lecture 1: life

Question 1

prokaryote

Answer 1

◆ DNA contained in circular plasmids
◆ no nucleus, no membrane-bound organelles
◆ reproduce asexually

obtain energy in diverse ways:
a. autotrops
b. heterotrophs
c. chemotrophs
d. phototrophs

Question 2

eukaryote

Answer 2

◆ DNA in membrane-enclosed nucleus
◆ contain membrane enclosed organelles (mitochondria)
◆ includes algae, plants, fungi, animals

Question 3

anaerobe

Answer 3

any organism that does not require molecular oxygen for growth

Question 4

aerobe

Answer 4

organism that requires an oxygenated environment

Question 5

autotroph (photo- and chemo-)

Answer 5

generate their own food
◆ likely formed the first life in the oceans
◆ types of prokaryote

phototroph = energy comes from light
chemotroph = energy comes from organic compounds

note: not all photoautotrophs do oxygenic photosynthesis

Question 6

heterotroph

Answer 6

consume other organisms for food (ex: bacteria)

Question 7

plastid

Answer 7

any of a class of small organelles containing pigment or food (ex: chloroplast)

Question 8

plasmid

Answer 8

a genetic structure in a cell that can replicate independently of the chromosomes, typically a small circular DNA strand in the cytoplasm of a bacterium

Question 9

binary fission

Answer 9

after doubling in size, single cell splits into two cells

NOT equivalent to mitosis (i.e., no splitting of nucleus)
- form of asexual production
- DNA is duplicated

Question 10

stromatolite

Answer 10

type of fossil, calcified biofilm, found in shallow water

Question 11

cyanobacteria

Answer 11

obtain energy via photosynthesis. also evolved capacity to fix nitrogen