lesson 1: understanding sciencemrsparsiolashomepage.weebly.com/uploads/1/3/3/4/13347586/... · web...

Environmental Science Name: ____ Period Date:

Section 1: Ecosystems: Everything is Connected

Objectives: Distinguish between the biotic and abiotic factors in an ecosystem Describe how a population differs from a species Explain how habitats are important for organisms

A. Definitions

1. Ecosystem : a community of organisms and their abiotic environment; all the organisms living in an area together with their physical environment

2. Biotic factor : an environmental factor that is associated with or results from the activities of living organisms

3. Abiotic factor : an environmental factor that is not associated with the activities of living organisms

4. Organism : a living thing; anything that can carry out life processes independently

5. Species : a group of organisms that are closely related and can mate to produce fertile offspring; also the level of classification below genus and above subspecies

6. Population : a group of organisms of the same species that live in a specific geographical area and interbreed

7. Community : a group of various species that lie in the same habitat and interact with each other

8. Habitat : the place where an organism usually lives

B. Ecosystems are connected

1. Seemingly unconnected things in nature can be linked together in a complex web.

Example: Gypsy moths kill oak trees. Scientists removed mice, which eat gypsy moths from an oak forest. Young moths increased dramatically. Scientists then added acorns, which attracted mice. The mice population increased and the gypsy moth population decreased. Acorns also attracted deer, which carry ticks. Ticks infested the mice and picked up the organism that causes Lyme disease from the mice. Ticks can bite and infect humans.

Ch.4 – The Organization of Life (pp. 92-115) 1


2. Oak forest ecosystem – mice, deer, moths, oak trees, and ticks

3. Other ecosystems examples – coral reef, vacant lot

4. People often think of ecosystems as isolated from each other, but ecosystems do not have clear boundaries.

C. The components of an Ecosystem

1. In order to survive, ecosystems need five basic components:a. energy – majority comes from the sunb. mineral nutrients c. water d. oxygen e. living organisms

2. Biotic and Abiotic Factors

a. Biotic factors are the living and once living parts of an ecosystem, which includes dead organisms, dead parts of organisms, such as leaves, and the organisms’ waste products.

b. Abiotic factors are the nonliving parts of the ecosystem, which includes air, water, rocks, sand, light, and temperature.

3. Various levels to the organization of living things: Biosphere – ecosystem – community – population – organism



4. Organisms – an individual living thing



a. History Connection: Swedish naturalist, Carolus Linnaeus, was the father of the binomial system used to identify species today. A species has a two-part Latin name: genus and species.

b. All humans belong to the species Homo sapiens.

5. Populations a. Important characteristic of a population – members usually breed with

one another rather than with members of other populationsb. example: bison in the same herd will mate or wildflowers in the same

field will pollinate with others nearby

6. Communitiesa. An organism does not live alone and neither does a population. Every

population is part of a community.

b. Example: Pond community includes all the populations of plants, fish, and insects that live in and around the pond.

c. Most obvious difference between communities – types of species in them

d. Land communities are often dominated by a few species of plants. Example: Colorado forest – ponderosa pine trees ; Louisiana swamp – bald cypress trees

C. Habitat

1. Examples of different habitats: pine forest for squirrel; rain forest for howler monkey; desert for cactus; pond for waterlily; damp forest floor for salamander

2. You can think of a habitat as an organism’s address.



3. Every habitat has specific characteristics that organisms need to survive. If any of these factors change, then the habitat changes.

4. Organisms tend to be very well suited to their habitats and cannot survive for long periods of time away from their natural habitat.



