The graph shows the neurogenesis and dendritic growth in a mammal during embryonic stages and after birth.
Neurogenesis is the development of new neurons. Describe neurogenesis.
Important Questions on Practice Exam Papers
The diagram illustrates a transverse section of a human eye.
(b) Draw an arrow showing the direction of the light rays when observing an object.
Transgenic rice plants have been genetically modified by adding genes from different species to promote resistance to herbicides.
Explain one method by which these transgenic rice plants could have been genetically modified.
The following questions are for HL candidates only.
Part of the sequence of the protein cytochrome c was compared in different organisms. The alignment is shown below. A dash shows the amino acid is repeated and a space that there is no amino acid.
(a) State the organism whose cytochrome c sequence is most similar to humans.
What is a database in bioinformatics? Mention their two fundamental types.
The table shows the number of plants of each species counted in a sand dune.
| Species | Number |
| Sea holly (Acanthus ebracteatus) | 3 |
| Sand couch (Sporobolus virginicus) | 6 |
| Baby grass (Sporobolus pungens) | 1 |
| Total | 10 |
(b) Comment on the richness and evenness of this sand dune community.
The sand dune community was compared with that of a forest where 240 organisms were counted in a total of 10 species. The Simpson diversity index of this forest was 14.
The study of species interactions in urban versus rural environments can improve the understanding of shifts in ecological processes due to urbanization. The leaves of the English oak (Quercus robur) in urban and adjacent rural areas were assessed to determine whether urbanization affected leaf nitrogen content.
Outline two factors in the soil that could affect the nitrogen concentration in leaves of Q. robur.
The graph shows the mean Standard deviation of the nitrogen concentration in leaves of Q. robur growing in urban and rural habitats of large, medium and small cities.
The study of species interactions in urban versus rural environments can improve the understanding of shifts in ecological processes due to urbanization. The leaves of the English oak (Quercus robur) in urban and adjacent rural areas were assessed to determine whether urbanization affected leaf nitrogen content. Describe the effect of city size and urbanization on the Q. robur leaf nitrogen concentration.
