Which of the following statements about the plant stem is correct? MCQ with Answer and Explanation

Explanation:
Thigmonasty (seismonasty) is a non-directional, rapid response to touch or vibration, exemplified by the drooping of Mimosa pudica leaves. Thigmotropism is directional growth towards/away from touch (e.g., tendrils). Phototropism is light-directed growth, geotropism gravity-directed.

Explanation:
The pancreas is a mixed gland: exocrine acini secrete digestive enzymes (trypsin, lipase, amylase) into the duodenum, while endocrine islets secrete insulin and glucagon into the blood. The liver produces bile, not digestive enzymes. Spleen filters blood, gall bladder stores bile.

Explanation:
Phycoerythrin is a red pigment found in red algae (Rhodophyta), masking the green chlorophyll. Fucoxanthin is brown (brown algae), chlorophyll is green, carotene is orange/yellow. Phycoerythrin absorbs blue light, allowing red algae to live in deeper waters.