4.2.2 classification and evolution

Question 1

order of classification
4.2.2(a)

Answer 1

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 2

what is the Genus and Species in homosapians
4.2.2(b)

Answer 2

genus-Homo
Species-sapiens
all should be underlined and genus should be capital

Question 3

why is using a latin binomial name better than common name
4.2.2(b)

Answer 3

-universally accepted
-specifies genus of organism

Question 4

what is comparative biochemistry
4.2.2(c)

Answer 4

evidence from biological molecules can help determine how closely related one species is to another
-two organisms with similar molecules have a more recent common ansetor as they have not evolved separately for long
-two organisms with very different versions of the molecule have a less recent common ansestor as they have evolved separately for longer

Question 5

what are some molecules that are commonly compared
4.2.2(c)

Answer 5

-ribosomal RNA base sequence
-Haemaglobin primary structure sequence
-cytochrome C protein primary structure

Question 6

how can a base sequence of a gene for a certain protein be compared
4.2.2(c)

Answer 6

the base sequence of a gene for a certain protein can be compared
-base sequence is similar=closely related
-more differences=less closely related

Question 7

what is the 3 domain system based on
4.2.2(c)

Answer 7

there are many fundamental differences between bacteria and eukaryotes but also between bacteria and archaea

Question 8

what are 4 differences between bacteria and archaea
4.2.2(c)

Answer 8

-different cell membrane structure
-different flagella structure
-different versions of RNA polymerase
-different mechanisms for DNA replication

Question 9

what are 3 differences between bacteria and eukaryotes
4.2.2(C)

Answer 9

-Eukaryotes have
-nucleus
-MBOs
-80S ribosomes

Question 10

what are some similarities between eukaryotes and archaea
4.2.2(c)

Answer 10

-similar RNA polymerase primary structure
-Similar mechanisms for DNA replication and transcription
-both contain histones

Question 11

what is phylogeny
4.2.2(d)

Answer 11

study of evolutionary relationships between species using comparative biochemistry

Question 12

how can you determine how closely related 2 organisms are
4.2.2(d)

Answer 12

the more recent there common ancestor is the more closely related they are

Question 13

how are evolutionary relationships dictated
4.2.2(d)

Answer 13

by a phylogenetic tree

Question 14

how did Wallace contribute to Darwin’s theory of evolution by natural selection
4.2.2(e)

Answer 14

-collected similar results which showed results are reproducible
-he arrived at the conclusion independently
-published paper together

Question 15

what is comparative anatomy
4.2.2(e)

Answer 15

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

Question 16

what is a homologous structure
4.2.2(e)

Answer 16

Structure that appears to be different but has the same underlying structure
Eg-bat arm and human arm

Question 17

what does the homologous structure provide evidence for
4.2.2(e)

Answer 17

divergent evolution- how species have evolved from common ancestors

Question 18

what is comparative biochemistry
4.2.2(e)

Answer 18

making comparisons between cytochrome C and Ribosomal RNA this means they have a similar amino acid base sequence so a more similar primary structure so are more closely related or have a more similar base sequence

Question 19

what is observable evolution
4.2.2(e)

Answer 19

we can observe evolution in organisms that evolve rapidly

Question 20

what are the 2 pieces of evidence for evolution
4.2.2(e)

Answer 20

-fossils-shows similarities between extinct and current species
However we have an incomplete fossil record
More similar=more closely related
-molecular evidence-DNA

Question 21

what is intraspecific variation
4.2.2(f)

Answer 21

variation within the same species

Question 22

what is interspecific variation
4.2.2(e)

Answer 22

variation between different species

Question 23

what is some ways genetic variation can occur
4.2.2(e)

Answer 23

-crossing over during prophase 1 of meiosis
-independent assortment of homologous chromosomes during metaphase 1 of meiosis
-independent assortment of chromatids during metaphase 2 of meiosis
-random fertilisations
-mutations

Question 24

what are some environmental factors that can influence variation
4.2.2(e)

Answer 24

-light intensity-can influence plant height
-food availability-adult height

Question 25

what is discontinuous variation
4.2.2(e)

Answer 25

using controlled by 1 gene loci
not affected by the environment

Question 26

how is discontinuous variation shown
4.2.2(e)

Answer 26

bar chart

Question 27

what is continuous variation
4.2.2(e)

Answer 27

shows a normal distribution
usually influence by more than 1 gene (polygeneic)
is influenced by the environment

Question 28

how is continuous variation represented
4.2.2(e)

Answer 28

histogram

Question 29

what should you plot on the y-axis in a histogram
4.2.2(e)

Answer 29

frequency density

Question 30

how do you work out frequency density
4.2.2(e)

Answer 30

frequency / relative class width

Question 31

what is an adaptation
4.2.2(g)

Answer 31

characteristic that enhances survival and reproductive success

Question 32

what is an anatomical adaptation
4.2.2(g)

Answer 32

anatomical adaptation are structural features that increase an organisms fitness

Question 33

what is a behavioural adaptation
4.2.2(g)

Answer 33

behaviours that aid an organisms survival in its environment

Question 34

what is a physiological adaptation
4.2.2(g)

Answer 34

a process that takes place inside an organism that increases its fitness

Question 35

what are analogous structures
4.2.2(g)

Answer 35

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

Question 36

how do analogous structures arise
4.2.2(g)

Answer 36

analogous structure arise through convergent evolution when unrelated species share similar traits these evolve because organisms adapt to similar niches/selection pressures

Question 37

what is an example of convergent evolution
4.2.2(g)

Answer 37

marsupials and placental mammals both have a strong resemblance in overall shape, type of locomotion and feeding techniques as they have adapted to similar climates/ food supplies

Question 38

what are similar analogous structures that have developed though convergent evolution
4.2.2(g)

Answer 38

marsupial and placental moles both have
-cylindrical bodies
-small reduces eyes
-short fur and tail
-nose with tough skin for protection

Question 39

explain the natural selection mechanism
4.2.2(h)

Answer 39

1. mutations give rise to new alleles
   2.the creates genetic variation
2. selection pressures favour alleles with the advantagous phenotype as they as they have a higher fitness so are more likely to survive and reproduce
3. the beneficial alleles are passed onto offspring so the next generation will have a higher proportion of the advantagous allele and delirious alleles will die

Question 40

explain pesticide resistance in insects
4.2.2(i)

Answer 40

pests can cause damage to food crops so insecticides are used to kill them. However the use of insecticides is a selection pressure. The insects will the allele for resistance are more likely to survive and reproduce so there frequency in the population will increase.

Question 41

what are some problems concerned with insecticide resistance in insects
4.2.2(i)

Answer 41

insecticides build up in the food chain

Question 42

explain antibiotic resistance in bacteria
4.2.2(i)

Answer 42

same as insects

Question 43

give an example of a bug which is resistant to antibiotics
4.2.2(i)

Answer 43

MRSA