How do genes control the traits of an organism? Explain with the example of height in pea plants.

How to lay out the answer. Follow the frame, then write it in your own words.

1 · Define in one line. A gene is a section of DNA that gives the information for one protein.
2 · Gene to protein. The gene directs the making of an enzyme, and the enzyme controls a chemical process in the cell.
3 · Example: height in peas. Efficient enzyme → more plant hormone → tall plant; less efficient enzyme → less hormone → short plant.
4 · Chromosomes. Genes are carried on chromosomes: two copies of each in body cells, one copy in germ cells.
5 · Link to daily life. Like a recipe in a cookbook, a gene tells the cell what to make.
6 · Close in one line. Thus genes control traits through the proteins they code for.

Scoring tip: Write the chain gene → enzyme → hormone → height; it covers all three marks.