18 1 section objectives page 475
This presentation is the property of its rightful owner.
Sponsored Links
1 / 106

18.1 Section Objectives – page 475 PowerPoint PPT Presentation


  • 92 Views
  • Uploaded on
  • Presentation posted in: General

18.1 Section Objectives – page 475. Section Objectives: 18.1. Identify the different kinds of viruses and their structures. Compare and contrast the replication cycles of viruses. Section 18.1 Summary – pages 475-483. You’ve probably had the flu—influenza—at some time during your life.

Download Presentation

18.1 Section Objectives – page 475

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


18 1 section objectives page 475

18.1 Section Objectives – page 475

Section Objectives: 18.1

  • Identify the different kinds of viruses and their structures.

  • Compare and contrast the replication cycles of viruses.


Section 18 1 summary pages 475 483

Section 18.1 Summary – pages 475-483

  • You’ve probably had the flu—influenza—at some time during your life.

  • Nonliving particles called _______ cause influenza.

  • Viruses are composed of _____ ______ enclosed in a ______ coat and are smaller than the smallest bacterium.


Section 18 1 summary pages 475 4831

Section 18.1 Summary – pages 475-483

  • Most biologists consider viruses to be _______ because they don’t exhibit all the ______ for life.

  • They don’t carry out respiration, grow, or develop. All viruses can do is _______—make copies of themselves—and they can’t even do that without the help of living cells.

  • A cell in which a virus replicates is called the _____cell.


Section 18 1 summary pages 475 4832

Section 18.1 Summary – pages 475-483

  • Viruses, such as _____ viruses and _____ viruses, were named after the diseases they cause.

  • Other viruses were named for the _____ or ______ they infect.


Section 18 1 summary pages 475 4833

Section 18.1 Summary – pages 475-483

  • Today, most viruses are given a ______ name ending in the word “virus” and a ______ name.

  • However, sometimes scientists use ____ numbers to distinguish among similar viruses that infect the same ____.

  • A virus that infects a bacterium is called a __________ (bak TIHR ee uh fayj), or phage for short.


Section 18 1 summary pages 475 4834

Section 18.1 Summary – pages 475-483

  • A virus has an inner core of nucleic acid, either ___ or ___, and an outer protein coat called a ____.

Capsid

Nucleic

acid

Envelope


Section 18 1 summary pages 475 4835

Section 18.1 Summary – pages 475-483

  • Some relatively large viruses, such as human ___ viruses, may have an additional layer, called an _______, surrounding their capsids.

Capsid

Nucleic

acid

Envelope


Section 18 1 summary pages 475 4836

Section 18.1 Summary – pages 475-483

  • Envelopes are composed primarily of the same materials found in the ______ membranes of all cells.

Capsid

Nucleic

acid

Envelope


Section 18 1 summary pages 475 4837

Section 18.1 Summary – pages 475-483

Nucleic acid

  • ___ nucleic acid is either DNA or RNA and contains instructions for making copies of the virus.

Capsid

  • Some viruses have only four _____, while others have hundreds.


Section 18 1 summary pages 475 4838

Section 18.1 Summary – pages 475-483

Nucleic acid

  • The _____ _____ virus has a long, narrow _______ shape.

Capsid


Section 18 1 summary pages 475 4839

Section 18.1 Summary – pages 475-483

  • The arrangement of _____ in the capsid of a virus determines the virus’s _____.

Capsid

Nucleic acid

  • ________ viruses resemble small crystals.


Section 18 1 summary pages 475 48310

Section 18.1 Summary – pages 475-483

  • The protein arrangement also plays a role in determining what cell can be _______ and how the virus infects the cell.

Nucleic acid

Capsid


Section 18 1 summary pages 475 48311

Section 18.1 Summary – pages 475-483

  • Before a virus can replicate, it must ____ a host cell.

  • A virus recognizes and ______ to a host cell when one of its ______ interlocks with a molecular shape that is the ______ site on the host cell’s plasma membrane.


Section 18 1 summary pages 475 48312

Section 18.1 Summary – pages 475-483

  • A protein in the ___ fibers of the bacteriophage __ recognizes and attaches the T4 to its bacterial host cell.

