What Is Biology?• The study of living things.

Biologists Study?• Characteristics• Classifications• Interactions between organisms• Health & Disease

Goal of Science

• To investigate• To understand• To explain• To make predictions ABOUT the World!

Levels of Organization(Place in Order from Smallest to Largest)

Tissues Cells

Organs Atoms

Molecules Organ Systems

Levels Of Organization• Atom• Molecule• Cells • Tissues• Organs• Organ Systems

Levels of biological

organization

Largest

Smallest

Defining What It Means To Be Alive

Characteristics of Living Things

1. Made Up of Cells2. Reproduction3. Based on a Genetic Code 4. Growth and Development5. Need for Materials and Energy6. Response to the Environment7. Maintaining Internal Balance8. Adapt & Evolve

1. Living Things are made up of Cells.

✓ Cells are basic unit of life✓ CELL: Collection of living material

enclosed within a barrier

✓ Unicellular: one cell✓ Multicellular: many cells

Unicellular

Multicellular

2. Living Things Reproduce: ✓produce offspring which resemble parents

2 Types:

Asexual reproduction: only 1 parent

Sexual reproduction: 2 parents

Asexual

Sexual

3. Living Things are based on a Genetic Code/Organization

✓Inheritance of traits is carried on DNA

From Dog To DNA…………1. A dog is made up of more than a million cells.

2. Each cell contains a nucleus containing chromosomes.

3. The cell’s Nucleus

4. A Chromosome

5. DNA molecule folds to form a chromosome

6. DNA is made of 2 strands.

A Cell

4. Living things Grow and Develop✓ GROWTH: increase in size & shape

✓ DEVELOPMENT: mature over time

✓ Living things have a Lifespan

Growth

DevelopmentGrowth

5. Living Things Use & Need Energy Energy comes from food, used to maintain body

• AUTOTROPH: produce own food

• HETEROTROPH: must consume food

•DECOMPOSER: breaks down dead material for food

6. Living things respond to their surroundings

✓ React to a stimulus a signal or change causing an organism to respond.

- The change could be internal or external.

✓ A response is a reaction caused by an action.

Stimulus?

Response?

7. Living things maintain a Stable Internal Environment✓ HOMEOSTASIS or DYNAMIC EQUILIBRIUM

Examples: sweating, panting, shivering, etc.

HomeostasisHow Does Your Body Bring You Back To Normal?

& Why?

✓Perspiration

✓ Shivering

✓ Regurgitation

To stay cool & prevent overheating

To stay warm

Get rid of harmful wastes

HomeostasisIf you think about it, your body works the same way. Most

people maintain a constant body temperature around 98.6 degrees. That is your homeostasis. When facing conditions such as heavy exercise or hot weather, your body has numerous mechanisms to keep your temperature at homeostasis. Sweat is produced from glands in the dermis. As the water in the sweat changes from liquid to gas (evaporation), heat is lost allowing you to feel cooler. Your face gets red and flushed. This is due to the dilation of blood vessels which brings heat to the surface of your skin where it is lost to the environment.

8. Living things Adapt & Evolve ✓ Adapt to changes in the environment

✓ Change to better survive in environment

✓ Changes take place over a long period of time & involve the entire species.

Adaptation✓ A Cactus with horns

✓ A Camel’s Hump

✓ A Camel’s webbed feet, long eye lashes, & nostrils that close

To reduce water loss & protect from herbivores

To store fat & live off it when food & water are scarce

Prevent sinking in the sand & prevent sand from entering eyes, nose

Life Processes: Terms1. Nutrition

– taking materials & changing to a usable form (used for energy, growth, repair and maintenance)

➢ Digestion – large insoluble molecules changed into small soluble molecule by enzymes.➢ Ingestion – to consume (take in) a substance➢Nutrient- a substance taken in for energy

2 TypesAutotrophs – make their own food

Heterotrophs – get their food

• Photosynthesis for EnergyEquation: CO2 + H2O Sugar + Oxygen

Light energy Chemical energy

Sunlight

Photosynthesis

2. Transport– Substances enter and leave cells (movement

of stuff within organism)– A system in larger multicellular organismExample: Circulatory System (arteries/veins)

Transport of Materials

Outside Cell

Inside Cell

3. Cellular Respiration for Energy– Cells burn food (glucose) for fuel (chemical

energy)– Energy is stored in molecules called ATP– All cells continuously undergo this process

called cellular respiration in the MITOCHONDRIA

2 Types

• Aerobic Respiration

organisms use O2 to break food to make carbon dioxide & water.

• Anaerobic Respiration No O2 used to break

down food.

Cellular Respiration

Equation: Sugar + oxygen CO2 + H2O + Energy

ENERGY STORED ENERGY RELEASED

4. Synthesis– Simple substances combined (build) to form

more complex substances

(Needed for growth and repair)

5. Growth- More cells & bigger cells- Humans start as 1 cell & grow and

develop into an organism of about 50 trillion cells.

Examples:Unicellular- increase cell sizeMulticellular- go through growth

called development

6. Excretion– Removal of wastes from the body

4 Types of excretion: urination defecation exhaling sweating

7. Regulation

– All the activities that help maintain homeostasis

– Regulation occurs by nerve impulses (nervous system) & the release of chemical hormones (endocrine system)

– Needed to respond to the internal & external environment

8. Reproduction– Produce new organisms of their own

kind

Two types:

• Asexual – 1 parent with identical offspring

•Sexual – 2 parents with offspring not identical

9. Digestion

- Breakdown of COMPLEX food materials into simpler forms for organism to use.

10. Metabolism

• All the Chemical Reactions that occur in every cell to maintain normal functioning.

• The building & breaking down of complex substances.

• The continuous release of energy.

Virus

Virus Uses A Host’s Cell For Reproduction

Is A Virus Living?

Viruses have……..• No Growth• No Metabolism • No Reproduction (uses a host for

reproduction)

What Do You Think Now?

Resource

http://www.youtube.com/watch?v=_cpBK2t0Yeo Life in a drop of water Youtube