CLASSIFYING BACTERIA AND REPRODUCTION (lesson six)

Question 1

what are prokaryotes?

Answer 1

a cell that does not have its chromosomes surrounded by nuclear envelop and lacks membrane-bound organelles

Question 2

characteristics of bacteria

Answer 2

• are unicellular
• are prokaryotic
• have a single chromosome in the form of a loop of DNA called a plasmid
• most reproduce asexually by binary fission some reproduce sexually by conjugation
• thrive in moist environments

Question 3

Ways to classify bacteria

Answer 3

1. if they cause disease
2. Gram-positive vs gram-negative
3. shape
4. configuration
5. oxygen requirements
6. nutrition

Question 4

if they cause diseases

Answer 4

1. non-pathogenic
2. pathogenic

Question 5

what is Gram-positive?

Answer 5

• stain purple
• Cell wall contains peptidoglycan (protein)

Question 6

what is Gram-negative?

Answer 6

• stain pink
• cell wall does not contain peptidoglycan

Question 7

If the bacteria is spherical?

Answer 7

cocci

Question 8

if the bacteria is rod-shaped?

Answer 8

bacilli

Question 9

if the bacteria is spiral?

Answer 9

spirilla

Question 10

Configuration

Answer 10

• after division, many bacteria stay together in groups called colonies
• colonies are visible growths of microorganisms that contain millions of cells
• in colonies, bacterial cells stay together in typical arrangements

Question 11

in clumps add what prefix? (configuration?)

Answer 11

staphyllo

Question 12

in chains add what prefix (configuration?)

Answer 12

strepto

Question 13

in pairs add the prefix (configuration?)

Answer 13

diplo

Question 14

oxygen requirements

Answer 14

1. aerobes: need lots of O2
2. anaerobes: cannot survive in the presence of O2

Question 15

Nutrition

Answer 15

can be autotrophic, heterotrophic, photosynthetic, or chemosynthetic

Question 16

when will bacilli bacteria go into a dormant?

Answer 16

Under unfavorable environmental conditions, bacilli bacteria will go into a dormant or resting state called an endospore.

Question 17

what is endospore?

Answer 17

It is resistant to heat and other extreme conditions.

Question 18

what are the 2 types of Reproduction?

Answer 18

asexual reproduction (binary fission) and sexual reproduction ( conjugation)

Question 19

what is Asexual Reproduction?

Answer 19

Binary fission is another name for it.
-only one parent is needed
- offsprings are identical to parent and to each other

Question 20

what is Sexual Reproduction?

Answer 20

conjugation is another name for it.
- two parents are involved
- offsprings are different from parents and to each other

Question 21

Advantages of asexual reproduction?

Answer 21

• simple: only 1 parent
• offspring are fully formed (no maturation needed)
• very fast

Question 22

Disadvantages of asexual reproduction?

Answer 22

• no genetic variety (DNA is identical to parent)
• one unfavorable environmental condition can wipe out the whole population

Question 23

Advantages of sexual reproduction?

Answer 23

• genetic variety i.e. some are able to adapt to unfavourable conditions (ex: antibiotic resistance)

Question 24

Disadvantages of sexual reproduction?

Answer 24

• more complex: slower because must find a compatible partner
• no new individuals produced

Question 25

why are no new individuals produced?

Answer 25

no NEW individuals are produced because the donor cell is inserting plasmids into an already existing cell. therefore not creating a new cell but instead changing the old cell by inserting plasmid.

Question 26

Factors that affect bacterial growth

Answer 26

• Temperature
• Nutrients
• Oxygen availability
• Salt concentration
• pH