Capsid

Nucleic

acid

Tail

Tail fiber


Section 18 1 summary pages 475 48313

Section 18.1 Summary – pages 475-483

Capsid

  • In other viruses, the attachment protein is in the ____ or in the envelope.

Nucleic

acid

Tail

Tail fiber


Section 18 1 summary pages 475 48314

Section 18.1 Summary – pages 475-483

  • Each virus has a ________ shaped attachment protein. Therefore, each virus can usually attach to only a few kinds of cells.

  • In general, viruses are species specific, and some also are ____-type specific. For example, polio viruses normally infect only intestinal and nerve cells.


Section 18 1 summary pages 475 48315

Section 18.1 Summary – pages 475-483

  • The species specific characteristic of viruses is significant for controlling the spread of _____ diseases.


Section 18 1 summary pages 475 48316

Section 18.1 Summary – pages 475-483

  • Once attached to the plasma membrane of the host cell, the virus _____ the cell and takes over its ________.

  • Only then can the virus ________.

  • Viruses have ____ways of getting into host cells.


Section 18 1 summary pages 475 48317

Section 18.1 Summary – pages 475-483

  • The virus may _____its nucleic acid into the host cell like a syringe injects a vaccine into your arm.

  • The _____ of the virus stays attached to the outside of the host cell.

  • An ________ virus enters a host cell in a different way.


Section 18 1 summary pages 475 48318

Section 18.1 Summary – pages 475-483

  • After attachment, the plasma membrane of the host cell surrounds the virus and produces a virus-filled vacuole inside the host cell’s cytoplasm.

  • Then, the virus bursts out of the vacuole and releases its nucleic acid into the cell.


Section 18 1 summary pages 475 48319

Section 18.1 Summary – pages 475-483

  • Once inside the host cell, a virus’s genes are _________ and the substances that are produced take over the host cell’s genetic material.

  • The ____ genes alter the host cell to make new viruses.


Section 18 1 summary pages 475 48320

Section 18.1 Summary – pages 475-483

Bacteriophage

Bacterial DNA

Nucleic

acid

Bacterial

host cell

B. Entry

A. Attachment

The bacteriophage

injects its nucleic acid

into the bacterial cell.

E. Lysis and Release

The host cell breaks open and

releases new virus particles.

C. Replication

D. Assembly

The host’s metabolic

machinery makes viral

nucleic acid and proteins.

New virus particles

are assembled.


Section 18 1 summary pages 475 48321

Section 18.1 Summary – pages 475-483

  • The host cell uses its own _______, raw materials, and energy to make copies of viral genes that along with viral proteins are assembled into new viruses, which _____ from the host cell, killing it.


Section 18 1 summary pages 475 48322

Section 18.1 Summary – pages 475-483

  • The new viruses can then infect and kill other host cells. This process is called a ____ (LIH tik) _____.


Section 18 1 summary pages 475 48323

Section 18.1 Summary – pages 475-483

  • Not all viruses ____ the cells they infect.

  • Some viruses go through a ________ cycle, a replication cycle in which the virus’s nucleic acid is ________ into the host cell’s chromosome.


Section 18 1 summary pages 475 48324

Section 18.1 Summary – pages 475-483

  • A ________ cycle begins in the same way as a lytic cycle.

  • However, in a lysogenic cycle, instead of _________ taking over the host’s genetic material, the viral DNA is integrated into the host cell’s chromosome.


Section 18 1 summary pages 475 48325

Section 18.1 Summary – pages 475-483

  • Many disease-causing ______ have lysogenic cycles.

  • Three examples of these viruses are ____ _____ I, herpes simplex II that causes ______ herpes, and the _______ B virus that causes hepatitis B.


Section 18 1 summary pages 475 48326

Section 18.1 Summary – pages 475-483

  • Another lysogenic virus is the one that causes _____ ___.


Section 18 1 summary pages 475 48327

Section 18.1 Summary – pages 475-483

  • Having chicken pox, which usually occurs before age ten, gives lifelong protection from another infection by the ___. However, some chicken pox viruses may remain as _________ in some of your body’s nerve cells.


