Question

Assertion: In some social insect haploid cells divide by mitosis Reason: Growth of multicellular organism is due to mitosis

Short answer

The assertion is true and the reason is also true but the reason is not a correct explanation of the assertion.

Step-by-step solution

Define Cell Division

First, clarify what cell division means. It's the process by which a parent cell divides into two or more daughter cells. There are two types of cell division: mitosis, for growth and maintenance, and meiosis, for sexual reproduction.

Define Haploid Cells

Haploid cells are those which have a single set of chromosomes. In social insects like bees and ants, male insects (drones) are developed from the eggs of the queen which are not fertilized. Therefore, the drones are haploid.

Connect Haploid Cells and Mitosis

Even though haploid cells are most commonly connected with meiosis and not mitosis, in some special cases, such as this, with social insects, mitosis can occur with haploid cells.

Define Growth of a Multicellular Organism through Mitosis

The growth of a multicellular organism is indeed due to mitosis. Mitosis allows the organism to grow by increasing the number of cells.

Decision on the Truthfulness of Assertion and Reason

The assertion is true; haploid cells can divide through mitosis, especially in the case of social insects. The reason also is true; the growth of multicellular organisms is due to mitosis.

Correlation between Assertion and Reason

Even though both assertion and reason are true, the reason is not a correct explanation for the assertion. The reason explains the general role of mitosis in growing multicellular organisms, but not specifically the case of haploid cells in social insects.

Key concepts

Mitosis

Mitosis is one of the fundamental processes that drive the growth and maintenance of multicellular organisms. It's a form of cell division that involves a series of highly regulated steps, resulting in the production of two genetically identical daughter cells from a single parent cell. During this process, the chromosomes in the nucleus are duplicated and divided equally between the new cells.

It's crucial for the repair of tissues, regeneration of body parts, and overall growth.

Stages of Mitosis

Mitosis consists of four stages: prophase, metaphase, anaphase, and telophase. In prophase, the chromosomes condense and become visible under a microscope. During metaphase, chromosomes line up at the center of the cell. The chromatids separate in anaphase and move to opposite ends. Finally, in telophase and cytokinesis, the cell splits into two, completing the cycle.

Understanding mitosis aids in grasping how organisms increase their cell count, ensuring that each new cell has the appropriate genetic information to function correctly.

Haploid Cells

Haploid cells have a single set of chromosomes, which is denoted as 'n'. These cells are typically seen in the gametes, or sex cells, of organisms. They are critical for sexual reproduction, where they combine during fertilization to form a diploid cell with two sets of chromosomes.

Haploid Cells in Social Insects

In the unique case of social insects like bees and ants, haploid cells can divide by mitosis to produce more haploid cells. In these organisms, males are haploid and arise from unfertilized eggs, showcasing an interesting exception to the usual rule that mitosis occurs in diploid cells.

This adaptation has significant implications for the social structure and reproduction of these insects. It's a fascinating example of how cell division and genetics come together to influence the diversity of life strategies in different species.

Multicellular Organism Growth

The growth of a multicellular organism is an intricate process relying on the methodical division of cells. This growth is mainly attributed to mitosis, where cells divide to produce new, identical cells to replace old or damaged ones, as well as to add to the overall cell count as the organism matures.

Rather than transforming one cell into a larger one, growth is about increasing the total number of cells, which collectively contribute to the size and functionality of tissues and organs. Furthermore, the controlled nature of mitosis ensures that new cells receive the complete genetic blueprint needed to perform specialized functions. This process is continual throughout an organism's lifecycle and is essential for both development and healing.

The understanding of this concept helps to reveal how complex organisms emerge from a single fertilized egg and continue to maintain their structure and health through constant cellular renewal.