Final answer:
Analogies that represent the antiparallel strands of DNA are a two-lane highway with traffic moving in opposite directions and two pencils laid next to each other pointing in opposite directions.
Step-by-step explanation:
The antiparallel arrangement of strands in a double helix structure of deoxyribonucleic acid (DNA) can be analogized to certain objects based on how they are aligned relative to each other. Specifically, the aspects of DNA we are considering are that one strand runs from a 5' to 3' direction and the other from a 3' to 5', similar to a ladder with two sides facing opposite directions. In this model, the nitrogenous bases adenine pairs with thymine, and cytosine pairs with guanine, serving as the rungs connecting the two strands.
Given the choices provided, the analogies that apply would be:
- a. A two-lane, two-way highway with a divider/median: Each lane represents a strand and cars would travel in opposite directions, much like the antiparallel strands.
- d. Two pencils laid next to one another pointing in opposite directions: This directly represents the antiparallel nature of the DNA strands.
Option b, with pencils laid end-to-end, does not capture the antiparallel nature as they don't run in opposite directions. Option c, a single set of train tracks, implies parallel movement, not antiparallel.