evolution, fossils, speciation & classification (paper 2) TOPIC 6

Question 1

what is evolution

Answer 1

a change in the inherited characteristics of a population over time through the process of natural selection, which may relate in the formation of a new species

Question 2

what is the theory of evolution by natural selection

Answer 2

all species of living things have evolved from simpl life forms that first developed more than three billion years ago

Question 3

why does evolution actually happen

Answer 3

natural selection of varients that give rise to phenotypes best suited to their environment

Question 4

when has a new species formed

Answer 4

when two populations of one species become so different in phenotype that they can no longer interbreen to produce FERTILE offspring

Question 5

who invented the theory of evolution

Answer 5

charles darwin

Question 6

when do scientists think early life forms developed on earth

Answer 6

more than 3 billion years ago

Question 7

what did people believe about life on earth before evolution

Answer 7

that God created everything

Question 8

other than darwin, who else had a theory of evolution

Answer 8

Lamarck

Question 9

describe Lamarck’s theory of evolution

Answer 9

every type of animal evolved from worms and the change to other orgaisms was casued by the inheritance of acquired characteristics - giraffes used their neck a lot so it grew longer

Question 10

what were the problems with Lamarck’s theory

Answer 10

• not enough evidence
• people didn’t like the idea of desccending frfom worms
• could see it wasnt true in humans

Question 11

where did darwin discover evolution through natural selection

Answer 11

on the galapagous islands from the variety of finches from island to island

Question 12

what process did darwin suggest

Answer 12

natural selection

Question 13

explain darwin’s theory of natural selection

Answer 13

• individula organisms within a species show a wide ranger of variation for a characteristic
• mutation gives rise to new variants
• individuals with characteristic most suited are more likely to survive and breed successfully
• these characteristics are passed onto the next generation
• this occurs over many generations

Question 14

what was darwin’s book called

Answer 14

On the Origin of Species (1859)

Question 15

why was the theory of evolution by natural selection only gradually accepted

Answer 15

• theory challenged idea that God made life on earth
• insufficent evidence at the time
• mechanism of inheritance and variation was not know until 50 years after the theory was published

Question 16

how has bacteria evolved

Answer 16

become antibiotic resistant

Question 17

how have bacteria had time to evolve

Answer 17

because bacteria reproduce at a very fast rate

Question 18

how does antibiotic resistant bacteria occur

Answer 18

• there is variation in the population of bacteria
• mutations occur naturally and spontaneously
• mutations occur in the bacteria
• this produces new stains of bacteria
• some strains are resistant to anitbiotics

Question 19

how has bacteria become resistant to antibiotics

Answer 19

• overuse of antibiotics
• patients not completing course of medicine = can mutate
• argicultural use of bacteria in animals even when not ill

Question 20

why is it important to reduce the rate of development of antibiotic resistant stains

Answer 20

the development of new anitbiotics is expensive and slow and unlikely to keep up with hte emergence of new resistant strains

Question 21

what are fossils

Answer 21

remains of plants and animals from millions of years ago

Question 22

who created the theory of speciation

Answer 22

Alfred Wallace

Question 23

what is speciation

Answer 23

the development of new species when populations of the same species become so different that they can no longer successfully interbreed to produce fetile offspring

Question 24

what two factors lead to speciation

Answer 24

• isolation
• natural selection

Question 25

describe the process of speciation

Answer 25

- any population contains a wide range of alleles - in each population alleles are advantegous to help the organism survive (natural selection) - sometimes part of a population is isolated because of new environmental conditions - alleles will be selected for each of the populations in the new environments - this increases variation more between the population - evutally the populations become so different they cannot reproduce successfully and are two different species

Question 26

how might a population become isolated

Answer 26

- new mountain range - new river - area of land becomes an island - earthquake splits land - volcanoes porduce new land

Question 27

how old are fossils

Answer 27

millions of years old

Question 28

where are fossils found

Answer 28

in rocks

Question 29

what are the three ways fossils can have formed

Answer 29

- from parts of organisms tha thave not decayed becuase one or more conditions needed were absent - when parts of the organism are replaced by minerals as they decay (mineralisation) - as preserved traces of footprints (footprints, burrows, roots)

Question 30

what is mineralisation

Answer 30

when parts of the organism are replaced by minerals as they decay

Question 31

why are there only few traces of early life forms

Answer 31

because they were soft-bodied which means that what traces that were, have been destroyed by geological activity

Question 32

why are there gaps in the fossil records

Answer 32

- many of the earliest life forms were soft bodied and therefore left very few traces - most fossils have been destroyed by geological activity - most oragnisms that die do not fossilise - not all of them have been found yet

Question 33

why can scientists not be sure about how life began on earth

Answer 33

because there are too many gaps in fossil records as he earliest life forms were soft-bodied and left few traces

Question 34

what can we learn from fossils

Answer 34

how much or how little different organisms have changed as life developed on earth

Question 35

define extinction

Answer 35

the permanent loss of all the members of a species

Question 36

what might extinction be caused by

Answer 36

- changed to the environment - new predators - new diseases - new more successful competitors - a single catastrophic event

Question 37

what is mass extinction

Answer 37

the loss of many species at the same time

Question 38

what is classification

Answer 38

organisation of living things into groups according to their similararities

Question 39

suggest why biologists classify organisms

Answer 39

- make it easier to study them - make sense of the living world - understand how different groups of organisms are related - recognise the biodiversity on earth - gives scientists a common language

Question 40

who proposed the idea of clasification

Answer 40

carl linnaus

Question 41

what are the groups of classification

Answer 41

- domain - kingdom - phylum - class - order - family - genus - species (do keep penis' clean or forget good sex)

Question 42

in the binomial system how many words are the names given to each organism

Answer 42

2

Question 43

describe the formations of the names in the binomial system

Answer 43

- 1st name = genus = capital letter - 2nd name = species = lower case - write in italics

Question 44

in 1970s what idea did Carl Woese introduce

Answer 44

a higher level called a domain

Question 45

how many types of domains are there

Answer 45

3

Question 46

what are the three domains

Answer 46

- archaea - bacteria - eukaryota

Question 47

what type of things are in the archaea domain

Answer 47

early forms of bacteria that include ectremophiles, organisms that can live in extreme conditions; this contains one kingdom, the archaebacteria

Question 48

what type of things are in the bacteria domain

Answer 48

these are the true bacteria and cyanobacteria, bacteria-like organisms that can photosynthesise; this contains one kingdom, the eubacteria

Question 49

what type of things are in the eukaryota domain

Answer 49

these are all have cells that contain a nucleus enclosing the genetic material; there are four kingdoms - the protista, fungi, plants and animals

Question 50

how many kingdoms are there

Answer 50

6

Question 51

name the kingdoms

Answer 51

- protista - fungi - plants - animals - archaebacteria - eubacteria

Question 52

what are evolution trees

Answer 52

a method used by scientists to show how they believe organisms are related

Question 53

what do evolution trees show

Answer 53

- common accestors - relationships between species