B2

Question 1

Evolution

Answer 1

• Population of living things change over generations
• Organisms best adapted to their environment are most likely to survive (“survival of the fittest”)
• Evolution only occurs in populations, not individuals
• Cumulative change in heritable characterisitcs of a population

Question 2

Changing Earth- Fossils

Paleontology

Answer 2

Study of fossils

Burrows,footprints and chemicaals rcan remain in fossils

Question 3

Changing Earth- Fossils

Fossil Formation

Answer 3

• Teeth, shells, bones can resist weathering for long periods of time, in dry environments
• Insects may be trapped in amber
• Impressions/imprints can be left by plants/animals, tracks in soft mud
• fecal matter
• Intracellular spaces of skeletal material can be replaced with minerals (e.g. silica, calcium, iron)

Question 4

Changing Earth- Fossils

Patterns found

Answer 4

1. Different species lived on Earth at various different times
2. Complexity of organsims increased
3. Living species located in the same geographic region as thei most closely matching fossil

Question 5

Changing Earth- Fossils

Relative dating

Dating the past

Answer 5

Deeper the sedimantary rock layer= Older fossil

Question 6

Changing Earth- Fossils

Radiometric dating

Dating the past

Answer 6

Determines the age of rock or fossil by radioactive isotope decay rate

Question 7

Changing Earth- Biogeography

Biogeography

Answer 7

The study of the variation and geographic distrubution of life on Earth

Question 8

Changing Earth- Biogeography

225 million years ago Earth had one land mass

Theory of plate tectonics

Answer 8

Supercontinent (Pangea)

Question 9

Seperated the contintentd by shiftinh tectonic plates

Theory of plate tectonics

Answer 9

• Fossil species older than 150million years were on the same contintent
• The ones younger were on seperate
• Populations evolved after the break up of pangea

Question 10

Changing Earth- Anatomy

Homologous structures

Answer 10

• Features with similar structures but different functions
• Similiar origin but different use in diffrent species

Question 11

Changing Earth- Anatomy

Analougous structures

Answer 11

• Similair in function and appearence but not in origin

Question 12

Changing Earth- Anatomy

Convergent evolution

Answer 12

• Development of similair adaptations from unrelated species
• Occupy equivalant niches on differetn continents
• Due to similar environemtal conditions

Question 13

Changing Earth- Anatomy

Embryonic development

Answer 13

• Late 1800s: scientists noticed similarities in embryos of different species
• Many structures are similair to common ancestor
• Ex: Homologoud trait such as tailbones

Question 14

Changing Earth- Anatomy

Vestigal functions

Answer 14

• Rudimentary structures with no useful function
• May have been functional in ancestors
• Examples: Human appendix, wisdom teeth, tail bones, whale skeleton having hips and legs

Question 15

Changing Earth- Biochemistry

DNA

Answer 15

• Hereditary material in cells
• Each DNA molecule contain many different genes

Question 16

Changing Earth- Biochemistry

Gene

Answer 16

Segment of DNA that performs a specific function

Question 17

Scientific Theory

Answer 17

• Model that accounts for all known scientific evidenses
• Requires plausbale explantation
• Altered as new data is gained

Question 18

Timeline of the evidence of evolution

Lamarkism

Early 1800s, Jean-Baptiste Lamarck

Answer 18

• Inheritance of aquired characteristics
• False concept, but key recognition of environemntal role in driving evolutionary chanfe

Question 19

Timeline of the evidence of evolution

1830-1860, Charles Darwin

Answer 19

• Natural selection: Result of differiential reproductive success of individuals caused by variations in their limited charecteristics
• All species have inherited traits ehich make them better adapted to survive and reproduce= Survival becomes more common in populations= Evolved populations

Question 20

Darwins Theory

Overproduction

Answer 20

Number of offspring produced by a species is greater than can survive

Question 20

Darwins Theory

Competition

Answer 20

Organisms of different or the same species must be compete for limited resources

Question 20

Dawins Theory

Variation

Answer 20

• No two individuals are alike. sexual reproduction creates varaibility
• Offspring inherit most of the parents traits, not all. Some traits arose randomely

Question 20

Dawins Theory

Survival of the fittest

Answer 20

Environment ats to select favorable traits. Those with advantages survive and reproduce

Question 20

Dawins Theory

Speciation

Answer 20

Individuals do not change, populations do

Question 20

# Inherited Variation-mutations DNA

Answer 20

* Made out of nuecleotides that form genes, this gives the inherited traits * DNA is usually relicated the exact same but changes can occur sometimes

Question 20

# Inherited Variation-mutations Mutations

Answer 20

* Random changes in DNA * Can occur from environemtal fators and erros in copying * IB: Mutations can occur because of meiosis * New combinations of alleles are created due to crossing over

Question 21

# Inherited Variation-mutations Mutations-Neutral

Answer 21

No affect on individuals fintness or reproduction

Question 21

# Inherited Variation-mutations Mutations-Harmful

Answer 21

* May cause gene disorders or cancer * reduces individuals fitness

Question 22

# Inherited Variation-mutations Mutations-Beneficial

Answer 22

* Provides an advandtage to an individual

Question 23

# Inherited Variation Asexual Reproduction/Reproduction without male

Answer 23

* Recieve exact same DNA as parent * Offspring identical to parents and siblings * Only source of variation is mutation

Question 24

# Inherited Variation Sexual reproduction/Reproduction with two parents

Answer 24

* Are varaiable in phenotype(how they look) * Offspring inheritis random assortments of genes from either parent * Allows species to be variable

Question 25

Variability

Answer 25

1. 2 copies of each gene, one from mom, and one from dad 2. Random asortment of genes 3. Chose different mates

Question 26

# Inherited Variation Adaptations

Answer 26

* Change in charecteristic of an organism that increases its chance of survival * Variation in a trait may give adoptive advantage to a species * 3 types of adaptions 1. Structural 2. Behavioral 3. Physiological

Question 27

Structural adaptation

Answer 27

Physical characteristic that helps an organism survive in its environment

Question 27

Behavioral Adaptation

Answer 27

* Something an organism does in response to external stimulus to help them survive * Ex: hibernation, migration, courtship, nocturnal/diurnal

Question 27

Physiological Adaptation

Answer 27

A process inside of organisms body that helps it to survive in its environment

Question 27

# Speciation- Forming a new species Allopatric speciation

Answer 27

1. Physical barrier sepertes single interbreeding population into two. mutations not shared 2. Narural selection works on seperate populations- inherited differences. populations evolve independetly in response to varying environment 3. groups are no longer sexually compatable due to accumalted physical/behavioral differences-> 2 or more different species

Question 27

Dawins Theory- Speciation

Answer 27

* Individuals do not change, populations do * Accumaltion of new traits over long periods of times populations become new/different species

Question 27

Darwins Finches

Answer 27

* They become different species of finches due to geographical isolation * Overtime the food source they were adapted to distinguished them from one another

Question 27

Theory of Gradulism

Answer 27

* Speciation occurs slowly * Fossil records show abrupt changes but we are missing many pieces

Question 27

Theory of Punctuated Equllibrium

Answer 27

1. Many species evolve ver rapidly in evolutionary times 2. Speciation usually occurs in small isolated populations, so intemediate fossils are rare 3. After initial burst of evolution, spcies are well adapted to their environemt so they dont change much over long periods of time