Evolution and Speciation

Question 1

What is Evolution?

Answer 1

A change in the heritable characteristics of a population

Question 2

Darwin’s theory

Answer 2

All species of organisms have evolved from a small number of original species

Question 3

Lamark’s theory

Answer 3

Physical changes that occur during a lifetime can be passed on to the offspring (false)

Question 4

Heritable characteristics

Answer 4

Traits that are passed on by genetic information

Question 5

Inheritable characteristics

Answer 5

Traits that you get during your life time and cannot be passed on to an offspring

Question 6

How are base sequences in nucleic acids and amino acids evidence for evolution?

Answer 6

Similarity in the base sequences indicate common ancestry. Fewer differences in the base sequence –> supports the theory of evolution by natural selection

Question 7

Selective Breeding

Answer 7

Artificial breeding, whereby man intervenes in the breeding of species to produce desired offspring. (Causes rapid evolution)

Question 8

What is an example of selective breeding?

Answer 8

Dog breeding. For example, beagles were bred to be smaller to enter fox holes

Question 9

Homologous Structure

Answer 9

It has a similar structure and a different origin. Has a divergent evolution and adaptive radiation. It becomes different when performing different functions and is a natural classification.

Question 10

Analogous Structure

Answer 10

It has a different structure and similar function. It has a convergent evolution and becomes similar through performing a similar function. An artificial classification

Question 11

What is an example of a Homologous structure?

Answer 11

Mammals, reptiles, amphibians, and birds have a pentadactyl limb. They all have a similar arrangement of bones in their appendages based on a five-digit limb

Question 12

What is an example of an Analogous Structure?

Answer 12

Wings are found in birds and insects. Fins are found in whales and fish.

Question 13

Gradualism

Answer 13

Species change by steady and gradual transformations

Question 14

Punctuated Equilibrium

Answer 14

Species remain stable for long periods before undergoing abrupt and rapid change

Question 15

How does speciation occur?

Answer 15

Through reproductive isolation (geographical barriers) and differential survival.

Question 16

What is an example of a reproductive barrier?

Answer 16

Bonobos and common chimpanzees are separated by the congo river

Question 17

Allopatric Speciation (HL)

Answer 17

Speciation ccurred due to geographical barriers

Question 18

Sympatric Speciation (HL)

Answer 18

Speciation due to behavioural isolation or temporal isolation

Question 19

Adaptive Radiation (HL)

Answer 19

A pattern of diversification in which species that have evolved from common ancestors occupy various ecological roles. This increases diversity. (One ancestor –> evolves to like 5 species)

Question 20

Interspecific Hybrids (HL)

Answer 20

Produced by cross-breeding members of different species.

Question 21

Polyploidy (HL)

Answer 21

When an organism has more than two sets of chromosomes in every cell. It is caused by non-disjunction in the meiosis.

Question 22

Autopolyploidy (HL)

Answer 22

When a polyploid offspring is derived from a single parental species (usually via self-fertilization)

Question 23

Allopolyploidy (HL)

Answer 23

When a polyploid offspring is derived from two distinct parental species

Question 24

Prezygotic Isolation (HL)

Answer 24

Type of reproductive isolation where it occurs before fertilization can occur (no offspring are produced)

Question 25

Postzygotic Isolation (HL)

Answer 25

Type of reproductive isolation where it occurs after fertilization (offspring are either not viable or infertile)

Question 26

Temporal Isolation (HL)

Answer 26

Occurs when two populations differ in their periods of activity or reproductive cycles

Question 27

Behavioral Isolation (HL)

Answer 27

Occurs when two populations exhibit different specific courtship patterns

Question 28

Geographical Isolation (HL)

Answer 28

Occurs when two populations occupy different habitats