Advertisements
Advertisements
प्रश्न
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?
Advertisements
उत्तर
Mitosis is a cell division which results in the formation of two daughter cells from a cell with the same number of chromosomes. Zygote undergoes mitotic divisions to develop into an embryo which in turn, also undergoes mitotic divisions to become an adult. So, the constancy of chromosomes is maintained in these three stages.
APPEARS IN
संबंधित प्रश्न
Mention the changes a flower undergoes after fertilisation.
How is the process of pollination different from fertilization?
The process of fusion of the male and female gametes is called ______.
Mature ovary forms the ______.
Where are the pollen grains produced?
Explain the terms 'cross-pollination'?
(a) Draw a neat diagram of a flower showing its various parts. In this diagram mark stem, receptacle, sepals, petals, stamen and carpel.
(b) What name is given to (i) all the petals of a flower, and (ii) all the sepals of a flower?
(c) What are (i) stamen, and (ii) carpel, in a flower?
(d) What is the other name of carpel of a flower?
(e) What is the name of yellow powdery substance present in the anther of a flower?
Explain the process of fertilisation in flowers.
In the figure, the parts marked A, B and C are sequentially:
(A) Plumule, Radicle and Cotyledon
(B) Radicle, Plumule and Cotyledon
(C) Plumule, Cotyledon and Radicle
(D) Radicle, Cotyledon and Plumule
Distinguish between unisexual and bisexual flowers giving one example of each. Draw a diagram showing process of germination of pollen grains on stigma and label the following parts:
(a) Female germ cell
(b) Male germ cell
(c) Ovary
Fill in the blank by selecting suitable word:
Transfer of pollen grains from the anther to the stigma is known as______________.
Differentiate between self-pollination and cross-pollination.
Identify the parts A, B, C, and D?
Antipodal cells are present towards the ______ in an anatropous ovule.
Conidia are formed endogenously while zoospores are formed endogenously.
Which among the following statements are true for sexual reproduction in flowering plants?
- It requires two types of gametes
- Fertilisation is a compulsory event
- It always results in formation of zygote
- Offspring formed are clones
Double fertilization is essential for formation of ______.
In a plant flower the female whorl is ______.
Name the reproductive parts of an angiosperm. Where are these parts located? Explain the structure of its male reproductive part.
- Assertion: Primary endosperm nucleus is diploid.
- Reason: It is the product of double fertilisation.