Section 18 1 summary pages 475 48328

Section 18.1 Summary – pages 475-483

  • Later in your life, these proviruses may enter a lytic cycle and cause a disease called _______—a painful infection of some nerve cells.


Section 18 1 summary pages 475 48329

Section 18.1 Summary – pages 475-483

  • Either lysis, the bursting of a cell, or ______, the active transport process by which materials are expelled from a cell, release new viruses from the host cell.


Section 18 1 summary pages 475 48330

Section 18.1 Summary – pages 475-483

  • In exocytosis, a newly produced virus approaches the inner surface of the host cell’s _______ membrane.

  • The plasma membrane surrounds the virus, enclosing it in a _____ that then fuses with the host cell’s plasma membrane.

  • Then, the ______are released to the outside.


Section 18 1 summary pages 475 48331

Section 18.1 Summary – pages 475-483

  • Many viruses, such as the _____ _______________ ____(HIV) that causes the disease AIDS, are RNA viruses—RNA being their only nucleic acid.

HIV virus


Section 18 1 summary pages 475 48332

Section 18.1 Summary – pages 475-483

  • Once inside a human host, HIV infects _____ blood cells.

Normal white blood cells

  • Newly made viruses are released into the blood stream by ________ and infect other white blood cells.


Section 18 1 summary pages 475 48333

Section 18.1 Summary – pages 475-483

  • Infected host cells still function normally because the viral genetic material is a ______ that produces only a small number of new viruses at a time.

  • Because the infected cells are still able to function normally, an infected person may not appear _____, but they can still ____ the virus in their body fluids.


Section 18 1 summary pages 475 48334

Section 18.1 Summary – pages 475-483

  • Most people with an HIV infection eventually get ____ because, over time, more white blood cells are infected and produce new viruses.

  • Because white blood cells are part of a body’s ______-fighting system, their destruction interferes with the body’s ability to protect itself from organisms that cause disease, a symptom of AIDS.


Section 18 1 summary pages 475 48335

Section 18.1 Summary – pages 475-483

  • Some viruses have been linked to certain ______ in humans and animals.

  • These viruses disrupt the normal growth and division of cells in a host, causing abnormal growth and creating _______.


Section 18 1 summary pages 475 48336

Section 18.1 Summary – pages 475-483

  • Researchers have recently discovered some particles that behave somewhat like viruses and cause infectious diseases.

  • Prions are composed of proteins but have no nucleic acid to carry genetic information.


Section 18 1 summary pages 475 48337

Section 18.1 Summary – pages 475-483

  • Prions are thought to act by causing other proteins to fold themselves incorrectly, resulting in improper functioning.

  • Prions are responsible for many animal diseases, such as mad cow disease and its human equivalent, Creutzfeldt-Jakob disease.


Section 18 1 summary pages 475 48338

Section 18.1 Summary – pages 475-483

  • Viroids are composed of a single circular strand of RNA with no protein coat.

  • Viroids have been shown to cause infectious diseases in several plants.

  • The amount of viroid RNA is much less than the amount found in viruses.


Section 18 1 summary pages 475 48339

Section 18.1 Summary – pages 475-483

  • The first virus to be identified was a plant virus, called tobacco mosaic virus, that causes disease in tobacco plants.

Tobacco mosaic virus causes yellow spots on tobacco leaves, making them unmarketable.


Section 18 1 summary pages 475 48340

Section 18.1 Summary – pages 475-483

  • Viruses cause as many as 1000 plant diseases and are named according to their host plant.

  • Viruses can cause stunted growth and yield losses in their host plants.


Section 18 1 summary pages 475 48341

Section 18.1 Summary – pages 475-483

  • Plant viruses require wounds or insect bites to enter and infect a host, and do not use surface recognition.

  • They do not undergo lytic or lysogenic phases.


Section 18 1 summary pages 475 48342

Section 18.1 Summary – pages 475-483

  • Not all viral plant diseases are fatal or even harmful.

  • Some mosaic viruses cause striking patterns of color in the flowers of plants.

Rembrandt tulips


Section 18 1 summary pages 475 48343

Section 18.1 Summary – pages 475-483

  • For replication, viruses need host cells; therefore, scientists suggest that viruses might have originated from their host cells.

  • Some scientists suggest that viruses are nucleic acids that break free from their host cells while maintaining an ability to replicate parasitically within the host cells.


Section 2 objectives page 484

Section 2 Objectives – page 484

Section Objectives 18.2

  • Compare the types of prokaryotes.

  • Explain the characteristics and adaptations of bacteria.

  • Evaluate the economic importance of bacteria.


Section 18 2 summary pages 484 495

Section 18.2 Summary – pages 484-495

  • Recall that prokaryotes are _________organisms that do not have a nucleus or membrane-bound organelles.

  • They are classified in two kingdoms—_________ and ________.

  • Many _________ differences exist between these two types of prokaryotes.


Section 18 2 summary pages 484 4951

Section 18.2 Summary – pages 484-495

  • Because they are so different, many scientists propose that archaebacteria and eubacteria arose from a _______ ancestor several billion years ago.


Section 18 2 summary pages 484 4952

Section 18.2 Summary – pages 484-495

  • There are ____ types of archaebacteria that live mainly in extreme habitats where there is usually no free ______ available.

  • One type of archaebacterium lives in oxygen-free environments and produces ______ gas.


Section 18 2 summary pages 484 4953

Section 18.2 Summary – pages 484-495

  • These methane-producing archaebacteria live in marshes, lake sediments, and the digestive tracts of some ________, such as cows.


Section 18 2 summary pages 484 4954

Section 18.2 Summary – pages 484-495

  • They also are found at sewage disposal plants, where they play a role in the ______ of sewage.


Section 18 2 summary pages 484 4955

Section 18.2 Summary – pages 484-495

  • A second type of archaebacterium lives only in water with ____ concentrations of salt.

Dead Sea


Section 18 2 summary pages 484 4956

Section 18.2 Summary – pages 484-495

  • A third type lives in the hot, acidic waters of ______ springs.


Section 18 2 summary pages 484 4957

Section 18.2 Summary – pages 484-495

  • This type of anaerobic archaebacterium also thrives near cracks deep in the ocean floor, where it is the _______ producer for a unique animal community’s food chain.


Section 18 2 summary pages 484 4958

Section 18.2 Summary – pages 484-495

  • ________, the other kingdom of prokaryotes, includes those prokaryotes that live in places more hospitable than archaebacteria inhabit and that vary in nutritional needs.

  • The ____________ eubacteria live almost everywhere and use organic molecules as their food source.


Section 18 2 summary pages 484 4959

Section 18.2 Summary – pages 484-495

  • Some bacterial heterotrophs are ______, obtaining their nutrients from living organisms.

  • Others are _______—organisms that feed on dead organisms or organic wastes.


Section 18 2 summary pages 484 49510

Section 18.2 Summary – pages 484-495

  • A second type of eubacterium is the ___________ autotroph.

  • These eubacteria live in places with ________ because they need light to make the organic molecules that are their food.


Section 18 2 summary pages 484 49511

Section 18.2 Summary – pages 484-495

  • ___________ are photosynthetic autotrophs.

  • Most cyanobacteria are _______ and some are red or yellow in color.

Cyanobacteria


Section 18 2 summary pages 484 49512

Section 18.2 Summary – pages 484-495

  • Cyanobacteria commonly live in ponds, streams, and moist areas of land.

  • They are composed of chains of independent cells.

Cyanobacteria


Section 18 2 summary pages 484 49513

Section 18.2 Summary – pages 484-495

  • A third type of eubacterium is the _________ autotroph.

  • Unlike the photosynthetic bacteria, the chemosynthetic bacteria do not obtain the energy they need to make food from _______.


Section 18 2 summary pages 484 49514

Section 18.2 Summary – pages 484-495

  • Instead, they break down and release the energy of inorganic compounds containing sulfur and nitrogen in the process called ____________.


Section 18 2 summary pages 484 49515

Section 18.2 Summary – pages 484-495

  • A _________ consists of a very small cell.

