1. PLANTS: form and function Chapters 18 & 19

2. What is a Plant? Multi-celled Autotrophic Eukaryotic cells

3. Review of the typical Plant Cell

4. Plants: Grouped by characteristics Vascular Three main parts: PICTURE roots, stems and leaves Roots can be different sizes: Fibrous and tap roots Storage roots; beets, carrots, sweet potatoes and turnips Roots have different functions: anchoring the plant, taking in water and minerals, and store food. Nonvascular Simple; most grow in moist places No vascular tissues.

5. What do plants do? All plants are alike in one way. They need three things in order to survive Water carbon dioxide energy from sunlight What do you suppose the plants use these things for? Classify – to sort into groups based on similarities and differences

6.  They turn it into sugar! photosynthesis – a process by which plants change light energy from the sun and use it to make sugar  Plants and some protists conduct photosynthesis.

7. a protective covering that surrounds the seed anchor the plant in place and absorb water and other minerals from the soil. carries water and food to the rest of the plant. makes the plant's food. makes seeds.

8. Three Tissue System The cells of multi-celled organisms work together in groups called tissues. For plants, cells can be placed into 3 main tissue categories: Dermal tissue Vascular tissue Ground tissue

9. Three Tissue System, cont’d. Tissue System and Its Functions Component Tissues Location of Tissue Systems Dermal Tissue System protection prevention of water loss Epidermis Periderm (in older stems and roots) Ground Tissue System photosynthesis food storage regeneration support protection Parenchyma tissue Collenchyma tissue Sclerenchyma tissue Vascular Tissue System transport of water and minerals transport of food Xylem tissue (Tracheids and vessel elements) Phloem tissue (Sieve- tube members and companion cells)

10. Parenchyma cells Typical plant cell – most abundant in plants Thin walled (Walls contain cellulose, not lignin) Unspecialized – can either photosynthesize, or store starch Can be found in leaves – contain chloroplasts and carry out photosynthesis (mesophyll cells are an example) Can also be found in roots and other non-photosynthesizing parts and store starch in amyloplasts (related to chloroplasts) – in stems they are called the pith amyloplastschloroplasts

11. Collenchyma cells These cells are usually just under the epidermis of leaves, stems and roots Collenchyma cells are collectively also called the cortex Cells are columnar in shape Also lack lignin in their cell walls, but have thicker walls than parenchyma cells Give younger plants or plant parts support Because they have thick walls but lack lignin, they are able to provide support without restricting growth – hence found in young, growing parts Epidermis  Collenchyma  Parenchyma  Columnar Collenchyma

12. Parenchyma vs. Collenchyma cells

13. Sclerenchyma cells Thick walls that are fortified with lignin (secondary wall) making them much more rigid than collenchyma walls Mature sclerenchyma cells usually do not contain protoplasts and cannot grow/elongate, so these cells are located in regions of the plant that have stopped growing

14. Sclerenchyma cont’d. Two types of sclerenchyma cells: Fibers - long and thin, exist in bundles in stems, right above above vascular tissue Sclereids – shorter than fibers and give nutshells and seed coats their hardness. The gritty texture of certain fruit like pears is basically due to sclereids scattered among the parenchyma tissue

15. Major Plant Cells Parenchyma cells Parenchyma cells Collenchyma cells Collenchyma cells Sclerenchyma cells Sclerenchyma cells Fibers Fibers Schlereids Schlereids Water-conducting cells of the Xylem Water-conducting cells of the Xylem Tracheids Tracheids Vessel elements Vessel elements Food-conducting cells of the Phloem Food-conducting cells of the Phloem Sieve-tube members Sieve-tube members Companion cells Companion cells

16. Vascular Plants: Leaves Leaves come in variety of shapes and sizes Leaves are arranged in different ways

17. Types of leaves Compound Leaves Simple Leaves Single and double compound leaves

18. LEAF STRUCTURE When guard cells take up water, they become turgid and this opens the stomata. Loss of water from the cells makes them flaccid and this closes the stomata.

19. In a C3 leaf the palisade mesophyll cells typically form a layer in the upper part of the leaf; the corresponding mesophyll cells in a C4 leaf are usually arranged in a ring around the bundle sheath cells. The bundle-sheath cells of C4 plants have chloroplasts (dark green), those of C3 leaves usually lack them. C3 Leaf C4 Leaf Bundle sheath cells surround vascular bundles – thus the name.

20. Modified leaves Spines on cacti are actually leaves. The photosynthesis is carried out by the green stems Bracts on poinsettias are actually not petals, but leaves around the tiny yellow flowers Tendrils for grasping

21. Vascular Plants: Stems Function of stems Support, transport of water & food Most stems grow upward Some stems grow sideward Types of stems Green Woody Transport of materials Xylem & phloem

22. Plant Morphology Stems consist of alternating “nodes”, the site of leaf attachment The angle created where the leaf attaches to the stem is called the axil The axil contains an axillary bud, which can give rise to a lateral shoot or a branch The tip of the shoot is called the apex and holds the terminal bud The terminal bud and the apex is where the elongation of the shoot occurs The apical bud inhibits the growth of the axillary buds - therefore the advent of the practice of pruning

24. Vascular bundles in celery

25. Xylem Cells Water conducting Elongated Produce lignin-containing secondary walls Lack protoplasts after maturity Two types: Tracheids – spindle-shape, with hole (pits) in them through which water passes Vessel element cells are broader and lie end to end and form continuous hollow tubes for water to flow through

26. Phloem Cells Food conducting – sugar, minerals and other organic compounds Unlike xylem cells, phloem cells can contain protoplasts* (either complete or incomplete) Two types: Sieve-tube members – chains of cells that conduct food (partial protoplasts -lack nuclei and ribosomes) Companion cells – connected to sieve-tube cells, contain nuclei and ribosomes, so help maintain sieve-tube cells *see slide #31 for non-protoplast-containing phloem

