Chapter 1 (Campbell's Biology in Focus)
What is biology?
- The scientific study of life poses questions about the living world and seeks answers through scientific inquiry and central activities of biology
- ==A biosphere== consists of all life on Earth and all the places where life exists
- ==An ecosystem== consists of all the living things in a particular area along with the non-living components
- ==A biological community== is the array of organisms inhabiting a particular ecosystem
- ==A population== consists of all the individuals of a species living within the bounds of a specified area
- Individual living things are called organisms
The two types of cells
- A ==eukaryotic cell== contains membrane-enclosed organelles. Some organelles, such as the DNA-contained nucleus, are found in the cells of all eukaryotes; other organelles are specific to particular cell types
- ==Prokaryotic cells== lack a nuclear or other membrane-enclosed organelles(generally smaller than eukaryotic cells)
Evolution
- Evolution is the scientific explanation for the unity and diversity of organisms
The Three Domains of Life
- Prokaryotic organisms - these are single-celled organisms
- Eukarya - all the eukaryotes are grouped into this domain
- This domain contains three kingdoms of multicellular eukaryotes
- Plantae
- Fungi
- Animalia
Charles Darwin and the Theory of Natural Selection
- Species accumulate differences from their ancestors as they adapt to different environments over time.
- “Natural selection” is a primary cause of the descent with modification
- ==Natural selection== is when the natural environment consistently “selects” certain traits among naturally occurring variant traits in the population
Scientists and the study of nature
- ==An inquiry== is the search for information and explanations of natural phenomena
- ==Data== is recorded observations
- ==A hypothesis== is an explanation, based on observations and assumptions, that leads to testable predictions
- ==An experiment== is a scientific test, often carried out under controlled conditions