What is Biodiversity? (End of Test 1)

Question 1

What is biodiversity?

Answer 1

the sum of an area’s organisms, considering the diversity of species, their genes, their populations, and their communities

Question 2

What are the components of biodiversity?

Answer 2

• genetic diversity
• species diversity
• ecosystem diversity

Question 3

What is species diversity?

Answer 3

the number or variety of species in a particular region

Question 4

What is species richness?

Answer 4

number of species

Question 5

What is evenness, or relative abundance?

Answer 5

extent to which numbers or different species are equal or skewed

Question 6

What is a species?

Answer 6

• a particular type of organism
• a population of group of populations whose members share certain characteristics and can freely breed with one another and produce fertile offspring

Question 7

What is genetic diversity?

Answer 7

includes the differences in DNA compositon among individuals within a given species

Question 8

What can weed out genetic variants that are not successful?

Answer 8

adaptation to particular environmental conditions

Question 9

Why do populations benefit from genetic dievrsity?

Answer 9

avoid inbreeding or disease epidemics

Question 10

What does ecosystem diversity include?

Answer 10

diversity above species level

Question 11

What are some ways to categorize diversity above species level?

Answer 11

community, habitat, and landscape diversity

Question 12

What is taxonomy?

Answer 12

each species is classified within a hierarchy reflecting the evolutionary diversification of life

Question 13

What are the 3 types of spatial scales and diversity?

Answer 13

• alpha, beta, and gamma diversity

Question 14

What is alpha-diversity?

Answer 14

• measured locally, at a single site (richness)
• number of species that can coexist in the same ecosystem by using different portions of it

Question 15

What is beta-diversity

Answer 15

• measures the uniqueness; the difference between two sites
• the number of species unique to one region relative to another

Question 16

What is gamma diversity?

Answer 16

measured over a large scale, same concept as alpha-diversity (richness within a large region)*

Question 17

Where is beta diversity highest?

Answer 17

in region with savanna and wetlands (as opposed to*

Question 18

What are subspecies?

Answer 18

geographic variations of species

Question 19

How many species have been described by science?

Answer 19

1.75 million

Question 20

How many more species likely exist?

Answer 20

3 to 100 million

Question 21

Why are we unsure of the number of species on Earth?

Answer 21

• some areas are little explored
• many species are tiny and inconspicuous
• some species are very similar in appearance

Question 22

Are species evenly spread among different groups?

Answer 22

no, half of all species on earth are insects

Question 23

What is adaptive radiation?

Answer 23

when an ancestral species give rise to many species that fill different niches, adapting to them by natural selection

Question 24

What is latitudinal gradient?

Answer 24

species richness increases toward the equator

Question 25

What leads to an uneven distribution of biodiversity?

Answer 25

- adaptive radiation - latitudinal gradiant

Question 26

What is a theory for why latitudinal gradient exists?

Answer 26

tropical climates encourages specialist species that can pack tightly in a community (greater solar enegery, heat, and humidity promotes more plant growth; stable climate favors specialist species)

Question 27

What does endemic mean?

Answer 27

a species is endemic to a certain region if its distribution is restricted to that region

Question 28

What does endemism contribute?

Answer 28

to the uniqueness and special importance of the biodiversity in particular areas

Question 29

What place has high levels of endemism?

Answer 29

Madagascar (100% primates, 95% reptiles, and 99% amphibians)

Question 30

What does extinction mean?

Answer 30

last member of a species dies and the species vanishes forever from Earth

Question 31

What is extirpation?

Answer 31

disappearance of a particular population, but not the entire species globally

Question 32

What is the background rate of extinction?

Answer 32

one species goes extinct naturally every 500-1000 years

Question 33

How many mass extinction events has earth experienced?

Answer 33

5

Question 34

Is Earth undergoing a sixth mass extinction?

Answer 34

yes

Question 35

How do we know we are undergoing a mass extinction?

Answer 35

- humans have increased extinction rate by a factor of 1000 - 1,100 species are known to have gone extinct in the past 400 years - species of large mammals and birds plummeted with the arrival of humans independently, on each of 3 continents (Australia, NA, Madagascar/NZ) which suggests human hunting was the cause

Question 36

What are the criteria to qualify as a biodiversity hotspot?

Answer 36

- contain at least 1500 species of endemic vascular plants - site has to have lost at least 70% of its primary native vegetation

Question 37

Who came up with concept of biodiversity Hotspots

Answer 37

Norman Myers

Question 38

What was the most recent biodiversity hotspot?

Answer 38

NA coastal plain