Q5. Into which two classes are angiosperms divided?
Dicotyledons and monocotyledons (NCERT page 34).
Q6. What kind of venation do the leaves of most dicotyledonous plants have?
Reticulate venation, in which the veinlets form a network (NCERT Chapter 5, page 60).
Q7. How does a fibrous root system arise in a monocotyledon?
The primary root is short-lived and is replaced by a large number of roots that originate from the base of the stem (NCERT Chapter 5, page 58).
Q8. Are monocotyledonous seeds endospermic?
Generally yes, but some, as in orchids, are non-endospermic (NCERT Chapter 5, page 66).
Q9. What is triple fusion, and what does it produce?
The fusion of a male gamete with the two polar nuclei in the central cell of the embryo sac; it produces the triploid primary endosperm nucleus (NCERT Class 12 Biology, Section 1.3, page 18).
Q10. In which class does the leaf base expand into a sheath around the stem?
Monocotyledons (NCERT Chapter 5, page 60).
Q11. In a maize seed, which is larger, the endosperm or the embryo?
The endosperm, which is bulky and stores food; the embryo is small and lies in a groove at one end of it (NCERT Chapter 5, page 67).
Q12. Which part of a flower becomes the fruit, and which become the seeds?
The ovary matures into the fruit (NCERT Chapter 5, page 65); the ovules develop into seeds (page 66).