Advertisements
Advertisements
प्रश्न
Describe the events taking place during interphase.
Advertisements
उत्तर
Even though it is referred to be the resting phase, the interphase is highly metabolically active. It is the period of time when the cell gets ready to divide by going through a systematic process of both cell growth and DNA replication.
G1 (Gap 1) phase
S (Synthesis) phase
G2 (Gap 2) phase
The G1 phase refers to the period between the mitosis of the preceding cell cycle and the commencement of DNA replication. In the G1 phase, the cell is metabolically active and undergoes continuous growth without DNA replication. The synthesis phase, or S phase, denotes the time frame in which DNA replication or synthesis occurs. DNA doubles in each cell throughout this period. In animal cells, centrioles duplicate in the cytoplasm while DNA replication takes place in the nucleus during the S phase. DNA synthesis ceases during the G2 phase, but protein and RNA synthesis continues as the cell grows in preparation for mitosis.
APPEARS IN
संबंधित प्रश्न
What is the average cell cycle span for a mammalian cell?
Why is mitosis called equational division?
Name the phase of the cell cycle at which the following event occurs:
Crossing over between homologous chromosomes takes place.
Analyse the events during every stage of cell cycle and notice how the following two parameters change.
- Number of chromosomes (N) per cell
- Amount of DNA content (C) per cell
Most cytogenic activities occur during
Name the stage of mitosis in which chromosomes are arranged on the equator of spindle:
Match List - I with List - II.
| List I | List II | ||
| (a) | S phase | (i) | Proteins are synthesized |
| (b) | G2 phase | (ii) | Inactive phase |
| (c) | Quiescent stage | (iii) | Interval between mitosis and initiation of DNA replication |
| (d) | G1 phase | (iv) | DNA replication |
Choose the correct answer from the options given below.
The fruit fly has 8 chromosomes (2n) in each cell. During the interphase of Mitosis if the number of chromosomes in G1 phase is 8, what would be the number of chromosomes after the S phase?
Which of the phases of cell cycle is of longest duration?
Which tissue of animals and plants exhibits meiosis?
While examining the mitotic stage in a tissue, one finds some cells with 16 chromosomes and some with 32 chromosomes. What possible reasons could you assign to this difference in chromosome number. Do you think cells with 16 chromosomes could have arisen from cells with 32 chromosomes or vice versa?
Mitosis results in producing two cells which are similar to each other. What would be the consequence if the following irregularities occur during mitosis?
Duplication of DNA does not occur
Two key events take place, during S phase in animal cells, DNA replication and duplication of centriole. In which parts of the cell do events occur?
Name the phase of the cell cycle at which the following event occurs:
Centromere splits and chromatids separate.
Name the phase of the cell cycle at which the following event occurs:
Pairing between homologous chromosomes takes place.
