The gene that encodes Retinoblastoma (Rb) protein is a conserved gene in plants and animals. This gene has the primary control over whether the cell continues to divide or to differentiate. When it is activated, Rb represses the gene required to replicate the DNA. Which of the following happens when Rb is inactivated in the stem cells of vertebrates?

The vertebral column and cranium are found in:

Mesodermal endoskeleton is found in:

The figure below shows the phylogeny of amniotes.

Identify the incorrect statement about the phylogeny of amniotes:

Which one of the following characteristics are found in all chordates:

The evolutionary relationships of chordates are depicted in the diagram below. Which of the following groups belongs to the phylum Chordata?

A chordate was identified with the following features:

1. A vertebral column. 

2. A Skull 

3. Body covered with hair 

4. Mammary glands 

Which class would you like to assign that chordate based on the aforementioned characteristics?