Chapter 2 - Prokaryotes, Viruses, and Protists

Question 1

pathogen

Answer 1

a disease-causing micro-organism (e.g. bacteria, virus)

Question 2

plasmid

Answer 2

a small loop of DNA often found in prokaryotic cells, containing a small number of genes

Question 3

capsule

Answer 3

the protective outer layer of some bacteria; makes them appear shiny

Question 4

3 common shapes of bacteria

Answer 4

coccus/cocci - round
bacillus/bacilli - rod shaped
spirillum/spirilli - spiral/corkscrew shaped

Question 5

obligate aerobe

Answer 5

an organism that must have oxygen to survive

Question 6

facultative aerobe

Answer 6

an organism that can live with or without oxygen

Question 7

obligate anaerobes

Answer 7

organisms that cannot live in the presence of oxygen

Question 8

Describe the process of binary fission

Answer 8

• chromosome duplicates
• cell elongates
• cell splits into 2 identical daughter cells

Question 9

Describe the process of conjugation

Answer 9

• 2 cells join to exchange genetic information

- copy of plasmid is transferred to nearby cell through hollow pilus

Question 10

Describe the process of transformation

Answer 10

• bacteria cell picks up and uses pieces of DNA from environment
• incorporates new DNA into chromosome

Question 11

endospore

Answer 11

a structure highly resistant to extreme conditions that forms around the chromosome when under stress; will remain dormant until conditions improve

Question 12

Name the six major groups of bacteria

Answer 12

• Proteobacteria (purple bacteria)
• Green bacteria
• Cyanobacteria (blue-green algae)
• Gram-positive bacteria
• Spirochetes
• Chlamydias

Question 13

horizontal gene transfer

Answer 13

when one species picks up DNA from another species; AKA lateral gene transfer

Question 14

List 4 reasons why viruses are considered to be non-living.

Answer 14

1. They do not grow
2. They cannot reproduce
3. They do not produce/use energy
4. They cannot maintain homeostasis

Question 15

bacteriophage

Answer 15

a virus that infects a bacteria

Question 16

5 stages of the lytic cycle

Answer 16

1. ATTACHMENT to cell
2. PENETRATION of viral DNA or RNA (at which point it may continue with lytic or lysogenic cycle)
3. REPLICATION (biosynthesis) of new viral proteins and nucleic acids
4. ASSEMBLY (maturation) of the new viruses
5. RELEASE of new viruses into environment (cell lyses)

Question 17

4 stages of the lysogenic cycle

Answer 17

1. Phage DNA injected
2. Viral DNA joins host DNA to form prophage
3. Viral DNA replicated with binary fission
4. May enter lytic cycle or stay dormant

Question 18

viroid

Answer 18

small, circular RNA that only infects plants and does not have a protein coat (e.g. potato famine)

Question 19

prion

Answer 19

an infectious protein, causing neurological diseases in mammals (e.g. Mad Cow disease)

Question 20

gene therapy

Answer 20

a method of treating disease by introducing genes into a cell

Question 21

retrovirus

Answer 21

contains RNA (e.g. HIV)

Question 22

mutualism

Answer 22

a relationship between 2 species where each species benefits from the association

Question 23

Name the 3 common shapes of bacteria.

Answer 23

Coccus (round), bacillus (rod), spirillum (spiral/corkscrew)

Question 24

epidemic

Answer 24

a large scale (but confined) outbreak of disease

Question 25

pandemic

Answer 25

widespread, global outbreak of a disease

Question 26

endosymbiosis

Answer 26

a relationship in which a single celled organism lives inside the cell(s) of another organism

Question 27

Difference between haploid and diploid

Answer 27

haploid: a cell containing half the usual number of chromosomes (n) diploid: a cell containing two copies of each chromosome (2n)

Question 28

zygote

Answer 28

a cell formed when a sperm fuses with an egg

Question 29

sporophyte

Answer 29

a diploid organism that produces haploid spores

Question 30

gametophyte

Answer 30

a haploid organism that produces haploid sex cells

Question 31

alternation of generations

Answer 31

life cycle in which diploids produce spores that can create haploid individuals; haploids reproduce sexually to produce diploid sporophytes

Question 32

Where do heterotrophic bacteria obtain their nutrients?

Answer 32

From carbon-containing organic compounds

Question 33

In bacteria, the cell membrane is called the ____

Answer 33

plasma membrane

Question 34

If a bacteria cell can pick up a stain, it has a _______, and is said to be ______.

Answer 34

It has a thick peptidoglycan layer (in the cell wall), gram positive

Question 35

Name 3 shapes of viruses

Answer 35

Helical, Polyhedral and Complex

Question 36

Explain antibiotic resistance. `

Answer 36

- When a bunch of bacteria are exposed to antibiotics, most bacteria will die, but resistant bacteria will survive - The entire strain become resistant, and the antibiotics are no longer effective

Question 37

Name 4 groups of euryarchaeota.

Answer 37

Methanogens, Halophiles, Extreme thermophiles, Psychrophiles

Question 38

Characteristics of amoebas

Answer 38

- heterotrophs - pseudopods - hard outer skeletons - most animal-like

Question 39

Characteristics of euglenoids

Answer 39

- autotrophs - unicellular - have 2 flagella for movement

Question 40

Characteristics of ciliates

Answer 40

- heterotrophs - unicellular - many cilia, but no cell walls

Question 41

Characteristics of apicomplexa

Answer 41

- heterotrophs - unicellular - no cell wall - ALL are parasites of animals

Question 42

Characteristics of diatoms

Answer 42

- autotrophs - unicellular - move by gliding - covered by glass-like silica shells

Question 43

Characteristics of red algae

Answer 43

- autotrophs - almost all are multicellular - no cilia or flagella - cell walls made of cellulose

Question 44

Which protists are considered animal-like and which are considered plant-like?

Answer 44

Animal: amoeba, ciliates, apicomplexa Plant: red algae, euglanoids, diatoms