Final answer:
When preparing a slide with representatives of a unicellular organism, you do not need to draw all the organisms. A sample of 2 to 3 organisms is sufficient to record the variation seen among individuals.
Step-by-step explanation:
When preparing a slide containing representatives of a unicellular organism, it is not necessary to draw all the organisms present on the slide. Instead, a sample of 2 to 3 organisms will suffice to record the variation seen among individuals. This is because a larger sample size is not needed to accurately represent the variation within the population.