2. Why Bengali is called mixed origin- Explain with your logic 3. What is the impact of the Sena Dynasty, Pala Dynasty, and Mughal emperor in Bangladesh?

Yes, they are.

Explanation:

Bengalis are an Indic Aryan ethnolinguistic people who belong to Bengal or Green Delta, comprising mostly of Bangladesh and also of India's West Bengal and Karimganj. About more than 45% (lowest from Anglo-mixed) to 100% (highest from BD Sylheti) ancestry of a Bengali is Aryan. The Aryans settled in the Delta in about 750 BC. They were already mixed, with Bactro-Margianan (of BMAC), Harappan (of IVC) and Dravir/ Dravidian (formerly of BRWC, now only South India) genetic contribution. About 0% (lowest from Rohingyas) to 45% (highest from WB Dravir-mixed) ancestry of Bengalis are derived from Dravirs and Harappans. Speaking of Dravirs, they themselves are a mixture of mainly non-Aryan Iranians (60-100%) and some Adivasis (Australoid; 0-40%). Bengalis also derive about 5-less than 10% from East Asians (including SE Asians). This is the genetic heritage of Bengalis who mainly have R1a YDna haplogroup along with some O and H and R2. MtDna is mainly of U and M. This makes Bengalis (+Sylheti+Rohingya) most closely related to Maldivians, Sinhalese, Assamese and other B-A people.

Speaking of Palas, Senas, Turko-Mongol Mughals, the Pala and Sena were Bengali and Kannar respectively. Senas may have contributed some Dravir gene to WB people. But the Arabs, Persians, Turks (not Turkish) and Mongols (including Mughals) also contributed to Bengali gene, specifically the Bengali Muslim gene in BD. They have given 0 (in WB Muslims) to 10% (in Sylhetis) to BM. They are included among Aryan gene sometimes due to Persians being Aryans and Turko-Mongols being influenced both genetically and culturally by Aryan Iranians. As Persians are West Asian, Arabs are also mistaken. Anyways, they also contributed the J paternal haplogroup gene to Bengali(Muslim)s.