Plants
Chapter 22, 23, 24 Learning Goal
Relate the structure of each of the major plant organs and tissues to physiological processes. What are Plants?
•Plants are multicellular eukaryotes •Plants have cell walls made of cellulose. •Plants develop from multicellular embryos. •Plants carry out photosynthesis using the green pigments chlorophyll a and b. Nutrients for Plants
•Sunlight: to capture energy for photosynthesis. •Gas exchange: require carbon dioxide to make carbohydrates and release oxygen as a waste gas. •Water: raw material of photosynthesis, needed to make carbohydrates; also needed to transport nutrients. •Minerals: provides raw materials for plants to produce needed structures; examples phosphorus and nitrogen. Think fertilizer. Plant Classifications
Plants Non-Vascular Vascular Mosses & Liverworts Has a vascular system
Seeds Seedless Reproduce with seeds Reproduce without seeds Angiosperms Gymnosperms Reproduce with flowers Reproduce with cones Seed Plants
• Gymnosperm – Plants that reproduce using cones pine tree
• Angiosperm – Plants that reproduce using flowers
sunflower Plant Anatomy
Some plants have •Flowers •Fruits •Cones Leaf Anatomy
***Leaves are a plant’s photosynthetic organ*** • Cuticle • Epidermis • Mesophyll – (Palisade & Spongy) • Stomata • Guard Cells • Vascular tissue – (Xylem, Phloem & Bundle Sheath) Leaf Anatomy
Cuticle Waxy layer on outside of leaf whose primary function is to prevent water loss within the leaf Leaf Anatomy
Epidermis Single layer of cells that make up dermal tissue. Protects the cells on the inside of the plant. Stomata
Stoma/Stomata Tiny holes within the epidermis that allow for gas exchange. Guard cells on either side of the stoma open and close to regulate gas and water within the leaf. Leaf Anatomy
Mesophyll Made up of palisade layer & spongy layer.
Have a lot of chloroplasts - main sites of photosynthesis in the leaf. Leaf Anatomy
Vascular Tissue Xylem - Transports water from the roots to the leaves to aid in photosynthesis. Phloem – transports sugars, proteins and other nutrients throughout the plant. Bundle Sheath – cells of the outer layer of the vein. Flowers
• Angiosperms are plants that produce flowers. • Flowers are a plant’s reproductive organ. • Perfect flower – has both male and female parts. • Imperfect flower – has only male or only female parts. Flower Anatomy
Flowers are composed of several parts: • Petal • Sepal • Stalk – or peduncle • Stamen (male) • Carpel – or pistil (female) Flower Anatomy Male Flower Anatomy
• The stamen is the male reproductive part. • Comprised of a filament and an anther. • The anther produces pollen. • Pollen grains contain male gametes (flower sperm) Female Flower Anatomy
• The Carpel (or pistil) is the female reproductive part. • Comprised of a stigma, style and an ovary • The ovary contains ovules (eggs). Flower Reproduction
• Pollen grains transported by pollinators stick to the stigma. • A pollen tube extends down and fertilizes the ovules. • Fertilized ovules will become seeds, and the ovary will become the fruit. Reaping the Rewards of Plant Reproduction