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?
Three domains
Two domains
A.
The eubacteria form a clade
The eubacteria form a clade
B.
The eukaryotes share a common ancestor with the archaea
The common ancestor of all the eukaryotes is within the archaea
C.
The archaea form a clade
The archaea form a clade
D.
The eukaryotes are more closely related to the euryarchaeota than to any other group
The eukaryotes are more closely related to the lokiarchaeota than to any other group
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 features of cacti and euphorbias are homologous as they have been inherited from a common ancestor.
The features of cacti and euphorbias are homologous as they are structurally similar but have a different role.
The features of cacti and euphorbias are analogous as they are structurally different but have a similar role.
The features of cacti and euphorbias are analogous as they evolved independently of each other from different ancestors.
Which statement correctly explains the appearance of succulent cacti and euphorbias?
