Advertisements
Advertisements
प्रश्न
Answer the following question.
How does suitable pollination lead to fertilization?
Advertisements
उत्तर
As the pollen of the right type is deposited on to the stigma of the flower of the same species, quite often it leads to germination of pollen grain as a result of a chemical cross-talk between the pollen and the carpel. Germination leads to the growth and extension of the pollen tube through the style of the flower to its ovary. The pollen tube carries the male gametes all the way to the ovule inside the ovary, leading to fertilization of male gamete with the female gamete inside the ovule.
APPEARS IN
संबंधित प्रश्न
A student has to perform the experiment "To identify the different parts of an embryo of a dicot seed." Select from the following an appropriate group of seeds:
(a) Pea, gram, wheat
(b) Red kidney bean, maize, gram
(c) Maize, wheat, red kidney bean
(d) Red kidney bean, pea, gram
Mention the changes a flower undergoes after fertilisation.
Fill in the following blank with suitable word :
The term used to refer to the transfer of pollen from the stamen of one flower to the carpel of another flower of the same species is...........
Multiple choice question. Tick (✓) the correct choice:
The male gamete is present inside the which germinates.
- the style
- the stigma
- the anther
- the ovary
What are the male and female gametes in a flowering plant?
Write one main difference between asexual and sexual mode of reproduction. Which species is likely to have comparatively better chances of survival – the one reproducing asexually or the one reproducing sexually? Give reason to justify your answer.
The students of a class were asked by the teacher to study the different parts of an embryo of an angiosperm. Given below are the essential steps for the experiment :
A. Soak the seeds in plain water and keep them overnight.
B. Cut open the soaked seed and observe its different parts.
C. Take some healthy seeds in a petri-dish.
D. Drain the excess water, cover the seeds with a wet cotton cloth and leave them as it is for a day.
The correct sequence of these steps is
(a) C, A, D, B
(b) C, D, A, B
(c) A, C, D, B
(d) A, C, B, D
Draw a diagram of the longitudinal section of a flower exhibiting germination of pollen on stigma and label (i) ovary, (ii) male germ-cell, (iii) female germ-cell and (iv) ovule on it.
Is the chromosome number of zygote, embryonal cells and adult of a particular organism always constant? How is the constancy maintained in these three stages?
Where is the zygote located in the flower after fertilization?
