Question

(i) Identify the above structure and mention its location in a flower.
(ii) Label the parts numbered 1 and 2.
(iii) Explaintheterm‘DoubleFertilisation’.
(iv) Whatisthefateofthecalyxandcorollaafterfertilisation?
(v) Draw a neat, labelled diagram of a pollen grain.

Answer 1

Answer: Female Gametophyte

Explanation:

i) Embryo Sac (Female Gametophyte) are found in the Ovule of the flower.

ii) 1. Anti-Podals

2. Polar Nuclei

iii) Double Fertilization is a process in which the characteristics of plants in which one sperm cell of a

pollen grain fertilizes an egg cell while a second fuses with two polar nuclei to produce a triploid body that gives rise to the endosperm.

iv) The Function of Calyx and Corolla to Protect the flower but after fertilization they both falls off and reproductive functions are over.

Answer 2

The above structure is ovule or megasorangium or embryosac.                  

explaination :                    

• Ovule arises from placenta and is attached to the placenta by a stalk called funicle .        

• The labeled parts 1& 2 are antipodals cells these are located just opposited to micropyle at chalazal end.
• The term double fertilization was first demonstrated by Nawaschin in 1898 in fritillaria and lilium. the syngamy and triple fertilisation both with together is known as double fertilization .
•  Corolla or petal  and calyx or sepal attracts pollinators but once the pollination occurs and the ovary get fertilized then there is no use of them hence they shed off.