02 Mechanisms Driving Plant Evolution

Terminology you should know

heritability . dicer and RISC . silencing . transposons . retrovirusses . spontaneous and induced mutations . photolyase . transition and transversion . missense and nonsense mutations . eupolyploidy . facultative sexuality . apomixis . speciation . synthetic theory . allopatric and sympatric speciation . hybrid depression . allopolyploidy . U-triangle . descendence . central dogma of molecular biology . epigenetics 


Concepts you should know, be able to explain, and remember

  • You can explain, which two factors are central for the generation of genetic variation

  • You can explain what happens in a protein, when there is a missense mutation, what happens, when there is a nonsense mutation

  • You can explain 3hat is the evolutionary advantage of sexual propagation over asexual propagation

  • You can explain, what the term "allopatric" and "sympatric" speciation means


To think about

  1. How many different gametes can be generated (ignoring crossing over) during meiosis for n=2, n=3, n=4, and n=5 chromosomes?
  2. White flower colour is a recessive trait. Can you explain why? You have a population of Viola elatior, where 16 % of individuals have white flowers. What percentage of the population is heterozygous for this trait? Remark: before you go to solve this problem, refresh your knowledge on the Hardy-Weinberg-Equation.
  3. Rapeseed (Brassica napus) is a allopolyploid from Brassica rapa and Brassica oleraceae. Sketch down the chromosomes in meiosis I of a hybrid B. napus x B. rapa and a hybrid B. napus x B. oleraceae.
  4. Most flowers are hermaphroditic. Give two mechanisms (with a real example), how plants prevent self-fertilisation. 
  5. Many plants attract pollinators by mimicking their sexual signals - why confers this strategy a selective advantage?  


To read and deepen