Section 2: Evolution

Objectives: Explain the process of evolution by natural selection Explain the concept of adaptation Describe the steps by which a population of insects becomes resistant

to a pesticide

1. Definitions: a. natural selection : the process by which individuals that have favorable

variations and are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do

b. evolution : a change in the characteristics of a population from one generation to the next; the gradual development of organisms from other organisms since the beginnings of life

c. adaptation : the process of becoming adapted to an environment; an anatomical, physiological, or behavioral change that improves a population’s ability to survive

d. artificial selection : the selective breeding of organisms (by humans) for specific desirable characteristics

e. resistance : in biology, the ability of an organism to tolerate a chemical or disease-causing agent

2. Organisms tend to be well suited to where they live and what they do. How do they become so well suited to their environments?

a. Evolution is a change in a genetic characteristic of a population from one generation to another. Evolution can happen in several ways:

Natural selection



Artificial Selection Resistance

3. Evolution by Natural Selection In 1859, English naturalist Charles Darwin proposed an answer. He

observed that organisms in a population differ slightly from each other in form, function, and behavior. His case study is called Darwin’s Finches.

o Some of the difference is hereditary that is passed from parent to offspring.

o Darwin also believed that the environment played a very strong role over which offspring would survive.

o Darwin used the term natural selection to describe the unequal survival and reproduction that results from the presence or absence of particular traits.

He proposed that natural selection causes characteristics of populations to change.

o Darwin thought that nature selects the traits that will go on for survival.

o Example: Species adapt and those that adapt survive.



Deer in north have thicker fur than deer in South: Believed that southern deer strayed from group and only the deer with the thicker fur survived the winters in the north. These deer kept having offspring with thicker fur.

o Darwin’s finches: The finches that survived the drought survived because their bills were stronger and longer. They could dig for food, so their offspring had larger bills. They survived.



Organisms evolve adaptations to other organisms as well as to their physical environment. The process of two species evolving in response to long-term interactions with each other is called coevolution.

o Example: The Hawaiian honeycreeper used its curved beak to sip nectar from a lobelia flower which has evolved structures that ensure the bird gets pollen on it head.

4. Evolution by Artificial Selectiona. Many populations of plants and animals do not live in the wild by instead

are cared for by humans. People control how these plants and animals reproduce and therefore how they evolve.



b. The selective breeding of organisms by humans for specific characteristics is called artificial selection.

c. Examples: Humans have bred ancestors of today’s wolves to produce the variety of dog breeds we have today and saved seeds from the largest, sweetest fruits and most nutritious grains.

5. Evolution of Resistancea. Sometimes humans cause populations of organisms to evolve unwanted

adaptations.



Examples: insect pests resistant to pesticides or bacterial resistant to antibiotics

b. Resistance is the ability of one or more organisms to tolerate a particular chemical designed to kill it.

c. Survivors happen to have a gene that protects them from the pesticide and this gets passed on to their offspring.

d. The faster an organism reproduces, the faster its populations can evolve.



Section 3: The Diversity of Living Things

Objectives: Name the six kingdoms of organisms and identify two characteristics of

each Explain the importance of bacteria and fungi in the environment Describe the importance of protists in the ocean environment Describe how angiosperms and animals depend on each other Explain why insects are such successful animals

1. Definitions:a. bacteria : extremely small, single-celled organisms that usually have a

cell wall and reproduce by cell divisionb. fungus : an organism whose cells have nuclei, rigid cell walls, and no

chlorophyll and that belongs to the kingdom Fungic. protist : an organism that belongs to the kingdom Protistad. gymnosperm : a woody vascular seed plant whose seeds are not enclosed

by an ovary or fruite. angiosperm : a flowering plant that produces seeds within a fruitf. invertebrate : an animal that does not have a backboneg. vertebrate : an animal that has a backbone; includes mammals, birds,

reptiles, amphibians, and fish

2. The Diversity of Living Thingsa. Scientist classify organisms into six kingdoms based on different

characteristics.1. Archaebacteria 2. Eubacteria 3. Fungi 4. Protista 5. Plantae 6. Animalia



b. The cells of animals, plants, fungi, and protists contain a nucleus (membrane bound organelle containing the cell’s genetic material).

c. A characteristic shared by bacteria, fungi, and plants is the cell wall (a structure that surrounds a cell and provides it with rigid support).



