Chapter 1 - Exploring Life and Science Flashcards
Atom
Smallest unit of an element composed of electrons, protons and neutrons.
Molecule
Union of two or more atoms of the same or different elements.
Cell
The smallest unit that displays the properties of life. All organisms are composed of cells and new cells only come from pre-existing cells.
Tissue
A group of cells with a common structure and function.
Organ
Composed of tissues functioning together for a specific task.
Organ system
Composed of several organs working together.
Organism
Individual living thing
Population
Organisms of the same species in a particular area.
Community
Interacting populations in a particular area.
Ecosystem
Populations of organisms interact with each other in the physical environment.
Biosphere
Regions of the earth’s crust, waters, and atmosphere inhabited by living organisms.
Biology
The science of biology is the study of living organisms and their environments.
Photosynthesis
Process by which plants, algae, and some bacteria harvest the energy of the sun and convert it to chemical energy.
Metabolism
All the chemical reactions that occur in a cell
Homeostasis
Maintenance of normal internal conditions in a cell or an organism by means of self regulating mechanisms.
Stimulus
A stimulus is a detectable change in the internal or external environment.
Reproduce
When organisms reproduce they pass on their genetic information to the next generation.
Growth
Increase in the number of cells and/or the size of the cells. Example – fertilized egg into fetus
Development
The term development is used to indicate all the changes that occur from the time the egg is fertilized until death.
DNA
The genetic information of all life is deoxyribonucleic acid.
DNA contains the hereditary information that directs not only the structure of each cell but also it’s function.
Genes
Organisms contain coded information that dictates their form, function, and behavior.
Mutations
Alteration in chromosome structure or number and also an alteration in a gene due to change in DNA composition.
Evolution
The process by which a population changes over time. All organisms have a common ancestor, but each is adapted to a particular way of life.
Natural selection
The mechanism by which evolution occurs.