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Bell Work. Main word/ idea: Population(s) 1. Write as much information as you can about:_ ________________________________ 2. A ______________________________is like a _____________________________ because: 3. Describe why it is important to study ________________________________?
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Bell Work Main word/ idea: Population(s) 1. Write as much information as you can about:_________________________________ 2. A ______________________________is like a _____________________________ because: 3. Describe why it is important to study ________________________________? 4. What are some important characteristics of _______________________________________?
Population Ecology Chapter 19 pg 236-237 Characteristics of populations
Objectives TLW: review definition of population. TLW:List the characteristics used to describe a population.
Objectives TLW: review definition of population. TLW:List the characteristics used to describe a population. TLW: create science vocabulary cards for this chapter.
What is population biology? It is the study of how and why populations change
A Population • Group of organisms of the same species living in the same place at the same time • Individuals may come and go, but the population can remain the same
Characteristics of Populations Important characteristics of a populations ability to survive is based upon: Food supply Predation and disease Birth rate Death rate Immagration Emmagration
Today’s Assignment Period 1: Reading assignment Define and draw a picture to show Population Lag Exponential (log) Death phase Sigmoidal population growth curve (S curve) Immagration Emigration
Today’s Assignment Science vocabulary card group project Words for project: Population Immigration Emigration Exponential growth Limiting Factor Carrying capacity Density-dependent factor Density –independent factor
Bell Work How can you determine the size of a population of organisms when the organisms move around and are hard to locate?
Objectives • TLW: simulate the Mark-Recapture technique to determine population size.
Vocabulary • Quadrants • Indirect counting • Mark-recapture
Review: Population Density • The number of individuals of a species per unit or area or volume. • How do we measure the number of individuals in a given area? • In most cases it is impractical or impossible to count all the individuals in a population. • As a result, scientists use a number of sampling methods: Quadrants, indirect counting, and Mark- Recapture.
Sampling Techniques • Quadrants • Count # of species in a particular area. • Move Quadrant & repeat process • Next, average results to get a population estimate
Sampling Techniques • Indirect counting • Used when organisms move around a lot and are too difficult to see. • Involves counting nests, burrows, tracks, etc. Ex. African Termite population: Size and # of mounds are counted instead of individuals
Sampling Techniques • Mark – Recapture • Trap animals for study • Tag them • Release individuals • Trap animals again, counts # of marked and unmarked to get an estimate of population size.
Today’s Activity • Simulate the Mark-recapture sampling method. • Packums: determining population size
Bell Work Take a couple of minutes and update your I-notebook: Table of contents Loose papers Number pages, etc.
Ecology Population Growth
Objectives TLW:Identify factors that affect population size. TLW:Differentiate between exponential growth and logistic growth.
Vocabulary Immigration Emigration Exponential Growth Logistic Growth
Population Growth Populations can increase in number or decrease in number. Factors that affect population size: Number of births Number of deaths And number of individual entering or leaving the population.
Population Growth More births than deaths = population growth More deaths than birth = population decline Birth rates = death rates = population stays the same
Population growth Immigration: the movement of individuals into an area, can cause a population to grow. Emigration: the movement of individuals out of an area, can cause a population to shrink.
Population Growth Models There are two models that are used to explain population growth: Exponential growth model Logistic growth model
Population Growth Models If resources are unlimited, population will grow exponentially. Exponential growth: when the individuals in a population reproduce at a constant rate. Growth rate at first is slow, then as the population gets larger it grows more quickly. A J-shaped curve indicates that the population is in exponential growth.
Exponential Growth • Exponential growth: resources are unrestricted so the given population quickly grows.
Generation # of bacteria time 1 1 0 2 2 15min 3 4 30min 4 8 45min 5 16 1hr 6 32 75min 7 64 90min 8 128 105min 9 256 2hrs 10 512 11 1024 12 2048 13 4096 3hrs 14 8192 15 16,384 16 32,768 17 65,536 4hrs 18 131,072 19 262,144 20 524,288 21 1,048,576 5hrs 22 2,097,152 23 4,194,304 24 8,388,608
Population Growth Models A population cannot continue to grow at an exponential rate due to limited resources such as: Food shortages Lack of space Accumulation of own waste products Lack of other resources like oxygen, living space etc.
Population Growth As resources become less available, the growth rate of a population slows or stops, called logistic growth. The growth pattern curve is S-shaped
Logistic Growth • Logistic growth: resources are limited so the growth of the population slows or stops.
A comparison of the logistic growth model and the exponential growth model Exponential growth Carrying capacity Logistic growth
Show me what you know 1. The number of individuals of a single species per unit is known as: Carrying capacity Logistic growth Population density Population growth rate
Show me what you know 2. The movement of individuals into an area is called Demography Carrying capacity Immigration Emigration
Show me what you know 3. The range or area occupied by a population is its Growth rate Geographic distribution Age structure Population denisty
Show me what you know 4. This graph represents Carrying capacity Exponential growth Logistic growth Limiting factor
Today’s assignment Problem-solving lab 4.1 (left-hand side) Exponential Growth Worksheet Due tomorrow: Mark-recapture lab write-up
Bell Work Some bacteria can reproduce every twenty minutes. Calculate the growth of a population of 10 bacteria for 24 hours. (Don’t forget – 10 bacteria are at time 0)
Ecology Limits to Population Growth
Objectives TLW:Identify factors that limit population growth. TLW:Relate limiting factors and carrying capacity
Vocabulary Limiting factors Carrying capacity
Limits to population Growth Limiting Factors: A factor that causes a population growth to decrease. Competition Predation Parasitism & disease Drought (climate extremes) Human disturbances
Limits to Population Growth When environmental factors limit a population’s growth rate the population is said to have reached its carrying capacity. Carrying Capacity: The number of organisms in a population that the environment can maintain or “carry” with no increase or decrease in the population. Birth rate = death rate
Today’s Assignment Grade I-notebooks Lesson of the Kaibab activity