Plant Biology: Taxonomy, Anatomy, Metabolism, and Ecology - Prof. Thomas Smith, Study notes of Environmental Science

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EVSC 220 – Plants, People and Culture Outline with Key Terms and Concepts for Lecture 2 (8/30/07) Taxonomic Classification  Plants  Fungi  Animals  Protista  Monera Kingdom, Phylum, Class, Order, Family, Genus, Species Functional Classification of Plants  Nonvascular plants- lack a specialized conducting (vascular) system  Vascular plants- have a vascular system Germination: the development of a seed from its embryonic form to the birth of a new plant Angiosperms and Gymnosperms  Angiosperms- flowering plants (seeds enclosed in a fruit)  Gymnosperms- plants that lack flowers, but produce seeds (naked seeds) Monocotyledons (monocots) and dicotyledons (dicots)  Monocots- one cotyledon or embryonic leaf cotyledon stays below ground when the seed germinates  Dicots- contain two cotyledons that emerge above ground during germination, first photosynthetic leaves Annuals, biennials, and perennials  Annuals- completes its life cycle in 1 year  Biennial- requires all or pat of 2 years to complete its life cycle o First season it produces vegetative structures and food storage organs, second season it seeds, flowers, and fruits  Perennial- plants live more than two years Herbaceous plants  A plant that has leaves and stems that die at the end of the growing season to the soil level. Can be an annual, biennial, or perennial. Grasses and forbs o Grass- Monocotyledonous green plant or used to describe a plant that has a similar appearance o Forb- a flowering plant with a non-woody stem that is not a grass Woody plants  Non-herbaceous perennial plants which have stems above ground that remain alive during winter and grow shoots the next year from the above ground parts Trees, shrubs and vines o Tree- a large perennial woody plant larger than a shrub. At least 5- 6 m high and secondary branches supported by a main stem. o Shrub- multiple stems and lower height less than 5-6 m. Large number of plants can be either shrubs or trees depending on the growing conditions. o Vine- any climbing or trailing plant Plant Cell Structure Plasma or cell membrane- a flexible thin layer surrounding a small mass of jellylike living material called the cytoplasm Cell wall- surrounds the plasma membrane Nucleus- contains genetic material Organelles (chloroplasts and mitochondria)-  Chloroplast- photosynthesis is carried out by these  Mitochondria- breakdown carbs and sugar to produce ATP during respiration Plant tissue- group of cells with a specialized function Dermal, vascular (xylem and phloem) and ground  Dermal tissue- outer protective layer  Vascular tissue- consist of phloem and xylem which form a vascular system throughout the plant. Conducts water and solutes  Ground Tissue- serves a diversity of functions including the production and storage of food, packing, and support Root and Shoot system  Primary root  Lateral Root  Root Tip Roots Radicle- the embryonic root that extends by the division and elongation of cells to form the primary root Taproot and fibrous roots  Taproot- have one large mainroot with small lateral branch roots  Fibrous roots- high branched and lack a central main root Structure of root system (meristem, root tip, root hairs, vascular tissue, etc.)  Meristem- at the tip and manufactures new cells; its an area of cell division and growth  Root tip-  Root Hairs- small elongated epidermal cells that increase surface area Modified roots Storage roots- roots are enlarged and store large quantities of starch and toher carbohydrates, which may be used later for growth. Inflorescence- cluster of flowers Complete and incomplete flowers  If a flower has all four parts- sepals, petals, stamen, and pistil Perfect and imperfect flowers- if a flower contains both function stamens and pistils it’s a perfect flower if its lacking either its imperfect Monoecious and dioecious  Monoecious- plants have separate male and female flowers on the same plant  Diecious- species have separate male and female plants Pollination- transfer of pollen from an anther to a stigma Nectar- a sugar-rich liquid produced by plants to attract pollinating animals. Fertilization – fruit and seed formation  After fertilization takes place within the ovule, the ovule develops into a seed, and the ovary surrounding it develops into a fruit. A fruit may contain one or more seeds. Fruits provide protection and aid in dispersal Pericarp (exocarp, mesocarp and endocarp)  The fruit wall that develops into the ovary wall is the pericarp o Three layers  Exocarp- outer layer  Mesocarp- middle layer  Endocarp- inner layer Four basic types of fruits: simple fruits- develops from a single carpel or several fused carpels. aggregate fruits- multiple fruits accessory fruits Simple fruits – fleshy or