cells of bacteria and archaea: size and morphology

Question 0

what are the 3 major cell morphologies?

Answer 0

coccus
rod
spirillum

Question 1

what is cell morphology?

Answer 1

the cell shape

Question 2

what are cells with unusual shapes? 3

Answer 2

spirochetes
filamentous bacteria
appendaged bacteria

Question 3

describe coccus

Answer 3

spherical, ovoid (oval)

Question 4

describe rod shape

Answer 4

cylindrical

Question 5

describe spirillum shape

Answer 5

spiral

Question 6

morphology does NOT predict what 3 things about a prokaryotic cell?

Answer 6

physiology
ecology
phylogeny

etc….

Question 7

what are the 3 selective forces involved in the morphology determination of a cell?

Answer 7

1. optimization for nutrient uptake
2. swimming motility in viscous environments or near surfaces
3. gliding motility

Question 8

what types of cells are optimum for nutrient uptake?

Answer 8

small cells with high surface to volume ratios

Question 9

what type of cell shapes have swimming motility in viscous environments or near surfaces? 2

Answer 9

helical or spiral shaped cells

Question 10

what type of cells have gliding motility only?

Answer 10

filamentous bacteria

Question 11

what is the size range of prokaryotes?

Answer 11

.2 micrometer to >700 micrometers in diamater

Question 12

what is the size range for eukaryotes?

Answer 12

10 to >200 micrometers in diameter

Question 13

what size cells have higher surface to volume ratios?

Answer 13

small

Question 14

how is high s/v ratios beneficial to small cells? 2

Answer 14

• tend to grow faster than larger cells

- greater nutrient exchange per unit cell volume

Question 15

what are the 2 lower limits of cell size?

Answer 15

cell organisms smaller than .15 micrometers are unlikely to survive
and
open oceans contain small cells ranging .2-.4 micrometer diameter