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BOTANY BIOLOGICAL ORGANIZATIONS - Also known as Plant Biology, encompasses the origin, diversity, structure, and internal processes of plants as well as their relationships with other organisms and with the nonliving physical environment. D...

BOTANY BIOLOGICAL ORGANIZATIONS - Also known as Plant Biology, encompasses the origin, diversity, structure, and internal processes of plants as well as their relationships with other organisms and with the nonliving physical environment. Disciplines under Botany 1. Plant molecular biology – it is the study of structures and functions of important biological molecules. 2. Plant biochemistry – it is the study of the chemical interactions within plants, including the variety of chemicals that plants produce. 3. Plant cell biology – it encompasses the structures, functions, and life processes of plant Biosphere - all of the environments on Earth that cells. support life 4. Plant anatomy – it is the study of microscopic Ecosystem - all the organisms living ln a particular plant structures such as cells and tissues. area and the physical components with which the 5. Plant morphology – it refers to the structures of organisms interact plant parts including their evolution and Community - the entire array of organisms living in a development. particular ecosystem 6. Plant physiology – it is the study such processes Population - all the individuals of a species living in a as photosynthesis and mineral nutrition to specific area understand how plants function. Organism - an individual living thing 7. Plant genetics – it is the study of plant hereditary Organ system - several organs that cooperate in a and variation. specific function 8. Plant ecology – it is the study of the Organ - a structure that is composed of tissues interrelationships among plants and between Tissue – a group of similar cells that perform a plants and their environment. specific function 9. Plant systematics – it encompasses the Cell - the fundamental unit of life evolutionary relationships among different plant Organelle - a membrane-enclosed structure that groups. performs a specific function within a cell 10. Plant taxonomy – it is a subdiscipline of Molecule - a cluster of small chemical units called systematics, deals with the description, naming, atoms held together by chemical bonds. and classification of plants. 11. Ethnobotany – it is the study of botanical knowledge of a social group and its use of locally Sensitivity or Response to Stimuli - Organisms available plants. respond to diverse stimuli. 12. Paleobotany – it is the study of the biology and - A stimulus is anything that can trigger a physical the evolution of plants in the geologic past. or behavioral change. Applied Plant Biology Reproduction - formation of new individuals. When 1. Agronomy – field crops and soils reproduction occurs, genes containing DNA are 2. Horticulture – ornamental plants and fruit and passed along to an organism's offspring vegetable crops. A. Sexual - gametes 3. Forestry – forest conservation and forest products such as lumber 4. Economic botany – plants with commercial importance. Life is recognized by what living things do. Order - Organisms are highly organized, coordinated structures that consist of one or more cells.  THREE DOMAIN SYSTEM 1. Asexual - no gametes/no fertilization taken place THE SIX KINGDOMS OF LIFE Growth and Development – Organisms grow and 1. Animalia develop following specific instructions coded for by 2. Plantae their genes. These genes provide instructions that 3. Fungi will direct cellular growth and development, 4. Protista ensuring that a species’ young will grow up to exhibit 5. Eubacteria many of the same characteristics as its parents. 6. Archaebacteria Regulation – an ability to control an organism’s What makes plant different from other living internal environment within limits that sustain life. organism? - The word ‘plant’ encompasses a wide range of Plants regulate their internal ex. the movement and living organisms, all of which belong to the retention of water kingdom Plantae and share a range of characteristics. Energy processing – All organisms use a source of energy for their metabolic activities. Some Key Characteristics organisms capture energy from the sun and convert 1. Plants are multicellular organisms, easily it into chemical energy in food (photosynthesis); distinguished from other living things others use chemical energy in molecules they take in 2. Plant cell walls are rigid as they’re made of as food (cellular respiration). cellulose. A plant cell also has a large central vacuole that holds on to the water and lets the plant stay turgid. 3. Plants are autotrophs. Plants are photosynthetic and contain a green pigment called chlorophyll, which enables plants to convert energy from the sun into food. Plants store their food as starch. 4. The life cycle of plants includes both a sporophyte and a gametophyte generation. 