dry Berry- a fleshy fruit that has soft tissues throughout and contains few to many seeds. Tomato, grapes, blueberries, cranberries Pepo- a modified berry in which the fruit wall is a leathery rind. Pumpkin, squash, watermelon Hesperidium- has a leathery fruit wall with numerous oil glands surrounding the succulent cavities where the seeds occur. Citrus Fruits Drupe- a fleshy or fibrous fruit that contains a hard stone surrounding a single seed. Peaches, cherries, avocados, olives Dehiscent and indehiscent- many simple fruits are dry at maturity  Dehiscent- split open along the structures to release their seeds  Indehiscent- does not split open at maturity Follicle- a simple, dry fruit that splits along one suture to release its seeds Legume- a simple fry fruit that splits along two sutures (top and bottom) Pea Pods Capsule- a simple, dry fruit that splits open along multiple sutures or pores Caryopsis (grain)- Do not split open and contain one seed. Corn and wheat Nut- simple dry fruits that have a stony wall and do not split open at maturity. Nuts Achene- similar to the caryopsis in that it is simple and dry , does not plit open at maturity and contains a single seed. But the seed coat is not fused. Sunflower seed Aggregate fruit- formed from a single flower that contains separate (free) carples. After fertilization, each ovary from each individual carpel enlarges. They may fuse to form a single fruit. Raspberries Multiple fruit- which forms from the carples of many flowers that grow close to one another on a common floral stalk. The carpel from each flower fuses. Pineapple Accessory fruit- other plant tissues are used in addition to the ovary tissue to make up the fruit. Strawberry with the leaves on top Seed dispersal- can be dispersed by animals digestive systems to move the seeds away from the parent plant. Outline with Key Terms and Concepts for Lecture 5 Genetics and Plant Breeding DNA- chemical blueprint Genes- DNA is contained within units called genes Alleles- alternate forms of a gene Chromosomes – homologous chromosomes  Threadlike structures in the cell. Most multi-cellular organisms have two copies of each chromosome one from the mother and one from the father. Two copies of one genes are homologous Genotype- the genetic makeup of an organism Phenotype- the expressed traits of an organisms genetic makeup Phenotypic plasticity- ability for different phenotypic expressions of the same genotype under different environmental conditions Asexual vs sexual reproduction-  Asexual – produces exact copies through budding  Sexual- through pollination allows for genetic recombination Modes of gene action Complete dominance- the heterozygous individual expresses the same phenotype as one of the homozygotes Recessive and dominant alleles (genes)  When two alleles are different, if one allele is fully expressed while the other has no noticeable effect on the organisms outward appearance, the allele that is expressed is dominant while the other which is no expressed is recessive. Incomplete dominance- heterozygous individual is intermediate between the homozygous types Population- a group of individuals of the same species, living in a given area at a given time (potential for individuals to interbreed) Gene pool- sum of the genetic information within a population Inheritance- Mutation- a permanent change in the DNA sequence of a gene Natural selection Selective breeding/artificial selection- manipulating plant species to favor characteristics that enhances their usefulness Outline with Key Terms and Concepts for Lecture 6 Topics in Plant Ecology Plant carbon balance  Carbon gain of the plant will be a function of the rate of photosynthesis and total amount of leaves  Carbon loss of the plant will be a function of the total plant mass (leaves, stems, and roots) Carbon allocation- the process in which plants allocate the carbon taken-up in photosynthesis to the production of new tissues Change in carbon allocation under different levels of soil resources (water and nutrients)- as certain resources become limiting to plant growth, carbon must be allocated to the production of tissues that allow for access and acquisition of those resources. Roots provide access to water and nutrients. As these become limiting the plant will allocate more resources to production of new roots Differences in carbon allocation between different plant life forms (grasses, shrubs and trees) and the consequences to their interactions with environmental conditions (such as water availability)-  Plants from dry and or low nutrient environments allocate more of their carbon to the production of roots. This increased allocation to root production reduces allocation to leaves Geographic distribution of C3 and C4 plants and relationship to environment  Less C4 plants as you move north into higher latitudes C3 plants begin to take over