THINK! How do you know something is alive?

7 characteristics of living things:

1. Cells

2. Reproduction

3. Homeostasis/metabolism

4. DNA

5. Growth & development

6. Respond to environment

7. Evolve

1. Living things are made of cells

• Unicellular or single-celled organisms can sustain all life functions

• Multicellular organisms exhibit cell specialization and organizationCelltissuesorgans

organism

2. Reproduction

• Asexual reproduction : only one parent (cell) required to produce new organism– i.e. bacteria

• Sexual reproduction: requires two parents. Union of 2 cells (male&female sex cells) to produce new organism

3. Homeostasis/Metabolism

Homeostasis: ability to maintain a stable internal environment

Metabolism: sum total of all chemical reactions (ingestion,digestion,excretion)– Anabolism/synthesis “building” i.e. muscle from

protein– Catabolism/hydrolysis “breaking apart” i.e. breaking

muscle into protein (&simpler)

http://www.teachersdomain.org/resource/tdc02.sci.life.reg.fevervid/

4. DNA

• Deoxyribonucleic Acid• Molecule carrying genetic code• Carry info of traits from parent to offspring

5. Growth & development

• THINK! Is growth just getting bigger in size?

• i.e. Single cell multicellular

This is more or less how we all started..

6. Respond to Environment

• Stimulus- something that triggers a response/activity

• Response- action or activity resulting from stimulus

7. Evolve

• As a group (species), organisms change over time

• Inheritable characteristics that increase survival can result in evolution

Q: What is Biology?

• Study of Life• Levels of organization for Life

• Biosphere• Biome• Ecosystem• Community• Population• Organism• Groups of cells (tissues, organs)• Cells• Molecules

Organism

Groups ofCells

Cells

Molecules

Individual livingthing

Tissues, organs,and organ systems

Smallest functionalunit of life

Groups of atoms;smallest unit of most chemicalcompounds

Bison

Nervous tissue Nervous systemBrain

Nerve cell

Water DNA

Section 1-3

Figure 1-21 Levels of Organization continued

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Biosphere

Ecosystem

Community

Population

The part of Earththat contains allecosystems

Community and its nonliving surroundings

Populations thatlive together in a defined area

Group of organisms of onetype that live in the same area

Biosphere

Hawk, snake, bison, prairie dog, grass, stream, rocks, air

Hawk, snake, bison, prairie dog, grass

Bison herd

Section 1-3

Figure 1-21 Levels of Organization

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Branches of Biology Project

• Research

• Brief Presentation

• Create a poster

(See hand out for details)