Final answer:
Mitosis is an essential process for growth and repair occurring throughout a plant's life, while meiosis is part of the reproductive cycle, forming haploid gametes for genetic diversity.
Step-by-step explanation:
In multicellular organisms, mitosis and meiosis play specific roles at different times during an organism's life cycle. Mitosis occurs throughout the organism's lifetime in the somatic (body) cells and is responsible for growth and repair. This process includes phases such as prophase, metaphase, anaphase, and telophase, followed by cytokinesis, ultimately leading to two genetically identical daughter cells.
On the other hand, meiosis occurs specifically during the production of gametes (sex cells). In plants, meiosis takes place in the life cycle phase known as alternation of generations. During meiosis, the chromosome number is halved, resulting in haploid gametes, which upon fertilization, restore the diploid condition.
So, in a plant's life cycle, mitosis is an ongoing process assisting in growth and cellular repair, while meiosis is part of the reproductive cycle, ensuring genetic diversity through the formation of haploid gametes.