Growth and Development in Unicellular Organisms

What is Growth and Development?

Growth and development are two fundamental processes in biology that define the progress of a living organism. Both these terms are used interchangeably but actually they are significantly different in their meaning. Growth refers to the physical aspect of the living organism and typically involves increase in cell mass, number of cells, and organ complexity. However, development encompasses not only the physical aspect but also includes the structural, functional, and behavioural changes. This process involves growth, differentiation, metamorphosis, psychological maturation, reproductive maturation, etc. In simple terms growth is a quantitative measure whereas development is a qualitative measure....

Characteristics of Growth and Development

Growth and development have some typical characteristics that help us to use these terms differently. These characteristics are discussed below....

Growth and Development in Unicellular Organisms

Unicellular organisms are made up of a single cell. So they can grow by increasing their cell size through nutrient absorption and metabolic activities. Growth in them is marked by increased cellular dimensions or doubled genetic material. The term “development” is not conventionally used in the context of unicellular organisms, they undergo adaptive changes and life cycle stages. For example, certain protozoa can form cysts during unfavorable conditions, representing a protective stage in their life cycle, showcasing a rudimentary form of developmental adaptation in response to environmental challenges....

Growth and Development in Plants

Plants exhibit growth and development throughout their life. Growth in plants can be classified as primary growth and secondary growth.The primary growth occurs at the tips of roots and shoots, leading to an increase in length. Whereas secondary growth involves the thickening of stems and roots through the activity of lateral meristems, such as the vascular cambium and cork cambium. Along with these, growth in plants can also be classified as vegetative growth and reproductive growth. Vegetative growth refers to the growth of plant that occurs before it gets ready to flower. Reproductive growth occurs when the plant begins to prepare for producing flower, fruits, and seeds....

Growth and Development in Animals

In animals growth is usually seen upto a certain age. However, in some cases organs and tissues can resume growth spontaneously as and when required. The growth in animals is marked by increase in their body mass, size, height, etc. For example a human baby grows into a young kid to a teenager and then into an adult. We can mark his growth by observing increase in his height, body weight, muscular growth etc. The growth rate is influenced by genetic factors, nutrition, and hormonal regulation....

Factors Affecting Growth and Development in Organisms

Both growth and development are affected by a variety of factors. These factors can be broadly categorized into genetic, environmental, and hormonal. Some key factors are discussed below....

FAQs- Growth and Development

1. What are the 5 Different Areas of Growth and Development in Organisms?...