h/o of earth, prokaryotes, and eukaryotes

Question 1

Stipe adaptation

Answer 1

stalk-like structure brings blade closer to ocean surface and therefore light

similar to land plant stalk; see pic

Question 2

Background extinction rate used by Dr. Cabellero to determine if we were in a 6th extinction period

Answer 2

2 extinctions/10,000 species/100 years

Every 100 years, 2 of every 10,000 species are expected to go extinct

Question 3

Which otes came first (prokaryotes or eukaryotes)

Answer 3

prokaryotes for several billion years•

Question 4

sporopollenin:

Answer 4

tough polymer (coating) that protects plant games from desiccation (drying out)

Question 5

Why background extinction rate used by Dr. Cabellero (to determine if we were in a 6th extinction period) was so high

Answer 5

helped to prevent false positives

If background extinction rate estimate is too low, modern extinction rates may seem much higher just because background rate was so low

Question 6

“Protists”

Answer 6

“big, sloppy, disorganized’ subgroup of eukaryotes that includes most eukaryotes

Not very well defined/valid

Question 7

2 ways antibiotics kill bacteria

Answer 7

1. Prevent bacteria from making cell wall (vancomycin, bacitracin)
2. Disrupt small bacterial ribosomes that make protein needed for bacteria to live (tetracycline)

Question 8

What domains does eukaryote include?

Answer 8

protists
plants
fungi
animals

Question 9

When early homosapiens arrived

Answer 9

~100,000 years ago

Question 10

3 class examples of adaptation observed by studying fossils

Answer 10

1. Tiktaalik: front appendages for pushing, upward facing eyes
2. Burgess shale group: organisms with large spikes covering bodies
3. Ediacarionbiota: large group of eukaryotes, exclusively soft-bodied

Question 11

why fossils are useful to study

Answer 11

Bc you can try to determine what environmental pressures were present by looking at how adaptations/changes in organisms occurred over

Question 12

background extinction rate

Answer 12

normal, low level of species loss you can expect to occur each year

Question 13

example of mutualistic bacteria from class

Answer 13

Gut flora: allow proper digestion of food and protect your bowels from pathogenic bacteria (~1-3% of your body weight is bacteria)

Question 14

What domains does prokaryote include?

Answer 14

Bacteria and Archaea

Question 15

•Blade adaptation

Answer 15

leaf-like structures increase photosynthetic surface areas

Very similar to land plant leaf; see pic

Question 16

6 Prokaryote characteristics

Answer 16

Generally have smaller genomes than eukaryotes

Chromosomes are circular rather than linear

Also have plasmids: small, independently replicating, circular DNA molecules

often carry alleles for antibiotic resistance

Gene translation to proteins similar to eukaryotes, but with much smaller ribosomes

Reproduce by binary fission: splitting one cell into two after replication of genetic information

Question 17

Exp from class about determining if we were in a 6th extinction period

Answer 17

Dr. Caballero U of Mexico:

1. overestimated background extinction rate

Question 18

2 ways green algae are NOT adapted for life on land

Answer 18

1. Flagellated gametes

2. No internal structural support (bc they’re supported by water)

Question 19

When first homospecies arrived

Answer 19

2 million years ago

Question 20

Carotenoids:

Answer 20

orange-ishbrown photosynthetic pigment found in plastids of kelp cells

Question 21

Extinction:

Answer 21

the loss of all individuals of a species

Happens constantly at some level and is described as background extinction

Question 22

HIGHLY conservative way to estimate background extinction rate

Answer 22

includes only species classified as extinct

Question 23

Cabellos’ idea of a ‘conservative’ background extinction estimate

Answer 23

one in which the background estimate is estimated too low, such that the current rate (likelihood of 6th mass extinction) appears super high by comparison

between 0.1 and 1 species lost/10,000 species/100 years

Question 24

intertidal zones:

Answer 24

areas that are sometimes submerged, sometimes not

Question 25

Flagellated gametes:

