Advertisements
Advertisements
Question
How does fertilisation occur in flowers? Name the parts of the flower that develop into (i) seed, and (ii) fruit after fertilisation.
Advertisements
Solution
Fertilization in plants: In plants, pollination is followed by fertilization. Once the pollen grains are deposited on the stigma, they form tubes called pollen tubes. The pollen tubes grow through the ovules and reach the ovary where ovules are located. The pollen tube normally enters the ovule through a small opening called micropyle. Inside the ovule, the pollen tube releases two male gametes into the embryo sac.
The embryo sac of the ovule contains the egg. One male gamete fuses with the egg. This fusion of male and female gamete is called syngamy and its product is called zygote. The other male gamete fuse with two polar bodies and this process is called triple fusion, where three nuclei are involved in the fusion process, one male gamete and two polar nuclei. Thus, inside each embryo sac, two fusions, syngamy and triple fusion, takes place. This mechanism of two fusions occurring in an embryo sac is called double-fertilization.
After fertilization, ovules develop into the seeds and ovary develops into the fruit.
APPEARS IN
RELATED QUESTIONS
A student while observing an embryo of a pea seed in the laboratory listed various parts of the embryo as given below:
Testa, Tegmen, Radicle, Plumule, Micropyle, Cotyledon.
On examining the list the teacher remarked that only three parts are correct. Select three correct parts from the above list:
(a) Testa, Radicle, Cotyleddon
(b) Tegmen, Radicle, Micropyle
(c) Cotyledon, Plumule, Testa
(d) Radicle, Cotyledon, Plumule
Explain the terms 'self pollination'
Fill in the blanks:
A carpel consists of ________ , ________ and ________.
Give one example each of unisexual and bisexual flowers. Differentiate between the two types of pollination that occur in flowers. What happens when a pollen lands on a suitable stigma? Write about the events that occur till the seed formation in the ovary.
Identify the odd. Stigma, Style, Pollen, Ovary.
Give scientific reason.
Flower is a structural unit of sexual reproduction in plants.
Double fertilization is essential for formation of ______.
In a plant flower the female whorl is ______.
What is the function of calyx?
Name the reproductive parts of an angiosperm. Where are these parts located? Explain the structure of its male reproductive part.
