Question

D Question 45 2 pts Which of the following is a characteristic of all angiosperms? o complete reliance on wind as the pollinating agent O ovules that are not contained within ovaries carpels that contain microsporangia O double internal fertilization O free-living gametophytes

Answer 1

45) Answer

correct option : 4th option

Double fertilization :

Angiosperm undergoes in double fertilization.

One of the male gametes fuses with the egg cell to form a zygote. The other male gamete fuses with the diploid secondary nucleus. This is called triple fusion. Because of the involvement of two fusions this event is termed as double fertilization an unique to angiosperms

Incorrect options.

1st option :

Angiosperms participate by wind or water or various other biotic agencies.

2nd option :

In angiosperms ovules are present within the ovaries only.

3rd option :

Pistil consists of an ovary enclosing one or many ovules. Within the ovules a megaspore mother cell presant.

5th option :

In angiosperms gamatophyte is highly reduced female gametophyte termed embryo-sac. In male gametophyte is microscopic transfer through water, wind or animals.

Angiosperms are double fertilized so because it features in the formation of

3rd option :

One embryo, two egg cell fertilized by single sperm cell.

The pollen grain germinate on stigma to produce a pollen tube, in pollen tube the pollen grain shad into to male gamets (a vegitative cell and generative cell) the genarative cell divide into two male gamets during the growth of the pollen tube in the stigma, they reach ovary one of the male gamete fuse with egg cell to form a zygote . The other male gamete fuses with the diploid secondary nucleus (PEN). This is called triple fusion. Because of involment of two fusions, this event is termed as double fertilization.