Lectures 7-9 Outline
Lectures 7-9 Outline Bio 1023
Popular in Plants and humans
Popular in Biological Sciences
This 5 page Class Notes was uploaded by Katy Davit on Friday March 4, 2016. The Class Notes belongs to Bio 1023 at Mississippi State University taught by Outlaw in Summer 2015. Since its upload, it has received 24 views. For similar materials see Plants and humans in Biological Sciences at Mississippi State University.
Reviews for Lectures 7-9 Outline
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 03/04/16
PLANTS!&!HUMANS!LECTURE!7! ! Soils and Stems: Soils: •! Soils are the source of minerals for plants •! There are different layers of soil •! Four basic soil components: mineral particles, water, air and organic matter •! How do Roots modify soil? o! Aerate soil o! When they die, they contribute organic matter o! Hold in topsoil o! Prevent erosion o! Soil movement o! Cause of erosion: Wind, water, tillage o! Roots also provide a service, food (sweet potato, cassava) Stems: •! 3 Main Functions o! Support: for leaves & reproductive structures o! Conduction: Water/minerals, carbohydrates o! Growth apical & lateral meristems •! Secondary Growth in Stems o! Growth rings or annual rings o! Secondary xylem: created by lateral meristem o! Each ring represents one year of growth •! Dendrochronology: The study of tree tings o! Important for, meteorologists, anthropologists, ecologists •! Heartwood/Dry wood o! Darker b/c resin & tannis clog up xylem tissue o! Denser= stronger •! Sapwood o! Functioning tissue o! Lighter in color •! Why is heartwood more desirable for furniture production? o! More dense, hence sturdier o! Tannis resist decay o! Long lasting •! Bark o! Inner bark= phloem o! Outer bark= protective barrier •! Stem Adaptations o! Modified by adaptation to their environment !! Rosette plants, leaves are protection, water collection !! Stolons/Runners, horizontal above-ground stems, a-sexual reprouduction !! Vines, weak stems attached to surfaces, leaves and flowers not shaded !! Thorns, sharp pointed modified stems !! Succlulent stems, cacti/dessert plants, hot and dry enviorment PLANTS!&!HUMANS!LECTURE!7! ! !! Rhizomes, belowground stems, horizontal underground stems, cold enviorment !! Tubers, belowground stems, horizontal swollen stems, cold eviornment !! Bulbs, vertical swollen stems, cold enviorment PLANTS!&!HUMANS!LECTURE!8! ! Plant Organ Systems: Leaves Leaves: •! Main organs of photosynthesis •! Gas exchange •! Evaporation water loss •! Generally thin with a lot of surface area •! 2 main types of leaves, simple and compound o! Simple leaves !! Petiole: short stalk attaches leaf to stem !! Blade: leaf itself !! Leaf: blade + petiole o! Compound !! Leaf function !! Photosynthesis and diffusion of gases !! Leaf structure, majority of tissue is mesophyll !! Between upper and lower layers of epidermis •! CAT o! C- Cohesion: water ▯sticks “to other water molecules o! A- Adhesion: water sticks to other polar molecules o! T- Tension: Evaporation from leaves Leaf Structure: •! Stomata, pores found on underside of leaf, allows for gas station •! Transpiration, the evaporation of water vapor from aboveground tissues (usually leaves) Leaf Function: •! Adaptations to reduce transpiration •! Deciduous plants- drop leaves in autumn, go dormant during winter months, and produce more sugar to store than evergreens •! Evergreen plants- small surface area reduces rate of transpiration, do not drop needles modified leaves •! Modified leaves- tendrils (twining leaves, support for weak stem), spines (prevent herbivores from eating the plant, bracts (protect unopened flower bud and support an open flower), and succulent leaves (store water, asexual reproduction) •! Other adaptations- carnivorous plants (modified leaves trap prey) PLANTS!&!HUMANS!LECTURE!9! ! Flowers and Fruits: What is the function of the flower? •! Site of sexual reproduction Flowering Plants are the Angiosperms: •! Perianth- sterile tissues •! Petal- brightly colored to attract pollinators •! Sepal- “bracts” o! These two structures are not directly involved in reproduction •! Stamen- male reproductive structures •! Pistil- AKA Carpal, female reproductive structures •! Stigma- site where pollen (sperm) sticks •! Style- hollow tube connecting stigma to ovary •! Ovary- site where eggs are found Angiosperm Life Cycle: •! Flowers produce egg and sperm •! Egg is produced in the ovary of the pistil •! Sperm is produced in anther of the stamen •! Fertilization- fusion of egg and sperm to produce zygote fertilized egg •! It occurs through pollination •! Pollination- transfer of pollen from stamen to stigma of same or distant flower of the same species Co-Evolution between Plants and their Pollinators: •! Attractants o! Visual cues: nectar guides, flower color and changes, flower shape o! Oder cues: for pollinators with poor sight •! Rewards o! Nectar o! Pollen •! Pollination o! Wind o! Water o! Other organisms such as insects, animals Fruits: •! Develop a fertilized ovary •! Protect developing seeds •! Parts of a fruit: o! Endocarp- innermost layer, surrounds seeds o! Mesocarp- middle layer, usually fleshy o! Exocarp- outermost layer, “skin” o! Pericarp- all PLANTS!&!HUMANS!LECTURE!9! ! •! Types of Fruit o! Pome, apples and pears o! Drupe, endocarp is a “pit” peaches and plums o! Berry, all parts are fleshy, tomatoes and blueberries o! Hesperidium, Exocarp is a leathery rind with oil glands, orange and lemons o! Pepo, Exocarp is a thick hard rind, melons and cucumbers o! Multiple fruits, derived from a tight cluster of separate individual flowers on a single structure, pineapples o! Aggregate fruits, derived from a fusion of many ovaries, strawberries and raspberries