Bacteria and Viruses
Life Science - Middle School
Six Kingdoms of Life
Multimedia Lesson
Classification
Presentation
Six Kingdoms Overview
Presentation
Archaebacteria and Eubacteria
Presentation
Classifying Organisms
Virtual Lab
Kingdom Identification
Interactive
Bacteria and Viruses
Study Guide
Bacteria and Viruses
Quiz
Bacteria and Viruses
Flash Cards
Bacteria and Viruses
Worksheet
Bacteria and Viruses
Game
Bacteria and Viruses
Vocabulary List
Microlife - Bacteria, Fungi & Protists
Flip Chart
Microlife - Bacteria, Fungi & Protists
Flip Chart
Microlife
Flip Chart
Archaebacteria and Eubacteria
Flip Chart
Study Guide Bacteria and Viruses
❮
1
/
5
❯
BACTERIA AND VIRUSES Types of Bacteria Bacteria are the most abundant organisms on the planet and they live in almost every area on our Earth. Anton van Leeuwenhoek discovered them in the late 1600’s using a home-made microscope. Bacteria are single celled organisms that differ with other single celled organisms. No Nucleus They are prokaryotes, meaning that their DNA is in the cytoplasm because they do not have a nucleus. In addition to not having a nucleus, bacteria also do not have many of the other structures that are found in a eukaryotic cell. However, they still meet the criteria for being a living organism. Bacteria Structure There are three different shapes of bacteria: spiral, rod, and spherical shaped. The bacterium’s shape is determined by the chemicals that are found in the cell wall. This cell wall is rigid and protects it from most threats. Common structures that are found within the bacterial cell are ribosomes, cytoplasm, cell wall, cell membrane, and DNA. Lesson Checkpoint: What are the three possible shapes of bacteria? © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Flagella Bacteria also have flagella, which are hair-like structures that help an organism move by rotating. Flagella are fixed to the cell membrane and exit the cell wall through a pore. Bacteria can have one flagellum, more than one flagellum, or no flagella. If a bacterial cell does not have a flagellum then they cannot move unless another force, like the wind, helps them to move. Two Kingdoms of Bacteria There are two kingdoms of bacteria: Archaebacteria and Eubacteria. Archaebacteria thrive in extreme conditions that other organisms are not able to withstand. Most eubacteria do not live in extreme conditions. Rather, they live in places like our bodies. As you read this, there are billions of bacteria that are moving around on your body. Don’t worry; we have a mutually symbiotic relationship with them. Autotrophic eubacteria are thought to be responsible for the oxygen levels that exist in our atmosphere today. Reproduction of Bacteria Bacterial cells use a process of binary fission to reproduce, which is when one cell divides to form two identical daughter cells. Binary fission is a form of asexual reproduction. What Is Asexual Reproduction? Asexual reproduction is a process of cellular division that requires only one parent cell and produces two identical daughter cells. Some species of bacterial cells reproduce using a process known as sexual reproduction. Sexual reproduction produces a unique individual from genetic material from two parents. Bacteria sexually reproduce using a process known as conjugation. Conjugation is a process where a threadlike object joins the two prokaryotes together until the one of the bacterial cells DNA has been © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
transferred to the other. When the DNA has transferred completely, the two bacterial cells separate. Conjugation allows the DNA to be varied in the offspring. Role of Bacteria in Nature Overall, bacteria are more helpful than they are harmful. They help us to break down food within our bodies and they help to clean up the environment. Of course, there are some species of bacteria that are harmful and will give an organism some type of disease or cause other harmful effects. Bacteria produce many common foods that we eat on a regular basis, including yogurt, cheese, milk, pickles, etc. On the other hand, some bacteria cause food to spoil or go bad. This is done by the bacteria breaking the food chemicals down. Spoiled foods normally smell very bad and can make you sick if you eat those foods. Bacteria that live in soil keep our environment cleaner by helping to decompose dead organisms. Decomposers break down the large molecules of a dead organism into smaller molecules, which allows living organisms to use the molecules again. These bacteria are known as the recyclers because of their ability to change unusable molecules into usable molecules. Some species of bacteria feed on oil and gas. These bacteria are used by scientists to clean up an oil spill or a gas leak. They change the harmful chemicals of the oil and gas into harmless substances. Bacteria are also capable of causing infectious disease. An infectious disease is an illness that can be passed from one organism to another either directly of indirectly. An infectious disease can be spread directly by hugging, kissing, or touching a person that is infected. An infectious disease can be spread indirectly by sharing food or a drink or even inhaling particles of an infected person’s sneeze. In the year 1928, scientists developed a medicine that cured diseases caused by bacteria called antibiotics. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
