Practice A3.2 Classification and cladistics (HL) with authentic IB Biology exam questions for both SL and HL students. This question bank mirrors Paper 1A, 1B, 2 structure, covering key topics like cell biology, genetics, and ecology. Get instant solutions, detailed explanations, and build exam confidence with questions in the style of IB examiners.
Paper
Level
Question 1
HLPaper 1A
A newly discovered aquatic species possesses both vertebrae and lungs but lacks the ability to see ultraviolet (UV) light and does not produce amniotic eggs. Based on the cladogram, which organism is it most closely related to?
Question 2
SLPaper 1A
The cladogram shows some of the groups in the three domains.
What domains do X, Y and Z represent?
| Domains | |||
|---|---|---|---|
| X | Y | Z | |
| A. | prokaryote | archaea | eukaryote |
| B. | archaea | eubacteria | prokaryote |
| C. | eubacteria | archaea | eukaryote |
| D. | eubacteria | prokaryote | eukaryote |
Question 3
HLPaper 1B
The figure shows a phylogenetic tree of land plants, Charophyta, and various green algae clades (Chlorophyta, Prasinodermophyta).
1.[2]
Based on the phylogenetic tree, list two major evolutionary clades that fall under Chlorophyta.
2.[2]
Explain why molecular (gene or protein sequence) data is often preferred over morphological traits when building phylogenetic trees like this.
3.[2]
Describe two advantages of classifying organisms based on shared evolutionary ancestry (cladistics) rather than superficial similarities.
4.[2]
Some relationships on the tree are marked with dashed lines. State what these indicate about the certainty of these relationships, and how might future data resolve them?
5.[1]
Using the tree, evaluate which group is more closely related to land plants: Picocystophyceae or Charophyta.
Question 4
HLPaper 1A
The cladogram shows one theory of how species of hominin evolved.
What can be deduced using the information in the cladogram?
Question 5
HLPaper 1A
What is the most reliable way to determine evolutionary relationships among plants?
Question 6
SLPaper 1A
The cladogram shows one theory of how species of hominin evolved.
What can be deduced using the information in the cladogram?
Question 7
HLPaper 1A
What is the primary advantage of using cladistics for classification?
Question 8
HLPaper 1A
In the cladogram of vertebrate groups which of the following groups shares the most recent common ancestor with sharks?
Question 9
SLPaper 1A
The figwort family is a large one consisting of many flowering plants that look similar. For what reason have some members of the family been reclassified into a new family?
Question 10
HLPaper 2
1.[5]
Explain how scientists identify an outgroup in a cladogram.
2.[5]
Explain the importance of identifying an outgroup in a cladogram.