Although DNA is present in all organisms, the genetic code contained in the DNA creates differences between all species. The DNA of an amphibian, such as a frog, is different from
the DNA in a human because a frog's DNA
A. contains a different number and sequence of nitrogenous bases
B. contains larger, more inclusive phosphate groups
C. lacks guanine and adenosine
D. does not contain as many hydrogen bonds between base pairs.

The DNA of an amphibian, such as a frog, is different from the DNA in a human because a frog's DNA contains a different number and sequence of nitrogenous bases (option A).

Explanation:

DNA is the molecule that contains all the genetic information of the different species of living beings, being a molecule that is present in all of them.

Although the DNA of all living beings has the same basic structure —four nitrogenous bases, a deoxyribose and a phosphate group— what makes the differences between species is the length of the DNA molecule and the different sequences of nitrogenous bases present in the molecule. It is for this reason that frog DNA is different from human DNA.

The other options are not correct because:

    B. There are no differences in the phosphate groups from one species to another.

    C. All DNA molecules contain guanine and adenine.

    D. Hydrogen bonds between nitrogenous bases depend on the amount of paired bases, but are not related to differences in DNA between species.

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.