2.1

Question 1

What is a population?

Answer 1

A group of the same species in the same area at the same time

Question 2

What is population density?

Answer 2

The average amount organisms per unit of area

Question 3

What is population distribution?

Answer 3

How organisms are spread throughout an area.

Question 4

What makes population distribution different from population density?

Answer 4

Population distribution is how organisms are spread throughout a certain area, meaning that while you could have a small population density, the distribution could be in large clumps of the organism.

Question 5

What are the main types of population distribution?

Answer 5

Uniform - spaced out mostly evenly from one organism to another (penguins)

Clumped - clusters of an organism that are all throughout the area. (bison)

Random - organisms are in random spots. (plants carried by wind)

Question 5

What are the main reasons that organisms are in uniform, clumped, or random patterns?

Answer 5

Uniform - territoriality, resource scarcity, or uniform placement of resources.

Clumped - resource location or organism behavior

Random - Resources are uniform, but not scarce and organisms are independent of each other

Question 5

How do you calculate population density?

Answer 5

(total # of organisms)/(total area)

Question 5

What are the 2 main ways of indirectly counting a population?

Answer 5

Random sampling - done by using an area within a square called a quadrat to estimate the total number of organisms in a population (modeled with (# of organisms in sample)/(area of sample) = (total # of organisms)/(total area))

Mark and recapture - done by capturing a number of organisms, count and mark them, then release them. Then you recapture another number of that organism, count them and also count how many have marks. Using this, you then estimate the total number of organisms within a population (modeled with (total # of organisms)/(total marked) = (total # recaptured)/(# of recaptured with marks)

Question 6

Which way of indirect counting is best for plants?

Answer 6

Random sampling

Question 7

Which way of indirect counting is best for animals?

Answer 7

Mark and recapture

Question 8

You are collecting data on the estimated amount of dandelions in your backyard. You have counted 5 quadrats that are 1mx1m over the total area of 10m^2.

Quadrat 1 = 3 dandelions
Quadrat 2 = 1 dandelion
Quadrat 3 = 5 dandelions
Quadrat 4 = 2 dandelions
Quadrat 5 = 6 dandelions

Find the estimated size of the population?

Answer 8

x = total # dandelions

(total # of dandelions in sample)/(area of sample) = (x)/(total area)

= (17/5) * 10 = (x/10) * 10

= (170/5) = x
= 34 = x

Question 9

You are collecting data on the amount of rats there are in your yard. On one night, you capture and mark 30 rats in your yard. On the next night, you capture 25 rats, 10 of which are marked. What is the estimated size of the population?

Answer 9

x = total # of rats

(x)/(total marked) = (total recaptured)/(# recaptured with marks)

= (x/30) * 30 = (25/10) * 30
= x = (750/10)
= x = 75