Biologists use ball-and-stick models to study complex molecules by representing atoms with balls and bonds with sticks. DNA is a biological molecule that contains millions of atoms. What is a limitation of using a ball-and-stick model for DNA?
Some kinds of atoms that are found in DNA must be left out of the models.
DNA has so many atoms that the size and cost of a model could be too great.
It is impossible to distinguish different kinds of atoms with models.
The chemical bonds between the atoms in DNA must be part of the models.

Question

Biologists use ball-and-stick models to study complex molecules by representing atoms with balls and bonds with sticks. DNA is a biological molecule that contains millions of atoms. What is a limitation of using a ball-and-stick model for DNA?
Some kinds of atoms that are found in DNA must be left out of the models.
DNA has so many atoms that the size and cost of a model could be too great.
It is impossible to distinguish different kinds of atoms with models.
The chemical bonds between the atoms in DNA must be part of the models.

anonymous · Answer

Some kinds of atoms that are found in DNA must be left out of the models

anonymous · Answer

In an experiment, the weight that mice gain is the dependent variable and the temperature of the environment is the independent variable. What must be held constant to obtain valid experimental results?
the weight of the mice
the color of the mouse cages
the type of food given to the mice
the temperature of the laboratory rooms

anonymous · Answer

Which scientific design has the fewest limitations?
modeling an ocean ecosystem with a saltwater aquarium
observing the behavior of male caribou on the arctic tundra
using dissection to study the general structure of lily flowers
growing algae in different environments found on a spacecraft