Question

How to determine the number of cells present after each successive division during cleavage.

A) Count the number of mitotic spindles visible under a microscope to estimate the number of dividing cells.
B) Measure the volume of the embryo and divide it by the average volume of a single cell to calculate cell number.
C) Use time-lapse imaging to track cell divisions in real-time, allowing precise determination of cell numbers.
D) Divide the embryo into smaller sections and count the cells in each section individually, then sum the counts.

Answer 1

The most accurate method to determine the number of cells present after each division during cleavage is to use time-lapse imaging to track cell divisions in real-time, which allows a precise count of cell numbers as they undergo mitotic stages.

Step-by-step explanation:

To determine the number of cells present after each successive division during cleavage, the best method would be C) Use time-lapse imaging to track cell divisions in real-time. This allows for precise determination of cell numbers as the cells progress through the stages of the cell cycle. By using time-lapse imaging, it's possible to visualize and record the stages of each cell - particularly the mitotic stages which are readily identifiable compared to the stages of interphase. Additionally, by examining a microscope slide of a blastula cross-section, one can count the cells in each identifiable cell-cycle stage to estimate the time it takes for a cell to complete that stage. This count gives insight into the frequency of divisions and the number of cells formed during cleavage.