(a) Describe any two devices in a flowering plant which prevent both autogamy and geitonagamy.
(b) Explain the events upto double fertilization after the pollen tube enters one of the synergids in an ovule of an angiosperm .

(a) Describe any two devices in a flowerings plant which prevent both autogamy and geitonogamy (b) Explain the events up to double fertialisation after the pollen tube enters one of the synergids in an ovule of an angisoperm.

In which of the following plant ovules are not enclosed by any ovary wall and remains exposed both before and after fertilization ?

(a) State one difference and one similarity between geitonogamy and xenogamy. (b) Explain any three devices developed in flowering plants to discourage self pollination and encourage cross pollination.

(a) State one difference and one similarity between geitonogamy and xenogamy. (b) Explain any three devices developed in flowering plants to discourage self pollination and encourage cross pollination.

(i) What are the ways through which the pollen tube enters into the ovule ? Explain. (ii) What is the fateof pollen tube after reaching the embryo sac ?

From among the situations given below, choose the one that prevents both autogamy and geitonogamy (A) Monoecious plant bearing unisexual flowers (B) Dioecious plant bearing only male or female flowers (C) Monoecious plant with bisexual flowers (D) Dioecious plant with bisexual flowers

Draw a neat diagram showing fertilisation in a flower and label (a) pollen tube (b) male germ cell (c) female germ cell on it. Explain the process of fertilisation in a flower . what happens to the ( i ) ovary and (ii) ovule after fertisation.

During double fertilization , the pollen tube enters the embryo sac through (a) Egg cell (b) Persistent synergid (c) Degenerating synergid (d) Central cell

a) Draw a L.S. of a pistil showing pollen tube entering the embryo-sac in an angiosperm and label any six parts other than stigma, and ovary. b) Write the changes a fertilized ovule undergoes within the ovary in an angiosperm plant.