1. Introduction to Biology & Characteristics of Life

2.  What is Biology ?
Photo Credit: © Andrew Syred/Science Photo Library/Photo Researchers, Inc.

3. Biology is the study of all living things
Living things are called organisms.
Organisms include bacteria, protists, fungi, plants, & animals 3 3

4. Characteristics of Living Things
No single characteristic is enough to describe a living thing.
Some nonliving things share one or more traits with living things.

5. Living things share the following characteristics:
made up of units called cells
Reproduce
based on a universal genetic code (DNA)
grow and develop
obtain and use materials and energy
respond to their environment
maintain a stable internal environment (homeostasis)
change over time (evolve)

6. 1. Cells
A cell is the smallest unit of an organism that can be considered alive.

7. 2. Reproduce
In sexual reproduction, cells from two different parents unite to form the first cell of the new organism.
In asexual reproduction, a single parent produces offspring that are identical to itself.

8. 3. Growth & Development
During an organism’s development, cells differentiate, which means that the cells look different from one another and perform different functions.

9. 4. Genetic Material (DNA)
Organisms store the information they need to live, grow, and reproduce in a genetic code in a molecule called DNA (deoxyribonucleic acid).

10. 5. Obtain Food & Energy Use
Autotrophs can make their own food
Photoautotrophs use sunlight to make food (photosynthesis)
Chemoautotrophs use chemicals such as iron & sulfur as their energy 10 10

11. Heterotrophs can NOT make their own food
They must consume other organisms
Herbivores eat plants
Carnivores eat meat
Omnivores eat plants & animals
* The combination of chemical reactions through which an organism builds up or breaks down material is called metabolism. 11 11

12. 6. Respond to Stimuli
Organisms Respond to stimuli (temperature, water, food supplies, etc.) in order to survive & reproduce 12 12

13. 7. Maintain a stable internal environment (homeostasis)
Stable internal conditions of pH, temperature, water balance, etc must stay the same, despite external changes. 13 13

14. 8. Change Over Time (Evolution)
Groups of organisms (not individuals) change over time in order to survive within changing environments.
Fossil records show changes in groups of organisms. 14 14

15. Branches of Biology Branches of Biology Zoology = Anatomy = Cytology =
Herpetology =
Ichthyology =
Ornithology =
Botany =
Dendrology =
Mycology =
Paleontology =

16. Biology in Everyday Life
provides information about the food you need and the methods for sustaining the world’s food supplies.
describes the conditions of good health and the behaviors and diseases that can harm you.
is used to diagnose and treat medical problems.

17. Biology in Everyday Life
identifies environmental factors that might threaten you
helps you understand what affects the quality of your life.
provides decision makers with useful information and analytical skills needed to predict and affect the future of the planet.

18. An increase in size is known as
growth.
metabolism.
development.
differentiation.

19. Which of the following is NOT a characteristic of all living things?
use of energy
made of cells
stable internal environment
need for oxygen

20. Which of the following are branches in the study of biology?
cells, tissues, organs, and organisms
botany, cell biology, ecology, and zoology
populations, communities, and ecosystems
the genetic code, evolution, and the biosphere

21. The genetic code is carried in
water.
DNA.
proteins.
soil.