Biology: Jan. 25-Feb. 5
Biology: Jan. 25-Feb. 5 Biology 1120-001
Popular in Biology
verified elite notetaker
Popular in Biology
verified elite notetaker
This 5 page Class Notes was uploaded by Anzlee on Sunday February 7, 2016. The Class Notes belongs to Biology 1120-001 at Middle Tennessee State University taught by Andrew Brower in Spring 2016. Since its upload, it has received 88 views. For similar materials see Biology in Biology at Middle Tennessee State University.
Reviews for Biology: Jan. 25-Feb. 5
Report this Material
What is Karma?
Karma is the currency of StudySoup.
Date Created: 02/07/16
Biology: January 25 Febuary 5 th th The sun is the power of life on earth (photosynthesis) Plants provide: o food by beginning the food chains (producer) o fuel by either being burned directly or through fossil fuels o building materials (cotton, wood, etc.) o medicines (aspirinbark of elm tree, etc.) o ecosystem services (habitat, prevent erosion, produce oxygen) Plant Lineage and Important Adaptations: NonFlowering Plants Green Algae Chlorophyta may be unicellular or colonial and multicellular species mostly aquatic, produce a lot of oxygen can live in harsh conditions, even inside rocks have been classified as protists, but are very closely related to terrestrial plants (share chloroplast with both chlorophylls a and b, starch as a storage of sugar, and cellulose cell walls) became abundant around 700 million years ago, because oxygen levels increased and diversification of heterotrophic food chains help us understand the evolution of multicellularity *note bluegreen algae is not the same as green algae Land Plants very abundant, and many adaptations to prevent water loss most plants are protected from desiccation by a waxy cuticle and stomata, which prevent too much evaporation of water and take in the correct amount of carbon dioxide example of evolution: increased photosynthetic area defining characteristic protection of embryos; some produce seeds; all have haploid and diploid phases; most have vascular tissue xylem water transport; phloem food transport Plant Life Cycles Haplodiplontic: Sporophyte diploid generation Gametophyte haploid generation Basics of life cycle: diploid produced spores through meioisis; spores divide by mitosis producing a haploid gametophyte; gametes are produced through mitosis (then two gametes fuse together again to form a 2n diploid zygote) Bryophytes non vascular plants: liverworts (hepiticophta), mosses (bryophyta), and hornworts (anthocerophyta) examples of important use: peat (composed of moss) source of energy; drives global warming by drying out and releasing carbon dioxide dioecious two separate sexes are included in the life cycle moss and liverwort life cycles gametophyte is longer than sporophyte stage, sperm swim to egg then fertilization occurs (water must be present) moss life cycle sporophyte actually grows out of the gametophyte Vascular Plants xylem and phloem evolution has allowed these to grow taller to gain access to the sun (lignin is part of the structure) Ferns Lycophyta and Pterophyta club mosses, no roots, seeds, or flowers o whisk fernssimplest morphology, 6 species, evenly spaced stems o horsetail 15 species, sporophytes at the top life cycle: does not pollinate itself, but instead mixes genes for diversity and maximized offspring; monoecious; sporophyte stage is more dominant than the gametophyte stage; a structure called the thalus grows out of the archegonia (female part) of the gametophyte stage Seed Plants Gymnosperms cycadophyta (cone bearing, dioecious), ginkophyta (gender different via tree; very old unchanged species with loose leaves), coniferophyta (cone bearing; dioecious) protection, dispersal, dormant phase; increase embryo survival by waiting for favorable environmental conditions life cycle: sporophyte phase dominates life cycle; female cones contain megasporocytes while male cones contain microsporocytes Flowering plants Angiosperms characterized from flowers and fruits; ovule enclosed within diploid tissue very diverse group of plants evolution of land plants; success of angiosperms may be because of pollination and seed dispersal interactions with animals; ex. colors seed plants are heterosporous: microsporangia sperm; macrosporangia egg; seeds have a dormant stage, and allow for more efficient dispersal and the spread of genetics pollen sperm no longer needs water for dispersal; wind, birds, insects, etc. embryo seeds package them with a food supply and protect them from desiccation (nutritive tissue and protective coat) life cycle: anther meiosis takes place to produce male pollen grain with three nuclei (1 is tube, 2 is fertilization); ovule/megaspore female (ovary grows into fruit while the ovule grows into seed); pollen lands and produces pollen tube, then double fertilization takes place structure of flowers: Examples of Types of Angiosperms: o amborella most basal lineage o star anise o nymphaeales water lilies o magnoliales magnolias, avacados, nutmeg, etc. o monocots monophyletic group; seed with single cotyledon, no true wood, flower parts usually in multiples of three, parallel venation; ex bananas, asparagus o dicots 2 cotyledons; parts in multiples of 4 or 5; branches venation; ex beans o eudicots many species, ex. cacti, pitcher plants, cacao pods Growth and Structure o growth is often indeterminate; initiated from meristems (many cells divide here rapidly and allow the plant to continue growth) o Primary vs. Secondary Growth: primary growth is when the plant grows into the soil and up into the air through apical meristems secondary growth is when the plant grows wider and thicker through lateral meristems o variation in shoot (above ground):root (below ground) ratio dependent on nutrient levels in soil o parenchyma cells function in photosynthesis and gas exchange o collenchyma cells are sturdier and act as a support o sclerenchyma support, transport, protection (secondary cell wall lignin) o epidermal outermost, secretes waxy cuticle o guard cells open/close to limit water loss, o trichomes hair like projections for defense and water loss o Types of Tissues: ground tissue vascular tissue xylem: sclerenchyma cells dead at maturity; vessel elements and tracheids; phloem sieve tube elements and companion cells dermal tissue: root hairs increase surface area for absorption of minerals and water, Plant Transport Water transport through the xylem is passive (direction: up) o 8090% of herbaceous plants are made of water; 50% of woody plants o Must maintain turgor pressure (stomata opens and closes to maintain this) o Water potential tendency of water to move from high to low pressure; solute + pressure potential = water potential (solutions have negative solute potentials and water has zero solute potentials) o Most water is absorbed by root hairs and travels to xylem, through: transmembrane route (straight through water channels) apoplastic route (between pores/cell walls) symplastic route (through plasmodesmata) o Does water get pushed or pulled? Pulled through transpiration!! Sugar/nutrient transport through the phloem is active (bidirectional) o Phloem moves products of synthesis o Cells include: sievetube cells that act as doors; companion cells provide support o Essential Macronutrients: Nitrogen Potassium Calcium Phosphorous Magnesium Sulfur o Examples of micronutrients: chlorine, manganese, iron, zinc, boron