Why do the lateral and polar views of chromosomes of the same cell in metar look different?
The correct answer and explanation is :
The lateral and polar views of chromosomes in a cell at metaphase appear different due to the orientation of the chromosomes relative to the observer’s viewpoint and the way the spindle fibers interact with them.
Explanation:
During metaphase, chromosomes align at the metaphase plate, a central plane of the cell, with their centromeres attached to spindle fibers. The appearance of these chromosomes changes depending on whether they are viewed laterally (from the side) or polarly (from above or below the spindle axis).
- Lateral View (Side View):
- When observed laterally, the chromosomes appear elongated and aligned in a row along the metaphase plate.
- The chromatids are clearly visible, with the centromere serving as a constriction point.
- The spindle fibers extending from the centrosomes at opposite poles of the cell are visible, connecting to the kinetochores of the chromosomes.
- Polar View (Top or Bottom View):
- From a polar perspective, the chromosomes appear as a circular arrangement around the spindle fibers.
- Instead of seeing them as elongated structures, they appear more compact and sometimes like a cluster of dots or X-shaped figures.
- The centromeres of the chromosomes are seen as the attachment points to the spindle fibers, creating a star-like or radial pattern.
Why the Difference?
- The key factor is the three-dimensional arrangement of chromosomes and the perspective of observation.
- In the lateral view, the focus is on the alignment of chromosomes along the metaphase plate, showing their full structure.
- In the polar view, the chromosomes are seen from the top, where their arrangement around the spindle axis is emphasized rather than their length.
This difference in appearance helps researchers analyze chromosome organization, movement, and division during mitosis.