  • Although tiny, a bacterial cell has all the ________ necessary to carry out its life functions.


Section 18 2 summary pages 484 49516

Section 18.2 Summary – pages 484-495

  • Prokaryotic cells have ribosomes, but their ribosomes are smaller than those of eukaryotes.

  • They also have genes that are located for the most part in a single circular chromosome, rather than in paired chromosomes.


Section 18 2 summary pages 484 49517

Section 18.2 Summary – pages 484-495

Ribosome

Cytoplasm

Chromosome

Flagellum

Cell Membrane

Gelatinlike

capsule

Cell Wall


Section 18 2 summary pages 484 49518

Section 18.2 Summary – pages 484-495

  • A typical bacterium, such as _____________would have some or all of the structures shown in this diagram of a bacterial cell.

Cell Wall

Capsule

Chromosome

Plasma membrane

Flagellum

Plasmid

Pilus


Section 18 2 summary pages 484 49519

Section 18.2 Summary – pages 484-495

  • A bacterial cell remains intact as long as its cell ____ is intact.

  • If the cell wall is damaged, ____ will enter the cell by osmosis, causing the cell to burst.

  • Scientists used a bacterium’s need for an intact cell wall to develop a weapon against bacteria that cause ________.


Section 18 2 summary pages 484 49520

Section 18.2 Summary – pages 484-495

  • In 1928, Sir Alexander Fleming accidentally discovered _______, the first antibiotic—a substance that destroys bacteria—used in humans.


Section 18 2 summary pages 484 49521

Section 18.2 Summary – pages 484-495

  • Later, biologists discovered that penicillin can _______ with the ability of some bacteria to make cell walls.

  • When such bacteria grow in penicillin, holes develop in their cell walls, water enters their cells, and they rupture and die.


Section 18 2 summary pages 484 49522

Section 18.2 Summary – pages 484-495

  • One trait that helps categorize bacteria is how they react to _____ stain.

  • Gram staining is a technique that distinguishes ___ groups of bacteria because the stain reflects a basic difference in the composition of bacterial cell walls.


Section 18 2 summary pages 484 49523

Section 18.2 Summary – pages 484-495

  • After staining, Gram-_______ bacteria are _____ and Gram-_______ bacteria are _____.

Gram-positive bacteria

Gram-negative bacteria


Section 18 2 summary pages 484 49524

Section 18.2 Summary – pages 484-495

  • Gram-positive bacteria are affected by different antibiotics than those that affect Gram-negative bacteria.

Gram-positive bacteria

Gram-negative bacteria


Section 18 2 summary pages 484 49525

Section 18.2 Summary – pages 484-495

  • Bacterial cell walls also give bacteria different _____.


Section 18 2 summary pages 484 49526

Section 18.2 Summary – pages 484-495

  • The three most common shapes are spheres, called _____; rods, called _____; and spirals, called ________.


Section 18 2 summary pages 484 49527

Section 18.2 Summary – pages 484-495

  • In addition to having one of these shapes, bacterial cells often grow in characteristic _______ that provide another way of categorizing them.


Section 18 2 summary pages 484 49528

Section 18.2 Summary – pages 484-495

  • _____–is a prefix that refers to a paired arrangement of cell growth.

  • The prefix _______–describes an arrangement of cells that resemble grapes.

  • _______–is a prefix that refers to an arrangement of chains of cells.


Section 18 2 summary pages 484 49529

Section 18.2 Summary – pages 484-495

  • Bacteria reproduce ______ by a process known as ______ _______.

  • To reproduce in this way, a bacterium first copies its chromosome. Then the original chromosome and the copy become attached to the cell’s plasma membrane for a while.


Section 18 2 summary pages 484 49530

Section 18.2 Summary – pages 484-495

  • The cell grows ____, and eventually the two chromosomes separate and move to opposite ends of the cell.


Section 18 2 summary pages 484 49531

Section 18.2 Summary – pages 484-495

  • Then, a _______ forms between the chromosomes. This partition separates the cell into ___ similar cells.


Section 18 2 summary pages 484 49532

Section 18.2 Summary – pages 484-495

  • Because each new cell has either the original or the copy of the chromosome, the resulting cells are genetically identical.


