speciation

Question 1

speciation

Answer 1

formation of new species

Question 2

speciation can occur when members of a species no longer

Answer 2

reproduce with each other

Question 3

lack of gene flow allows species to

Answer 3

become different

Question 4

biological species concept

Answer 4

population that can naturally reproduce to produce FERTILE offspring

Question 5

according to biological species concept, species share

Answer 5

a single large gene pool

Question 6

limitations to biological species concept

Answer 6

-difficult to determine gene flow
-does not work for asexual organisms

Question 7

morphological species concept separates species by

Answer 7

body shape and structure

Question 8

enological species concept separates species by

Answer 8

how they interact with their environment

Question 9

ecological species concept emphasized … of each species

Answer 9

living requirements

Question 10

_____ _____ is required to form truly distinct biological species

Answer 10

reproductive isolation

Question 11

to form distinct species, enough differences must develop so that species can no longer

Answer 11

breed with each other

Question 12

two forms of reproductive barriers

Answer 12

-prezygotic barriers
-postzygotic barriers

Question 13

prezygotic barriers

Answer 13

prevents species form successfully attempting to reproduce

Question 14

habitat isolation (prezygotic barrier)

Answer 14

species are never in same place

Question 15

behavioral isolation (prezygotic barrier)

Answer 15

methods of attracting a mate are different

Question 16

temporal isolation (prezygotic barrier)

Answer 16

reproduce at different times

Question 17

mechanical isoltion (prezygotic barrier)

Answer 17

reproductive organs are not compatible

Question 18

gene isolation (prezygotic barrier)

Answer 18

proteins on egg and sperm don’t match

Question 19

post zygotic barriers

Answer 19

prevent growth in a viable fertile adult

Question 20

hybrid

Answer 20

offspring of two Dif species

Question 21

hybrid inviablility (postzygotic barrier)

Answer 21

embryo cannot complete development because genetic instructions are incomplete

Question 22

hybrid sterility (postzygotic barrier)

Answer 22

hybrid cannot produce gametes (sometimes due to odd number of chromosomes)

Question 23

hybrid reduced offspring viability (postzygotic barrier)

Answer 23

offspring of hybrids do not survive well

Question 24

3 steps needed for speciation

Answer 24

 Isolation of populations of species
 Changes in gene pools of the isolated species
 Creation of reproductive isolation between populations

Question 25

allopatric speciation

Answer 25

physical barrier or distance blocks gene flow between 2 populations (physically isolated from each other)

Question 26

sympatric speciation

Answer 26

occurs in SAME location -nonphysical reproduction isolation prevents gene flow

Question 27

examples of sympatric speciation barriers

Answer 27

-reproduce at Dif times -live in Dif parts of environment -sudden genetic change in 1 population

Question 28

polyploidy

Answer 28

doubling number of chromosomes

Question 29

example of sympatric speciation in maggot flies

Answer 29

 Several populations live in same area  Some live on apple trees, some live on hawthorn shrubs  Flies mate when plant produces fruit  Hawthorn and apple trees produce fruit 1 month apart  Very little genetic flow between hawthorn and apple flies since they don’t mate at the same time  Apple and hawthorn populations different strongly in the frequency of some alleles

Question 30

polyploidy results from mistakes when

Answer 30

cells divide

Question 31

polyploidy occurs mostly in

Answer 31

plants (can evolve fast by doubling genetic material)

Question 32

polyploidy instantly results in

Answer 32

a new species

Question 33

can new species resulting from polyploidy reproduce with original species?

Answer 33

NO, new species have different # of chromosomes

Question 34

polyploidy can enable ____ plants to reproduce:

Answer 34

hybrid; Doubling the number of chromosomes fixes the problem of having an odd number of chromosomes

Question 35

autopolyploid has more than ...

Answer 35

2 sets of chromosomes from same species

Question 36

how does autopolyploidy occur?

Answer 36

meiosis error can create diploid gametes and combination of 2n gametes produces 4n offspring

Question 37

allopolyploid

Answer 37

hybrid between species

Question 38

how can hybrid infertility be overcome?

Answer 38

double number of chromosomes again OR hybridize again with parent species

Question 39

adaptive radiation is a mixture of

Answer 39

allopatric and sympatric speciation

Question 40

hybrid zones help us tell that ___ occurred

Answer 40

speciation

Question 41

what is a hybrid zone?

Answer 41

area where members of different species mate

Question 42

hybrid zones: observed patterns

Answer 42

reinforcement, fusion and stability

Question 43

reinforcement (hybrid zones)

Answer 43

strengthens or reinforces barriers to hybridization

Question 44

example of reinforcement in hybrid zones

Answer 44

male species looks different from male of other species in only that area so that females can tell them apart

Question 45

fusion (hybrid zones)

Answer 45

weakens barriers to hybridization (increases gene flow)

Question 46

what might reverse speciation and result in 1 species again?

Answer 46

fusion

Question 47

stability (hybrid zone)

Answer 47

-hybridization remains possible -hybrids continue to be produced