unit 1 part 3

Question 1

characteristics used to identify a species:
4

Answer 1

• morphological traits
• ability to interbreed
• phylogenetic relationships
• ecological relationships

Question 1

species

Answer 1

a group of orgs that maintains a distinctive set of attributes in nature

difficulties
- subspecies
- ecotypes

Question 2

morphological traits

Answer 2

used to determine a species based on fossil records
(form and structure of the animal)

Question 3

phylogenetic relationship

Answer 3

identifies relationships between animals based on similar DNA, RNA, protein sequences, and comparison of anatomical features

Question 4

limitations of defining a species based on reproductive isolation

Answer 4

some species can interbreed, doesnt apply to asexual species or extinct

Question 5

limitations of defining a species based on molecular features

Answer 5

the degree of dissimilarity that should be cutoff is undefined

Question 6

limitations of defining a species based on phylogenic relationships

Answer 6

requires measurements of morphological traits

Question 7

limitations of defining a species based on ecological characteristics

Answer 7

many species have similar ecology

Question 8

multiplication of species

Answer 8

genetic distance between species of the same common ancestor.
requires reproductive isolation

Question 9

Prezygotic barrier: habitat isolation

Answer 9

Species occupy different areas or habitats
* Geographic barrier prevents contact

Question 10

Prezygotic barrier: temporal isolation

Answer 10

Reproduce at different times

Question 11

Prezygotic barrier: behavioral isolation

Answer 11

Courtship rituals and other behaviors unique to a
species are effective barriers

Question 12

Prezygotic barrier:
mechanical isolation

Answer 12

Morphological differences can prevent successful
mating: size or incompatible genitalia

Question 13

Prezygotic barrier:
gametic isolation

Answer 13

• Fertilization unsuccessful due to gamete
  incompatibility
• Important in species that release gametes into the
  water or air

Question 14

Postzygotic barrier: hybrid inviability

Answer 14

fertilized egg cannot develop past an early embryo

Question 15

Postzygotic barrier: hybrid sterility

Answer 15

Interspecies hybrid
viable but sterile

cant reproduce

Question 16

Postzygotic barrier: hybrid breakdown

Answer 16

hybrids are viable and fertile but generations have genetic abnormalities.

Question 17

allopatric speciations

Answer 17

the most COMMON speciation. members get geographically sepatated

Question 18

sympatric speciation

Answer 18

no physical barriers but leads to asserted mating. (new species)

Question 19

polyploidy

Answer 19

a type of sympatric speciation. when gametes are no longer compatible

Question 20

sexual selection

Answer 20

a. type of sympatric speciation.

Question 21

biological species concept

Answer 21

defines species as members of a pop that can interbreed

Question 22

hybrid zone

Answer 22

areas where genetically distinct populations meet, mate, and leave offspring of mixed ancestry

Question 23

adaptive radiation

Answer 23

single species evolves into an array of descendants