Section 18 2 summary pages 484 49533

Section 18.2 Summary – pages 484-495

  • Under ideal conditions, some bacteria can reproduce every ___ minutes, producing enormous numbers of bacteria quickly.

  • But bacteria don’t always have ideal growing conditions. They run out of nutrients and water, they poison themselves with their own ______, and predators eat them.


Section 18 2 summary pages 484 49534

Section 18.2 Summary – pages 484-495

  • In addition to binary fission, some bacteria have a form of sexual reproduction called ______________.

  • During conjugation (kahn juh GAY shun), one bacterium ______ all or part of its chromosome to another cell through or on a bridge-like structure called a ____ that connects the two cells.


Section 18 2 summary pages 484 49535

Section 18.2 Summary – pages 484-495

  • Conjugation results in a bacterium with a ___ genetic composition.

  • This bacterium can then undergo binary fission, producing more cells with the same genetic makeup.


Section 18 2 summary pages 484 49536

Section 18.2 Summary – pages 484-495

  • Based on fossil evidence, some scientists propose that ______ bacteria were probably among the first photosynthetic organisms, producing not only their own food but also oxygen.

  • As the concentration of oxygen increased in Earth’s atmosphere, some bacteria probably _______ over time to use oxygen for respiration.


Section 18 2 summary pages 484 49537

Section 18.2 Summary – pages 484-495

  • Modern bacteria have diverse types of ______________.

  • Many bacteria require ________ for respiration. These bacteria are called ______ _________.

  • There are other bacteria, called obligate _________, that are killed by oxygen.


Section 18 2 summary pages 484 49538

Section 18.2 Summary – pages 484-495

  • There are still other bacteria that can live either with or without oxygen, releasing the energy in food _________ by cellular respiration or anaerobically by _______.


Section 18 2 summary pages 484 49539

Section 18.2 Summary – pages 484-495

  • Some bacteria, when faced with unfavorable environmental conditions, produce _______.

  • An _________ is a tiny structure that contains a bacterium’s ___ and a small amount of its ________, encased by a tough outer covering that resists drying out, temperature extremes, and harsh chemicals.


Section 18 2 summary pages 484 49540

Section 18.2 Summary – pages 484-495

  • As an ________, the bacterium rests and does not _________.

  • When environmental conditions improve, the endospore ________, or produces a cell that begins to grow and reproduce.


Section 18 2 summary pages 484 49541

Section 18.2 Summary – pages 484-495

  • __________ can survive a temperature of 100˚C, which is the boiling point of water.


Section 18 2 summary pages 484 49542

Section 18.2 Summary – pages 484-495

  • To kill endospores, items must be ________—heated under high pressure in either a pressure cooker or an _______.


Section 18 2 summary pages 484 49543

Section 18.2 Summary – pages 484-495

  • Canned food must be sterilized and _______.

  • This is because the endospores of the bacterium called ________ ________ easily get into foods being canned.


Section 18 2 summary pages 484 49544

Section 18.2 Summary – pages 484-495

  • If the endospores of C. botulinum get into improperly sterilized canned food, they germinate.

  • Bacteria grow in the ________ environment of the can and produce a powerful deadly poison, called a _____, as they grow.

  • This deadly toxin saturates the food and, if eaten, causes the disease called _______.


Section 18 2 summary pages 484 49545

Section 18.2 Summary – pages 484-495

  • A different bacterium, Bacillus _______, lives in the soil.

  • B. anthracis causes ______, a disease that commonly infects cattle and sheep, but can also infect humans.

  • Most human anthrax infections are fairly harmless and occur on the ___ as a result of handling animals.


Section 18 2 summary pages 484 49546

Section 18.2 Summary – pages 484-495

  • The bacterial _________ can become airborne, however, and if inhaled in large amounts, can germinate in a person’s lungs, causing an infection.

  • This infection is more serious than a skin infection and often _______.


Section 18 2 summary pages 484 49547

Section 18.2 Summary – pages 484-495

  • Disease-causing bacteria are few compared with the number of harmless and beneficial bacteria on Earth.

