Chapter 10- microbial world

Question 1

Pathogen

Answer 1

A foreign invader that causes a disease

Question 2

Virus

Answer 2

• smallest infectious agent
• considered biologically inert
• can’t be seen with light microscopes
• not all viruses affect humans

Question 3

Biologically inert

Answer 3

Somewhere between simple biomolecules (proteins or DNA) and living organisms (bacteria)

Question 4

Viruses do not meet the basic criteria scientists use to characterize life

Answer 4

1. They do not perform metabolism
2. They have no capacity for reproduction (by itself)
3. Do not respond to stimuli
4. No cellular composition (acellular)
5. No complex growth

Question 5

Acellular

Answer 5

No cellular composition

Question 6

Eukaryotic cells

Answer 6

Membrane- bound nucleus

has organelles

Question 7

Prokaryote cells

Answer 7

No membrane- bound nucleus
No organelles
Unicellular

Question 8

Bacteriophage

Answer 8

Structure: rod and icosahedral (solid with 20 faces) mix

Only infect bacteria

Question 9

Capsid

Answer 9

Protein she’ll that encloses the genetic material

- made up of smaller pieces called capsomeres

Question 10

How do viruses replicate

Answer 10

By attaching to a host cell

Question 11

Step 1: recognition

Answer 11

Viruses must be recognized by a cell to enter that cell
- usually contains specificity for one small group/ type of species

Envelope protein/spike protein needs to be recognized by the host cell’s receptors

Question 12

Step 2: injection

Answer 12

The virus injects it’s genetic material or is brought into the cell (completely intact through endocytosis)

Question 13

Step 3: transcription and translation

Answer 13

• The virus disassembles

- viral DNA is transcribed and translated by the host cell

Question 14

Step 4: reassembly

Answer 14

Capsid protein re-assembles and releases new viral particles when there are many copies of viral DNA
- sometimes this destroys the cells

Question 15

Lytic cycle

Answer 15

Host cell is terminated (lyses) at the end or replication cycle
- happens once many viruses have been generated

Question 16

Lysogenic cycle

Answer 16

Rather than hijacking the cell, the virus inserts its viral DNA into the host’s genome creating a prophage

• cell continues to replicate, where the DNA remains silent
• host cell is not destroyed
• an environmental factor causes a switch into the lyric cycle causing the infected cell to lyse

Question 17

Receptors

Answer 17

Allow virus to enter and exit without damaging the cell

Question 18

Antibiotic

Answer 18

Inhibits then growth of or destroys bacteria

Question 19

Shapes of bacteria

Answer 19

Cocci (ball)
Bacilli (rod-shaped)
Spirilla (spiral-shaped)

Question 20

Shapes/2

Answer 20

Strepto: chain
Diplo: two
Staphylo: bunched together

Question 21

Horizontal gene transfer

Answer 21

Exchanging genetic material

Question 22

Conjugation

Answer 22

Plasmids are transmitted through pili

Question 23

Binary fission

Answer 23

Produces two identical daughter cells
-begins at origin of replication

Cell elongates
-once there are two copies cell pinches in the middle

Question 24

Bioremediation

Answer 24

Use of fungi to decompose pollutants in the soil

Question 25

Mycology

Answer 25

Study of fungi

Question 26

Morphology

Answer 26

Study of the forms of things

Question 27

Hyphae

Answer 27

Filamentous network that supports the fungus

Question 28

Mycelium

Answer 28

Collective network | -allows for nutrients, growth, and production

Question 29

Mycorrhizae

Answer 29

Symbiotic relationship between the mycelium and roots | -allows for growth and life

Question 30

Parasitic fungi

Answer 30

Infect and kill insects

Question 31

Saprobic fungi

Answer 31

Have their mycelium relationship with dead organic matter

Question 32

Cap

Answer 32

Reproductive function of a fungus

Question 33

Gills

Answer 33

Site of spore production

Question 34

Hymenium

Answer 34

Tissue layer of spore production

Question 35

Stalk (stipe)

Answer 35

Stem-like feature that supports the cap

Question 36

Annulus or partial veil

Answer 36

Ring of tissue below the cap | - covers hymenium throughout development and detached once hymenium matures

Question 37

Asexual reproduction (fungus)

Answer 37

Cap produces spore that are carried by wind or water to new places

Question 38

Sexual reproduction (fungus)

Answer 38

Hyphae from 2 colonies grow close together and share genetic info.

Question 39

Protist

Answer 39

Eukaryotic organism that can’t be classified as animals, plants, or fungi

Question 40

Animal-like protists

Answer 40

``` Food: heterotrophs Features: unicellular Movement: free-swimming Reproduction: asexual and sexual Common name: protozoans ```

Question 41

Zooflagellates (animal-like)

Answer 41

Swim with flagella

Question 42

Ciliates (animal-like)

Answer 42

Move using cilia and feed using cilia

Question 43

Plant-like protist

Answer 43

``` Food: autotrophs Features: unicellular and multicellular Movement: free-swimming or attached Reproduction: asexual and sexual Common name: algae (unicellular) and seaweed (multicellular) ```

Question 44

Diatoms (plant-like)

Answer 44

Produce thin, delicate cell walls rich in silicon (Si- main component of glass)

Question 45

Fungus-like protists

Answer 45

Food: heterotrophs (absorb nutrients from dead and decaying matter) Features: unicellular, but often live in colonies -fungus-like protists have centrioles but lack cell walls made of chitin Movement: move during some parts of their life cycle Reproduction: asexual

Question 46

Slime molds (fungus-like)

Answer 46

Play key role in recycling organic matter | -use spores to reproduce