Classification & Cladistics (HL IB Biology)

Which of the following is not an important reason for the binomial system of naming organisms?

Which of the following are reasons for the development of the three domain system of classification?

1.  The prokaryote family was too large and needed to be divided into smaller taxa.
2. The ribosomes of the archaea are distinct from those of the rest of the prokaryotes.
3. The archaea share a similar cell structure to the rest of the prokaryotes.

Which of the following species are most closely related?

1.  Marsh tit (Poecile palustris)
2. Coal tit (Periparus ater)
3. Marsh warbler (Acrocephalus palustris)
4. Willow tit (Poecile montanus)

The data below shows the number of DNA base sequence matches found between four species of marine mammal when a short section of their DNA is sequenced.

What can be concluded from the data?

Which of the following is not a feature of a clade? 

Which of the following cannot be concluded from the cladogram below?

Cytochrome C is a protein which is common to all organisms and is therefore a useful gene sequence to study when constructing phylogenetic trees to represent evolutionary relationships.

The table shows the number of nucleotide differences in the cytochrome C genes of several different species.

Which of the following shows the correct order of the organisms if arranged from the most closely related to the least closely related compared to humans?

RNA analysis led to the development of the three domains system of classifying organisms. More recent methods of building evolutionary trees has led to the proposal of the two domains system. The image compares the three domains tree and the two domains tree.

Which of the following pairs of statements correctly compares the three domains and two domains trees?

The graph shows the rate at which amino acids are substituted in three different types of protein; some amino acids can be substituted multiple times over a long period of time. Note that land plants are thought to have evolved around 500 million years ago, insects are thought to have evolved around 400 million years ago, and mammals around 170 million years ago.

Which of the statements about amino acid substitution are correct?

I. Amino acids in cytochrome C proteins are substituted at a rate of 5 per 100 million years.

II. All proteins are equally useful for determining the length of time since species diverged from each other.

III. Cytochrome C proteins are likely to be involved in a chemical process that is highly conserved across all living organisms.

IV. Analysis of amino acid sequences in fibrinopeptide proteins can be used to classify arthropoda.

The photograph shows a succulent cactus plant (left) of the family cactacae and a succulent euphorbia plant (right) of the family euphorbiaceae. The diagram below shows a representation of a cladogram that includes both plant types. The horizontal lines crossing the branches of the cladogram indicate the evolution of some plant characteristics.

Cactus image courtesy of Nabin K Sapkota licensed under the Creative Commons Attribution-Share Alike 4.0 International license, and adapted and redistributed under conditions found at https://creativecommons.org/licenses/by-sa/4.0/deed.en and euphorbia image courtesy of Bernard Dupont licensed under the Creative Commons Attribute-Share Alike 1.0 Generic license, and adapted and redistributed under conditions found at https://creativecommons.org/licenses/by-sa/2.0/

Which statement correctly explains the appearance of succulent cacti and euphorbias?

The table shows a short section of the DNA base sequence of three different species.

Which cladogram best represents the relationships between species 1, 2, and 3?