Living Things InteractUnit B Chapter 2

Number of Insects Found

Red Blue Green Yellow

Hunt 1

Hunt 2

Hunt 3

Hunt 4

Investigation

1. Look at the different colored piece of paper in the container. These colored pieces will stand for insects that a bird is hunting.

2. Predict which color will be the easiest to find in grass, and the hardest. Record your predictions.

3. Spread the insects across the desk.

4. Each member will have 15 seconds to pick up as many insects as they can. You can only pick up one at a time.

5. Record the number of pieces for each color your group collected.

6. Put the collect insects back in the container and continue to fill in the chart. Total each column at the end.

Lesson 3:Ways in Which Organisms Compete

Why do you think we must compete for resources such as; food, water and shelter?

Competition for Limited Resources

Animals and plants must compete for resources because they are limited.

Competition -is a contest among organisms for different resources. Plants compete for:

Water

Sunlight

Animals compete for:

Food

Water

Shelter

Camouflage

Sharing Resources

In some communities animals live together and share resources.

A single tree can be a habitat for many organisms.

When resources become scarce some animals may die or have to find other forms of food.

Symbiosis

Symbiosis – is a long-term relationship between different kinds of organisms.

Mutualism – is when both organisms benefit. Bees and flowers is an

example

Instincts and Learned Behaviors

Instinct – a behavior that an organism inherits or is born with. Examples:

Penguins know how to swim.

Horses can walk soon after birth.

Spiders know how to spin a web.

Learned Behavior – behaviors learned from your parents, not inherited. Examples:

Playing a sport or an instrument.

Completing Math problems.

Review Questions

1. Why does a female sea turtle lay more than a thousand eggs at a time?

It increases their chance of survival.

2. How might the number of oak trees in a park affect the number of squirrels that can live there?

The more trees there, the more squirrels can live there.

3. What resources are sometimes shared by squirrels and certain birds?

Habitats, food, water

4. Think of an animal that lives in your area. What behaviors does it have for survival?

5. Which of the following is not a survival instinct for birds?

a) Building nests

b) Migrating

c) Eating insects

d) Learning to talk

Vanishing Habitats Investigation Log in to the computer using the proper log in for your

section.

Locate Ecuador, a small country in South America.

Study the table. It shows the size of Ecuador’s rain forests and the size of its human population between 1961 and 1991.

Calculate and record the changes in rain – forest area of each of the periods shown (61-71, 71-91). Then calculate and record the changes in population size for the same periods.

Year 1961 1971 1981 1991

Rain Forest(square km)

173,000 153,000 No Data 112,000

Population(in millions)

5.162 7.035 No Data 10.782

Continued

Create a double bar graph that shows changes in forest area and population size for these periods.

Open a Word Document from Microsoft Office.

Create a double bar graph using the graphing option.

What do you think causes most populations to become extinct or decline?

Population Decline

Most declines in populations are caused by humans.

Exotic – organisms not native to an area. Causes diseases

Reducing the size of natural habitats is caused by: Building roads

Houses

Businesses

Population Decline

Natural Disasters can change the environment and cause populations to decline. Floods

Droughts

Fire

Volcanoes

Hurricanes

This decline is usually temporary, unlike human activity.

Extinction

Extinct – the entire population dies and the organism is gone forever.

Dinosaurs aren’t the only extinct organisms.

A lot of other organisms are in danger of becoming extinct.

Organisms with populations spread out have a higher survival rate.

Endangered vs. Threatened

Endangered – organisms that are likely to become extinct if steps aren’t taken to save them right away.

Threatened – Organisms that are likely to become endangered if they are not protected.

Success!

DDT was a chemical used to kill insects, but it has harmed the environment.

One animal impacted was Bald Eagles.

Although they are still threated, the population is increasing thanks to scientists improving habitats and raising them in captivity.

Review Questions

1. Name a natural cause of decline in a population.

Natural disasters and food shortages

2. How is a threatened organism different from an endangered on?

A threated organism is not yet endangered, but become endangered if steps are taken to stop it from decreasing.

3. How many living individual are their in a population that is extinct?

None

4. Think of an animal or plant in your state. What changes in the environment could caused it become endangered or extinct?

5. It is impossible for an endangered organisms to recover if:

a) Its habitat is restored

b) Its population is too small

c) Hunting is stopped

d) It is bred in captivity