An antibiotic is a compound that kills bacterial cells without damaging an organism’s own cells. Antibiotics have saved countless lives since their discovery. Types of Viruses A virus is very small particle that is nonliving and that invades and reproduces within a living cell. A virus is considered to be nonliving because it is not a cell. They also don’t use energy, grow, or respond to their environment. The only similarity that a virus has with a living cell is that it is able to reproduce. A virus needs a living cell in order to reproduce. The organism which a virus invades is called a host. As we learned in Topic 8, the host is an organism that is harmed by a parasite. Remember that this is a symbiotic relationship. Viruses act like a parasite; nearly all of them will destroy the cell that they invade. Every living organism could potentially be infected by a virus. A virus can be many different shapes and sizes. <image similar to the one at: http://www.bact.wisc.edu/themicrobialworld/Viruses2.jpg> A type of virus called a bacteriophage, meaning “bacteria eater,” infects bacterial cells. All viruses contain an outer coat with the genetic material inside of that coat. The DNA of a virus contains the information necessary to make new viruses. Lesson Checkpoint: What type of symbiotic relationship exists between a virus and the cell it invades? © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Bacteria, Viruses, and Disease Soon after a virus attaches to a cell, it quickly enters the cell. The virus’ DNA takes the cell over, directing all the cell functions. There are two different types of virus: active and hidden. The active virus takes charge of the cell immediately, telling the cell’s DNA to make new virus proteins and replicate the virus’ DNA. The DNA and proteins become new viruses. This process will continue until the cell has produced so many new viruses that the cell can no longer hold anymore and it bursts. The hidden virus enters a cell and its DNA joins together with the cell’s DNA. The virus will stay immobile until it decides to turn on and take over the functions of the cell. If you have ever had a cold, the flu, or chicken pox then you have had a viral infectious disease. Moderate viral infectious diseases include influenza, measles, rabies, and polio. With advances in medicine, these viral infectious diseases are generally mild. There are other viral infectious diseases that can cause death, such as acquired immunodeficiency syndrome (AIDS). There are no cures for viral infections, but there are medicines that relieve some of there symptoms. A vaccine is a molecule that causes the body to produce chemicals that will wipe out the virus or bacterial cells. Vaccines help to prevent the spread of infectious diseases by putting a dead or a changed version of the virus or bacterial cell into the body. This will put the body on alert to target and kill the invading virus or bacterial cell. © Copyright NewPath Learning. All Rights Reserved. Permission is granted for the purchaser to print copies for non-commercial educational purposes only. Visit us at www.NewPathLearning.com.
Table Of Contents: Six Kingdoms of Life
1. Classification
2.1. Why Do Scientists Classify Organisms?
There are millions of types of organisms that live on Earth. A classification system helps scientists study, record and share information about organisms in a systematic and useful way.
2.2. How Are Organisms Classified?
The science of classification is called taxonomy. Organisms are classified according to shared characteristics such as cell structure, physical appearance, how they obtain food and method of reproduction.
2.3. DNA Technology and Classification
DNA technology is also playing a role in classification. The study of gene sequences and mutations has enabled scientists to understand the evolutionary relationships between different organisms.
2.4. Levels of Classification
There are seven levels of classification—kingdom, phylum, class, order, family, genus and species.
2.5. Scientific Name
Each organism is identified by its scientific name, which includes the genus and species. For example, humans are called Homo sapiens.
2. Six Kingdoms Overview
3.1. What Are the Six Kingdoms?
All organisms are classified into six different kingdoms—archaebacteria, eubacteria, protists, fungi, plants and animals.
3.2. Archaebacteria and Eubacteria
From an evolutionary perspective, archaebacteria and eubacteria are the simplest organisms, having evolved billions of years ago.
3.3. Protists
Protists are more complex organisms with a variety of characteristics. Scientists believe that protists evolved from bacteria.
3.4. Fungi, Plants and Animals
Fungi, plants and animals all evolved from different types of protists.
3. Archaebacteria and Eubacteria
4.1. Characteristics of Bacteria
Bacteria are simple unicellular organisms that can be found in nearly every environment on Earth. All bacteria are prokaryotic—they do not have a true nucleus or organelles with membranes.
4.2. Two Bacterial Groups
DNA studies suggest that there are two distinct groups of bacteria. Therefore bacteria are divided into two kingdoms—archaebacteria and eubacteria.
4.3. Where Are Archaebacteria Found?
Some archaebacteria are found in extreme environments, such as hot springs and salt lakes, while other species live in the ocean and soil.
4.4. Where Are Eubacteria Found?
Eubacteria are more common than archaebacteria and are found in soil, water and our bodies.
4.5. Beneficial and Harmful Bacteria
Archaebacteria and eubacteria are diverse kingdoms of organisms that contribute to oxygen production, food production, decomposition, medical applications and biotechnology. Some bacteria are harmful and cause disease.
4. Protists
5.1. Characteristics of Protists
Protists are eukaryotic organisms that have a true nucleus and membrane-bound organelles. They typically live in or near water and can be unicellular or multicellular.
5.2. Variety of Protists
The protist kingdom includes organisms that are not classified as plants, animals or fungi. Protists are difficult to categorize because there is a wide variation of characteristics among species.
