Practise IB Biology SL A Unity and Diversity through questions on water, nucleic acids, cells, viruses, biodiversity, classification and evolution.
This redwood tree (Sequoia sempervirens) was blown over in 1936, but five side branches formed new roots and are now separate trees.
Three of the new trees formed from side branches of the original tree
State the molecule that trees such as redwoods use as genetic material.
Outline the cell theory.
Psammonobiotus balticus belongs to a group of protists (unicellular eukaryotic organisms) that have a shell surrounding most of the cell, which provides shelter from predators. The graph shows the frequency of varying shell lengths in a population of P. balticus.
State, giving a reason, the type of variation shown by shell length.
Draw a labelled diagram of a eukaryotic plant cell as seen in an electron micrograph.
Explain how the process of evolution occurs.