10 - Classification and evolution

Question 1

classification systems - taxonomic

Answer 1

Kingdom
phylum
class
order
family
genus
species

Question 2

why do scientist classify organisms

Answer 2

• to identify species
• to predict characteristics
• to find evolutionary links

Question 3

how are organisms classified?

Answer 3

• begins by separating organism into the three domains archaea, bacteria and eukarya
• s move down the groups there are fewer organisms in each, they become more similar and share more characteristics

Question 4

species

Answer 4

• contains only one type of organisms
• a group or organisms that are able to reproduce to produce fertile offspring

Question 5

how to name organism

Answer 5

binomial nomenclature
Genus species

Question 6

the five kingdoms

Answer 6

• prokaryotae (bacteria)
• Protoctista (unicellular eukaryotes)
• Fungi (yeast, mould and mushrooms)
• Plantae (the plants)
• Animalie (the animals)

Question 7

Prokaryotae

Answer 7

• prokaryotes
• unicellular
• no nucleus or other membrane bound organelles
• small ribosomes - naked DNA
• no visible feeding mechanism - nutrients absorbed through the cell wall or produced by PHS
• Staphylococcus aureus

Question 8

Protoctista

Answer 8

• mainly unicellular
• eukaryotes
• a nucleus and membrane bound organelles
• some chloroplasts
• some are sessile, other move by cillia, flagella or by amoeboid mechanisms
• nutrients acquired by PHS of by ingestion of other organisms
• Amoeba and paramecium

Question 9

Fungi

Answer 9

• eukaryotes
• uni or multicellular
• a nucleus and membrane bound organelles and a cell wall made of chitin
• no chloroplast or chlorophyll
• no mechanism for locomotion
• most have a body or mycelium made of threads of hyphae
• nutrients acquired by absorption - mainly form decaying material (saprophytic)
• store food as glycogen
• mushrooms, mould and yeast

Question 10

plantae

Answer 10

• eukaryotes
• multicellular
• a nucleus and membrane bound organelles like chloroplasts and a cell wall made of cellulose
• contains chlorophyll
• most don’t move but gametes can by cillia or flagella
• nutrients from PHS
  -store food as starch

Question 11

Animalia

Answer 11

• eukaryotes
• multicellular
• nucleus and membrane bound organelles
• no cell wall
• no chloroplast
• move with cillia, flagella or contractile proteins
• nutrients form ingestion
• store food as glycogen

Question 12

what is the Three Domain System

Answer 12

• organisms are classified into 3 domains and 6 kingdoms based on differences in nucleotides in rRNA, membrane lipid structures and sensitivity to antibiotics
• Eukarya, Archaea and bacteria

Domain -> kingdom
Bacteria - > eubacteria
Archaea -> archaebacteria
Eukarya -> protoctista, plantae, fungi and animalia

Question 13

Eukarya

Answer 13

• 80s ribosomes
• RNA polymerase contains 12 proteins

Question 14

archaea

Answer 14

• 70s ribosomes
• RNA polymerase have between 8 to 10 proteins and are similar to eukaryotic ribosome

Question 15

Bacteria

Answer 15

• 70s ribosomes
• RNA polymerase contains 5 proteins

Question 16

archaebacteria

Answer 16

• can live in extreme environments
• like hot thermal vent, anaerobic conditions and highly acidic conditions

Question 17

Eubacteria

Answer 17

‘true bacteria’

Question 18

phylogeny

Answer 18

• evolutionary relationships
• shows how related organisms are

Question 19

evidence for evolution

Answer 19

• palaeontology - study of fossils
• comparative anatomy - study of similarities and differences between anatomy
• comparative biochemistry- similarities and differences between the chemical makeup of organism

Question 20

Fossils

Answer 20

formed when animal and plant remains are preserved in rocks
- over time sediment on the earths surfaces forms layers (strata) of rock
- different layers correspond to different geological era, so can show how organisms change over time

Question 21

evidence provided by the fossil record

Answer 21

• fossils of the simplest organisms like bacteria are found in the oldest rocks. More complex ones are found in recent rocks, SO simple life forms gradually evolved over a long time into something more complex
• sequence in how organisms are found matches their ecological links to each other
• similarities in anatomy of fossils show how closely related organisms have evolved from the same ancestor

Question 22

comparative anatomy

Answer 22

the study of similarities and differences in the anatomy of different living species

Question 23

Homologous structures

Answer 23

• a structure that appears superficially different in different organism, it has the same underlying structure
• they have evolved from a common ancestor and the structure has evolved from the same structures
• it is evidence for divergent evolution
  -> how from a common ancestor, different species have evolved with a different set of features (adapting to different environment)

