Question

Compare chromosomal separation in plant and animal cells.

Short answer

Answer: The mechanism of chromosomal separation during anaphase is largely similar in plant and animal cells, involving spindle fibers and motor proteins pulling apart sister chromatids towards the opposite poles of the cell. However, plant cells lack centrioles, and spindle fibers in these cells form from microtubule organizing centers. Furthermore, cytokinesis processes differ, with animal cells forming a cleavage furrow and plant cells forming a cell plate to divide the two daughter cells.

Step-by-step solution

Understand the general mechanism of chromosomal separation in both plant and animal cells

Both plant and animal cells undergo the process of mitosis, which is composed of several stages, namely prophase, prometaphase, metaphase, anaphase, and telophase. During anaphase, the main chromosomal separation occurs, where chromosomes are pulled apart and chromatids are separated. The similarities between plant and animal cell divisions in mitosis include DNA replication, spindle fiber formation, and chromosome alignment.

Identify the role of centrioles in animal cells

In animal cells, centrioles play a significant role in chromosome separation. Located outside the nucleus, centrioles duplicate and migrate to the opposite poles of the cell during prophase. With the help of spindle fibers, they contribute to the alignment and separation of chromosomes during cell division. Plant cells do not have centrioles but still form spindle fibers.

Discuss the formation of spindle fibers in plant cells

Although plant cells lack centrioles, spindle fibers still form during prophase. In plant cells, microtubules nucleate from microtubule organizing centers, which are composed of polar and acentriolar microtubules. Spindle fibers attach to kinetochores of chromosomes and help in their separation during anaphase.

Compare chromosomal separation during anaphase

During anaphase of mitosis in both plant and animal cells, sister chromatids separate and are pulled apart toward the opposite poles of the cell. This process occurs with the help of spindle fibers and motor proteins, like dynein and kinesin. Overall, the mechanism of chromosomal separation during anaphase remains similar in plants and animals.

Highlight the differences in cytokinesis between plant and animal cells

While chromosomal separation remains similar in plant and animal cells, the process of cytokinesis differs. In animal cells, cytokinesis occurs via a cleavage furrow, where the cell membrane constricts due to the action of actin and myosin proteins, ultimately dividing the cell. In plant cells, cytokinesis occurs via the formation of a cell plate. The cell plate is formed at the equatorial plane, which eventually expands outwards and fuses with the plasma membrane, thus completing cell division and forming new cell walls between the two daughter cells.