27. Sieve-tube elements and companion cells of the Phloem

28. Modified Stems 1. Bulb (e.g. onions)when sliced in half, will show concentric rings. 2. Clove bulblike structures (e.g. garlic) will separate into small pieces when broken apart. 3. Tuber (e.g. potatoes and daylilies) these structures are either on strings or in clusters underneath the parent plants. 4. Rhizome are large creeping rootstock or underground stems and many plants arise from the "eyes" of these roots (e.g. ginger) 5. Stolons – Horizontal, aboveground stems (e.g. Strawberries) 6. Corm are similar to bulbs but are solid when cut rather than possessing rings. 7. Crown (e.g. the type of root structure found on plants such as asparagus) looks much like a mop head under the soil's surface.

29. Bulb

30. TUBERS A tuber is a solid, enlarged, horizontal, shortened stem; it's a storage area for reserve food. Note in the center of the picture the production of young tubers arising from the rhizome. On the tubers, the so-called "eyes" are the nodes, where new shoots arise at the axil of a scale (modified leaf); these new shoots can give rise to new plants.

31. Purpose of roots The entire root structure serves to anchor the plant/tree in the soil Absorption of water and nutrients from the soil actually occurs only at the tips of each root fiber Millions of tiny roots hairs in these tip areas help absorption by increasing surface area

32. Fibrous vs. Tap Roots Seedless vascular plants (ferns) and Moncot angiosperms such as grasses have fibrous roots Dicot angiosperm have tap roots

33. More modified roots Storage Roots: Beets, radish, turnip, horseradish, sweet potato, and cassava (tapioca).

34. Photosynthesis A movie of photosynthesis A movie of photosynthesis chlorophyll – the green substance found in plants that traps energy from the sun and gives plants their green color carbon dioxide – a gas found in air  As a plant makes sugar, oxygen is released  When the plant uses the sugar, water and carbon dioxide are released.

35. How Do Plants Get Energy Plant leaves change light energy into energy the plant can use. Stomata are tiny holes on the bottom of the leaf that let air (CO 2. ) in and (O 2 )out. They get sunlight, water, and air (CO 2. ) The veins of a leaf bring water and minerals to the leaf from the stems and roots. Roots get water and minerals directly from the soil.

36. Because of this process Scientists are able to classify living things by the way they get their food. Plants are producers (autotrophs) producer – it is a living thing that uses sunlight to make sugar. This sugar feeds others.

37. How Do Other Living Things Get Energy? All living things need energy to survive Consumer – a living thing that gets energy by eating plants and other animals

38. Animals cannot use light energy to make sugar. Animals depend on plants for food. Decomposer – a consumer that puts materials from dead plants and animals back into the soil, air, and water

39. Plants are classified by characteristics. Plants that make seedsPlants that do not make seeds Flowering Plants ConifersFernsMosses Plants reproduce differently Reproduce – it means “ to make more of the same kind ”

40. What Are the Parts of a Flower Most flowers have four parts Flower parts Sepal – one of the leaf- like parts that protects a flower bud and that is usually green Pistil – part of a flower that makes the eggs that grow into seeds Stamen – part of a flower that makes pollen Pollen – tiny grains that make seeds when combined with a flower ’ s egg

41. How Do Flowers Make Seeds and Fruits? Great Plant Escape- Plant parts Great Plant Escape- Plant parts Ovary – the bottom part of the pistil in which seeds form Ovule - the inner part of an ovary that contains an egg embryo – tiny part of a seed that can grow into a new plant

42. How Seeds Form After fertilization the flower dries up and petals fall off, leaving just the pistil and its ovary. The top of the pistil falls off and the ovary gets larger as one or more seeds form inside it. When the seeds are formed, the ovary dries up and the seeds fall out. Corn, Beans, and Peas are seeds that we eat

43. How Fertilization Occurs When a pollen grain reaches a pistil, it grows a thin tube to the ovary. Sperm from the pollen grain combines with an egg, and a seed forms. Fertilization – the combination of sperm from a pollen grain with an egg to form a seed

44. How Pollination Occurs Butterflies may carry pollen from the stamen of one flower to the pistil of the the same flower. Sometimes the butterfly may carry pollen from the stamen of one flower to the pistil of another flower of the same kind. Pollen: Nothing to Sneeze At Pollination- the movement of pollen from a stamen to a pistil

45. What is the Life Cycle of a Flowering Plant Dormant Seed Takes in water and the seed coat gets soft. If the seed has enough oxygen and the right temperature, it will begin to germinate. dormant – the resting stage of a seed

46. Geminating Seed First a root pushes through the seed coat and grows downward. The top part of the root grows upward and becomes the stem. The stem carries the seed coat and the seed leaves with it. The seed coat falls off. The seed leaves provide food for the plant. Two small leaves begin to grow from between the seed leaves.

47. Seedling When the stored food within the original seed leaves is used up, they dry up and drop off. More leaves grow from buds on the stem as the plant grows taller. The new leaves can trap energy from sunlight and make sugar. Plants use the energy in the sugar to grow.

48. Some flowering plants are dicot seed – a seed that has two seed leaves that contain stored food monocot seed – a seed that has one seed leaf and stored food outside the seed leaf

50. Consider this…. What is one way to classify all plants into two groups How do plants that do not make seeds reproduce? In what part of a flower are seeds made? How are flowers pollinated? How is a monocot seed different from a dicot seed?

51. What do seedlings need to grow into mature plants? How does a bean plant grow from a bean seed? What is the main source of energy for plants What do plants need to make sugar? How do animals – herbivores, carnivores, and omnivores – get the energy they need to survive? How are decomposers important?