5. Most plants are rooted to one place. Some plants can orientate leaves towards the sun and some respond to touch. Evolutionary adaptation – adaptations evolve over 6. Develop from embryos supported by maternal many generations, as individuals with traits best tissue suited to their environments have greater reproductive success and pass their traits to Plants are multicellular organisms, easily offspring. distinguished from other living things The stem of a cactus (a species of Echinocactus is shown) functions for both photosynthesis and water storage. The leaves of cacti are modified into spines for protection.  GREEN ALGAE: PRECURSORS OF LAND PLANTS THE LIFE CYCLE OF PLANTS INCLUDES BOTH A Chlorophytes SPOROPHYTE AND A GAMETOPHYTE GENERATION. - Chlorella - Chlamydomonas, the - The two generations alternate, each giving rise “sea lettuce” to the other. This is called ‘alternation of - Ulva, generations’. - Volvox Charophytes The haploid gametophyte (gamete producing plant) - Desmids produced haploid gametes-eggs and sperm-that fuse - Spirogyra during fertilization, forming diploid zygotes. - Coleochaete - Chara Mitotic division of the zygote produces a Charophytes, particularly Chara multicellular diploid sporophyte (spore-producing and Coleochaete - are the closest plant). Meiosis in a mature sporophyte produces living relatives of land plants haploid spores, reproductive cells that can develop into a new haploid organism. The earliest plant fossils suggest that plants moved onto the land between 490 and 443 million years ago (during the Ordovician Period) Bryophytes are small sporebearing plants that typically grow in moist areas. - The structure of the plant body is simple and typically lacking vascular tissue like xylem and phloem. - Bryophytes need water in order to reproduce. Embryophytes (Land Plants) - Embryophytes are multicellular, autotrophic, typically terrestrial organisms that retain and nourish their embryos (hence the name). EVOLUTION OF LAND PLANTS PHYLUM PHYLUM PHYLUM BRYOPHYTA HEPATOPHYTA ANTHOCEROPHYTA Seedless vascular plants are plants that contain vascular tissue, but do not produce flowers or seeds. - Club Mosses - Horsetails - Whisk Ferns - Ferns Phylum Lycopodiophyta: Club Mosses - The club mosses, or phylum Lycopodiophyta, are the earliest group of seedless vascular plants. - Also known as the “Fern Allies” Sori are clusters of sporangia found only in ferns Seed Plants - Gymnosperms - plants that have "naked" seeds that are not enclosed in ovaries. Their seeds are Phylum Monilophyta: Class Equisetopsida exposed on modified (Horsetails) - Horsetail, (genus Equisetum), also called scouring leaves (sporophylls) that rush. usually form cones - The single extant genus Equisetum is the survivor (strobili). of a large group of plants. - Angiosperms- are seed plants that produce the reproductive structures called flowers and fruits. The name angiosperm (from the Greek anglon, container) refers to seeds contained in SPORES - Usually single-celled - Most spores have much shorter lifetimes Phylum Monilophyta: Class Psilotopsida (Whisk - No protection from harsh conditions Ferns) - Must grow where it lands - Whisk fern, either of the two species of the SEEDS primitive fern genus Psilotum - have a multicellular layer of tissue, the seed coat, - A whisk fern has water- and food-conducting that provides extra protection to the embryo tissues but lacks true leaves and roots. - have a supply of stored food which enables a seed to remain dormant for days, months, or even years - Can Dispersed in different ways GYMNOSPERMS: First Plant to have seeds - Vascular plant that reproduces by means of an exposed seed. The seeds of many gymnosperms (literally “naked seeds”) are borne in cones and Phylum Monilophyta: Class Polypodiopsida (Ferns) are not visible until maturity - Fern, (class Polypodiopsida), class of nonflowering vascular plants that possess true roots, stems, and complex leaves and that reproduce by spores. Division Cycadophyta (the Cycads) DIFFERENCES BETWEEN MONOCOT AND DICOT - Frequently confused with ferns or Palms - Cycads have very thick leaves, that look like very tough versions of fern fronds. Division Coniferophyta (The Conifers) - The conifers are the largest and most successful group of living gymnosperms. - They are all trees of moderate to gigantic size Biggest + oldest Height: coast redwoods (Sequoia sempervirens) >100 m tall Mass: giant redwoods (Sequoiadendron gigantea) > 26 m. circumference Age: bristlecone pine (Pinus aristata) 4900 years old Division Ginkgophyta (the Maidenhair tree) - Contains a single living species, Ginkgo biloba (Maidenhair tree) - It looks very much like a large dicot tree with a stout trunk and many branches It has deciduous broad fanlike leaves, that turn gold in autumn Division Gnetophyta (The Gnetophytes) - Division Gnetophyta contains three groups of enigmatic plants, each of which is often placed in its own order: Gnetum, Ephedra and Welwitschia mirabilis, - Mainly xerophytes, plants that are adapted to dry conditions. - Usually found on deserts - They share a close common ancestor with flowering plants. Angiosperms: The flowering plants - Flowering plants, the most recently evolved and most diverse of all plant groups - Classified together in a single division, division Magnoliophyta, also known as division Anthophyta. - The key adaptations in the evolution of angiosperms are flowers and fruits