1. Bacteriaa. Characteristics:

1. single-celled organisms 2. lack nuclei 3. reproduce by dividing in half 4. usually have cell walls 5. live in every habitat on Earth (hot springs to animal bodies)

b. Two main kinds1. Archaebacteria – live in extreme environments; methanogens,

thermophiles, halobacteria



2. Eubacteria – most bacteria, including disease-causing and soil-dwelling

c. Role in environment1. break down the remains and wastes of other organisms and

return nutrients to soil2. recycle mineral nutrients, such as nitrogen and phosphorous 3. converting nitrogen in the air into a usable form for plants –

Nitrogen is a main component in proteins and genetic material.4. Escherichia coli (E. coli) – found in the human intestine – helps

digest food and release vitamins that humans need

2. Fungia. Characteristics

1. Have nuclei, cell walls, and no chlorophyll (the pigment that makes plants green)

2. Absorb their food from their surroundings by releasing chemicals that help break down organic matter (decaying organisms)

3. Huge network of threads that grow through the soil, dead wood, or other material

b. Examples1. Yeast 2. Mushrooms 3. Molds 4. Mildews

c. Roles in Environment1. Break down the bodies and body parts of dead organisms 2. Some cause disease , such as athlete’s foot



3. Add flavor to food , such as taste of blue cheese4. Used in cooking , mushrooms for flavor, yeast produces gas that

makes bread rise or used in fermentation process at a brewery

3. Protistsa. Characteristics

1. most are unicellular, but some are multicellular 2. most live in water

b. Examples1. Amoeba – animallike unicellular

organism

2. Diatoms – float on the ocean’s surface

3. Plasmodium – unicellular organism that causes malaria

4. Algae – plantlike organisms that produce their own food from the sun’s energy: kelp, pond “scum”, seaweed, phytoplankton (initial source of food in most ocean and freshwater ecosystems)

4. Plantsa. Characteristics

1. multicellular 2. make their own food by photosynthesis 3. have cell walls



b. Examples1. lower plants

ferns mosses

2. trees 3. herbs 4. grasses

c. Plants have a vascular tissue, which is a system of tubes that carry water and food from the roots to the leaves and act as a support for the plant.

d. Plants have roots that tap mineral and water resources from underground; and leaves that intercept light, oxygen, and carbon dioxide from the air.

e. Pine trees and other evergreens are common examples of gymnosperms. Pine trees are called conifers because they bear cones.

f. Gymnosperm adaptations1. produce pollen – protects and moves sperm between plants2. produce seeds – protect developing plants from drying out3. conifer’s needle-like leaves lose little water

g. Most land plants are angiosperms. The flower is the reproductive structure of the plant.

1. Grasses have small flowers that produce pollen carried by the wind.

2. Large flowers of other angiosperms attract insects or birds that carry their pollen to other plants.



h. Most land animals are dependent on flowering plants for food. We eat wheat, rice, beans, oranges, and lettuce, which come from flowering plants. Building materials and fibers, such as oak or cotton, also come from flowering plants.

5. Animalsa. Characteristics

1. multicellular 2. no cell walls 3. ingest their food from their environment 4. live on land and in water

b. Two kinds1. Invertebrates 2. Vertebrates

c. Insects are the most successful type of animal on Earth.

d. Reasons why insects are so successful:



1. waterproof external skeleton 2. move quickly 3. reproduce quickly 4. most can fly 5. need little food and can hide from enemies in small spaces due to

their size

e. Many insects and plants have evolved together and depend on each other to survive. Example: insect pollination

f. Insects eat other insects that we consider pests.

g. Humans and insects are often enemies. Example: mosquitoes transmit human disease like malaria, sleeping sickness, and West Nile virus. They also eat our crops.

h. Vertebrate adaptations:1. amphibians partially aquatic – return to water to lay their eggs

2. reptiles – 1st land vertebrate – have an almost waterproof egg, which allows the egg to hatch on land away from predators in the water

3. birds – warm-blooded – have hard shell eggs

4. mammals – warm-blooded – have fur and feed their young milk

5. High body temperature allows birds and mammals to live in cold areas, where other animals cannot survive.



The Organization of Life


An ecosystem

biotic factors abiotic factors

populations

species habitats

community

is made of

which include

of different which live in

that form a

lesson 1: understanding sciencemrsparsiolashomepage.weebly.com/uploads/1/3/3/4/13347586/... · web...

Documents