Speciation

Question 1

Natural Selection

Answer 1

Individuals that have adaptations/phenotypes best stuited for the environment, have greater chance to survive and reproduce therefore pass their alleles onto the next generation.

Question 2

Selection Pressures

Answer 2

External factors that affect an organisms’ ability to survive in a given environment

Question 3

Speciation

Answer 3

The process of forming a new species

Question 4

Species

Answer 4

A group of organisms that can breed and produce viable offspring

Question 5

Allopatric

Answer 5

members of the same species are separated due to a geographical barrier/physical barrier

Question 6

sympatric

Answer 6

members of the original species are in the same geographical location

Question 7

Gene flow

Answer 7

The movement of genes from one population to another via breeding

Question 8

post-zygotic

Answer 8

a reproductive isolating mechanism that prevents reproduction after fertilisation

Question 9

prezygotic

Answer 9

a reproductive isolating mechanism that prevents mating and fertilisation

Question 10

temporal

Answer 10

a RIM that prevents breeding due to differences in timing

Question 11

ethological

Answer 11

a RIM that prevents breeding due to behavioural differences

Question 12

hybrid inavailability

Answer 12

the reproductive failure of a hybrid organism of two different species due to gene incompatibility

Question 13

hybrid breakdown

Answer 13

a hybrids inability to mature and grow into a healthy adult

Question 14

cline

Answer 14

the gradual change of a phenotype over an environmental gradient

Question 15

ring species

Answer 15

an interconnected series of populations around a geographical barrier; adjacent populations can breed while the extremes cannot

Question 16

polyploidy

Answer 16

an organism with more than two sets of chromosomes

Question 17

diploid

Answer 17

two sets of chromosomes; 2n

Question 18

triploid

Answer 18

three sets of chromosomes; 3n, sterile

Question 19

nondisjunction

Answer 19

the failure of chromosomes to separate properly during meiosis

Question 20

hybrid vigour

Answer 20

improved or increased function in offspring compared to their parents

Question 21

adaptive radiation

Answer 21

a type of divergent evolution when manu new species form from a common ancestor

Question 22

divergent

Answer 22

two or more species evolve from a common ancestor

Question 23

convergent

Answer 23

when 2 or more unrelated species evolve to have similar phenotypes due to similar selection pressures in their environment

Question 24

co-evolution

Answer 24

When the relationship between two species causes each to evolve in response to the other

Question 25

homologous structures

Answer 25

structural similarities between organisms due to a common ancestor, which have adapted to suit a purpose

Question 26

analogous structures

Answer 26

structures that have the same function and often appearance, but they arose from different origins

Question 27

punctuated equilibrium

Answer 27

periods of gradual change (stasis) with short bursts of rapid evolution that produces new species quickly

Question 28

phylogeny

Answer 28

the history via lines of descent

Question 29

comparative embryology

Answer 29

using similarities and differences in embryo development to determine relatedness

Question 30

reproductive isolation

Answer 30

two organisms which are not able to interbreed and produce fertile offspring

Question 31

stabilising selection

Answer 31

the type of natural selection where the middle variety is favoured over the extremes

Question 32

gradualism

Answer 32

the gradual change in a species over time

Question 33

evolution

Answer 33

the change in the allele frequency of a gene pool of a population over successive generations which leads to formation of new species.

Question 34

biogeography

Answer 34

the study of the distribution of species across geographical areas over time

Question 35

molecular biology

Answer 35

the study of the structure and function of genes, proteins and chromosomes

Question 36

endemic

Answer 36

a plant or animal that is only found in that location

Question 37

disruptive selection

Answer 37

the type of natural selection where both extremes are selected for in an environment

Question 38

direction selection

Answer 38

the type of natural selection where one extreme is selected for over the others in an environment

Question 39

allele

Answer 39

a different form of a gene

Question 40

founder effect

Answer 40

the movement of few individuals from a population that colonise a different location with no gene flow with the original population

Question 41

hybrid sterility

Answer 41

a hybrids inability to produce offspring

Question 42

Genetic drift

Answer 42

The loss or change of alleles of a gene pool in a small population due to chance or random events

Question 43

sexual selection

Answer 43

When some species show physical differences amongst the males and females.

Question 44

mutation

Answer 44

the creation of totally new alleles upon which the mechanisms of natural selection can act

Question 45

gametic mutation

Answer 45

gametic mutations can be inherited. Testes of males, ovaries of females

Question 46

somatic mutation

Answer 46

in normal body cells occuring beyond zygote formation, not inherited but may affect the person during their lifetime

Question 47

reproductive isolating mechanisms (RIM)

Answer 47

Barriers that keep the populations apart, therefore preventing individuals of the population from breeding (no gene flow)

Question 48

types of prezygotic RIMs

Answer 48

- geographical isolation - habitat preference -temporal isolation -behavioural isolation -structural incompatibility - gamete mortality

Question 49

types of postzygotic RIMs

Answer 49

- zygote mortality - poor hybrid fitness - hybrid sterility

Question 50

autopolyploidy

Answer 50

polyploids that arise from parents of the same species

Question 51

allopolyploidy

Answer 51

this occurs when two species interbreed to produce a new hybrid with chromosomes from each of the parent species