Question

Which of the following periods belonged to the Palaeozoic era?
A. Triassic
B. Cambrian
C. Jurassic
D. Cretaceous

Answer 1

Hint: Evolutionary biology is defined as the history of study of life forms present on the earth. Evolution is defined as the orderly and sequential change from one form to another . Organisms evolve due to their needs to survive in the environment . Different organisms evolve with time in different eras.

Complete answer:
Plants evolve in different eras . These include Palaeozoic , Mesozoic and Cenozoic with their periods like Silurian, Jurassic, Quaternary, etc. Chlorophyte ancestors are the aquatic green algae which are supposed to give rise to all the green land plants (i.e. Bryophytes and Tracheophytes). Bryophytes (nonvascular land plants) diverged from chlorophyte ancestors in the carboniferous period.
Now let us gather information about given options:
> Triassic :- this period belongs to the Mesozoic era . It is the first period of the Mesozoic era . This period is conferred with the extinction of the dinosaur thecodont.
> Cambrian :- this period belongs to the Palaeozoic era . Permian , carboniferous , Devonian and Silurian also exist in this era . The lycopods are dominant during this era.
> Jurassic :- this period belongs to the Mesozoic era. This is the second period of the Mesozoic era . It is characterised by having ferns , conifers and cycads.
> Cretaceous :- this period belongs to the Mesozoic era. This is the last period of the Mesozoic era. This is dominated by the sphenopsids , Gingkos , Gnetales and Dicotyledons .

Our correct option is B that is Cambrian.

Note:
Zosterophyllum is a genus of vascular land plants which diverged from Tracheophytes in the Silurian
Period. These were dominant in the Silurian and Devonian Period. The lycopods are the oldest extant (living) arborescent lycopods were dominant during the Paleozoic era but most of them became extinct by the end of the Palaeozoic era.