Plants suitable for experiments in genetics must not

Analyze the question: We are asked which characteristic a plant suitable for genetic experiments must not have. So we look for the undesirable trait.

Concept: Good organisms for genetics experiments (like Mendel's garden pea, or Arabidopsis) share these features:

• They produce many offspring (numerous seeds), so results can be analyzed statistically.
• They have a short life cycle, so many generations can be studied quickly.
• They have a small number of chromosomes, which makes it easier to track and study inheritance.
• They are easy to grow and cross-pollinate, and they show clear contrasting traits.

Checking each option:

• A. Producing numerous seeds in a short time is desirable, so it is not the answer.
• B. A small chromosome number is desirable because it makes studies simpler, so it is not the answer.
• C. A relatively short life cycle is desirable, so it is not the answer.
• D. Producing one generation over a large period of time is undesirable. It would take too long to observe several generations, so this is what a suitable plant must not do.

Answer: The correct option is D.

Exam tip: When a question says "must not" or "except," flip your thinking. Find the disadvantage and eliminate the good qualities. For genetics organisms, remember "fast, many, simple": a fast life cycle, many offspring, and simple chromosomes.