CH 4 Organism and Population Ecology and Evolution PDF

Preview

Summary

Download CH 4 Organism and Population Ecology and Evolution PDF

Description

CH4: Organism and Population Ecology and Evolution 4.1 The Cell - The Fundamental Unit of Life Fats provides our body with energy. Carbon is found in all organic compounds. Light provides plants the energy they need to make organic molecules. Cytoplasm ● Area inside the cell, bound by the plasma membrane, composed of a gel-like substance and various cellular structures exclusive of the nucleus. Eukaryote ● Organisms whose cells contain an organized nucleus and membrane-bound organelles. ● Range from single-celled algae to fungi, and animals that are made of millions of cells. Prokaryote ● Single-celled organism, including bacteria and archaea, that lack a nucleus. Cellular respiration ● An aerobic process that converts the chemical energy found in glucose into the chemical energy found in ATP; it produces ATP from carbohydrates. ● All organisms use energy to power their physical, behavioral, and reproductive functions. ● This process breaks down carbohydrates and stores the energy in ATP molecules. ● By-products of cellular respiration ○ Heat, CO2, and H2O Biochemical functions that store energy ● Photosynthesis ○ Used by plants and some protists and bacteria ○ Uses sunlight, CO2 , and H2 O ○ Important because it produces carbohydrates (sugars) and O2 , which are used in cellular respiration by most prokaryotes and eukaryotes. ○ Carbohydrates - store chemical energy

●

○ Chemosynthesis ○ Creates sugars from inorganic chemicals CO2 and O2 ○ Energy from H2 S to S (sulfur) ○ Used by bacteria in ecosystems with no light ■ Ocean depths 1

CH4: Organism and Population Ecology and Evolution Biochemical functions that use stored energy ● Aerobic respiration ○ Process through which cells use oxygen to break down food to produce energy. ○ Carbohydrates broken ○ Releases CO2 and H2O ○ Nearly all organisms use ○ Requires oxygen (aerobic) ○ Most cells use this process to produce ATP ● Anaerobic respiration ○ The process in which carbohydrates are partially broken down in the absence of oxygen, producing ATP for energy, CO2 and smaller carbohydrate molecules. ○ Yields less energy ○ Produces energy for the yeast. ○ CO2 and H2 O and ethanol are by-products that are released. Cellular respiration ● The process by which energy in carbohydrate molecules is retrieved and used to carry out cell functions and facilitate growth. 4.2 DNA Is the key to the Diversity of Life Asexual reproduction ● Simple cell division in which a single parent produces offspring that produces genetically identical offspring Sexual reproduction ● Mating between two parents that produces offspring that are genetically unique. ● Requires two individuals ○ Gametes produced to form a zygote ● Genetically diverse offspring ● The parent and offspring are genetically different 4.3 The Growth of Populations Organism ● A single fish living in the lake’s shallow water near the shoreline Community ● A group of fish of the same species inhabiting the shallow water near the shoreline Population ● The number of organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding 2

CH4: Organism and Population Ecology and Evolution Population size (number/area) is affected by 4 factors: ● Immigration ● Emigration ● Births (+) ● Deaths (-) Reproduction is an example of positive feedback ● Offspring adds on to the population Population growth rate ● The multiple by which an exponentially growing population increases. Growth rate: number of individuals (population)/time ● Growth rate = inputs - outputs ○ Inputs = Birth rate + Immigration rate ■ Birth rate ● #births/time ■ Immigration rate ● number entering population/time ○ Outputs = Death rate + Emigration rate ■ Death rate ● #deaths/time (mortality rate) ■ Emigration rate ● number leaving population/time Patterns of change ● Exponential growth ○ Growth rate accelerates with each generation ○ Population size grows faster as the population gets bigger ● Arithmetic growth ○ Growth is constant ● Logistic growth ○ Growth rate accelerates, then stops ○ Population growth slowing down as the population approaches carrying capacity.

● 3

CH4: Organism and Population Ecology and Evolution

(Infant) Mortality rate ● The percentage of infants within a population who die before age 1. Exponential growth (A Case Study) ● In 1890, 60 european starlings released in NYC ● 10 years later, tens of thousands ● 1920s, millions of starlings across New England ● 1970, starlings across entire United States ● Exponential growth Fertility rates ● Potential number offspring ● Generation time ○ Average difference in age between mothers and their offspring Age-specific fertility rates ● Offspring produced at age ranges Total fertility rate ● The potential number of offspring born per female in her reproductive years ● Rate of reproduction ○ Changes with age Survivorship ● Probability of an organism dying during a particular interval ● Species survivorships vary widely ○ Types 1: Most die old ○ Type 2: Young and old die equally ○ Type 3: Most die young 4.4 Limits on Population Growth Carrying capacity ● The maximum population a habitat can support ● The population size at which a population uses resources equal to the rate at which ○ those resources are supplied ○ the birth rate = the death rate ○ The population growth rate becomes 0

4...