A) A mixture because they can be taken apart without changing the physical form
The mass of a tree is primarily carbon. The carbon comes from carbon dioxide used during photosynthesis. During photosynthesis, plants convert the sun's energy into chemical energy which is captured within the bonds of carbon molecules built from atmospheric carbon dioxide and water.
Frogs exchange gases through their skin and the lining of their mouths. This exchange of gases is referred to as respiration. During the larval stage in frogs development, it lacks functional lungs but they can take in oxygen through gills which are in process of metamorphosis.
The gills take in oxygen when water is being passed over them. Once lungs are mature, they lose their gills and are able to bring in oxygen through lungs.
They rely on lungs to breath when they are active and they need more oxygen than what skin respiration alone can provide.
Although they have oxygen, most of their respiration occurs through the skin.
Answer:
Frequency of heterozygous animals with agouti fur is 
%
Explanation:
As per the Hardy Weinberg's equation -
represents the frequency of population with phenotype expressed by homozygous recessive genotype
represents the frequency of population with phenotype expressed by homozygous dominant genotype
and 
represents the frequency of population with phenotype expressed by homozygous recessive genotype
Given -
As per first principle of Hardy Weinberg's equilibrium
Substituting the value of q in above equation, we get -
As per second principle of Hardy Weinberg's equilibrium
Substituting the given values in above equation, we get -
Frequency of heterozygous animals with agouti fur is %
