A person who scientifically studies animals is called -

• A person who scientifically studies animals is called - Zoologist.

Zoologist:
English Meaning: A person who scientifically studies animals.
Bangla Meaning: প্রাণিবিজ্ঞান; প্রাণিবিদ্যা।

Others Option & Meaning:
Geologist:
English Meaning: a person who studies geology.
Bangla Meaning: ভূতত্ত্ববিদ; ভূতাত্ত্বিক।

Botanist:
English Meaning: A scientist who studies plants.
Bangla Meaning: উদ্ভিদতত্ত্ববিদ।

Entomologist:
English Meaning: One who studies insect life.
Bangla Meaning: পতঙ্গবিশারদ।

Source:
1. Cambridge Dictonary.
2. Accessible Dictionary.