BIO101 – Topic 16: Growth and Development in Living Organisms
Course Code: BIO 101
Course Name: General Biology
© Lesuyai Organic Guides 2025
(Original | Educational | Professional | Plagiarism-Free | A4 Format)
16.1 Introduction to Growth and Development
Growth and development are essential life processes that enable organisms to increase in
size, mature, and attain full functionality.
Growth is the permanent increase in size and dry mass of an organism due to cell division
and enlargement.
Development refers to the series of changes that occur in an organism as it matures into an
adult form.
Growth involves quantitative changes, while development involves qualitative changes in
form and function.
16.2 Characteristics of Growth
1. Irreversible increase in size or mass.
2. Requires energy from respiration.
3. Occurs through cell division (mitosis) and cell enlargement.
4. Affected by both internal and external factors.
5. Usually slow at old age but rapid during early life stages.
16.3 Measurement of Growth
Growth can be measured using various parameters:
Increase in length – measured using ruler / meter rule
Increase in mass – weighing scale
Increase in number of cells – microscope
Increase in volume – water displacement
A growth curve is obtained by plotting measurements against time, showing phases such as
lag, log (exponential), stationary, and decline phases.
16.4 Phases of Growth in Organisms
1. Lag Phase: Slow initial growth as cells adapt to the environment.
2. Log (Exponential) Phase: Rapid cell division and growth rate.
3. Stationary Phase: Growth rate slows as resources become limited.
4. Decline Phase: Growth stops or decreases due to aging or unfavorable conditions.
Course Code: BIO 101
Course Name: General Biology
© Lesuyai Organic Guides 2025
(Original | Educational | Professional | Plagiarism-Free | A4 Format)
16.1 Introduction to Growth and Development
Growth and development are essential life processes that enable organisms to increase in
size, mature, and attain full functionality.
Growth is the permanent increase in size and dry mass of an organism due to cell division
and enlargement.
Development refers to the series of changes that occur in an organism as it matures into an
adult form.
Growth involves quantitative changes, while development involves qualitative changes in
form and function.
16.2 Characteristics of Growth
1. Irreversible increase in size or mass.
2. Requires energy from respiration.
3. Occurs through cell division (mitosis) and cell enlargement.
4. Affected by both internal and external factors.
5. Usually slow at old age but rapid during early life stages.
16.3 Measurement of Growth
Growth can be measured using various parameters:
Increase in length – measured using ruler / meter rule
Increase in mass – weighing scale
Increase in number of cells – microscope
Increase in volume – water displacement
A growth curve is obtained by plotting measurements against time, showing phases such as
lag, log (exponential), stationary, and decline phases.
16.4 Phases of Growth in Organisms
1. Lag Phase: Slow initial growth as cells adapt to the environment.
2. Log (Exponential) Phase: Rapid cell division and growth rate.
3. Stationary Phase: Growth rate slows as resources become limited.
4. Decline Phase: Growth stops or decreases due to aging or unfavorable conditions.
