Chapter 24 Flashcards Preview

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Flashcards in Chapter 24 Deck (14):
1

What is required for the formation of new species?

Absence of gene flow

2

What are the 2 types of barriers?

-Prezygotic barriers
-Postzygotic barriers

3

What are the types of prezygotic barriers?

-Habitat
-Temporal
-Behavioral
-Mechanical
-Gametic

4

What occurs in habitat isolation?

Two species occupy different habitats

5

How does mechanical isolation occur?

Morphological differences prevent 2 species from mating

6

How does gametic isolation occur?

Sperm is not able to fertilize egg

7

What are the types of postzygotic barriers?

-Reduced hybrid viability
-Reduced hybrid fertility
-Hybrid breakdown

8

What are the 2 main ways that speciation can occur?

-Allopatric
-Sympatric

9

What are the 3 mechanisms that can lead to sympatric speciation?

-Polyploidy
-Habitat differentiation
-Sexual selection

10

What is polyploidy? What are the 2 types of polyploids?

-Condition that results in extra chromosomes
-Autopolyploid (all from same species) and allopolyploid (sets deriving from different species

11

What is a hybrid zone?

Area in which different species meet and mate

12

What are the 3 possible outcomes when 2 related species meet and mate in a hybrid zone?

-Strengthen reproductive barriers
-Weaken reproductive barriers
-Continued formation of hybrids

13

Punctuated equilibrium

Period of stasis for organism followed by sudden change

14

Speciation

Process by which one species splits into two