5.3. Protist Groups
Protists are often grouped according to whether they are animal-like, plant-like or fungus-like.
5.4. Protozoa
Animal-like protists are known as protozoa. They are single-celled organisms that move to find food. Amoeba and paramecium are classified as protozoa.
5.5. Algae
Plant-like protists, called algae, contain chloroplasts and make their own food by the process of photosynthesis. They are primarily found in fresh water. Examples include volvox, euglena and spirogyra.
5.6. Fungus-Like Protists
Fungus-like protists are heterotrophs that feed on decomposing matter. They reproduce using spores. Water molds, downy mildew and slime molds are fungus-like protists.
5. Pause and Interact
6.1. Review
Use the whiteboard text tool to complete the activity.
6. Fungi
7.1. Characteristics of Fungi
Fungi are heterotrophic eukaryotes that absorb nutrients from decomposing matter. Most are multicellular, but some, like yeast, are unicellular.
7.2. Parts of a Fungus
The bodies of most fungi are composed of filaments called hyphae. These hyphae grow into a large mass of cells called mycelium.
7.3. Fungus Reproduction
Most fungi reproduce using spores. Fungi are classified into three groups according to their sexual reproductive structures—zygote, sac and club fungi.
7.4. Beneficial Fungi
Many fungi are beneficial organisms, contributing to the recycling of nutrients, food production and medical advances.
7.5. Harmful Fungi
There are some fungi that are harmful and cause disease in animals and plants.
7. Plants
8.1. Plant Characteristics
Plants are multicellular eukaryotes that live primarily on land. They are autotrophic, obtaining energy through photosynthesis.
8.2. Cellulose and Chloroplasts
Plant cells are distinct because they have cell walls composed of cellulose. Chloroplasts inside the cells contain the pigment chlorophyll that is needed for photosynthesis.
8.3. How Are Plants Classified?
Plants are classified according to whether they have vascular systems, produce seeds and develop flowers.
8.4. Nonvascular Plants
Nonvascular plants absorb water and nutrients directly from their surroundings. They are seedless and are considered to be the most ancient land plants. Examples include liverworts, mosses and hornworts.
8.5. Seedless Vascular Plants
Ferns, club mosses and horsetails are seedless vascular plants that reproduce using spores. The vascular tissues, xylem and phloem, carry water and nutrients throughout the plant.
8.6. Gymnosperms
Gymnosperms are vascular plants that produce seeds, but do not have flowers. The seeds of most gymnosperms develop in the scales of cones.
8.7. Angiosperms
Angiosperms are flowering vascular plants that produce seeds inside a fruit.
8. Pause and Interact
9.1. Review
Use the whiteboard tools to complete the activity.
9. Animals
10.1. Animal Characteristics
All organisms in the animal kingdom are multicellular heterotrophs, and their cells lack cell walls. Most animals reproduce sexually, have some type of nervous system and are capable of movement.
10.2. Major Animal Groups
There are over 1.5 million known species of animals. This branching tree shows how major animal groups are possibly related.
10.3. Invertebrates
Invertebrates are animals without backbones. These animals live in water and on land. They account for over 95% of the known animal species.
10.4. Invertebrate Groups
Some of the major groups of invertebrates include sponges, worms, mollusks, echinoderms, cnidarians and arthropods.
10.5. Vertebrates
Vertebrates have a spinal cord encased by protective vertebrae. They also have an endoskeleton that is composed of cartilage or bone. Fish, amphibians, reptiles, birds and mammals are all vertebrates.
10. Pause and Interact
11.1. Kingdom Identification
Drag and drop each organism into the correct kingdom.
11. Vocabulary Review
12.1. Six Kingdoms of Life Vocabulary Matching
All organisms in the animal kingdom are multicellular heterotrophs, and their cells lack cell walls. Most animals reproduce sexually, have some type of nervous system and are capable of movement.
12. Virtual Investigation
13.1. Classifying Organisms
In this virtual investigation you will classify several organisms according to their distinguishing characteristics. Use the information provided and your knowledge of the six kingdoms to help identify each organism.
13. Assessment
14.1. Six Kingdoms of Life
NewPath Learning
About Us Our Team Awards & Endorsements Grants & Funding Product Suggestions Custom Publishing Collaborate Online Our BlogSolutions
Review & Reinforcement Intervention & Enrichment Test Prep After School/Summer School Parental Involvement Professional DevelopmentShop By Product
Curriculum Mastery Games Flip Charts Visual Learning Guides Curriculum Learning Modules E-Books/Workbooks Posters & Charts Study/Vocabulary Cards Digital Curriculum Online Learning Online Printable WorksheetsShop By Grade
Early Childhood First Grade Second Grade Third Grade Fourth Grade Fifth Grade Sixth Grade Seventh Grade Eighth Grade High School
© 2024 NewPath Learning all right reserved | Privacy Statements | Term of use | Website design WinMix Soft
