4.3-classification and evoluion

Question 1

What is taxonomy ?

Answer 1

Classification using physical similarities between different species.

Question 2

What is phylogeny?

Answer 2

Classification using evolutionary relationships, so that each group shares a common ancestor.

Question 3

Why do we classify living things ?

Answer 3

• convenience
• to make the study of living things more manageable
• to make it easier to identify organisms
• to help us see the relationships between species

Question 4

What are the 8 taxonomic levels ?

Answer 4

Domain 
Kingdom 
Phylum 
Class
Order 
Family 
Genus 
Species

Question 5

What are the 5 kingdoms ?

Answer 5

Plantae 
Animalia
Fungi 
Protoctista 
Prokaryotae

Question 6

What are the 3 domains ?

Answer 6

Archaea
Eubacteria
Eukaryotae

Question 7

Why does using a common name not work well?

Answer 7

1) Same organism may have completely different common name in different parts of 1 country
2) different common names are used in different countries
3) translation of languages or dialects any give different names
4) same common name could be used for different species in other parts of the world

Question 8

What is the binomial system of naming organisms ?

Answer 8

A system that uses the genus name and the species name to avoid confusion when naming organisms.

Question 9

what are the features of prokaryotae ?

Answer 9

• no nucleus
• a loop of dna- no chromosomes
• naked dna- no histone proteins
• no membrane bound organelles
• smaller ribosomes
• smaller cells than eukaryotes
• may be free living or parasitic

Question 10

What are the features of protoctista ?

Answer 10

• eukaryotic
• mostly single celled (exception=algae)
• show a wide variety of forms
• the only thing they have in common is that they don’t qualify to belong in any of the 4 kingdoms

Question 11

What are the features of fungi ?

Answer 11

• eukaryotic
• can exist as single cells (yeasts) or they have a mycelium that consists of hyphae
• chitin walls
• multinucleate nucleus
• mostly saprophytic

Question 12

What does saprophytic mean ?

Answer 12

Cause decay of organic matter

Question 13

What are the features of plantae ?

Answer 13

• eukaryotic
• multicellular
• cellulose cell wall
• autotrophic
• contain chlorophyll

Question 14

What does autotrophic mean ?

Answer 14

Absorb simple molecules and build them into larger organic molecules

Question 15

What are the features of animalia ?

Answer 15

• eukaryotic
• multicellular
• heterotrophic

Question 16

What does heterotrophic mean?

Answer 16

Digest large organic molecules to form smaller molecules for absorption

Question 17

what is cytochrome c?

Answer 17

a protein used in the process of respiration

Question 18

how can cytochrome c be used in classification?

Answer 18

if we compare the sequence of amino acids in cytochrome c from 2 different species, we can see how similar they are, so how closely related they are.

Question 19

why is cytochrome c a good biological molecule to use in classification?

Answer 19

same between the same species

differs between different species.

Question 20

what is the three domain classification?

Answer 20

dividing prokaryotae into 2 different domains-bacteria and archaea.

Question 21

why are bacteria different from archaea?

Answer 21

bacteria have:

• different cell membrane structure
• flagella with a different internal structure
• different enzymes (rna polymerase ) for synthesising rna
• no proteins bound to their genetic material
• different mechanisms for dna replication and for synthesising rna

Question 22

why are archaea similar to eukaryotes?

Answer 22

they have similar enzymes (rna polymerase) for synthesising rna.
they have similar mechanisms for dna replication and synthesising rna
they both have proteins bound to their dna.

Question 23

what is artificial classification?

Answer 23

classifications done for convenience, eg have all the yellow flowers on one page, all blue flowers on the next page

Question 24

what are the features of artificial classification?

Answer 24

• based on only a few characteristics
• doesn’t reflect any evolutionary relationships
• provides limited information
• stable

Question 25

what is natural classification?

Answer 25

• uses many characteristics
• reflects evolutionary relationships
• provides a lot of useful information
• may change with advancing knowledge

Question 26

why could natural classification be useful in conservation?

Answer 26

if you want to find out about an endangered species, you wouldn’t want to risk harming any of the few surviving members BUT if you know of a similar species hat’s not endangered you can carry out research on that instead that also applies to the endangered species.

Question 27

what 4 observations did Darwin make?

Answer 27

1) offspring generally appear similar to their parents
2) no 2 individuals are identical
3) organisms have the ability to produce large numbers of offspring
4) populations in nature tend to remain fairly stable in size.

Question 28

what were Darwin’s three conclusions?

Answer 28

1) there is a struggle to survive
2) better adapted individuals survive and pass on their characteristics
3) over time a number of changes may give rise to new species.

Question 29

how does recent study of biological molecules provide evidence for evolution?

Answer 29

-the fact that certain molecules are found throughout the living world is evidence in itself-suggests that all species came from a foreign ancestor.

Question 30

what is continuous variation?

Answer 30

variation where there are 2 extremes and a full range of values in between

Question 31

what is discontinuous variation?

Answer 31

where there are distinct categories and nothing in between

Question 32

how is it best to graph continuous variation?

Answer 32

histogram

Question 33

how is it best to graph discontinuous variation?

Answer 33

bar chart

Question 34

what is the correlation coefficient ?

Answer 34

measures how closely 2 sets of data are correlated- a value of 1 means perfect correlation, eg spearman

Question 35

what is standard deviation?

Answer 35

a measure of spread around a mean

Question 36

what is a student’s t test?

Answer 36

a test used to compare 2 means

Question 37

what is a well adapted organism able to do?

Answer 37

• find enough food/photosynthesise
• find enough water
• gather enough nutrients
• defend itself from predators and disease
• survive physical conditions of its environment eg changes in temp, light, water availability
• respond to changes in its environment
• have sufficient energy for successful reproduction

Question 38

what are the 3 kind of adaptation?

Answer 38

anatomical
behavioural
physiological

Question 39

how does natural selection work?

Answer 39

1) mutation creates alterative versions of a gene (alleles)
2) this creates genetic variation between the individuals of a species-INTRASPECIFIC VARIATION
3) when resources are scarce, the environment will select those variations that give an advantage -there is a selection pressure.
4) individuals with advantageous characteristics will survive and reproduce
5) they will pass on their advantageous characteristics -inheritance
6) the next generation will have a higher proportion of individuals with the successful characteristics. over time, the group of organisms becomes well adapted to its environment (adaptation)

Question 40

what is an example of an insecticide that insects have become resistant to?

Answer 40

DDT