The Pistil, Megosporangium and Embryo Sac

Question 1

single pistil

Answer 1

monocarpellary

Question 2

more than one pistil

Answer 2

multicarpellary

Question 3

fused pistils

Answer 3

syncarpous

Question 4

free pistil

Answer 4

apocarpous

Question 5

locule

Answer 5

ovarian cavity

Question 6

where is the placenta located

Answer 6

in the locule

Question 7

what does the placenta give rise to

Answer 7

megasporangia(ovules)

Question 8

what is the ovule attached to and how

Answer 8

to the placenta through a funicle(stalk) through a region called hilum(junction)

Question 9

envelopes of the ovule

Answer 9

integuments

Question 10

what do the integuments cover

Answer 10

nucellus

Question 11

basal part of the ovule

Answer 11

chalaza

Question 12

tip of the ovule

Answer 12

micropyle

Question 13

nucellus

Answer 13

a mass of cells that have reserve food materials

Question 14

where is the embryo sac or the female gametophyte located

Answer 14

in the nucellus

Question 15

Megasporogenesis

Answer 15

formation of 4 megaspores from the megaspore mother cell through meoisis

Question 16

what happens to one of the megaspores

Answer 16

only one is functional while the other three degenerate and develops into the female gametophyte.(monosporic development)

Question 17

formation of embryo sac

Answer 17

functional megaspore divides mitotically- 2 celled

again mitotically 4 celled n then 8-celled. 6 cells are surrounded by cell walls and are organized into cells but 2 are situated at the large central cell as the polar nuclei.

Question 18

structure of embryo sac

Answer 18

3 cells at the micropylar end which have synergids that have cellular thickenings called the filiform apparatus that helps in guiding the pollen tube.

other 3 at the chalazal end and are called the antipodals

2 at the center as the polar nuclei

Question 19

egg apparatus

Answer 19

1 egg cell + 2 synergids

Question 20

nature of the embryo sac

Answer 20

8 nucleate- 7 celled