4.2.2: classification and evolution

Question 1

what are the taxonomic groups?

Answer 1

kingdom
phylum
class
order
family
genus
species

Question 2

what are the three domains?

Answer 2

1) archaea
2) bacteria
3) eukarya

Question 3

why do scientists classify organisms?

Answer 3

• to identify species
• to predict characteristics
• to find evolutionary links
• by using a single classification system, organisms can be identified worldwide

Question 4

what is a species?

Answer 4

a group of organisms that are able to produce fertile offspring

Question 5

how does the binomial nomenclature mean?

Answer 5

genus first then species in italics or underlined

Question 6

what are the 5 kingdoms?

Answer 6

• prokaryotae
• protoctista
• fungi
• plantae
• animalia

Question 7

what are the general features of prokaryotae?

Answer 7

• unicellular
• no nucleus or other membrane bound organelles
• small ribosomes
• no visible feeding mechanism

Question 8

what are the general features of protoctista?

Answer 8

• mainly unicellular
• a nucleus and membrane bound organelles
• some have chloroplast
• nutrients acquired by photosynthesis and digestion

Question 9

what are the general features of fungi?

Answer 9

• uni and multicellular
• nucleus and cell wall containing chitin
• no chloroplasts
• most store food as glycogen
• nutrients are acquired by absorption

Question 10

what are the general features of plantae?

Answer 10

• multicellular
• nucleus with membrane bound organelles
• all contain chlorophyll
• food stored as starch
• nutrients acquired by photosynthesis

Question 11

what are the general features of animalia?

Answer 11

• multicellular
• nucleus with membrane bound organelles
• no cell wall
• no chloroplast
  -food stored as glycogen
• nutrients acquired by ingestion

Question 12

what are the key features of eukarya?

Answer 12

• have 80s ribosomes
• rna polymerase, responsible for most mrna transcription

Question 13

what are the key features of archaea?

Answer 13

• have 70s ribosomes
• rna polymerase of 8 to 10 proteins

Question 14

what are the key features of bacteria?

Answer 14

have 70s ribosomes
RNA polymerase contains 5 proteins

Question 15

what are archaebacteria?

Answer 15

can live in extreme environments

Question 16

what is eubacteria?

Answer 16

“true” more common bacteria

Question 17

what is phylogeny?

Answer 17

name given to evolutionary relationships

Question 18

what are the advantages phylogenetics?

Answer 18

can be used to compared to classification systems
- scientists are forced not force classifications
- classification systems imply organisms are similar even though they may not be

Question 19

what is the evidence of evolution?

Answer 19

• palaeontology - study of fossil records
• comparative anatomy - similarities and diffs between organism’s anatomy
• looking at biochemistry of diff organisms

Question 20

what is the difference between interspecific and intraspecific variation?

Answer 20

• interspecific = between members of different species
• intraspecific = differences between organisms within a species

Question 21

what are the causes of variation?

Answer 21

• genetic mutations
• change in environment

Question 22

what are the genetic causes of variation?

Answer 22

• alleles (genes have different alleles
• mutations (change in dna sequence - genes - proteins that are produced)
• meiosis (two parents genetic material mixed)
  random fertilisation

Question 23

what is the difference between continuous and discontinuous variations?

Answer 23

• continuous = a characteristic can take any value from one extreme
• discontinuous = no in between values, variation determined purely by genetic factors into this category

Question 24

what are normal distribution curves?

Answer 24

when continuous variation data is plotted onto a graph resulting in a bell-shaped curve

Question 25

what are the 3 types of adaptations?

Answer 25

1) anatomical - physical features
2) behavioural - the way an organism acts
3) physiological - the processes that take place inside on organism

Question 26

what are 3 examples of anatomical adaptations?

Answer 26

• body covering
• camouflage
• teeth

Question 27

what are three examples of behavioural adaptations?

Answer 27

• survival behaviours e.g. playing dead
• courtship
• migration

Question 28

what are 3 examples of physiological adaptations?

Answer 28

• poison production
• antibiotic production
• water holding

Question 29

what are analogous structures?

Answer 29

when they perform the same role, but the structure is very different

Question 30

why does natural selection occur?

Answer 30

due to pressures or a change in the environment

Question 31

what is the process of natural selection?

Answer 31

1. means there are different alleles present within the population
2. the organisms that are best adapted to the selection pressure (have the advantageous allele) have increased chance of survival
3. they are more likely to outcompete, survive and reproduce
4. they pass on the advantageous allele to their offspring, making it more widespread in the population

Question 32

how has drug resistance occurred in microorganisms?

Answer 32

• mrsa has developed resistance to many antibiotics
• bacteria reproduce rapidly so they evolve in a short time
• when bacteria replicate, their dna can be altered = die or mutations
• s.aureus developed mutations to be resistant to methicillin
• when bacteria were exposed to antibiotioc, resistant inndividuals survived and reproduced, passing on resistant alleles