Glossary: I-M

Meiosis

Definition: A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores. Meiosis is a two-step process that involves two rounds of cell division.

Examples:

• Spermatogenesis: The process of producing sperm cells in males.
• Oogenesis: The process of producing egg cells in females.
• Spore Formation: The process of producing spores in plants and fungi.

Context/Function: Meiosis is essential for sexual reproduction. It ensures that the offspring have the correct number of chromosomes and that there is genetic variation in the population.

Metabolism

Definition: The chemical processes that occur within a living organism in order to maintain life. Metabolism is divided into two categories: catabolism and anabolism.

Examples:

• Catabolism: The breakdown of complex molecules into simpler ones, which releases energy.
• Anabolism: The synthesis of complex molecules from simpler ones, which requires energy.

Context/Function: Metabolism is essential for all living organisms. It provides the energy and building blocks that are needed for growth, reproduction, and all other life processes.

Mitosis

Definition: A type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth. Mitosis is a one-step process that involves one round of cell division.

Examples:

• Growth: Mitosis is responsible for the growth of multicellular organisms.
• Repair: Mitosis is used to repair damaged tissues.
• Asexual Reproduction: Some organisms, such as bacteria and yeast, reproduce asexually by mitosis.

Context/Function: Mitosis is essential for the growth, repair, and asexual reproduction of living organisms. It ensures that each daughter cell receives a complete set of chromosomes.

Mutation

Definition: The changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations. Mutations can be caused by a variety of factors, including errors in DNA replication, exposure to radiation, and chemical mutagens.

Examples:

• Point Mutation: A change in a single nucleotide in a gene.
• Insertion: The addition of one or more nucleotides to a gene.
• Deletion: The removal of one or more nucleotides from a gene.

Context/Function: Mutations are the ultimate source of genetic variation. They can be beneficial, harmful, or neutral. Beneficial mutations can lead to new traits that help an organism to survive and reproduce. Harmful mutations can cause genetic diseases. Neutral mutations have no effect on the organism.