Exam 2 Study Guide - Plants and Humans | BIO 1023, Study notes of Biology

Download Exam 2 Study Guide - Plants and Humans | BIO 1023 and more Study notes Biology in PDF only on Docsity! Module 2 Ecosystem—all the organisms and physical factors within a given area. Abiotic—non living environment Biotic—living environment. Population—all the members of one species, living together in a particular habitat. Community—all the organisms in a particular habitat. Producers—photosynthesizers, autotrophs. Primary consumers—herbivores and browsers Secondary—carnivores and preditors Decomposers—bacteria, fungi protists, invertibrets, Food web—producers, primary consumers, secondary consumers, third consumers. Competition—interaction between two or more organisms where resources are limited. Parasite—Organisms that obtain their energy and nutrients from another living organism (host). Harming Mutualism—both organisms benefit. Ex. Plants (angiosperms) and their pollinators How do plants discourage herbivores from eating them? Four principles of Natural Selection 1. Organisms have a tendency to produce more than survive 2. Only a fraction of the offspring in a population live to produce offspring. Not all make it to the reproductive years. 3. Individuals in a population vary and these variations are inheritable 4. Individuals with favorable characteristics produce on average more offspring that survive to reproduce than those with unfavorable characteristics. “Survival of the Fitest” Selection Pressures—One the environmental conditions that determine the outcome of natural selection. The force that drives natural selection. Artificial selection—Practice of humans to select for certain traits in organisms and control mating. Human’s select for: 1) Bigger Fruit 2) More nutrients 3) Disease resistant 4) Sweeter fruit Module 3 4 types of plant tissues: Meristems Apical—primary growth results in increase in length Lateral—secondary growth, results in increase in growth which is diameter. Ground Tissue—the filling of the plant body. Dermal—covers plant body Vascular—xylem, phloem Xylem—conducts water and minerals from roots up the plant body. Phloem—conducts food through the plant like carbohydrates. Difference in taproot and fibrous root—Taproot the structures is one primary root and many smaller branch roots, and that is the storage of carbs. Selective advantage is it grows deep underground to get water. Fibrous is highly branched lateral roots. Selective advantage is subsurface soil after a rain. Functions of a root—Anchorage, water and mineral absorbtion and starch storage. Parts of a root and what goes on in each zone— Root Cap covers the tip , and secretes mucigel. Zone of cell division—behind the root cap Zone of Cell elongation—behind cell division, intake of water causes cell to stretch. This action forces meristem and root cap through soil. Zone of Cell maturation—cells take on specific function, where the root hairs appear. Mucigel—protection from drying out, lubrication, water absorbtion, nutrient absorption. Energy storage form in plants--photosynthesis Knees of cypress trees—aerial roots Epiphytes—plants that grow on other plants; get nutrients through aerial roots Mycorrhizal roots—Association between root and fungus—mutualistic relationship. Fungus absorbs nutrients (4x more phosphorus) and in turn hose plant provides organic molecules, sugars, a.a.’s. Nitrogen-fixing bacteria in roots—Found in roots of legumes (beans/peas). Take atmospheric nitrogen and convert it to a form useable by plant (ammonium nitrate, nitrite) N2 means vigorous growth, why soybeans have extra protein, good for agriculture. Soil Layers 1. Frosting, surface litter 2. Top Soil, uppermost layer. 10%-15% organic matter (darker in color) 3. Sub soil, little organic matter (lighter in color) mostly minerals and mature roots. 4. Weathering bedrock, rock fragments, lacks organic matter. Mineral Parts of soil—sand, silt, clay. Humus—decomposing organic matter of soil. Five components of soil—mineral parts, humus, air, water, living organisms 3 main functions of a stem 1. Support for leaves and reproductive structures. Thick fibers on external surface that function like steel girders to keep plant upright. 2. Conduction a. Water and minerals—through xylem—wood b. Carbohydrates—through phloem tissue c. Growth—apical meristem, lateral meristem Heartwood—dry wood, darker because compounds like resinst tarnins clog up xylem, tissue non-functioning. Sapwood—functioning tissue, lighter in color. 2 parts of bark—innerbark, phloem, outerbark, protective barrier. Rosette plants—stems do not elongate. Allows them to resist freezing by using leaves as insulation. Also collect water that narrows during the day and stores heat for the night. Stolons/runners—horizontal stems that grow along the top of the ground. Asexual reproduction, plantlets (clones) grow from stolons. Thorns—sharp pointed modified stems, deters herbivores from eating it.