Study GuidePlant Biology–Tissues1. Growth and DevelopmentThe wordsgrowthanddevelopmentare often used as if they mean the same thing. In botany,however, they describedifferent but closely related processesthat help shape a plant as itmatures.1.1What Is Development?Developmentrefers to the overall process by which a plant becomes mature. For example, when afertilized egg slowly turns into a fully grown tree, development is taking place.Development includes three main processes:•Growth–an increase in size•Morphogenesis–the formation of shape and structure•Differentiation–the specialization of cellsPlant development is controlled bygenetic instructionsinherited by the cells and byenvironmentalfactorssuch as light, water, and nutrients. Together, these determine how the plant forms its tissuesand organs.1.2What Is Growth?Growthis anirreversible increase in sizeof cells or plant organs. This happens in two main ways:1.Cell division–new cells are produced2.Cell enlargement–cells become biggerCell enlargement occurs because:•Thecell wall becomes more elastic•Thevacuole increases in size and water contentGrowth can occur in two patterns:•Determinate growth–growth stops after reaching a certain size•Indeterminate growth–growth continues for an unlimited timeMost plants showindeterminate growth, meaning they can keep growing throughout their lives.Preview Mode
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