  • Bacteria help to _______ fields, to recycle nutrients on Earth, and to produce foods and ________.


Section 18 2 summary pages 484 49548

Section 18.2 Summary – pages 484-495

  • All organisms need ________ because the element is a component of their proteins, ____, ____, and ___.

  • Yet few organisms, including most plants, can directly use _______ from the air.


Section 18 2 summary pages 484 49549

Section 18.2 Summary – pages 484-495

  • Several species of bacteria have enzymes that convert __into ammonia (___) in a process known as _______ _______.

  • Other bacteria then convert the ammonia into nitrite ____and nitrate ______which plants can use.

  • _______ are the only organisms that can perform these chemical changes.


Section 18 2 summary pages 484 49550

Section 18.2 Summary – pages 484-495

  • Some nitrogen-fixing bacteria live ________ within the roots of some trees and ______.

  • Farmers grow legume crops after the harvesting of crops such as _____, which depletes the soil of nitrogen.


Section 18 2 summary pages 484 49551

Section 18.2 Summary – pages 484-495

  • ________ bacteria and also plants and algae, which are at the bottom of the food chains, use the nutrients in the food they make.

  • This food is passed from one _________ to the next in food chains and webs.

  • In the process of making food, many autotrophs replenish the supply of ______ in the atmosphere.


Section 18 2 summary pages 484 49552

Section 18.2 Summary – pages 484-495

  • Some foods that you eat—mellow Swiss cheese, crispy pickles, tangy yogurt—would not _____ without bacteria.


Section 18 2 summary pages 484 49553

Section 18.2 Summary – pages 484-495

  • Specific bacteria are used to make different foods, such as ______, cheeses, and ________.

  • Bacteria also inhabit your _______ and produce _______ and _______ that help digest food.


Section 18 2 summary pages 484 49554

Section 18.2 Summary – pages 484-495

  • In addition to food, some bacteria produce important ________ that destroy other types of bacteria.

  • ________, ________, bacitracin, and neomycin are some of these antibiotics.


Section 18 2 summary pages 484 49555

Section 18.2 Summary – pages 484-495

  • Bacteria cause diseases in plants and animals, causing crops and livestock losses that impact humans indirectly.

  • Bacteria also cause many human diseases.

  • Disease-causing bacteria can enter human bodies through openings, such as the mouth.


Section 18 2 summary pages 484 49556

Section 18.2 Summary – pages 484-495

  • Bacterial diseases harm people in two ways.

  • The growth of the bacteria can interfere with the normal function of body _)___, or it can release a _____ that directly attacks the host.


Section 18 2 summary pages 484 49557

Section 18.2 Summary – pages 484-495

Diseases Caused by Bacteria

Treatment

Transmission

Symptoms

Disease

Fever, sore throat,

swollen neck glands

Antibiotic

Inhale or

ingest through

mouth

Strep throat

(Streptococcus)

Antibiotic

Inhale

Fatigue, fever, night

sweats, cough, weight

loss, chest pain

Tuberculosis

Puncture

wound

Stiff jaw, muscle

spasms, paralysis

Tetanus

Open and clean wound,

antibiotic; give antitoxin

Rash at site of bite,

chills, body aches,

joint swelling

Antibiotic

Lyme disease

Bite of

infected tick

Remove and fill the

destroyed area of tooth

Bacteria

in mouth

Destruction of tooth

enamel, toothache

Dental

cavities (caries)

Vaccination to prevent, antibiotics

Sore throat, fever,

heart or breathing

failure

Inhale or

close contact

Diptheria


Section 18 2 summary pages 484 49558

Section 18.2 Summary – pages 484-495

  • In the past, bacterial illnesses had a greater effect on human populations than they do now.

  • In the last 100 years, human life expectancy has increased to about __ years.


Section 18 2 summary pages 484 49559

Section 18.2 Summary – pages 484-495

  • This increase is due to many factors, including better public health systems, improved ____ and sewage treatment, better ________, and better medical care.

  • These improvements, along with _________, have reduced the death rates from bacterial diseases to low levels.


  • Login