Answer 25

(aquatic plant) gametes that can swim

Question 26

4 things you should do/understand before attempting to interpret a graph

Answer 26

1. You should know what each individual part is meant to represent
2. Know the units
3. Know which direction the numbers are going in
4. whether the different bars/trend lines have different color codes

Question 27

Cabellos’ idea of a HIGHLY ‘conservative’ background extinction estimate

Answer 27

one in which the background estimate is estimated pretty high, such that the current rate (likelihood of 6th mass extinction) WON’T seem super high by comparison

2 species lost/10,000 species/100 years

Question 28

Mass extinction:

Answer 28

a rapid decline in a large number of species, much higher than background extinction rate

exp. from class: shown by spikes on a graph

Question 29

chloroplasts

Answer 29

type of (plastid) plant cells that contains chlorophyl and in which photosynthesis takes place

Question 30

Adaptive radiations:

Answer 30

periods of evolutionary change in which organisms form many new species with adaptations specialized to different niches

Question 31

How protist group is defined (in words)

Answer 31

a group of mostly unicellular eukaryotic organisms that are not fungi, plants, or animals

Question 32

Holdfast adaptation

Answer 32

Adaptations for aquatic life and photosynthesis:•anchors plant to seafloor

similar to land plant root; see pic

Question 33

exp of protist from class

Answer 33

Brown algae:

large, multicellular photosynthetic algae with Carotenoids

Question 34

conservative way to estimate background extinction rate

Answer 34

includes species classified as extinct, extinct in the wild, and presumed extinct

Question 35

Prokaryote: Pathogenic bacteria

Answer 35

bacteria associated with disease

Question 36

How protist group is defined on a phylogenetic tree

Answer 36

paraphyletic group defined by what it’s not (rather than by what it is)

Question 37

3 Archaea traits

Answer 37

often

Extreme thermophiles/heat lovers
thrive in extreme heat
(e.g. hot springs of Yellowstone)

Extreme halophiles/salt lovers
live in extremely salty environments
(e.g. the Dead Sea in Israel)

Question 38

Endosymbiont theory:

Answer 38

mitochondria and chloroplasts derived from ancestral prokaryotes that were then engulfed by another cell, and the relationship became symbiotic

Question 39

Eukaryotes:

Answer 39

organisms with cells that have membrane-bound organelles and a membrane-bound nucleus (domain Eukarya)

Question 40

How old life is

Answer 40

•Life: 3.5 billion years old

Question 41

plastids

Answer 41

class of plant cells/organelles (e.g. chloroplasts) that do things like photosynthetic carbon fixation

Question 42

How old the universe is

Answer 42

13.8 billion years old

Question 43

How old the Earth is

Answer 43

4.6 billion years old

Question 44

Eukaryotes:

Answer 44

organisms with cells that have a membrane-bound nucleus and organelles

Question 45

Number of mass extinctions the earth has seen so far

Answer 45

5

Question 46

the closest relatives of land plants

Answer 46

Red and Green algae

Question 47

What usually happens to genetic diversity after a mass extinction

Answer 47

It shoots up (as species expand into newly available niches)

Question 48

3 ways that “International Union for the Conservation of Nature” classifies species as extinct

Answer 48

1. Extinct (none remaining)
2. Extinct in the wild (exist only in captivity)
3. Presumed extinct (very likely extinct, but not confirmed)

Question 49

2 ways green algae are adapted for life on land

Answer 49

1. Often live in intertidal zones

2. Zygotes coated with sporopollenin

Question 50

Prokaryotes:

Answer 50

organisms with cells that lack membrane-bound organelles and a membrane-bound nucleus•

Question 51

For the exam: if given a description of a fossil adaptation,, you should be able to:

Answer 51

make an educated guess about the novel environmental pressure that the change is adapted to/for

Question 52

Is most life on earth unicellular or multicellular?

Answer 52

uni