BIOLOGY NOTES CYCLE 1.pdf

SESSION 1-2 BIOPHYSICS INTRODUCTION TO BOTANY ○ Application of physical principles and methods to biological problems BOTANY - The Scientific Study...

SESSION 1-2 BIOPHYSICS INTRODUCTION TO BOTANY ○ Application of physical principles and methods to biological problems BOTANY - The Scientific Study of Plants BIOTECHNOLOGY ○ Use of biology to develop new products, BRANCHES OF BOTANY methods, organisms PLANT MORPHOLOGY ○ Study of physical form and external MICROBIOLOGY structure of plants ○ Study of Microorganisms - viruses, bacteria, microfungi, etc PLANT ANATOMY ○ Study of internal plant structure MOLECULAR BIOLOGY ○ Studies composition, structure, and HISTOLOGY interactions of cellular molecules ○ Study of cells and tissues with microscope CYTOLOGY GENETIC ENGINEERING ○ Detailed study of cells ○ Manipulation of genetic material(DNA) PHYSIOLOGY PLANTS ARE MULTICELLULAR EUKARYOTES ○ Study of various vital activities of the plant TWO SERIOUS DISEASES: PLANT TAXONOMY POTATO LATE BLIGHT - caused by Phytophthora ○ Classifying and naming plants infestans ECOLOGY STEM RUST FUNGUS - Ug99 threatens wheat ○ Study of relationships between living organisms and their environment Why study plants? - Studying plants increases knowledge about GENETICS life in general —--------------------------------------------------------------- ○ Study of Heredity and variations SESSION 3-4 PLANT BREEDING ○ Development of improved varieties of MULTICELLULAR PLANT BODY plants PLANT CELL TYPES PLANT EMBRYOLOGY GROUND TISSUE CELLS ○ Study of development of sporangia, ○ Makes up majority of a herbaceous plant gametophytes, and embryos in the land ○ Consists of Parenchyma, Collenchyma, plants, the embryophytes Sclerenchyma PALEOBOTANY PARENCHYMA: ○ Study of Fossil Plants Most Abundant Alive at Maturity ECONOMIC BOTANY Thin primary cell walls ○ Study of plants with reference to products Can divide - response to injury or changing environment PLANT PATHOLOGY Functions - photosynthesis, ○ Types of disease of plants respiration, gas exchange, storage of starch and other materials ORGANIC EVOLUTION ○ Evolution of complex organisms PHYTOCHEMISTRY ○ Study of Phytochemicals, chemicals for plants  COLLENCHYMA: Indeterminate Elongated living cells Plants that continue growing as long Unevenly thickened primary cell walls as environmental conditions allow it Function: elastic support Ex: majority of tomato varieties —--------------------------------------------------------------- SCLERENCHYMA: MERISTEMS Inelastic support to non-growing plant Regions undergoing active mitotic cell parts division Dead at Maturity Patches of “immortality” that allow a plant to Thick, rigid secondary cell walls grow, replace damaged parts, and respond to Lignin - tough, complex molecule that environmental change adds strength to cell walls TYPES: —-------------------------------------------------------------- ○ Apical VASCULAR TISSUE CELLS Small patches of actively dividing cells ○ Transports water, minerals, near the tip of roots and shoots carbohydrates, and other dissolved compounds throughout the plant ○ Lateral Produce cells that thickens a stem or XYLEM: root Tracheids ○ Long, narrow cells that overlap at SHOOT APICAL MERISTEM their tapered ends ○ Primary growth ○ Water moves from tracheid to Lengthens shoot or root tip by adding tracheid through pits cells Pits - thin areas of the cell wall New cells originate at the apical Vessel Elements meristems ○ Short, wide, barrel-shaped ○ Stack end to end, forming long, Daughter cells give rise to ground continuous tubes tissue, epidermis, and vascular tissue ○ Side walls - have pits ○ End walls - perforated or absent Stem elongates as the vacuoles of the ○ Water movement is faster than new cells absorb water, pushing the tracheids apical meristem upward PHLOEM: New leaves originate on the flanks of SIEVE TUBE ELEMENTS the meristem ○ Main conducting cells of phloem ○ Align end to end to form sieve tube ○ Remnants remain in the axillary buds that form at stem nodes ○ Alive but no nucleus and little cytoplasm ○ Buds may remain dormant or awaken to form sider branches COMPANION CELLS ○ Adjacent to sieve tube element ○ When a shoot loses its terminal bud, ○ Specialized parenchyma cell cells in one or more dormant axillary ○ Transfer carbohydrates in and out buds begin to divide of the sieve tube elements ○ Provide energy and proteins to the ROOT APICAL MERISTEM conducting cells ○ Some cells produced differentiate into the root cap —----------------------------------------------------------- ○ Other cells elongate by absorbing ○ Cells enlargement - root grows farther DETERMINATE VS INDETERMINATE GROWTH in the soil ○ Zone of maturation - cells complete Determinate their differentiation and mature into Plants that stop growing after functional ground, dermal, and reaching mature size vascular tissues Ex: bush types  LATERAL MERISTEMS ○ Secondary Growth Increases the girth of stems and roots ○ Cuticle in woody plants Waxy layer that coats the epidermis of the leaves and stem ○ Vascular cambium Internal cylinder of meristem tissue Conserves water and protects the Produces thin layer between primary plant from predators and fungi xylem and phloem Impermeable not only to water but ○ Vascular cambium cell - daughter cell - also to CO2 and O2 remain a meristem cell ○ Stomata Pores through which leaves and ○ Vascular cambium cell - daughter cell - stems exchange gases with the matures inside- secondary xylem / atmosphere matures outside- secondary phloem Guard cells - surrounds stomata and ○ Cork Cambium controls its opening and closing Gives rise to parenchyma to the inside and cork to the outside VASCULAR TISSUE Cork - densely packed, waxy ○ Xylem cells on the surface of mature Transport water and dissolved stems and roots minerals from the roots to all parts ○ Waterproof, insulating of the plant ○ Dead at maturity and form layers Water conducting cells are elongated and have thick, lignin-rich secondary Heartwood - innermost wood, darker cell walls Gradually becomes unstable to conduct water through time ○ Phloem Dark-colored chemicals Transports dissolved organic accumulate compounds, primarily sugar Sapwood - outer portion, layer Transports water and dissolved ○ Vascular bundle minerals Strand of tissue containing xylem and phloem, often with collenchyma —--------------------------------------------------------------- tissue or sclerenchyma fibers ○ Xylem and phloem shuttle minerals and food throughout the plant’s body ○ Other function: PLANT TISSUES Support - lignin strengthens walls of GROUND TISSUE xylem cells and sclerenchyma fibers ○ Fills the space between more specialized Enables vascular plants to cell types inside roots, stems, leaves, tower over their nonvascular fruits, and seeds counterparts - important for ○ Cells that compose ground tissue are competition important sites of photosynthesis, respiration, and storage DERMAL TISSUE ○ Covers the plant ○ Herbaceous plant Epidermis - single layer of packed, flat, transparent, parenchyma cells ○ Woody plant Tough bark