Asked by kelvin calin

Compare all the organisms. What trend do you see?

The proportions of DNA bases vary greatly among organisms.

The proportions of DNA bases are similar in closely related organisms, but different in organisms that are not closely related.

The proportions of DNA bases are similar among all organisms.
A 5-column table labeled Relative Proportions of Bases in D N A has 7 rows. The first column is labeled Organism with entries human, chicken, grasshopper, sea urchin, wheat, yeast, and E. coli. The second column is labeled A with entries 30.9, 28.8, 29.3, 32.8, 27.3, 31.1, 24.7. The third column is labeled T with entries 29.4, 29.2, 29.3, 32.1, 27.1, 32.9, 23.6. The fourth column is labeled G with entries 19.9, 20.5, 20.5, 17.7, 22.7, 18.7, 26. The fifth column is labeled C with entries 19.8, 21.5, 20.7, 17.3, 22.8, 17.1, 25.7.

All Answers 1

Answered by GPT-5 mini AI
The second statement is correct: the proportions of DNA bases are similar in closely related organisms but different in organisms that are not closely related.

Evidence from the table:
- Animals (human, chicken, grasshopper, sea urchin) have very similar A and T (~28–33%) and G and C (~17–21%).
- Wheat (a plant) and yeast (a fungus) show different patterns (wheat has higher G+C ~22–23%; yeast has relatively high A/T and low G/C).
- E. coli (a bacterium) differs most, being relatively G+C rich (G ≈ 26%, C ≈ 25.7%).

Note also that in every organism A ≈ T and G ≈ C, reflecting base pairing (Chargaff’s rule).