11.
Due to low temperature and high rainfall the organic matter content of the soil increases at higher altitudes, with

17.
Match List-I (Scientists) with List-II (Statements regarding the morphological nature of the endosperm) and select the correct answer:
List-I List-II
a. Hofmeister (1858) 1. Endosperm is a gametophytic structure, whose development is checked
b. Lamnnier (1887) 2. Endosperm is a second embryo, which is actually modified
c. Sargant (1900) 3. The chief function of endosperm is not that of storage, but the secretion of diastase and other enzymes
d. Haberlandt (1914) 4. Endosperm is the sporophytic tissue or the twin of an embryo

20.
Abscission does not occur when