Chapter 35 Plant Growth AP Biology Indeterminate growth
Chapter 35. Plant Growth AP Biology
Indeterminate growth § Unlike animals most plants grow throughout their life u annuals § life cycle within 1 year § germination flowering seed production u perennials § live many years § does not die of old age, only disease or trauma AP Biology
Meristem § Regions of growth perpetually embryonic tissue u regenerate new cells u § apical shoot meristem w growth in length w primary growth § apical root meristem w growth in length w primary growth § lateral meristem w growth in girth w secondary growth AP Biology
Apical meristems AP Biology shoot root
Root structure & growth AP Biology
Shoot growth § Apical bud & primary growth of shoot region of stem growth u axillary buds “waiting in the wings” u AP Biology
Shoot growth § Since woody plants grow from year to year, they evolved a different growth system than herbaceous plants which die back each year AP Biology woody herbaceous
Growth in woody plants § Woody plants grow in height from tip u u primary growth apical meristem § Woody plants grow in diameter from sides u u secondary growth vascular cambium § vascular meristem layer AP Biology
Growth in woody plants § Primary growth tips of roots & shoots (apical meristem) u restricted to youngest parts of plant u shoot AP Biology root
Growth in woody plants § Secondary growth u thickens & strengthens older part of tree u cork cambium makes bark § growing ring around tree u vascular cambium makes xylem & phloem § growing ring around tree AP Biology
Woody stem § Phloem produced to the outside § Xylem produced to the inside cork cambium bark phloem late vascular cambium AP Biology xylem early
cork cambium Woody stem How old is this tree? vascular cambium late early xylem AP Biology phloem bark
Tree trunk anatomy tree girdling What does girdling do to a tree? AP Biology
Where will the carving be in 50 years? AP Biology
Global effects of plant growth What trends do you observe in global CO 2? AP Biology
Any Questions? ? Any Questions? AP Biology
- Slides: 16