1. The Science of Biology
Chapter 1

2. What is Science?
The study of the natural world and the search for patterns and connections between events
Only with the natural world
Scientists collect and organize information (scientific method)
Propose explanations by testing hypotheses

3. What is Science? Way of knowing
Don’t just memorize facts
Scientific understanding is changing—it’s not static
Scientists question the world around them
Science reaches into health, medicine, and relationships between living and nonliving environment

4. What is Biology? Study of life
Bios = life
-ology = study of
Science that seeks to understand the living world
In this class we will discuss a recurring theme:
Organisms evolve and adapt to meet the needs of a changing environment - Natural Selection drives the change in species

5. Characteristics of Living Things
All living things have the following characteristics:
Made up of cells
Reproduce
Grow and develop
Based on a universal genetic code
Get and use energy
Respond to their environment
Maintain a stable internal environment
As a group, living things change over time
We will discuss each in detail

6. 1. Made up of cells
Cell = collection of living matter surrounded by a membrane that separates it from its environment
Smallest unit of an organism that’s considered alive
Unicellular = organism made of only 1 cell
Multicellular = organism made of many cells
Cells are never formed by nonliving things

7. 2. Reproduce Reproduction = produce new organisms of the same type
Sexual reproduction = 2 cells from different individuals unite to produce new individual
Genetic diversity
Asexual reproduction = single organism can reproduce without another organism
Identical organisms

8. 3. Grow and Develop All grow at least part of their lives
Some just increase in size
Some develop = specialize cells

9. 4. Based on a Universal Genetic Code
Directions for inheriting traits is carried by DNA
Determines the inherited traits of every organism on Earth

10. 5. Get and Use Energy
Obtain energy from environment in order to grow, reproduce, and respond to their environment
Need energy to build substances that make up cells
Metabolism = combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes
Plants, some bacteria, algae = energy from sunlight (photosynthesis)
Animals = energy from food (some eat plants, some eat animals)
Decomposers = energy from organisms that have died

11. 6. Respond to their Environment
Organisms respond to stimuli in their environment
Stimulus = a signal that an organism reacts to (ex: light, heat, sound, etc.)
External stimuli = come from environment (ex: temperature—goose bumps)
Internal stimuli = come from within organism (ex: levels of sugar in blood is low—feel hungry)
Respond in order to improve chance of survival

12. 7. Maintain a Stable Internal Environment
Organisms must keep their internal environment constant even as outside environment changes
Ex: water, temperature
Homeostasis
Also includes feedback mechanisms = something externally changes  body reacts to maintain stable environment

13. 8. Evolution As a group, organisms change over time
As an individual, traits it inherited usually will not change
Over many generations, changes become dramatic
This is evolution

14. Branches of Biology Biology is divided into different fields
Paleontology, zoology, botany, ecology, etc.
Molecular = study of life at molecular level (DNA)
Cellular = studies cells and problems at cellular level
Multicellular = studies organisms
Population = studies groups of organisms
Ecologists = organisms and their environment on a global level

15. How does biology affect you?
Diagnose and treat medical problems
Identifies environmental problems
Provides information regarding food and food production
Understand what affects the quality of your life
LIST AT LEAST 3 THINGS YOU ARE INTERESTED IN STUDYING THIS YEAR!