Question 24

comparative biochemistry

Answer 24

• the study of similarities and differences between the proteins and other molecules that control life processes
• they are highly conserved
  -main ones are cytochrome c and rRNA
• can discover how closely two species are related by comparing the order of DNA bases in a gene for a protein
• the number of differences are plotted against the rate the molecules undergoes neutral substitutions
  -more similar the more related

Question 25

variation

Answer 25

differences in the characteristics between organisms

Question 26

interspecific variation

Answer 26

variation between members of different species

Question 27

intraspecific variation

Answer 27

variation between members of the same species

Question 28

factors of variation

Answer 28

- genetic variation - differences in genetic material - environmental variation

Question 29

causes of genetic variation

Answer 29

- Alleles - Mutations - Meiosis - sexual reproduction - chance

Question 30

Alleles - causes of genetic variation

Answer 30

- genes have different alleles (alternative forms) - different alleles form different effects - depending on the parental combination, different characteristic of the offspring happen - individuals in a species population may inherit different alleles of a gene

Question 31

Mutations - causes of genetic variation

Answer 31

- changes in DNA sequences changes the proteins coded for - this can change the physical and metabolic characteristic - if a mutation is in a somatic cell it only affects the individual - if it is in the gamete it is passed to offspring

Question 32

Meiosis - causes of genetic variation

Answer 32

genetic material inherited from the parents is mixed up by independent assortment and crossing over - leading to the gametes showing variation

Question 33

sexual reproduction - causes of genetic variation

Answer 33

- offspring inherit genes from two parents, each individual produced differs from the parents

Question 34

Chance - causes of genetic variation

Answer 34

- many different produced from the parents genome - it is a result of chance as to which two gametes combine

Question 35

discontinuous variation

Answer 35

- characteristic can only result in a certain value - no in between values - variation determined purely by genetic factors is discontinuous - use a bar chart or pie chart

Question 36

continuous variation

Answer 36

- can take any value within a range - height and mass - characteristic are controlled by many genes and influenced by the environment - frequency table and histogram

Question 37

normal distribution curve

Answer 37

- when continuous variation data is plotted it is bell shaped - mean=median=mode - bell shaped, symmetrical about the mean - 50% of the values are less than and more than the mean - most values lie close to the mean

Question 38

standard deviation

Answer 38

measures how spread out the data is

Question 39

students t-test

Answer 39

compare the means of data values of two populations

Question 40

spearman's rank correlation coefficient

Answer 40

used to consider relationships between two sets of data - no correlation = 0 - positive = +1 - negative =-1

Question 41

adaptations

Answer 41

are characteristic that increase a organisms chance of survival and reproduction in its environment - anatomical - physical - behavioural - how they act - physiological - processes in the organisms

Question 42

anatomical adaptations

Answer 42

- body coverings - camouflage - teeth - mimicry

Question 43

Behavioural adaptations

Answer 43

- survival behaviours - courtship - seasonal behaviours- migration, hibernation can fall in to two categories - innate - inherited through genes - learned - adaptations learnt from observing other animals

Question 44

physiological adaptations

Answer 44

- poison production - antibiotics - water holding

Question 45

analogous structures

Answer 45

structures that have adapted to perform the same function but have different genetic origin

Question 46

what does analogous structures provide evidence for

Answer 46

convergent evolutions -> when unrelated species begin to share similar traits -organisms have adapted to similar environments or selection pressures

Question 47

selection pressure

Answer 47

factors that affect the organisms chances of survival or reproductive success

Question 48

natural selection overview

Answer 48

- organism that are best adapted to the environment are more likely to survives and reproduce then those who are poorly adapted - these adaptations become more common as the characteristics are passed on to the next generation

Question 49

natural selection steps

Answer 49

- organisms in a species show variation in their characteristics caused by differences in their genes - organisms whose characteristic is best adapted to a selection pressure like competition have an increased chance of surviving and successfully reproduced. well less adapted ones die or fails to reproduce - successful organisms pass the allele encoding the advantageous characteristic onto their offspring. organisms that possess the non-advantageous allele are less likely to successfully pass it on - this process is repeated over generation. Over time the proportion of individuals with the advantageous adaptation increases. So the frequency of the allele increases in the populations gene pool - over a long time this process can lead to the evolution of a new species

Question 50

modern examples of evolution

Answer 50

- antibiotic resistant bacteria - peppered moths - sheep blowflies flavobacterium

Question 51

antibiotic resistant bacteria - modern examples of evolution

Answer 51

- bacteria reproduce very fast and can evolve in a sort time. when they replicate, DNA can be altered and some mutations can provide resistances the biotics - when exposed to the antibiotics, they survives and reproduces, passing on the advantageous allele - eventually becoming the main characteristic.