7th Science Bateria & Virus Outlines

Question 1

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

Answer 1

Prokaryotes

Question 2

_______ are microscopic prokaryotes.

Answer 2

Bacteria

Question 3

There are two types of prokaryotes - bacteria and ______.

Answer 3

Atchaea

Question 4

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

Answer 4

cytoplasm

Question 5

Bacterial cytoplasm also contain _______.

Answer 5

Ribosomes

Question 6

Bacterial DNA occurs in one coiled, circular ________.

Answer 6

Chromosome

Question 7

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

Answer 7

Pieces

Question 8

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

Answer 8

Pili

Question 9

Bacteria are much _______ than plant or animal cells.

Answer 9

Smaller

Question 10

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

Answer 10

Spiral

Question 11

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

Answer 11

Energy; living

Question 12

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

Answer 12

Light

Question 13

________ bacteria can survive without oxygen.

Answer 13

Anaerobic

Question 14

________ bacteria need oxygen, as humans do.

Answer 14

Aerobic

Question 15

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

Answer 15

Flagella

Question 16

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

Answer 16

Fission; indentical

Question 17

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

Answer 17

Conjugation

Question 18

_______ is transferred between bacteria during conjugation.

Answer 18

DNA

Question 19

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

Answer 19

Diversity

Question 20

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

Answer 20

Endospores

Question 21

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

Answer 21

Drought; dormant

Question 22

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

Answer 22

Arachaea

Question 23

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

Answer 23

Eukaryotes

Question 24

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

Answer 24

Extreme

Question 25

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

Answer 25

Bacteria

Question 26

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

Answer 26

Intestines

Question 27

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

Answer 27

Cellulose

Question 28

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

Answer 28

Decomposition

Question 29

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

Answer 29

Decomposers

Question 30

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

Answer 30

Nitrogen Fixation

Question 31

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

Answer 31

Nodules

Question 32

_______ 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 _______.

Answer 32

Bioremediation: fertilizers

Question 33

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

Answer 33

Bacteria

Question 34

Some bacteria are called _______ - agents that cause disease.

Answer 34

Pathogens

Question 35

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

Answer 35

Immune

Question 36

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

Answer 36

Food you eat; reproduce

Question 37

Some bacteria make people sick by damaging ______.

Answer 37

Tissue

Question 38

Some bacteria cause illness by releasing ________.

Answer 38

Toxins

Question 39

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

Answer 39

Antibiotics

Question 40

Bacteria can become ________ to antibiotics.

Answer 40

Resistant

Question 41

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

Answer 41

Mutations

Question 42

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

Answer 42

Reproduce

Question 43

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

Answer 43

Resistant

Question 44

Eating food contaminated by some bacteria can cause ________.

Answer 44

Food poisoning

Question 45

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

Answer 45

Pasteurization

Question 46

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

Answer 46

Virus

Question 47

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

Answer 47

Cell wall

Question 48

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

Answer 48

Alive

Question 49

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

Answer 49

Organisms

Question 50

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

Answer 50

Host

Question 51

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

Answer 51

RNA

Question 52

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

Answer 52

Inactive

Question 53

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.

Answer 53

Destroys; infect

Question 54

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

Answer 54

Mutates

Question 55

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

Answer 55

Attach

Question 56

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

Answer 56

Diseases

Question 57

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

Answer 57

Diseases; plants

Question 58

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

Answer 58

Infection; latent

Question 59

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

Answer 59

Changing

Question 60

Antibodies work only against _______, not viruses.

Answer 60

Bacteria

Question 61

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

Answer 61

Contact

Question 62

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

Answer 62

Immunity

Question 63

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

Answer 63

Antibody

Question 64

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

Answer 64

Pathogen

Question 65

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

Answer 65

Natural Immunity

Question 66

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

Answer 66

Vaccine; antibodies

Question 67

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

Answer 67

Preventing

Question 68

Scientists are studying the link between viruses and ______.

Answer 68

Cancer

Question 69

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

Answer 69

Gene Transfer