Ch.1-3 Studying Life

Biology – The study of life, living things

◦Bio- = life

◦–ology= study of

To be considered living things it must possess all of the characteristics of life.

Some non-living things may possess some of the characteristics.

8 Characteristics of Living Things

◦Unicellular=a single cell

◦Multicellular=more than a single cell

1) Living things are made up of many units called cells.

◦Sexual reproduction= DNA from two parents; offspring different than parent

◦Asexual reproduction=single parent; offspring the same as parent

2) Living things reproduce

DNA

3) Living things are based on a universal genetic code.

Become larger

Change over time

◦Differentiation=cells begin to look different and perform different functions.

4) Living things grow and develop.

Metabolism=chemical reactions in the body that build and break down materials

Generally: ◦plants=photosynthesis◦animals=eating

5) Living things obtain and use materials and energy.

Stimulus=a signal to which we respond (bell ringing)

Response=a reaction to a stimulus(move to next class)

6) Living things respond to their environment.

Homeostasis=internal conditions remain constant (lizards sun themselves)

7) Living things maintain a stable internal environment.

Evolution

8) Taken as a group, living things change over time.

Zoologists= study of animals

Botanists=study of plants

Paleontologists= study of ancient life

Branches of Biology

(from most simple to most complex)

Living things may be studied at different levels

MoleculesGroups of atoms

Examples:

Water DNA

Cells Smallest unit of life

Example:

Nerve cell

Groups of Cells Tissues, organs, and organ systems

Example:

Nervous tissue Brain Nervous system

Organism Individual living thing

Example:

Bison

Population Group of organisms of one type that live in

the same area

Bison herd

Community Populations that live together in a defined

area

Hawk, snake, bison, prairie dog, grass

Copyright Pearson Prentice Hall

Ecosystem Community and its nonliving surroundings

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

Biosphere The part of Earth that contains all

ecosystems