Question

Analyze the data about nitrogenous base content of DNA from various species. Percentages of Bases in Five Organisms Source of DNA A T G C Streptococcus 29.8 31.6 20.5 18.0 Yeast 31.3 32.9 18.7 17.1 Herring 27.8 27.5 22.2 22.6 Human 30.9 29.4 19.9 19.8 E. Coli 24.7 23.6 26.0 25.7 Which of these statements are supported by the data? Select all that apply. A. In any one species, the amount of adenine closely approximates that of thymine. B. In any one species, the amount of guanine closely approximates that of cytosine. C. The amounts of A, T, G, and C in DNA is constant across species. D. The amounts of A, T, G, and C in DNA varies from species to species.

Answer 1

Answer:

When analyzing data on the nitrogenous base content of the DNA of various species, the claims are supported by the data:

• In any one species, the amount of adenine closely approximates that of thymine.  
• In any one species, the amount of guanine closely approximates that of cytosine.  
• The amounts of A, T, G, and C in DNA varies from species to species.

(options A, B and D)

Explanation:

Organizing the data has to:

Source of DNA      A            T            G            C

Streptococcus    29.8       31.6        20.5       18.0

Yeast                   31.3        32.9       18.7         17.1

Herring                27.8       27.5       22.2       22.6

Human                30.9       29.4       19.9        19.8

E. Coli                  24.7       23.6        26.0      25.7

DNA is the molecule that contains the genetic information of each species, formed by sequences of nitrogenous bases Adenine, Thymine, Cytosine and Guanine.

Since Adenine and Thymine -as well as Cytosine and Guanina- are complementary, the percentage of them will be very similar in each DNA molecule.

The genetic information -which determines the physical and functional characteristics of each organism- is encoded in the DNA and is different for each species, so the percentages of nitrogenous bases vary from species to species.