A4.1 HL only

Question 1

Speciation

Answer 1

evolutionary process by which populations evolve to become distinct species

Question 2

gene flow

Answer 2

any movement of individuals, and/or the genetic material they carry, from one population to another

Question 3

Allopatric speciation

Answer 3

speciation that occurs when biological populations of the same species become isolated due to geographical changes such as mountain building or social changes such as emigration.

Question 4

Sympatric speciation

Answer 4

the splitting of an ancestral species into two or morereproductively isolatedgroups without geographical isolation of those groups

Question 5

Behavioral isolation

Answer 5

when species arereproductively isolatedfrom others due to differences in behavior

Question 6

Temporal isolation

Answer 6

areproductive barrierwhich prevents interbreeding between distinct but closely related species due to differences in the timing of mating receptivity, activity, or fertility

Question 7

Adaptive radiation

Answer 7

diversificationof a group oforganismsinto forms filling differentecologicalniches

Question 8

Mass extinction

Answer 8

when at least half of all species die out in a relatively short time—have occurred only a handful of times over the course of our planet’s history

Question 9

Pioneer species

Answer 9

the species that first colonize new habitats created by disturbance

Question 10

galapagos finches

Answer 10

Darwin’s finches, named after Charles Darwin, aresmall land birds, 17 of which are endemic to the Galapagos Islands

Question 11

silversword plants

Answer 11

a long-lived composite plant (Argyroxiphium sandwicense) of Maui and Hawaii that has a rosette of lanceolate leaves covered with silvery hairs

Question 12

Hybrids

Answer 12

the offspring resulting from combining the qualities of two organisms of different varieties, subspecies, species or genera through sexual reproduction

Question 13

prezygotic barriers

Answer 13

a mechanism that prevents fertilization from occurring. Apostzygoticreproductive barrier is a mechanism that reduces the viability or reproductive capacity of hybrid offspring

Question 14

postzygotic barriers

Answer 14

a mechanism that blocks reproduction after fertilization and zygote formation

Question 15

Habitat isolation

Answer 15

a form ofreproductive isolation, in which reproduction between two populations (generally two species that are capable of interbreeding) is restricted because each population occupies a different habitat

Question 16

Mechanical isolation

Answer 16

a type of reproductive isolation where two species physically cannot undergo fertilization

Question 17

Gametic isolation

Answer 17

a type of prezygotic barrier where the gametes (egg and sperm) come into contact, but no fertilization takes place

Question 18

Reduced hybrid viability

Answer 18

it is less likely to mature into a healthy, fit adult. The chances of the hybrid surviving and reproducing are decreased compared to the parent species

Question 19

Hybrid breakdown

Answer 19

a type of reproductive failure that appears after the F2 generation of crosses between different species or subspecies

Question 20

Abrupt Speciation

Answer 20

the discontinuity in a lineage that occurs through genetic mutations, chromosomal aberrations or other evolutionary mechanisms that cause reproductively isolated individuals to establish a new species population.

Question 21

Polyploidy

Answer 21

the heritable condition of possessing more than two complete sets of chromosomes

Question 22

diploid

Answer 22

the presence of two complete sets of chromosomes in an organism’s cells, with each parent contributing a chromosome to each pair

Question 23

haploid

Answer 23

the presence of a single set of chromosomes in an organism’s cells

Question 24

triploid

Answer 24

the presence of three sets of haploid (single) chromosomes in an organism or cell line and is termed 3n

Question 25

tetraploid

Answer 25

having four sets of chromosomes, symbolized as 4n

Question 26

hexaploid

Answer 26

an organism made up of cells containing six sets of chromosomes

Question 27

Autopolyploidy

Answer 27

Presence of three or more sets of homologous chromosomes or chromosomes from the same origin within a single cell or organism

Question 28

unreduced gamete

Answer 28

male or female gametes that have somatic chromosome numbers

Question 29

Allopolyploidy

Answer 29

when organisms contain two or more sets of chromosomes that are from different species

Question 30

Allium genus

Answer 30

a genus of monocotyledonous flowering plantswith hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives

Question 31

Coastal Redwoods

Answer 31

coniferous evergreen timber tree of the cypress family(Cupressaceae), the tallest of all living trees