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7th Grade Science > 7th Science Bateria & Virus Outlines > Flashcards

7th Science Bateria & Virus Outlines Flashcards

1
Q

_______ are unicellular organism that do not have a nucleus or other membrane-bound organelles.

A

Prokaryotes

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2
Q

_______ are microscopic prokaryotes.

A

Bacteria

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3
Q

There are two types of prokaryotes - bacteria and ______.

A

Atchaea

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4
Q

A typical bacterium consists of DNA and ____ surrounded by a cell membrane and a cell wall.

A

cytoplasm

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5
Q

Bacterial cytoplasm also contain _______.

A

Ribosomes

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6
Q

Bacterial DNA occurs in one coiled, circular ________.

A

Chromosome

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7
Q

A bacterium might also have smaller, circular __________ that are separate from its other DNA.

A

Pieces

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8
Q

Many bacteria have capsules with hairlike structures called ________ that help the bacteria stick to surfaces.

A

Pili

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9
Q

Bacteria are much _______ than plant or animal cells.

A

Smaller

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10
Q

Bacteria generally have one of three basic shapes - sphere, rod, or ______.

A

Spiral

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11
Q

Some bacteria take in food and break it down and obtain _______. The food can come from dead organisms or ________ hosts.

A

Energy; living

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12
Q

Other bacteria make their food using energy from ______ or chemical reactions.

A

Light

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13
Q

________ bacteria can survive without oxygen.

A

Anaerobic

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14
Q

________ bacteria need oxygen, as humans do.

A

Aerobic

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15
Q

Many bacteria have long whiplike structures called _____ that they use for movement.

A

Flagella

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16
Q

Bacteria reproduce asexually by ________. This type of cell division forms two genetically _______ cells.

A

Fission; indentical

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17
Q

During _______, two bacteria of the same species attach to each other and combine their genetic material.

A

Conjugation

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18
Q

_______ is transferred between bacteria during conjugation.

A

DNA

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19
Q

Conjugation results in new combinations of genes and increases genetic ______.

A

Diversity

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20
Q

A(n) __________ forms when a bacterium builds a thick inner wall around its chromosome and part of the cytoplasm.

A

Endospores

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21
Q

An endospore can protect a bacterium from intense heat, cold, or ________. It can remain ________ for months or even centuries.

A

Drought; dormant

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22
Q

Like a bacterium, a(n) ________ has a cell wall but no nucleus or membrane-bound organelles.

A

Arachaea

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23
Q

The ribosomes of archaea more closely resemble the ribosomes of ________ than those of bacteria.

A

Eukaryotes

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24
Q

Archaea often live in _______ environments, such as hot springs and salt lakes.

A

Extreme

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25
Q

Many organisms, including humans, depend on ______ to survive.

A

Bacteria

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26
Q

Bacteria living inside the ______ of humans and other animals help digest food, make vitamin K, and prevent harmful bacteria from growing.

A

Intestines

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27
Q

Bacteria in the rumens of cows break down a substance in grass called _______ into smaller molecules that the cow can use.

A

Cellulose

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28
Q

__________, the breaking down of dead organisms and organic waste, is an important process in nature.

A

Decomposition

29
Q

As bacteria and other _______ break down dead organic mater, they release molecules such as carbon and phosphorus into the soil.

A

Decomposers

30
Q

______ is the conversion of atmospheric nitrogen into nitrogen compounds that living things can use.

A

Nitrogen Fixation

31
Q

Bacteria is the root ______ of certain plants carry out nitrogen fixation.

A

Nodules

32
Q

_______ uses organisms, such as bacteria, to clean up environmental pollution. These organisms break down harmful substances, such as sewage, into less harmful materials that can be used as landfill or _______.

A

Bioremediation: fertilizers

33
Q

______ are used to make food such as pickles, yogurt, cheeses, buttermilk, vinegar, and soy sauce.

A

Bacteria

34
Q

Some bacteria are called _______ - agents that cause disease.

A

Pathogens

35
Q

Some pathogens that normally live in the body cause illness only when the person’s _______ system is weakened.

A

Immune

36
Q

Some pathogens can enter the body through a cut, in air, or on _______. After they are inside the body, they can ______ and cause disease.

A

Food you eat; reproduce

37
Q

Some bacteria make people sick by damaging ______.

A

Tissue

38
Q

Some bacteria cause illness by releasing ________.

A

Toxins

39
Q

_________ are medicines that stop the growth and reproduction of bacteria.

A

Antibiotics

40
Q

Bacteria can become ________ to antibiotics.

A

Resistant

41
Q

Random _______ to a bacterium’s DNA enable it to survive a specific antibiotic.

A

Mutations

42
Q

Only the bacteria with the mutation survive, they ______ and become more common.

A

Reproduce

43
Q

When bacteria become ______- to an antibiotic, a different antibiotic must be used to fight the disease.

A

Resistant

44
Q

Eating food contaminated by some bacteria can cause ________.

A

Food poisoning

45
Q

_______ heats food to a temperature that kills most harmful bacteria.

A

Pasteurization

46
Q

A(n) ______is a strand of DNA or RNA surrounded by a layer of protein that can infest and replicate in a host cell.

A

Virus

47
Q

A virus does not have a(n) ________, any other organelles, or a cell membrane.

A

Cell wall

48
Q

Scientists do not consider viruses to be _______ because they do not have all the characteristics of a living organism.

A

Alive

49
Q

Viruses must use ______ to carry on the processes that we usually associate with a living cell.

A

Organisms

50
Q

The living cell that a virus infects is called a(n) ______ cell.

A

Host

51
Q

After a virus attaches to the host cell, its DNA or ______ enters the host cell.

A

RNA

52
Q

When a virus enters a cell, it can be ______ for years before taking over the cell.

A

Inactive

53
Q

After a virus replicates in the host cell, it _______ the host cell. Copies of the virus are then released into the host organism, where they can _______ other cells.

A

Destroys; infect

54
Q

As viruses replicate, their DNA or RNA frequently ______ or changes.

A

Mutates

55
Q

As viruses change, they can produce new ways to _____ to host cells.

A

Attach

56
Q

These changes happen so rapidly that it can be difficult to cure or prevent viral _________ before the virus mutates again.

A

Diseases

57
Q

Viruses cause many human _______, such as chicken pox, influenza, HIV, and the common cold. Viruses can also affect other animals and _______.

A

Diseases; plants

58
Q

Viruses such as influenza cause symptoms soon after _____. __________ viruses such as HIV might not cause symptoms right away.

A

Infection; latent

59
Q

Viral diseases can be difficult to treat because viruses are constantly _______.

A

Changing

60
Q

Antibodies work only against _______, not viruses.

A

Bacteria

61
Q

One of the best ways to prevent infection is to limit _______ with an infected organism.

A

Contact

62
Q

__________ occurs when a person is infected by a virus and then becomes immune to it.

A

Immunity

63
Q

When a virus infects a person, the body begins to make special proteins called ________.

A

Antibody

64
Q

An antibody is a protein that prevents a(n) ________ in the body.

A

Pathogen

65
Q

_______ develops when a mother passes antibodies to her unborn baby.

A

Natural Immunity

66
Q

A(n) ________ is a mixture containing material from one or more deactivated pathogens, such as viruses. It triggers the production of ______.

A

Vaccine; antibodies

67
Q

Scientists are researching new ways to treat and ______ viral disease in humans, animals, and plants.

A

Preventing

68
Q

Scientists are studying the link between viruses and ______.

A

Cancer

69
Q

Viruses are being tested as treatments for genetic disorders and cancer using ______.

A

Gene Transfer

7th Grade Science (19 decks)

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