Assertion (A): Pea plants were chosen by Mendel for his experiments. Reason (R): Pea plants have many contrasting characters and are self-pollinating. MCQ with Answer and Explanation

Explanation:
The gall bladder, a small pear-shaped sac under the liver, stores and concentrates bile produced by the liver, releasing it into the duodenum in response to cholecystokinin (CCK). The liver makes bile, pancreas secretes enzymes, duodenum is the entry point.

Explanation:
Black stem rust of wheat is caused by the fungus Puccinia graminis tritici, a basidiomycete that produces reddish-brown uredospores and black teliospores. It requires barberry as an alternate host. It is a major disease causing significant crop losses.

Explanation:
Chondrichthyes are cartilaginous fishes with a skeleton made entirely of cartilage, a ventral mouth, and lack operculum. Pristis (sawfish), Scoliodon (dogfish), and Carcharodon (great white shark) belong to this class. Labeo rohita (Rohu) and Catla catla are Osteichthyes (bony fishes). Hippocampus (seahorse) is also a bony fish. Exam tip: Chondrichthyes = cartilaginous; Osteichthyes = bony.