Introduction to Human Biology
Human Biology is the study of the human body, the environment in which people live, and the ways people interact with that environment. It combines several areas of knowledge, including anatomy, physiology, hygiene, evolution, and ecology.
Areas covered by Human Biology
- Anatomy: the study of the structure of the human body.
- Physiology: the study of how the parts of the human body function.
- Hygiene: practices that help to keep the body and the environment clean and healthy.
- Evolution: the study of changes through which modern humans developed from earlier human forms.
- Ecology: the study of how people interact with other organisms and with their physical environment.
Man as a living organism
Human beings are living organisms because they carry out the characteristics of life. These characteristics include movement, respiration, growth, nutrition, excretion, sensitivity, and reproduction.
| Characteristic | Meaning in human beings |
|---|---|
| Movement | Changing the position of the whole body or a body part. |
| Respiration | Releasing energy from food within cells. |
| Growth | A permanent increase in size and dry mass. |
| Excretion | Removing metabolic waste products from the body. |
| Sensitivity | Detecting and responding to changes in the internal or external environment. |
| Reproduction | Producing new individuals of the same species. |
Classification of human beings
Human beings are classified scientifically as follows:
| Taxonomic rank | Classification |
|---|---|
| Kingdom | Animalia |
| Phylum | Chordata |
| Class | Mammalia |
| Order | Primates |
| Family | Hominidae |
| Genus | Homo |
| Species | Homo sapiens |
Levels of organisation in the human body
The human body is made of structures arranged in increasing levels of organisation. Each level is more complex than the one before it.
- Cell: the smallest structural and functional unit of a living organism.
- Tissue: a group of similar cells working together to perform a particular function.
- Organ: a structure made of different tissues working together.
- Organ system: a group of organs that cooperate to carry out a major body function.
- Organism: a complete living individual made up of interacting organ systems.
The animal cell
An animal cell is the basic structural and functional unit of the human body. It contains specialised structures called organelles. The nucleus controls many cell activities and contains genetic material. The plasma membrane controls the movement of substances into and out of the cell. Mitochondria release energy during respiration, while ribosomes are involved in protein production.
Summary
- Human Biology combines the study of human structure, function, health, and environmental interactions.
- Human beings show all the main characteristics of living organisms.
- Humans are classified as Homo sapiens.
- The levels of organisation are cell, tissue, organ, organ system, and organism.
- Specialised organelles enable animal cells to carry out particular functions.
Revision questions
- Define Human Biology.
- State four characteristics of living organisms shown by human beings.
- Write the classification of human beings from kingdom to species.
- Arrange these levels in order of increasing complexity: organ, tissue, organism, cell, organ system.
- State one function each of the nucleus, plasma membrane, mitochondrion, and ribosome.
