classification and evolution

Question 1

continuous variation meaning

Answer 1

theres a range if values no defined categories and influenced by genes and environment.
One type of variation is described as continuous
• Continuous variation is the effect of many genes controlling a characteristic
• Continuous variation is affected by the genotype and the environment
• Continuous variation is quantitative
• There are intermediate values which do not fall into distinct or discrete groups
• Body mass and wingspan are examples of continuous variation in the bats

Question 2

discontinous variation

Answer 2

single genes so theres no discrete categories and have little environmental effect
Discontinuous variation is the other type of variation
• Discontinuous variation is the effect of one or two genes
• It has little or no environmental effects
• Results fall into discrete categories with no intermediates and its results are qualitative
• High-pitched or low pitched echolocation are examples of discontinuous variation

Question 3

domains/kingdoms

Answer 3

there are 3 domains and 5 kingdoms. the domains are bacteria eukarya and archae. kingdoms are prokayotes protoctista animalia plantea fungi. all prokaryotes are in the same kingdom.domain classification based on RNA.

Question 4

how can you confirm that theyre the same species

Answer 4

possible to confirm by interbreeding if theyre from the same theyll have offspring.

Question 5

why do offspring look similar

Answer 5

characteristics are inherited by the next generation

Question 6

phylogeny meaning

Answer 6

phylogeny is the evolutionary relationship between organisms and are used in classification. the closer the evolutinary relationships the closer the taxonomic groups.

Question 7

theory of evolution support

Answer 7

Evidence that supports the theory of evolution is:
• differences in DNA/ biochemistry
• differences in base sequence
• differences in cytochrome c
• differences in order of amino acids in proteins
• similarities between any of the above implies a close relationship
• idea of evolution within human history
• differences in physiology / behaviour

Question 8

how do fossils provide evidence

Answer 8

Fossils show changes over time
 Fossils can be dated
 The simplest fossils are found in the oldest rocks
 Fossils show the relationships between different species
 Fossils give us information about organisms that no longer exist
 DNA can also be extracted from some fossils

Question 9

interspecific vs intraspecific

Answer 9

Interspecific variation is the variation between species eg weight of a pigeon and crow
Intraspecific variation is the variation within species eg weights of a pigeon

Question 10

standard deviation

Answer 10

measures the spread of data around the mean value. low sd means its more reliable so high repeatability

Question 11

spearmans

Answer 11

Spearman’s rank correlation determines whether there is correlation between variables that don’t show a normal distribution

Question 12

convergent evolution

Answer 12

when two species from different parts of the world have evolved and become very similar.They dont share a common recent ancestor.

Question 13

taxonomy

Answer 13

the study of classification

Question 14

analogous vs homologous traits

Answer 14

analogous-similar features that have evolved separately with no ancestral history.
homologous-similar features due to a common ancestor.

Question 15

how does natural selection occur.

Answer 15

Natural selection arises as a result of genetic variation
 A mutation occurs
 Mutations are random or spontaneous
 Resistance to wheat is the selection pressure
 Individuals with resistance survive to reproduce
 They pass on the allele for resistance to the next generation
 Over many generations the frequency of this allele in the gene pool increases

Question 16

when do you reject the nul hypothesis

Answer 16

when the t value is lower than the critical value