Q5. Assertion: pea has marginal placentation. Reason: its ovary has a single carpel whose ovules are borne on a ridge along the ventral suture. Are both true, and does the reason explain the assertion?
Both are true, and the reason explains the assertion (NCERT page 65).
Q6. How does a legume open?
Along both sutures, the ventral and the dorsal, into two valves.
Q7. Which bacterium fixes nitrogen in the root nodules of legumes?
Rhizobium (NCERT Class 12 Biology, Section 8.6, page 158; the Class 11 book, Chapter 2, pages 13–14, names nitrogen fixation in legume roots).
Q8. In which subfamily is the posterior petal outermost in the bud, and in which is it innermost?
Outermost in Papilionoideae (vexillary, descending imbricate: the standard covers the wings); innermost in Caesalpinioideae (ascending imbricate), as in Cassia and gulmohur.
Q9. How many carpels does a pea flower have, and is its ovary superior?
One carpel (monocarpellary), in a superior ovary.
Q10. Name two legumes used as fodder.
Berseem (Trifolium) and Sesbania.