NEET 2013
- Exam
- NEET
- Year
- 2013
- Subject
- Botany
- Chapter
- Cell Cycle and Cell Division
NEET 2013 · Botany · Cell Cycle and Cell Division
A stage of mitosis is shown in the diagram. Which stage is it and...
A stage of mitosis is shown in the diagram. Which stage is it and what are its characteristics?
Options
- AMetaphase - Spindle fibers attached to kinetochores, centromeres split and chromatids separate.
- BMetaphase- Chromosomes moved to spindle equator, chromosomes made up of two sister chromatids.
- CAnaphase- Centromeres split and chromatids separate and start moving away.
- DLate prophase - Chromosomes move to spindle equator
Correct answer
B. Metaphase- Chromosomes moved to spindle equator, chromosomes made up of two sister chromatids.
Step-by-step solution
Prophase is marked by the initiation of condensation of chromosomal material. The chromosomal material becomes untangled during the process of chromatin condensation. Initiation of the assembly of mitotic spindle, the microtubules, the proteinaceous components of the cell cytoplasm help in the process. Metaphase is characterized by all the chromosomes coming to lie at the equator with one chromatid of each chromosome connected by its kinetochore to spindle fibres from one pole and its sister chromatid connected by its kinetochore to spindle fibres from the opposite pole.
Anaphase stage is characterised by following key events like Centromeres split and chromatids separate and Chromatids move to opposite poles. As each chromosome moves away from the equatorial plate, the centromere of each chromosome is towards the pole and hence at the leading edge, with the arms of the chromosome trailing behind.
Telophase is characterised by chromosomes cluster at opposite spindle poles and their identity is lost as discrete elements. Nuclear envelope assembles around the chromosome clusters. Nucleolus, Golgi complex and ER reform.
Stages of mitosis:
