Copy of 9A Items (Supporting) (5/2/2026)

MED - STAAR 2022 9A

A phylogenetic tree based on genetic similarities is shown.

Which numbered location on the phylogenetic tree identifies characteristics shared by species B, C, and D?

MED - STAAR 2021 (9A)

A cladogram of five species is shown.

Based on the cladogram, the ancestral species most likely had —

HIGH- Modification of STAAR 2018 (9A)

Scientists can determine relatedness among organisms by comparing partial amino acid sequences. The table (below) shows five partial amino acid sequences from five different organisms.

Which organism is most closely related to the horse? Provide evidence to support your claim.

MED

Select the common ancestor for Arthropoda and Platyhelminthes on the diagram below:

LOW - STAAR 2013 (9A) - different image used

The limbs of several different organisms are shown in the illustration below. Scientists sometimes compare the limbs of these organisms to look for evidence of common ancestry.

These limbs provide evidence of common ancestry, because they...

LOW - STAAR 2017 (9A)

"Cetaceans" are whales and their relatives. The diagram below shows some fossils of cetaceans.

Which statement provides the best evidence that "Ambulocetus natans" is an ancestor of "Basilosaurus isis"?

MED - 9A

A cladogram of five species is shown.

Based on the cladogram, the frog has which physical characteristics?

MED - STAAR 2014 (9A)

The opossum, which is native to North America, and the kangaroo, which is native to Australia, are marsupials.

The fact that both of these mammals incubate (keep warm) their immature offspring in a pouch provides evidence that they...