Plants Exam 2 Review

Tissues and their function

  1. Major tissues in plants- vascular (xylem, phloem, pith, pericycle), ground, meristematic (node, apical meristem, procmbium, protoderm, pericycle, cork cambium, vascular cambium, ground meristem), epidermal

  2. function of pericycle is to protect the plant from pathogens. it can become meristematic tissue and form lateral roots if the root cap gets damaged. only one cell layer thick.

  3. the meristematic regions are the apical meristem, the pericycle, the procambium, ground meristem, and protoderm. the apical meristem is responsible for growing cells. the pericycle can grow lateral roots. the procambium produces primary xylem and phloem. protoderm gives rise to the epidermis (outer stem layer). the ground meristem produces the pith and cortex, which are both composed of parenchyma cells

Stems

  1. You can tell the age of a branch by the number of groups of bud scale scars on the base of the branch.

  2. The internodes are the stem region between notes on the outside of a woody stem. The length of the internode tells you the conditions it is growing in. In longer internodes, conditions were less favorable but more favorable with short ones. It tells you how stressed the plant is.

  3. Terminal/apical bud is the bud at the top part of the branch. Terminal bud is larger because it has to keep producing length towards where it is going (plan a). Axillary bud are located on the axil. they become branches or flowers in flowering plants. they grow branches to the side (plan b). if terminal bud is damaged or removed, the axillary buds take over.

  4. Leaf scars are formed when the plant builds callus tissues when it drops the leaf. Without it, the plant could get infected. It starts before they fall. It leaves behind the vascular bundle scars where the xylem and phloem used to be.

  5. The leaf primordium protects the apical meristem in the shoots so it doesnt get damaged.

  6. Vascular tissue is formed in embryonic tissue so that it is already filled with water from the start so when the cells die there is water potential.

  7. protoderm to epidermis; procambium to primary xylem and phloem; ground meristem to ground tissue; pericycle to lateral roots

  8. xylem and phloem connect from the apical meristem of root to apical meristem of shoot/ stomata of leaf where they are being made to the top of the tree; it is continuous and always connected.

  9. vascular cambium has

  10. cork cambium builds tree bark, it protects the cork cambium and vascular cambium. it builds sclerenchyma cells (reinforces plant).

  11. Herbaceous are leafy green plants that are more flexible. They lack bark and they have only primary xylem and phloem. woody plants have bark. lots of dead tissues inside (heartwood, sapwood). it can live without the intermost contents because they are dead and the only living parts are the outside.

  12. tree stumps can produce branches from the vascular cambium (true shoots). adventitious shoots can form from the roots if stil living. advantageous shoots come from the ground tissue that get reprogramed to become shoots.

  13. Learn vascular arrangements

  14. hollow out tree live because only outermost tissue living

  15. softwood grow fast hardwoods grow slow and steady

  16. corms are modified stems with papery leaves, bulbs are modified leaves that create bulb structure, tubers are modified stems (potatoes)

Roots and Soil

  1. root responsible for absorption of water and nutrients from root hairs, transports water and nutrients, storage of nutrients and water, comminucation between microbes and plant, anchorage of plant, retaining soil around the plant, can build adventageous shoots

  2. LEARN MONOCOT AND DICOT

  3. prop roots, aerial roots that are photosynthetic, buttress roots

  4. root cap

  5. df

  6. radicle to root, phleum to shoot, buds to leaves, pericycle to lateral roots

  7. epidermis is only part that can grow root hairs in mature cells (also lateral roots). they are efficient because it is one cell thick that is very stretched that increase surface area a lot which increases absorption by diffusion. the plant needs to constantly produce them because it is always growing and they get damaged easily so they don’t live long.

  8. cortex stores water and utrients, it is made of parenchyma cells, its role in winter is to do chemical breakdown of nutrients to produce energy which releases heat (constantly doing respiration) this keeps the root from freezing

  9. stele

  10. endodermis has casparian strip which protects spores and viruses and sends it into the cell which will destroy the pathogen

  11. path of water from soil to xylem and phloem

  12. formation of lateral root from pericycle

  13. determinate growth has a set stopping point and. indeterminate growth is the plant continues to grow

  14. root modification examples and structures

  15. fungus, symbiosis. constant communication. plant provide organic carbon and sugars, fungus provide N, K, P.

  16. the rhizobium is a type of soil bacteria that forms a symbiosis with legume plants to fix nitrogen. bacteria is just a small single celled organism; bacteroid is a modified bacteria that lives inside the host organism to fix nitrogen.

Soils

  1. bedrock gets broken up over long periods of time. lichen usually first thing to colonize new soils and produces acidic exoenzymes that help breakdown the stone quicker. rock erosion allows other plants to come in.

  2. erosion factors are wind and water

  3. humus is the top most layer of soil and composed of dead decaying organic material. topsoil is the dark top layer that is 10-20 cm deep that is darkened with organic material. the topsoil is part of the A horizon. the B horizon is 30-90 cm deep and is the subsoil layer, it typically has more clay and is lighter in color than the A horizon. the C horizon layer varies in depth. it is the parent material that extends to bedrock.