Lecture 4 - The Diversity of Life

Question 1

What are the 3 domains of life?

Answer 1

bacteria, archaea, and eukarya

Question 2

What does eukarya include?

Answer 2

fungi, protista, plants, animals

Question 3

What were the first organisms to live on earth?

Answer 3

prokaryotes in 3.5 bya. They live in crazy places due to their ability to adapt

Question 4

Are prokaryotes unicellular or multicellular?

Answer 4

they are unicellular

Question 5

What is the common shape of a prokaryotic cell?

Answer 5

cocci aka round, bacilli aka rod , or spiral

Question 6

Whats the capsule?

Answer 6

it surrounds the cell wall; it is a sticky dense layer of polysaccharide or protein

Question 7

What is the cell wall of bacteria made of?

Answer 7

peptidoglycan: polymer of sugars and amino acids

Question 8

What is the cell wall of archaea made of?

Answer 8

mostly glycoproteins

Question 9

What are the different types of appendages for prokaryotic cells?

Answer 9

flagella, pili, and fimbriae

Question 10

DNA in prokaryotic cells?

Answer 10

dna: single circular chromosome located in the nucleoid, there are also small plasmids of dna in the cell.

Question 11

How do prokaryotic cells reproduce?

Answer 11

they divide via binary fission

Question 12

What are the energy sources for living things?

Answer 12

sunlight and chemical: by breaking down chemical bonds for energy when we eat food

Question 13

Living things need nutrients from a?

Answer 13

carbon source. carbon creates macromolecules. theres 2 types of carbon source. 1) organic compounds: when carbon is taken from sources such as protein lipid or carbs 2) inorganic compounds: carbon taken from co2

Question 14

What is a phototroph?

Answer 14

energy source is sunlight

Question 15

What is a chemotroph?

Answer 15

energy source is chemical energy

Question 16

What is an autotroph?

Answer 16

carbon source is co2

Question 17

What is a heterotroph?

Answer 17

carbon source is from organic compound

Question 18

what are the 4 nutritional modes?

Answer 18

1) photoautotroph: protists, prokaryotes, plants
2) chemoautotroph: prokaryotes
3) photoheterotrophs: prokaryotes
4) chemoheterotrophs: prokaryotes, protists, fungi, animals, some plants

Question 19

Obligate aerobes vs obligate anaerobes vs facultative anaerobes

Answer 19

aerobes: must use o2
anaerobes: poisoned by 02
facultative: use o2 if there but can survive without it

Question 20

what is decomposition?

Answer 20

breaking down of dead organisms or waste ad recycle nutrients back into soil for uptake by plants. prokaryotes are ESSENTIAL for nutrient cycling

Question 21

How do organisms oxygenate the atmosphere

Answer 21

photosynthesis: cyanobacteria were the first photosynthetic organisms on earth

Question 22

What is nitrogen important for?

Answer 22

required to make dna/rna/proteins. prokaryotes can conduct nitrogen fixation = convert the nitrogen from the atmosphere into ammonia

Question 23

symbiosis?

Answer 23

a relationship in which 2 species live in close contact. The larger organism is called the host and the smaller organism is called the symbiont.

Question 24

What are the 3 types of symbiotic relationships?

Answer 24

mutualism, commensalism, and parasitism

Question 25

What is mutualism?

Answer 25

an interaction that benefits both the host and the symbiont. Example: bacteria gives usable nitrogen to plant and plant gives sugar to bacteria

Question 26

What is commensalism?

Answer 26

an interaction that benefits one species but not the other. eg: e coli in the gut; nutrients are given to the bacteria and safe place to live but they dont harm or help you

Question 27

What is parasitism?

Answer 27

an interaction that benefits one species while causing harm to the other. Eg: food borne illnesses

Question 28

What is bioremediation?

Answer 28

some types of bacteria eat pollutants and metabolize them into harmless products

Question 29

What are the similarities between bacteria and archaea?

Answer 29

cell wall, ribosomes, single circular chromosome, lack nucleus and organelles

Question 30

What are the differences between bacteria and archaea?

Answer 30

- composition of the cell wall - dna structure - different proteins used to copy dna - different start codon for building proteins

Question 31

What does extremophiles mean?

Answer 31

some archaea are extreme loving

Question 32

extreme thermophiles vs extreme halophiles?

Answer 32

thermophiles: dna stable at temp up to 120 degrees celcius halophiles: tolerate or need extreme salinity: majority of extremophiles are archaea

Question 33

What are methanogens?

Answer 33

archaea that live in anoxic environments. 0% oxygen. eg: gut of cow. when cows fart they release methane

Question 34

Thaumarchaeota?

Answer 34

live in soil and in skin, protect against skin infections, aid in nitrogen cycling, lower skin pH

Question 35

How did we go from organelle-less prokaryotic cells to eukaryotic cells with membrane bound organelles?

Answer 35

too long to type but explain it

Question 36

What is endosymbiont?

Answer 36

symbiotic relationship where the symbiont lives within the host cell

Question 37

Protists?

Answer 37

eukaryotes that are not fungi, plants, or animals. - majority are unicellular

Question 38

Animal like protists?

Answer 38

chemoheterotrophs: feed by consuming other organisms, can move, lack cell wall. EX: amoeba and plasmodium(causes malaria)

Question 39

Plant like protists?

Answer 39

photoautotrophs: have chloroplasts and a cell wall, make sugar using photosynthesis, volvox, seaweed

Question 40

fungi like protists?

Answer 40

chemoheterotrophs: feed by absorption, decompose dead material and recylce nutrients, have a cell wall, they are molds

Question 41

Fungi?

Answer 41

chemoheterotrophs, release enzymes and digest food outside the body and absorb nutrients, multicellular except for yeast, cell walls are composed of chitin, they have hyphae which absorb water and nutrients

Question 42

Whats the largest organism on earth?

Answer 42

fungi: armillaria ostoyae

Question 43

whats the first antibiotic made by fungi?

Answer 43

penicillin