Explanation:
Genetic variation can be caused by mutation, recombination between chromosomes during meiosis and by fusion of two genetically different gametes during sexual reproduction.
This genetic variation is necessary for the evolution of any population. Natural selection acts on every individual and it decreases the frequency of those alleles that are not suited for the environment and increase the frequency of those alleles which helps the individual to survive in the changing environment.
Therefore genetic variation must be present in the population before natural selection act on the.
